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android-kvm / linux / 9fbe565cb78d10ca2619ee23eac27262cff45629 / . / drivers / gpio / gpiolib.c
blob: 4fa075d49fbc9d68a3ff80def5ccc449bba3961d [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0
#include <linux/bitmap.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/spinlock.h>
#include <linux/list.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>
#include <linux/gpio.h>
#include <linux/idr.h>
#include <linux/slab.h>
#include <linux/acpi.h>
#include <linux/gpio/driver.h>
#include <linux/gpio/machine.h>
#include <linux/pinctrl/consumer.h>
#include <linux/cdev.h>
#include <linux/fs.h>
#include <linux/uaccess.h>
#include <linux/compat.h>
#include <linux/anon_inodes.h>
#include <linux/file.h>
#include <linux/kfifo.h>
#include <linux/poll.h>
#include <linux/timekeeping.h>
#include <uapi/linux/gpio.h>
#include "gpiolib.h"
#include "gpiolib-of.h"
#include "gpiolib-acpi.h"
#define CREATE_TRACE_POINTS
#include <trace/events/gpio.h>
/* Implementation infrastructure for GPIO interfaces.
*
* The GPIO programming interface allows for inlining speed-critical
* get/set operations for common cases, so that access to SOC-integrated
* GPIOs can sometimes cost only an instruction or two per bit.
*/
/* When debugging, extend minimal trust to callers and platform code.
* Also emit diagnostic messages that may help initial bringup, when
* board setup or driver bugs are most common.
*
* Otherwise, minimize overhead in what may be bitbanging codepaths.
*/
#ifdef DEBUG
#define extra_checks 1
#else
#define extra_checks 0
#endif
/* Device and char device-related information */
static DEFINE_IDA(gpio_ida);
static dev_t gpio_devt;
#define GPIO_DEV_MAX 256 /* 256 GPIO chip devices supported */
static struct bus_type gpio_bus_type = {
.name = "gpio",
};
/*
* Number of GPIOs to use for the fast path in set array
*/
#define FASTPATH_NGPIO CONFIG_GPIOLIB_FASTPATH_LIMIT
/* gpio_lock prevents conflicts during gpio_desc[] table updates.
* While any GPIO is requested, its gpio_chip is not removable;
* each GPIO's "requested" flag serves as a lock and refcount.
*/
DEFINE_SPINLOCK(gpio_lock);
static DEFINE_MUTEX(gpio_lookup_lock);
static LIST_HEAD(gpio_lookup_list);
LIST_HEAD(gpio_devices);
static DEFINE_MUTEX(gpio_machine_hogs_mutex);
static LIST_HEAD(gpio_machine_hogs);
static void gpiochip_free_hogs(struct gpio_chip *gc);
static int gpiochip_add_irqchip(struct gpio_chip *gc,
struct lock_class_key *lock_key,
struct lock_class_key *request_key);
static void gpiochip_irqchip_remove(struct gpio_chip *gc);
static int gpiochip_irqchip_init_hw(struct gpio_chip *gc);
static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc);
static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc);
static bool gpiolib_initialized;
static inline void desc_set_label(struct gpio_desc *d, const char *label)
{
d->label = label;
}
/**
* gpio_to_desc - Convert a GPIO number to its descriptor
* @gpio: global GPIO number
*
* Returns:
* The GPIO descriptor associated with the given GPIO, or %NULL if no GPIO
* with the given number exists in the system.
*/
struct gpio_desc *gpio_to_desc(unsigned gpio)
{
struct gpio_device *gdev;
unsigned long flags;
spin_lock_irqsave(&gpio_lock, flags);
list_for_each_entry(gdev, &gpio_devices, list) {
if (gdev->base <= gpio &&
gdev->base + gdev->ngpio > gpio) {
spin_unlock_irqrestore(&gpio_lock, flags);
return &gdev->descs[gpio - gdev->base];
}
}
spin_unlock_irqrestore(&gpio_lock, flags);
if (!gpio_is_valid(gpio))
WARN(1, "invalid GPIO %d\n", gpio);
return NULL;
}
EXPORT_SYMBOL_GPL(gpio_to_desc);
/**
* gpiochip_get_desc - get the GPIO descriptor corresponding to the given
* hardware number for this chip
* @gc: GPIO chip
* @hwnum: hardware number of the GPIO for this chip
*
* Returns:
* A pointer to the GPIO descriptor or ``ERR_PTR(-EINVAL)`` if no GPIO exists
* in the given chip for the specified hardware number.
*/
struct gpio_desc *gpiochip_get_desc(struct gpio_chip *gc,
unsigned int hwnum)
{
struct gpio_device *gdev = gc->gpiodev;
if (hwnum >= gdev->ngpio)
return ERR_PTR(-EINVAL);
return &gdev->descs[hwnum];
}
EXPORT_SYMBOL_GPL(gpiochip_get_desc);
/**
* desc_to_gpio - convert a GPIO descriptor to the integer namespace
* @desc: GPIO descriptor
*
* This should disappear in the future but is needed since we still
* use GPIO numbers for error messages and sysfs nodes.
*
* Returns:
* The global GPIO number for the GPIO specified by its descriptor.
*/
int desc_to_gpio(const struct gpio_desc *desc)
{
return desc->gdev->base + (desc - &desc->gdev->descs[0]);
}
EXPORT_SYMBOL_GPL(desc_to_gpio);
/**
* gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs
* @desc: descriptor to return the chip of
*/
struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
{
if (!desc || !desc->gdev)
return NULL;
return desc->gdev->chip;
}
EXPORT_SYMBOL_GPL(gpiod_to_chip);
/* dynamic allocation of GPIOs, e.g. on a hotplugged device */
static int gpiochip_find_base(int ngpio)
{
struct gpio_device *gdev;
int base = ARCH_NR_GPIOS - ngpio;
list_for_each_entry_reverse(gdev, &gpio_devices, list) {
/* found a free space? */
if (gdev->base + gdev->ngpio <= base)
break;
else
/* nope, check the space right before the chip */
base = gdev->base - ngpio;
}
if (gpio_is_valid(base)) {
pr_debug("%s: found new base at %d\n", __func__, base);
return base;
} else {
pr_err("%s: cannot find free range\n", __func__);
return -ENOSPC;
}
}
/**
* gpiod_get_direction - return the current direction of a GPIO
* @desc: GPIO to get the direction of
*
* Returns 0 for output, 1 for input, or an error code in case of error.
*
* This function may sleep if gpiod_cansleep() is true.
*/
int gpiod_get_direction(struct gpio_desc *desc)
{
struct gpio_chip *gc;
unsigned offset;
int ret;
gc = gpiod_to_chip(desc);
offset = gpio_chip_hwgpio(desc);
/*
* Open drain emulation using input mode may incorrectly report
* input here, fix that up.
*/
if (test_bit(FLAG_OPEN_DRAIN, &desc->flags) &&
test_bit(FLAG_IS_OUT, &desc->flags))
return 0;
if (!gc->get_direction)
return -ENOTSUPP;
ret = gc->get_direction(gc, offset);
if (ret < 0)
return ret;
/* GPIOF_DIR_IN or other positive, otherwise GPIOF_DIR_OUT */
if (ret > 0)
ret = 1;
assign_bit(FLAG_IS_OUT, &desc->flags, !ret);
return ret;
}
EXPORT_SYMBOL_GPL(gpiod_get_direction);
/*
* Add a new chip to the global chips list, keeping the list of chips sorted
* by range(means [base, base + ngpio - 1]) order.
*
* Return -EBUSY if the new chip overlaps with some other chip's integer
* space.
*/
static int gpiodev_add_to_list(struct gpio_device *gdev)
{
struct gpio_device *prev, *next;
if (list_empty(&gpio_devices)) {
/* initial entry in list */
list_add_tail(&gdev->list, &gpio_devices);
return 0;
}
next = list_entry(gpio_devices.next, struct gpio_device, list);
if (gdev->base + gdev->ngpio <= next->base) {
/* add before first entry */
list_add(&gdev->list, &gpio_devices);
return 0;
}
prev = list_entry(gpio_devices.prev, struct gpio_device, list);
if (prev->base + prev->ngpio <= gdev->base) {
/* add behind last entry */
list_add_tail(&gdev->list, &gpio_devices);
return 0;
}
list_for_each_entry_safe(prev, next, &gpio_devices, list) {
/* at the end of the list */
if (&next->list == &gpio_devices)
break;
/* add between prev and next */
if (prev->base + prev->ngpio <= gdev->base
&& gdev->base + gdev->ngpio <= next->base) {
list_add(&gdev->list, &prev->list);
return 0;
}
}
dev_err(&gdev->dev, "GPIO integer space overlap, cannot add chip\n");
return -EBUSY;
}
/*
* Convert a GPIO name to its descriptor
* Note that there is no guarantee that GPIO names are globally unique!
* Hence this function will return, if it exists, a reference to the first GPIO
* line found that matches the given name.
*/
static struct gpio_desc *gpio_name_to_desc(const char * const name)
{
struct gpio_device *gdev;
unsigned long flags;
if (!name)
return NULL;
spin_lock_irqsave(&gpio_lock, flags);
list_for_each_entry(gdev, &gpio_devices, list) {
int i;
for (i = 0; i != gdev->ngpio; ++i) {
struct gpio_desc *desc = &gdev->descs[i];
if (!desc->name)
continue;
if (!strcmp(desc->name, name)) {
spin_unlock_irqrestore(&gpio_lock, flags);
return desc;
}
}
}
spin_unlock_irqrestore(&gpio_lock, flags);
return NULL;
}
/*
* Take the names from gc->names and assign them to their GPIO descriptors.
* Warn if a name is already used for a GPIO line on a different GPIO chip.
*
* Note that:
* 1. Non-unique names are still accepted,
* 2. Name collisions within the same GPIO chip are not reported.
*/
static int gpiochip_set_desc_names(struct gpio_chip *gc)
{
struct gpio_device *gdev = gc->gpiodev;
int i;
if (!gc->names)
return 0;
/* First check all names if they are unique */
for (i = 0; i != gc->ngpio; ++i) {
struct gpio_desc *gpio;
gpio = gpio_name_to_desc(gc->names[i]);
if (gpio)
dev_warn(&gdev->dev,
"Detected name collision for GPIO name '%s'\n",
gc->names[i]);
}
/* Then add all names to the GPIO descriptors */
for (i = 0; i != gc->ngpio; ++i)
gdev->descs[i].name = gc->names[i];
return 0;
}
static unsigned long *gpiochip_allocate_mask(struct gpio_chip *gc)
{
unsigned long *p;
p = bitmap_alloc(gc->ngpio, GFP_KERNEL);
if (!p)
return NULL;
/* Assume by default all GPIOs are valid */
bitmap_fill(p, gc->ngpio);
return p;
}
static int gpiochip_alloc_valid_mask(struct gpio_chip *gc)
{
if (!(of_gpio_need_valid_mask(gc) || gc->init_valid_mask))
return 0;
gc->valid_mask = gpiochip_allocate_mask(gc);
if (!gc->valid_mask)
return -ENOMEM;
return 0;
}
static int gpiochip_init_valid_mask(struct gpio_chip *gc)
{
if (gc->init_valid_mask)
return gc->init_valid_mask(gc,
gc->valid_mask,
gc->ngpio);
return 0;
}
static void gpiochip_free_valid_mask(struct gpio_chip *gc)
{
bitmap_free(gc->valid_mask);
gc->valid_mask = NULL;
}
static int gpiochip_add_pin_ranges(struct gpio_chip *gc)
{
if (gc->add_pin_ranges)
return gc->add_pin_ranges(gc);
return 0;
}
bool gpiochip_line_is_valid(const struct gpio_chip *gc,
unsigned int offset)
{
/* No mask means all valid */
if (likely(!gc->valid_mask))
return true;
return test_bit(offset, gc->valid_mask);
}
EXPORT_SYMBOL_GPL(gpiochip_line_is_valid);
/*
* GPIO line handle management
*/
/**
* struct linehandle_state - contains the state of a userspace handle
* @gdev: the GPIO device the handle pertains to
* @label: consumer label used to tag descriptors
* @descs: the GPIO descriptors held by this handle
* @numdescs: the number of descriptors held in the descs array
*/
struct linehandle_state {
struct gpio_device *gdev;
const char *label;
struct gpio_desc *descs[GPIOHANDLES_MAX];
u32 numdescs;
};
#define GPIOHANDLE_REQUEST_VALID_FLAGS \
(GPIOHANDLE_REQUEST_INPUT | \
GPIOHANDLE_REQUEST_OUTPUT | \
GPIOHANDLE_REQUEST_ACTIVE_LOW | \
GPIOHANDLE_REQUEST_BIAS_PULL_UP | \
GPIOHANDLE_REQUEST_BIAS_PULL_DOWN | \
GPIOHANDLE_REQUEST_BIAS_DISABLE | \
GPIOHANDLE_REQUEST_OPEN_DRAIN | \
GPIOHANDLE_REQUEST_OPEN_SOURCE)
static int linehandle_validate_flags(u32 flags)
{
/* Return an error if an unknown flag is set */
if (flags & ~GPIOHANDLE_REQUEST_VALID_FLAGS)
return -EINVAL;
/*
* Do not allow both INPUT & OUTPUT flags to be set as they are
* contradictory.
*/
if ((flags & GPIOHANDLE_REQUEST_INPUT) &&
(flags & GPIOHANDLE_REQUEST_OUTPUT))
return -EINVAL;
/*
* Do not allow OPEN_SOURCE & OPEN_DRAIN flags in a single request. If
* the hardware actually supports enabling both at the same time the
* electrical result would be disastrous.
*/
if ((flags & GPIOHANDLE_REQUEST_OPEN_DRAIN) &&
(flags & GPIOHANDLE_REQUEST_OPEN_SOURCE))
return -EINVAL;
/* OPEN_DRAIN and OPEN_SOURCE flags only make sense for output mode. */
if (!(flags & GPIOHANDLE_REQUEST_OUTPUT) &&
((flags & GPIOHANDLE_REQUEST_OPEN_DRAIN) ||
(flags & GPIOHANDLE_REQUEST_OPEN_SOURCE)))
return -EINVAL;
/* Bias flags only allowed for input or output mode. */
if (!((flags & GPIOHANDLE_REQUEST_INPUT) ||
(flags & GPIOHANDLE_REQUEST_OUTPUT)) &&
((flags & GPIOHANDLE_REQUEST_BIAS_DISABLE) ||
(flags & GPIOHANDLE_REQUEST_BIAS_PULL_UP) ||
(flags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN)))
return -EINVAL;
/* Only one bias flag can be set. */
if (((flags & GPIOHANDLE_REQUEST_BIAS_DISABLE) &&
(flags & (GPIOHANDLE_REQUEST_BIAS_PULL_DOWN |
GPIOHANDLE_REQUEST_BIAS_PULL_UP))) ||
((flags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN) &&
(flags & GPIOHANDLE_REQUEST_BIAS_PULL_UP)))
return -EINVAL;
return 0;
}
static long linehandle_set_config(struct linehandle_state *lh,
void __user *ip)
{
struct gpiohandle_config gcnf;
struct gpio_desc *desc;
int i, ret;
u32 lflags;
unsigned long *flagsp;
if (copy_from_user(&gcnf, ip, sizeof(gcnf)))
return -EFAULT;
lflags = gcnf.flags;
ret = linehandle_validate_flags(lflags);
if (ret)
return ret;
for (i = 0; i < lh->numdescs; i++) {
desc = lh->descs[i];
flagsp = &desc->flags;
assign_bit(FLAG_ACTIVE_LOW, flagsp,
lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW);
assign_bit(FLAG_OPEN_DRAIN, flagsp,
lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN);
assign_bit(FLAG_OPEN_SOURCE, flagsp,
lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE);
assign_bit(FLAG_PULL_UP, flagsp,
lflags & GPIOHANDLE_REQUEST_BIAS_PULL_UP);
assign_bit(FLAG_PULL_DOWN, flagsp,
lflags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN);
assign_bit(FLAG_BIAS_DISABLE, flagsp,
lflags & GPIOHANDLE_REQUEST_BIAS_DISABLE);
/*
* Lines have to be requested explicitly for input
* or output, else the line will be treated "as is".
*/
if (lflags & GPIOHANDLE_REQUEST_OUTPUT) {
int val = !!gcnf.default_values[i];
ret = gpiod_direction_output(desc, val);
if (ret)
return ret;
} else if (lflags & GPIOHANDLE_REQUEST_INPUT) {
ret = gpiod_direction_input(desc);
if (ret)
return ret;
}
atomic_notifier_call_chain(&desc->gdev->notifier,
GPIOLINE_CHANGED_CONFIG, desc);
}
return 0;
}
static long linehandle_ioctl(struct file *filep, unsigned int cmd,
unsigned long arg)
{
struct linehandle_state *lh = filep->private_data;
void __user *ip = (void __user *)arg;
struct gpiohandle_data ghd;
DECLARE_BITMAP(vals, GPIOHANDLES_MAX);
int i;
if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) {
/* NOTE: It's ok to read values of output lines. */
int ret = gpiod_get_array_value_complex(false,
true,
lh->numdescs,
lh->descs,
NULL,
vals);
if (ret)
return ret;
memset(&ghd, 0, sizeof(ghd));
for (i = 0; i < lh->numdescs; i++)
ghd.values[i] = test_bit(i, vals);
if (copy_to_user(ip, &ghd, sizeof(ghd)))
return -EFAULT;
return 0;
} else if (cmd == GPIOHANDLE_SET_LINE_VALUES_IOCTL) {
/*
* All line descriptors were created at once with the same
* flags so just check if the first one is really output.
*/
if (!test_bit(FLAG_IS_OUT, &lh->descs[0]->flags))
return -EPERM;
if (copy_from_user(&ghd, ip, sizeof(ghd)))
return -EFAULT;
/* Clamp all values to [0,1] */
for (i = 0; i < lh->numdescs; i++)
__assign_bit(i, vals, ghd.values[i]);
/* Reuse the array setting function */
return gpiod_set_array_value_complex(false,
true,
lh->numdescs,
lh->descs,
NULL,
vals);
} else if (cmd == GPIOHANDLE_SET_CONFIG_IOCTL) {
return linehandle_set_config(lh, ip);
}
return -EINVAL;
}
#ifdef CONFIG_COMPAT
static long linehandle_ioctl_compat(struct file *filep, unsigned int cmd,
unsigned long arg)
{
return linehandle_ioctl(filep, cmd, (unsigned long)compat_ptr(arg));
}
#endif
static int linehandle_release(struct inode *inode, struct file *filep)
{
struct linehandle_state *lh = filep->private_data;
struct gpio_device *gdev = lh->gdev;
int i;
for (i = 0; i < lh->numdescs; i++)
gpiod_free(lh->descs[i]);
kfree(lh->label);
kfree(lh);
put_device(&gdev->dev);
return 0;
}
static const struct file_operations linehandle_fileops = {
.release = linehandle_release,
.owner = THIS_MODULE,
.llseek = noop_llseek,
.unlocked_ioctl = linehandle_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = linehandle_ioctl_compat,
#endif
};
static int linehandle_create(struct gpio_device *gdev, void __user *ip)
{
struct gpiohandle_request handlereq;
struct linehandle_state *lh;
struct file *file;
int fd, i, count = 0, ret;
u32 lflags;
if (copy_from_user(&handlereq, ip, sizeof(handlereq)))
return -EFAULT;
if ((handlereq.lines == 0) || (handlereq.lines > GPIOHANDLES_MAX))
return -EINVAL;
lflags = handlereq.flags;
ret = linehandle_validate_flags(lflags);
if (ret)
return ret;
lh = kzalloc(sizeof(*lh), GFP_KERNEL);
if (!lh)
return -ENOMEM;
lh->gdev = gdev;
get_device(&gdev->dev);
/* Make sure this is terminated */
handlereq.consumer_label[sizeof(handlereq.consumer_label)-1] = '\0';
if (strlen(handlereq.consumer_label)) {
lh->label = kstrdup(handlereq.consumer_label,
GFP_KERNEL);
if (!lh->label) {
ret = -ENOMEM;
goto out_free_lh;
}
}
/* Request each GPIO */
for (i = 0; i < handlereq.lines; i++) {
u32 offset = handlereq.lineoffsets[i];
struct gpio_desc *desc = gpiochip_get_desc(gdev->chip, offset);
if (IS_ERR(desc)) {
ret = PTR_ERR(desc);
goto out_free_descs;
}
ret = gpiod_request(desc, lh->label);
if (ret)
goto out_free_descs;
lh->descs[i] = desc;
count = i + 1;
if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
set_bit(FLAG_ACTIVE_LOW, &desc->flags);
if (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN)
set_bit(FLAG_OPEN_DRAIN, &desc->flags);
if (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)
set_bit(FLAG_OPEN_SOURCE, &desc->flags);
if (lflags & GPIOHANDLE_REQUEST_BIAS_DISABLE)
set_bit(FLAG_BIAS_DISABLE, &desc->flags);
if (lflags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN)
set_bit(FLAG_PULL_DOWN, &desc->flags);
if (lflags & GPIOHANDLE_REQUEST_BIAS_PULL_UP)
set_bit(FLAG_PULL_UP, &desc->flags);
ret = gpiod_set_transitory(desc, false);
if (ret < 0)
goto out_free_descs;
/*
* Lines have to be requested explicitly for input
* or output, else the line will be treated "as is".
*/
if (lflags & GPIOHANDLE_REQUEST_OUTPUT) {
int val = !!handlereq.default_values[i];
ret = gpiod_direction_output(desc, val);
if (ret)
goto out_free_descs;
} else if (lflags & GPIOHANDLE_REQUEST_INPUT) {
ret = gpiod_direction_input(desc);
if (ret)
goto out_free_descs;
}
atomic_notifier_call_chain(&desc->gdev->notifier,
GPIOLINE_CHANGED_REQUESTED, desc);
dev_dbg(&gdev->dev, "registered chardev handle for line %d\n",
offset);
}
/* Let i point at the last handle */
i--;
lh->numdescs = handlereq.lines;
fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC);
if (fd < 0) {
ret = fd;
goto out_free_descs;
}
file = anon_inode_getfile("gpio-linehandle",
&linehandle_fileops,
lh,
O_RDONLY | O_CLOEXEC);
if (IS_ERR(file)) {
ret = PTR_ERR(file);
goto out_put_unused_fd;
}
handlereq.fd = fd;
if (copy_to_user(ip, &handlereq, sizeof(handlereq))) {
/*
* fput() will trigger the release() callback, so do not go onto
* the regular error cleanup path here.
*/
fput(file);
put_unused_fd(fd);
return -EFAULT;
}
fd_install(fd, file);
dev_dbg(&gdev->dev, "registered chardev handle for %d lines\n",
lh->numdescs);
return 0;
out_put_unused_fd:
put_unused_fd(fd);
out_free_descs:
for (i = 0; i < count; i++)
gpiod_free(lh->descs[i]);
kfree(lh->label);
out_free_lh:
kfree(lh);
put_device(&gdev->dev);
return ret;
}
/*
* GPIO line event management
*/
/**
* struct lineevent_state - contains the state of a userspace event
* @gdev: the GPIO device the event pertains to
* @label: consumer label used to tag descriptors
* @desc: the GPIO descriptor held by this event
* @eflags: the event flags this line was requested with
* @irq: the interrupt that trigger in response to events on this GPIO
* @wait: wait queue that handles blocking reads of events
* @events: KFIFO for the GPIO events
* @timestamp: cache for the timestamp storing it between hardirq
* and IRQ thread, used to bring the timestamp close to the actual
* event
*/
struct lineevent_state {
struct gpio_device *gdev;
const char *label;
struct gpio_desc *desc;
u32 eflags;
int irq;
wait_queue_head_t wait;
DECLARE_KFIFO(events, struct gpioevent_data, 16);
u64 timestamp;
};
#define GPIOEVENT_REQUEST_VALID_FLAGS \
(GPIOEVENT_REQUEST_RISING_EDGE | \
GPIOEVENT_REQUEST_FALLING_EDGE)
static __poll_t lineevent_poll(struct file *filep,
struct poll_table_struct *wait)
{
struct lineevent_state *le = filep->private_data;
__poll_t events = 0;
poll_wait(filep, &le->wait, wait);
if (!kfifo_is_empty_spinlocked_noirqsave(&le->events, &le->wait.lock))
events = EPOLLIN | EPOLLRDNORM;
return events;
}
static ssize_t lineevent_read(struct file *filep,
char __user *buf,
size_t count,
loff_t *f_ps)
{
struct lineevent_state *le = filep->private_data;
struct gpioevent_data ge;
ssize_t bytes_read = 0;
int ret;
if (count < sizeof(ge))
return -EINVAL;
do {
spin_lock(&le->wait.lock);
if (kfifo_is_empty(&le->events)) {
if (bytes_read) {
spin_unlock(&le->wait.lock);
return bytes_read;
}
if (filep->f_flags & O_NONBLOCK) {
spin_unlock(&le->wait.lock);
return -EAGAIN;
}
ret = wait_event_interruptible_locked(le->wait,
!kfifo_is_empty(&le->events));
if (ret) {
spin_unlock(&le->wait.lock);
return ret;
}
}
ret = kfifo_out(&le->events, &ge, 1);
spin_unlock(&le->wait.lock);
if (ret != 1) {
/*
* This should never happen - we were holding the lock
* from the moment we learned the fifo is no longer
* empty until now.
*/
ret = -EIO;
break;
}
if (copy_to_user(buf + bytes_read, &ge, sizeof(ge)))
return -EFAULT;
bytes_read += sizeof(ge);
} while (count >= bytes_read + sizeof(ge));
return bytes_read;
}
static int lineevent_release(struct inode *inode, struct file *filep)
{
struct lineevent_state *le = filep->private_data;
struct gpio_device *gdev = le->gdev;
free_irq(le->irq, le);
gpiod_free(le->desc);
kfree(le->label);
kfree(le);
put_device(&gdev->dev);
return 0;
}
static long lineevent_ioctl(struct file *filep, unsigned int cmd,
unsigned long arg)
{
struct lineevent_state *le = filep->private_data;
void __user *ip = (void __user *)arg;
struct gpiohandle_data ghd;
/*
* We can get the value for an event line but not set it,
* because it is input by definition.
*/
if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) {
int val;
memset(&ghd, 0, sizeof(ghd));
val = gpiod_get_value_cansleep(le->desc);
if (val < 0)
return val;
ghd.values[0] = val;
if (copy_to_user(ip, &ghd, sizeof(ghd)))
return -EFAULT;
return 0;
}
return -EINVAL;
}
#ifdef CONFIG_COMPAT
static long lineevent_ioctl_compat(struct file *filep, unsigned int cmd,
unsigned long arg)
{
return lineevent_ioctl(filep, cmd, (unsigned long)compat_ptr(arg));
}
#endif
static const struct file_operations lineevent_fileops = {
.release = lineevent_release,
.read = lineevent_read,
.poll = lineevent_poll,
.owner = THIS_MODULE,
.llseek = noop_llseek,
.unlocked_ioctl = lineevent_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = lineevent_ioctl_compat,
#endif
};
static irqreturn_t lineevent_irq_thread(int irq, void *p)
{
struct lineevent_state *le = p;
struct gpioevent_data ge;
int ret;
/* Do not leak kernel stack to userspace */
memset(&ge, 0, sizeof(ge));
/*
* We may be running from a nested threaded interrupt in which case
* we didn't get the timestamp from lineevent_irq_handler().
*/
if (!le->timestamp)
ge.timestamp = ktime_get_ns();
else
ge.timestamp = le->timestamp;
if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE
&& le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE) {
int level = gpiod_get_value_cansleep(le->desc);
if (level)
/* Emit low-to-high event */
ge.id = GPIOEVENT_EVENT_RISING_EDGE;
else
/* Emit high-to-low event */
ge.id = GPIOEVENT_EVENT_FALLING_EDGE;
} else if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE) {
/* Emit low-to-high event */
ge.id = GPIOEVENT_EVENT_RISING_EDGE;
} else if (le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE) {
/* Emit high-to-low event */
ge.id = GPIOEVENT_EVENT_FALLING_EDGE;
} else {
return IRQ_NONE;
}
ret = kfifo_in_spinlocked_noirqsave(&le->events, &ge,
1, &le->wait.lock);
if (ret)
wake_up_poll(&le->wait, EPOLLIN);
else
pr_debug_ratelimited("event FIFO is full - event dropped\n");
return IRQ_HANDLED;
}
static irqreturn_t lineevent_irq_handler(int irq, void *p)
{
struct lineevent_state *le = p;
/*
* Just store the timestamp in hardirq context so we get it as
* close in time as possible to the actual event.
*/
le->timestamp = ktime_get_ns();
return IRQ_WAKE_THREAD;
}
static int lineevent_create(struct gpio_device *gdev, void __user *ip)
{
struct gpioevent_request eventreq;
struct lineevent_state *le;
struct gpio_desc *desc;
struct file *file;
u32 offset;
u32 lflags;
u32 eflags;
int fd;
int ret;
int irqflags = 0;
if (copy_from_user(&eventreq, ip, sizeof(eventreq)))
return -EFAULT;
offset = eventreq.lineoffset;
lflags = eventreq.handleflags;
eflags = eventreq.eventflags;
desc = gpiochip_get_desc(gdev->chip, offset);
if (IS_ERR(desc))
return PTR_ERR(desc);
/* Return an error if a unknown flag is set */
if ((lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS) ||
(eflags & ~GPIOEVENT_REQUEST_VALID_FLAGS))
return -EINVAL;
/* This is just wrong: we don't look for events on output lines */
if ((lflags & GPIOHANDLE_REQUEST_OUTPUT) ||
(lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) ||
(lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE))
return -EINVAL;
/* Only one bias flag can be set. */
if (((lflags & GPIOHANDLE_REQUEST_BIAS_DISABLE) &&
(lflags & (GPIOHANDLE_REQUEST_BIAS_PULL_DOWN |
GPIOHANDLE_REQUEST_BIAS_PULL_UP))) ||
((lflags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN) &&
(lflags & GPIOHANDLE_REQUEST_BIAS_PULL_UP)))
return -EINVAL;
le = kzalloc(sizeof(*le), GFP_KERNEL);
if (!le)
return -ENOMEM;
le->gdev = gdev;
get_device(&gdev->dev);
/* Make sure this is terminated */
eventreq.consumer_label[sizeof(eventreq.consumer_label)-1] = '\0';
if (strlen(eventreq.consumer_label)) {
le->label = kstrdup(eventreq.consumer_label,
GFP_KERNEL);
if (!le->label) {
ret = -ENOMEM;
goto out_free_le;
}
}
ret = gpiod_request(desc, le->label);
if (ret)
goto out_free_label;
le->desc = desc;
le->eflags = eflags;
if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
set_bit(FLAG_ACTIVE_LOW, &desc->flags);
if (lflags & GPIOHANDLE_REQUEST_BIAS_DISABLE)
set_bit(FLAG_BIAS_DISABLE, &desc->flags);
if (lflags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN)
set_bit(FLAG_PULL_DOWN, &desc->flags);
if (lflags & GPIOHANDLE_REQUEST_BIAS_PULL_UP)
set_bit(FLAG_PULL_UP, &desc->flags);
ret = gpiod_direction_input(desc);
if (ret)
goto out_free_desc;
atomic_notifier_call_chain(&desc->gdev->notifier,
GPIOLINE_CHANGED_REQUESTED, desc);
le->irq = gpiod_to_irq(desc);
if (le->irq <= 0) {
ret = -ENODEV;
goto out_free_desc;
}
if (eflags & GPIOEVENT_REQUEST_RISING_EDGE)
irqflags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ?
IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING;
if (eflags & GPIOEVENT_REQUEST_FALLING_EDGE)
irqflags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ?
IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING;
irqflags |= IRQF_ONESHOT;
INIT_KFIFO(le->events);
init_waitqueue_head(&le->wait);
/* Request a thread to read the events */
ret = request_threaded_irq(le->irq,
lineevent_irq_handler,
lineevent_irq_thread,
irqflags,
le->label,
le);
if (ret)
goto out_free_desc;
fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC);
if (fd < 0) {
ret = fd;
goto out_free_irq;
}
file = anon_inode_getfile("gpio-event",
&lineevent_fileops,
le,
O_RDONLY | O_CLOEXEC);
if (IS_ERR(file)) {
ret = PTR_ERR(file);
goto out_put_unused_fd;
}
eventreq.fd = fd;
if (copy_to_user(ip, &eventreq, sizeof(eventreq))) {
/*
* fput() will trigger the release() callback, so do not go onto
* the regular error cleanup path here.
*/
fput(file);
put_unused_fd(fd);
return -EFAULT;
}
fd_install(fd, file);
return 0;
out_put_unused_fd:
put_unused_fd(fd);
out_free_irq:
free_irq(le->irq, le);
out_free_desc:
gpiod_free(le->desc);
out_free_label:
kfree(le->label);
out_free_le:
kfree(le);
put_device(&gdev->dev);
return ret;
}
static void gpio_desc_to_lineinfo(struct gpio_desc *desc,
struct gpioline_info *info)
{
struct gpio_chip *gc = desc->gdev->chip;
bool ok_for_pinctrl;
unsigned long flags;
/*
* This function takes a mutex so we must check this before taking
* the spinlock.
*
* FIXME: find a non-racy way to retrieve this information. Maybe a
* lock common to both frameworks?
*/
ok_for_pinctrl =
pinctrl_gpio_can_use_line(gc->base + info->line_offset);
spin_lock_irqsave(&gpio_lock, flags);
if (desc->name) {
strncpy(info->name, desc->name, sizeof(info->name));
info->name[sizeof(info->name) - 1] = '\0';
} else {
info->name[0] = '\0';
}
if (desc->label) {
strncpy(info->consumer, desc->label, sizeof(info->consumer));
info->consumer[sizeof(info->consumer) - 1] = '\0';
} else {
info->consumer[0] = '\0';
}
/*
* Userspace only need to know that the kernel is using this GPIO so
* it can't use it.
*/
info->flags = 0;
if (test_bit(FLAG_REQUESTED, &desc->flags) ||
test_bit(FLAG_IS_HOGGED, &desc->flags) ||
test_bit(FLAG_USED_AS_IRQ, &desc->flags) ||
test_bit(FLAG_EXPORT, &desc->flags) ||
test_bit(FLAG_SYSFS, &desc->flags) ||
!ok_for_pinctrl)
info->flags |= GPIOLINE_FLAG_KERNEL;
if (test_bit(FLAG_IS_OUT, &desc->flags))
info->flags |= GPIOLINE_FLAG_IS_OUT;
if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
info->flags |= GPIOLINE_FLAG_ACTIVE_LOW;
if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
info->flags |= (GPIOLINE_FLAG_OPEN_DRAIN |
GPIOLINE_FLAG_IS_OUT);
if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
info->flags |= (GPIOLINE_FLAG_OPEN_SOURCE |
GPIOLINE_FLAG_IS_OUT);
if (test_bit(FLAG_BIAS_DISABLE, &desc->flags))
info->flags |= GPIOLINE_FLAG_BIAS_DISABLE;
if (test_bit(FLAG_PULL_DOWN, &desc->flags))
info->flags |= GPIOLINE_FLAG_BIAS_PULL_DOWN;
if (test_bit(FLAG_PULL_UP, &desc->flags))
info->flags |= GPIOLINE_FLAG_BIAS_PULL_UP;
spin_unlock_irqrestore(&gpio_lock, flags);
}
struct gpio_chardev_data {
struct gpio_device *gdev;
wait_queue_head_t wait;
DECLARE_KFIFO(events, struct gpioline_info_changed, 32);
struct notifier_block lineinfo_changed_nb;
unsigned long *watched_lines;
};
/*
* gpio_ioctl() - ioctl handler for the GPIO chardev
*/
static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
struct gpio_chardev_data *priv = filp->private_data;
struct gpio_device *gdev = priv->gdev;
struct gpio_chip *gc = gdev->chip;
void __user *ip = (void __user *)arg;
struct gpio_desc *desc;
__u32 offset;
int hwgpio;
/* We fail any subsequent ioctl():s when the chip is gone */
if (!gc)
return -ENODEV;
/* Fill in the struct and pass to userspace */
if (cmd == GPIO_GET_CHIPINFO_IOCTL) {
struct gpiochip_info chipinfo;
memset(&chipinfo, 0, sizeof(chipinfo));
strncpy(chipinfo.name, dev_name(&gdev->dev),
sizeof(chipinfo.name));
chipinfo.name[sizeof(chipinfo.name)-1] = '\0';
strncpy(chipinfo.label, gdev->label,
sizeof(chipinfo.label));
chipinfo.label[sizeof(chipinfo.label)-1] = '\0';
chipinfo.lines = gdev->ngpio;
if (copy_to_user(ip, &chipinfo, sizeof(chipinfo)))
return -EFAULT;
return 0;
} else if (cmd == GPIO_GET_LINEINFO_IOCTL) {
struct gpioline_info lineinfo;
if (copy_from_user(&lineinfo, ip, sizeof(lineinfo)))
return -EFAULT;
desc = gpiochip_get_desc(gc, lineinfo.line_offset);
if (IS_ERR(desc))
return PTR_ERR(desc);
hwgpio = gpio_chip_hwgpio(desc);
gpio_desc_to_lineinfo(desc, &lineinfo);
if (copy_to_user(ip, &lineinfo, sizeof(lineinfo)))
return -EFAULT;
return 0;
} else if (cmd == GPIO_GET_LINEHANDLE_IOCTL) {
return linehandle_create(gdev, ip);
} else if (cmd == GPIO_GET_LINEEVENT_IOCTL) {
return lineevent_create(gdev, ip);
} else if (cmd == GPIO_GET_LINEINFO_WATCH_IOCTL) {
struct gpioline_info lineinfo;
if (copy_from_user(&lineinfo, ip, sizeof(lineinfo)))
return -EFAULT;
desc = gpiochip_get_desc(gc, lineinfo.line_offset);
if (IS_ERR(desc))
return PTR_ERR(desc);
hwgpio = gpio_chip_hwgpio(desc);
if (test_bit(hwgpio, priv->watched_lines))
return -EBUSY;
gpio_desc_to_lineinfo(desc, &lineinfo);
if (copy_to_user(ip, &lineinfo, sizeof(lineinfo)))
return -EFAULT;
set_bit(hwgpio, priv->watched_lines);
return 0;
} else if (cmd == GPIO_GET_LINEINFO_UNWATCH_IOCTL) {
if (copy_from_user(&offset, ip, sizeof(offset)))
return -EFAULT;
desc = gpiochip_get_desc(gc, offset);
if (IS_ERR(desc))
return PTR_ERR(desc);
hwgpio = gpio_chip_hwgpio(desc);
if (!test_bit(hwgpio, priv->watched_lines))
return -EBUSY;
clear_bit(hwgpio, priv->watched_lines);
return 0;
}
return -EINVAL;
}
#ifdef CONFIG_COMPAT
static long gpio_ioctl_compat(struct file *filp, unsigned int cmd,
unsigned long arg)
{
return gpio_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
}
#endif
static struct gpio_chardev_data *
to_gpio_chardev_data(struct notifier_block *nb)
{
return container_of(nb, struct gpio_chardev_data, lineinfo_changed_nb);
}
static int lineinfo_changed_notify(struct notifier_block *nb,
unsigned long action, void *data)
{
struct gpio_chardev_data *priv = to_gpio_chardev_data(nb);
struct gpioline_info_changed chg;
struct gpio_desc *desc = data;
int ret;
if (!test_bit(gpio_chip_hwgpio(desc), priv->watched_lines))
return NOTIFY_DONE;
memset(&chg, 0, sizeof(chg));
chg.info.line_offset = gpio_chip_hwgpio(desc);
chg.event_type = action;
chg.timestamp = ktime_get_ns();
gpio_desc_to_lineinfo(desc, &chg.info);
ret = kfifo_in_spinlocked(&priv->events, &chg, 1, &priv->wait.lock);
if (ret)
wake_up_poll(&priv->wait, EPOLLIN);
else
pr_debug_ratelimited("lineinfo event FIFO is full - event dropped\n");
return NOTIFY_OK;
}
static __poll_t lineinfo_watch_poll(struct file *filep,
struct poll_table_struct *pollt)
{
struct gpio_chardev_data *priv = filep->private_data;
__poll_t events = 0;
poll_wait(filep, &priv->wait, pollt);
if (!kfifo_is_empty_spinlocked_noirqsave(&priv->events,
&priv->wait.lock))
events = EPOLLIN | EPOLLRDNORM;
return events;
}
static ssize_t lineinfo_watch_read(struct file *filep, char __user *buf,
size_t count, loff_t *off)
{
struct gpio_chardev_data *priv = filep->private_data;
struct gpioline_info_changed event;
ssize_t bytes_read = 0;
int ret;
if (count < sizeof(event))
return -EINVAL;
do {
spin_lock(&priv->wait.lock);
if (kfifo_is_empty(&priv->events)) {
if (bytes_read) {
spin_unlock(&priv->wait.lock);
return bytes_read;
}
if (filep->f_flags & O_NONBLOCK) {
spin_unlock(&priv->wait.lock);
return -EAGAIN;
}
ret = wait_event_interruptible_locked(priv->wait,
!kfifo_is_empty(&priv->events));
if (ret) {
spin_unlock(&priv->wait.lock);
return ret;
}
}
ret = kfifo_out(&priv->events, &event, 1);
spin_unlock(&priv->wait.lock);
if (ret != 1) {
ret = -EIO;
break;
/* We should never get here. See lineevent_read(). */
}
if (copy_to_user(buf + bytes_read, &event, sizeof(event)))
return -EFAULT;
bytes_read += sizeof(event);
} while (count >= bytes_read + sizeof(event));
return bytes_read;
}
/**
* gpio_chrdev_open() - open the chardev for ioctl operations
* @inode: inode for this chardev
* @filp: file struct for storing private data
* Returns 0 on success
*/
static int gpio_chrdev_open(struct inode *inode, struct file *filp)
{
struct gpio_device *gdev = container_of(inode->i_cdev,
struct gpio_device, chrdev);
struct gpio_chardev_data *priv;
int ret = -ENOMEM;
/* Fail on open if the backing gpiochip is gone */
if (!gdev->chip)
return -ENODEV;
priv = kzalloc(sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
priv->watched_lines = bitmap_zalloc(gdev->chip->ngpio, GFP_KERNEL);
if (!priv->watched_lines)
goto out_free_priv;
init_waitqueue_head(&priv->wait);
INIT_KFIFO(priv->events);
priv->gdev = gdev;
priv->lineinfo_changed_nb.notifier_call = lineinfo_changed_notify;
ret = atomic_notifier_chain_register(&gdev->notifier,
&priv->lineinfo_changed_nb);
if (ret)
goto out_free_bitmap;
get_device(&gdev->dev);
filp->private_data = priv;
ret = nonseekable_open(inode, filp);
if (ret)
goto out_unregister_notifier;
return ret;
out_unregister_notifier:
atomic_notifier_chain_unregister(&gdev->notifier,
&priv->lineinfo_changed_nb);
out_free_bitmap:
bitmap_free(priv->watched_lines);
out_free_priv:
kfree(priv);
return ret;
}
/**
* gpio_chrdev_release() - close chardev after ioctl operations
* @inode: inode for this chardev
* @filp: file struct for storing private data
* Returns 0 on success
*/
static int gpio_chrdev_release(struct inode *inode, struct file *filp)
{
struct gpio_chardev_data *priv = filp->private_data;
struct gpio_device *gdev = priv->gdev;
bitmap_free(priv->watched_lines);
atomic_notifier_chain_unregister(&gdev->notifier,
&priv->lineinfo_changed_nb);
put_device(&gdev->dev);
kfree(priv);
return 0;
}
static const struct file_operations gpio_fileops = {
.release = gpio_chrdev_release,
.open = gpio_chrdev_open,
.poll = lineinfo_watch_poll,
.read = lineinfo_watch_read,
.owner = THIS_MODULE,
.llseek = no_llseek,
.unlocked_ioctl = gpio_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = gpio_ioctl_compat,
#endif
};
static void gpiodevice_release(struct device *dev)
{
struct gpio_device *gdev = dev_get_drvdata(dev);
list_del(&gdev->list);
ida_simple_remove(&gpio_ida, gdev->id);
kfree_const(gdev->label);
kfree(gdev->descs);
kfree(gdev);
}
static int gpiochip_setup_dev(struct gpio_device *gdev)
{
int ret;
cdev_init(&gdev->chrdev, &gpio_fileops);
gdev->chrdev.owner = THIS_MODULE;
gdev->dev.devt = MKDEV(MAJOR(gpio_devt), gdev->id);
ret = cdev_device_add(&gdev->chrdev, &gdev->dev);
if (ret)
return ret;
chip_dbg(gdev->chip, "added GPIO chardev (%d:%d)\n",
MAJOR(gpio_devt), gdev->id);
ret = gpiochip_sysfs_register(gdev);
if (ret)
goto err_remove_device;
/* From this point, the .release() function cleans up gpio_device */
gdev->dev.release = gpiodevice_release;
dev_dbg(&gdev->dev, "registered GPIOs %d to %d on %s\n", gdev->base,
gdev->base + gdev->ngpio - 1, gdev->chip->label ? : "generic");
return 0;
err_remove_device:
cdev_device_del(&gdev->chrdev, &gdev->dev);
return ret;
}
static void gpiochip_machine_hog(struct gpio_chip *gc, struct gpiod_hog *hog)
{
struct gpio_desc *desc;
int rv;
desc = gpiochip_get_desc(gc, hog->chip_hwnum);
if (IS_ERR(desc)) {
chip_err(gc, "%s: unable to get GPIO desc: %ld\n", __func__,
PTR_ERR(desc));
return;
}
if (test_bit(FLAG_IS_HOGGED, &desc->flags))
return;
rv = gpiod_hog(desc, hog->line_name, hog->lflags, hog->dflags);
if (rv)
gpiod_err(desc, "%s: unable to hog GPIO line (%s:%u): %d\n",
__func__, gc->label, hog->chip_hwnum, rv);
}
static void machine_gpiochip_add(struct gpio_chip *gc)
{
struct gpiod_hog *hog;
mutex_lock(&gpio_machine_hogs_mutex);
list_for_each_entry(hog, &gpio_machine_hogs, list) {
if (!strcmp(gc->label, hog->chip_label))
gpiochip_machine_hog(gc, hog);
}
mutex_unlock(&gpio_machine_hogs_mutex);
}
static void gpiochip_setup_devs(void)
{
struct gpio_device *gdev;
int ret;
list_for_each_entry(gdev, &gpio_devices, list) {
ret = gpiochip_setup_dev(gdev);
if (ret)
dev_err(&gdev->dev,
"Failed to initialize gpio device (%d)\n", ret);
}
}
int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data,
struct lock_class_key *lock_key,
struct lock_class_key *request_key)
{
unsigned long flags;
int ret = 0;
unsigned i;
int base = gc->base;
struct gpio_device *gdev;
/*
* First: allocate and populate the internal stat container, and
* set up the struct device.
*/
gdev = kzalloc(sizeof(*gdev), GFP_KERNEL);
if (!gdev)
return -ENOMEM;
gdev->dev.bus = &gpio_bus_type;
gdev->chip = gc;
gc->gpiodev = gdev;
if (gc->parent) {
gdev->dev.parent = gc->parent;
gdev->dev.of_node = gc->parent->of_node;
}
#ifdef CONFIG_OF_GPIO
/* If the gpiochip has an assigned OF node this takes precedence */
if (gc->of_node)
gdev->dev.of_node = gc->of_node;
else
gc->of_node = gdev->dev.of_node;
#endif
gdev->id = ida_simple_get(&gpio_ida, 0, 0, GFP_KERNEL);
if (gdev->id < 0) {
ret = gdev->id;
goto err_free_gdev;
}
dev_set_name(&gdev->dev, GPIOCHIP_NAME "%d", gdev->id);
device_initialize(&gdev->dev);
dev_set_drvdata(&gdev->dev, gdev);
if (gc->parent && gc->parent->driver)
gdev->owner = gc->parent->driver->owner;
else if (gc->owner)
/* TODO: remove chip->owner */
gdev->owner = gc->owner;
else
gdev->owner = THIS_MODULE;
gdev->descs = kcalloc(gc->ngpio, sizeof(gdev->descs[0]), GFP_KERNEL);
if (!gdev->descs) {
ret = -ENOMEM;
goto err_free_ida;
}
if (gc->ngpio == 0) {
chip_err(gc, "tried to insert a GPIO chip with zero lines\n");
ret = -EINVAL;
goto err_free_descs;
}
if (gc->ngpio > FASTPATH_NGPIO)
chip_warn(gc, "line cnt %u is greater than fast path cnt %u\n",
gc->ngpio, FASTPATH_NGPIO);
gdev->label = kstrdup_const(gc->label ?: "unknown", GFP_KERNEL);
if (!gdev->label) {
ret = -ENOMEM;
goto err_free_descs;
}
gdev->ngpio = gc->ngpio;
gdev->data = data;
spin_lock_irqsave(&gpio_lock, flags);
/*
* TODO: this allocates a Linux GPIO number base in the global
* GPIO numberspace for this chip. In the long run we want to
* get *rid* of this numberspace and use only descriptors, but
* it may be a pipe dream. It will not happen before we get rid
* of the sysfs interface anyways.
*/
if (base < 0) {
base = gpiochip_find_base(gc->ngpio);
if (base < 0) {
ret = base;
spin_unlock_irqrestore(&gpio_lock, flags);
goto err_free_label;
}
/*
* TODO: it should not be necessary to reflect the assigned
* base outside of the GPIO subsystem. Go over drivers and
* see if anyone makes use of this, else drop this and assign
* a poison instead.
*/
gc->base = base;
}
gdev->base = base;
ret = gpiodev_add_to_list(gdev);
if (ret) {
spin_unlock_irqrestore(&gpio_lock, flags);
goto err_free_label;
}
for (i = 0; i < gc->ngpio; i++)
gdev->descs[i].gdev = gdev;
spin_unlock_irqrestore(&gpio_lock, flags);
ATOMIC_INIT_NOTIFIER_HEAD(&gdev->notifier);
#ifdef CONFIG_PINCTRL
INIT_LIST_HEAD(&gdev->pin_ranges);
#endif
ret = gpiochip_set_desc_names(gc);
if (ret)
goto err_remove_from_list;
ret = gpiochip_alloc_valid_mask(gc);
if (ret)
goto err_remove_from_list;
ret = of_gpiochip_add(gc);
if (ret)
goto err_free_gpiochip_mask;
ret = gpiochip_init_valid_mask(gc);
if (ret)
goto err_remove_of_chip;
for (i = 0; i < gc->ngpio; i++) {
struct gpio_desc *desc = &gdev->descs[i];
if (gc->get_direction && gpiochip_line_is_valid(gc, i)) {
assign_bit(FLAG_IS_OUT,
&desc->flags, !gc->get_direction(gc, i));
} else {
assign_bit(FLAG_IS_OUT,
&desc->flags, !gc->direction_input);
}
}
ret = gpiochip_add_pin_ranges(gc);
if (ret)
goto err_remove_of_chip;
acpi_gpiochip_add(gc);
machine_gpiochip_add(gc);
ret = gpiochip_irqchip_init_valid_mask(gc);
if (ret)
goto err_remove_acpi_chip;
ret = gpiochip_irqchip_init_hw(gc);
if (ret)
goto err_remove_acpi_chip;
ret = gpiochip_add_irqchip(gc, lock_key, request_key);
if (ret)
goto err_remove_irqchip_mask;
/*
* By first adding the chardev, and then adding the device,
* we get a device node entry in sysfs under
* /sys/bus/gpio/devices/gpiochipN/dev that can be used for
* coldplug of device nodes and other udev business.
* We can do this only if gpiolib has been initialized.
* Otherwise, defer until later.
*/
if (gpiolib_initialized) {
ret = gpiochip_setup_dev(gdev);
if (ret)
goto err_remove_irqchip;
}
return 0;
err_remove_irqchip:
gpiochip_irqchip_remove(gc);
err_remove_irqchip_mask:
gpiochip_irqchip_free_valid_mask(gc);
err_remove_acpi_chip:
acpi_gpiochip_remove(gc);
err_remove_of_chip:
gpiochip_free_hogs(gc);
of_gpiochip_remove(gc);
err_free_gpiochip_mask:
gpiochip_remove_pin_ranges(gc);
gpiochip_free_valid_mask(gc);
err_remove_from_list:
spin_lock_irqsave(&gpio_lock, flags);
list_del(&gdev->list);
spin_unlock_irqrestore(&gpio_lock, flags);
err_free_label:
kfree_const(gdev->label);
err_free_descs:
kfree(gdev->descs);
err_free_ida:
ida_simple_remove(&gpio_ida, gdev->id);
err_free_gdev:
/* failures here can mean systems won't boot... */
pr_err("%s: GPIOs %d..%d (%s) failed to register, %d\n", __func__,
gdev->base, gdev->base + gdev->ngpio - 1,
gc->label ? : "generic", ret);
kfree(gdev);
return ret;
}
EXPORT_SYMBOL_GPL(gpiochip_add_data_with_key);
/**
* gpiochip_get_data() - get per-subdriver data for the chip
* @gc: GPIO chip
*
* Returns:
* The per-subdriver data for the chip.
*/
void *gpiochip_get_data(struct gpio_chip *gc)
{
return gc->gpiodev->data;
}
EXPORT_SYMBOL_GPL(gpiochip_get_data);
/**
* gpiochip_remove() - unregister a gpio_chip
* @gc: the chip to unregister
*
* A gpio_chip with any GPIOs still requested may not be removed.
*/
void gpiochip_remove(struct gpio_chip *gc)
{
struct gpio_device *gdev = gc->gpiodev;
unsigned long flags;
unsigned int i;
/* FIXME: should the legacy sysfs handling be moved to gpio_device? */
gpiochip_sysfs_unregister(gdev);
gpiochip_free_hogs(gc);
/* Numb the device, cancelling all outstanding operations */
gdev->chip = NULL;
gpiochip_irqchip_remove(gc);
acpi_gpiochip_remove(gc);
of_gpiochip_remove(gc);
gpiochip_remove_pin_ranges(gc);
gpiochip_free_valid_mask(gc);
/*
* We accept no more calls into the driver from this point, so
* NULL the driver data pointer
*/
gdev->data = NULL;
spin_lock_irqsave(&gpio_lock, flags);
for (i = 0; i < gdev->ngpio; i++) {
if (gpiochip_is_requested(gc, i))
break;
}
spin_unlock_irqrestore(&gpio_lock, flags);
if (i != gdev->ngpio)
dev_crit(&gdev->dev,
"REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
/*
* The gpiochip side puts its use of the device to rest here:
* if there are no userspace clients, the chardev and device will
* be removed, else it will be dangling until the last user is
* gone.
*/
cdev_device_del(&gdev->chrdev, &gdev->dev);
put_device(&gdev->dev);
}
EXPORT_SYMBOL_GPL(gpiochip_remove);
/**
* gpiochip_find() - iterator for locating a specific gpio_chip
* @data: data to pass to match function
* @match: Callback function to check gpio_chip
*
* Similar to bus_find_device. It returns a reference to a gpio_chip as
* determined by a user supplied @match callback. The callback should return
* 0 if the device doesn't match and non-zero if it does. If the callback is
* non-zero, this function will return to the caller and not iterate over any
* more gpio_chips.
*/
struct gpio_chip *gpiochip_find(void *data,
int (*match)(struct gpio_chip *gc,
void *data))
{
struct gpio_device *gdev;
struct gpio_chip *gc = NULL;
unsigned long flags;
spin_lock_irqsave(&gpio_lock, flags);
list_for_each_entry(gdev, &gpio_devices, list)
if (gdev->chip && match(gdev->chip, data)) {
gc = gdev->chip;
break;
}
spin_unlock_irqrestore(&gpio_lock, flags);
return gc;
}
EXPORT_SYMBOL_GPL(gpiochip_find);
static int gpiochip_match_name(struct gpio_chip *gc, void *data)
{
const char *name = data;
return !strcmp(gc->label, name);
}
static struct gpio_chip *find_chip_by_name(const char *name)
{
return gpiochip_find((void *)name, gpiochip_match_name);
}
#ifdef CONFIG_GPIOLIB_IRQCHIP
/*
* The following is irqchip helper code for gpiochips.
*/
static int gpiochip_irqchip_init_hw(struct gpio_chip *gc)
{
struct gpio_irq_chip *girq = &gc->irq;
if (!girq->init_hw)
return 0;
return girq->init_hw(gc);
}
static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc)
{
struct gpio_irq_chip *girq = &gc->irq;
if (!girq->init_valid_mask)
return 0;
girq->valid_mask = gpiochip_allocate_mask(gc);
if (!girq->valid_mask)
return -ENOMEM;
girq->init_valid_mask(gc, girq->valid_mask, gc->ngpio);
return 0;
}
static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc)
{
bitmap_free(gc->irq.valid_mask);
gc->irq.valid_mask = NULL;
}
bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gc,
unsigned int offset)
{
if (!gpiochip_line_is_valid(gc, offset))
return false;
/* No mask means all valid */
if (likely(!gc->irq.valid_mask))
return true;
return test_bit(offset, gc->irq.valid_mask);
}
EXPORT_SYMBOL_GPL(gpiochip_irqchip_irq_valid);
/**
* gpiochip_set_cascaded_irqchip() - connects a cascaded irqchip to a gpiochip
* @gc: the gpiochip to set the irqchip chain to
* @parent_irq: the irq number corresponding to the parent IRQ for this
* cascaded irqchip
* @parent_handler: the parent interrupt handler for the accumulated IRQ
* coming out of the gpiochip. If the interrupt is nested rather than
* cascaded, pass NULL in this handler argument
*/
static void gpiochip_set_cascaded_irqchip(struct gpio_chip *gc,
unsigned int parent_irq,
irq_flow_handler_t parent_handler)
{
struct gpio_irq_chip *girq = &gc->irq;
struct device *dev = &gc->gpiodev->dev;
if (!girq->domain) {
chip_err(gc, "called %s before setting up irqchip\n",
__func__);
return;
}
if (parent_handler) {
if (gc->can_sleep) {
chip_err(gc,
"you cannot have chained interrupts on a chip that may sleep\n");
return;
}
girq->parents = devm_kcalloc(dev, 1,
sizeof(*girq->parents),
GFP_KERNEL);
if (!girq->parents) {
chip_err(gc, "out of memory allocating parent IRQ\n");
return;
}
girq->parents[0] = parent_irq;
girq->num_parents = 1;
/*
* The parent irqchip is already using the chip_data for this
* irqchip, so our callbacks simply use the handler_data.
*/
irq_set_chained_handler_and_data(parent_irq, parent_handler,
gc);
}
}
/**
* gpiochip_set_nested_irqchip() - connects a nested irqchip to a gpiochip
* @gc: the gpiochip to set the irqchip nested handler to
* @irqchip: the irqchip to nest to the gpiochip
* @parent_irq: the irq number corresponding to the parent IRQ for this
* nested irqchip
*/
void gpiochip_set_nested_irqchip(struct gpio_chip *gc,
struct irq_chip *irqchip,
unsigned int parent_irq)
{
gpiochip_set_cascaded_irqchip(gc, parent_irq, NULL);
}
EXPORT_SYMBOL_GPL(gpiochip_set_nested_irqchip);
#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
/**
* gpiochip_set_hierarchical_irqchip() - connects a hierarchical irqchip
* to a gpiochip
* @gc: the gpiochip to set the irqchip hierarchical handler to
* @irqchip: the irqchip to handle this level of the hierarchy, the interrupt
* will then percolate up to the parent
*/
static void gpiochip_set_hierarchical_irqchip(struct gpio_chip *gc,
struct irq_chip *irqchip)
{
/* DT will deal with mapping each IRQ as we go along */
if (is_of_node(gc->irq.fwnode))
return;
/*
* This is for legacy and boardfile "irqchip" fwnodes: allocate
* irqs upfront instead of dynamically since we don't have the
* dynamic type of allocation that hardware description languages
* provide. Once all GPIO drivers using board files are gone from
* the kernel we can delete this code, but for a transitional period
* it is necessary to keep this around.
*/
if (is_fwnode_irqchip(gc->irq.fwnode)) {
int i;
int ret;
for (i = 0; i < gc->ngpio; i++) {
struct irq_fwspec fwspec;
unsigned int parent_hwirq;
unsigned int parent_type;
struct gpio_irq_chip *girq = &gc->irq;
/*
* We call the child to parent translation function
* only to check if the child IRQ is valid or not.
* Just pick the rising edge type here as that is what
* we likely need to support.
*/
ret = girq->child_to_parent_hwirq(gc, i,
IRQ_TYPE_EDGE_RISING,
&parent_hwirq,
&parent_type);
if (ret) {
chip_err(gc, "skip set-up on hwirq %d\n",
i);
continue;
}
fwspec.fwnode = gc->irq.fwnode;
/* This is the hwirq for the GPIO line side of things */
fwspec.param[0] = girq->child_offset_to_irq(gc, i);
/* Just pick something */
fwspec.param[1] = IRQ_TYPE_EDGE_RISING;
fwspec.param_count = 2;
ret = __irq_domain_alloc_irqs(gc->irq.domain,
/* just pick something */
-1,
1,
NUMA_NO_NODE,
&fwspec,
false,
NULL);
if (ret < 0) {
chip_err(gc,
"can not allocate irq for GPIO line %d parent hwirq %d in hierarchy domain: %d\n",
i, parent_hwirq,
ret);
}
}
}
chip_err(gc, "%s unknown fwnode type proceed anyway\n", __func__);
return;
}
static int gpiochip_hierarchy_irq_domain_translate(struct irq_domain *d,
struct irq_fwspec *fwspec,
unsigned long *hwirq,
unsigned int *type)
{
/* We support standard DT translation */
if (is_of_node(fwspec->fwnode) && fwspec->param_count == 2) {
return irq_domain_translate_twocell(d, fwspec, hwirq, type);
}
/* This is for board files and others not using DT */
if (is_fwnode_irqchip(fwspec->fwnode)) {
int ret;
ret = irq_domain_translate_twocell(d, fwspec, hwirq, type);
if (ret)
return ret;
WARN_ON(*type == IRQ_TYPE_NONE);
return 0;
}
return -EINVAL;
}
static int gpiochip_hierarchy_irq_domain_alloc(struct irq_domain *d,
unsigned int irq,
unsigned int nr_irqs,
void *data)
{
struct gpio_chip *gc = d->host_data;
irq_hw_number_t hwirq;
unsigned int type = IRQ_TYPE_NONE;
struct irq_fwspec *fwspec = data;
void *parent_arg;
unsigned int parent_hwirq;
unsigned int parent_type;
struct gpio_irq_chip *girq = &gc->irq;
int ret;
/*
* The nr_irqs parameter is always one except for PCI multi-MSI
* so this should not happen.
*/
WARN_ON(nr_irqs != 1);
ret = gc->irq.child_irq_domain_ops.translate(d, fwspec, &hwirq, &type);
if (ret)
return ret;
chip_dbg(gc, "allocate IRQ %d, hwirq %lu\n", irq, hwirq);
ret = girq->child_to_parent_hwirq(gc, hwirq, type,
&parent_hwirq, &parent_type);
if (ret) {
chip_err(gc, "can't look up hwirq %lu\n", hwirq);
return ret;
}
chip_dbg(gc, "found parent hwirq %u\n", parent_hwirq);
/*
* We set handle_bad_irq because the .set_type() should
* always be invoked and set the right type of handler.
*/
irq_domain_set_info(d,
irq,
hwirq,
gc->irq.chip,
gc,
girq->handler,
NULL, NULL);
irq_set_probe(irq);
/* This parent only handles asserted level IRQs */
parent_arg = girq->populate_parent_alloc_arg(gc, parent_hwirq, parent_type);
if (!parent_arg)
return -ENOMEM;
chip_dbg(gc, "alloc_irqs_parent for %d parent hwirq %d\n",
irq, parent_hwirq);
irq_set_lockdep_class(irq, gc->irq.lock_key, gc->irq.request_key);
ret = irq_domain_alloc_irqs_parent(d, irq, 1, parent_arg);
/*
* If the parent irqdomain is msi, the interrupts have already
* been allocated, so the EEXIST is good.
*/
if (irq_domain_is_msi(d->parent) && (ret == -EEXIST))
ret = 0;
if (ret)
chip_err(gc,
"failed to allocate parent hwirq %d for hwirq %lu\n",
parent_hwirq, hwirq);
kfree(parent_arg);
return ret;
}
static unsigned int gpiochip_child_offset_to_irq_noop(struct gpio_chip *gc,
unsigned int offset)
{
return offset;
}
static void gpiochip_hierarchy_setup_domain_ops(struct irq_domain_ops *ops)
{
ops->activate = gpiochip_irq_domain_activate;
ops->deactivate = gpiochip_irq_domain_deactivate;
ops->alloc = gpiochip_hierarchy_irq_domain_alloc;
ops->free = irq_domain_free_irqs_common;
/*
* We only allow overriding the translate() function for
* hierarchical chips, and this should only be done if the user
* really need something other than 1:1 translation.
*/
if (!ops->translate)
ops->translate = gpiochip_hierarchy_irq_domain_translate;
}
static int gpiochip_hierarchy_add_domain(struct gpio_chip *gc)
{
if (!gc->irq.child_to_parent_hwirq ||
!gc->irq.fwnode) {
chip_err(gc, "missing irqdomain vital data\n");
return -EINVAL;
}
if (!gc->irq.child_offset_to_irq)
gc->irq.child_offset_to_irq = gpiochip_child_offset_to_irq_noop;
if (!gc->irq.populate_parent_alloc_arg)
gc->irq.populate_parent_alloc_arg =
gpiochip_populate_parent_fwspec_twocell;
gpiochip_hierarchy_setup_domain_ops(&gc->irq.child_irq_domain_ops);
gc->irq.domain = irq_domain_create_hierarchy(
gc->irq.parent_domain,
0,
gc->ngpio,
gc->irq.fwnode,
&gc->irq.child_irq_domain_ops,
gc);
if (!gc->irq.domain)
return -ENOMEM;
gpiochip_set_hierarchical_irqchip(gc, gc->irq.chip);
return 0;
}
static bool gpiochip_hierarchy_is_hierarchical(struct gpio_chip *gc)
{
return !!gc->irq.parent_domain;
}
void *gpiochip_populate_parent_fwspec_twocell(struct gpio_chip *gc,
unsigned int parent_hwirq,
unsigned int parent_type)
{
struct irq_fwspec *fwspec;
fwspec = kmalloc(sizeof(*fwspec), GFP_KERNEL);
if (!fwspec)
return NULL;
fwspec->fwnode = gc->irq.parent_domain->fwnode;
fwspec->param_count = 2;
fwspec->param[0] = parent_hwirq;
fwspec->param[1] = parent_type;
return fwspec;
}
EXPORT_SYMBOL_GPL(gpiochip_populate_parent_fwspec_twocell);
void *gpiochip_populate_parent_fwspec_fourcell(struct gpio_chip *gc,
unsigned int parent_hwirq,
unsigned int parent_type)
{
struct irq_fwspec *fwspec;
fwspec = kmalloc(sizeof(*fwspec), GFP_KERNEL);
if (!fwspec)
return NULL;
fwspec->fwnode = gc->irq.parent_domain->fwnode;
fwspec->param_count = 4;
fwspec->param[0] = 0;
fwspec->param[1] = parent_hwirq;
fwspec->param[2] = 0;
fwspec->param[3] = parent_type;
return fwspec;
}
EXPORT_SYMBOL_GPL(gpiochip_populate_parent_fwspec_fourcell);
#else
static int gpiochip_hierarchy_add_domain(struct gpio_chip *gc)
{
return -EINVAL;
}
static bool gpiochip_hierarchy_is_hierarchical(struct gpio_chip *gc)
{
return false;
}
#endif /* CONFIG_IRQ_DOMAIN_HIERARCHY */
/**
* gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
* @d: the irqdomain used by this irqchip
* @irq: the global irq number used by this GPIO irqchip irq
* @hwirq: the local IRQ/GPIO line offset on this gpiochip
*
* This function will set up the mapping for a certain IRQ line on a
* gpiochip by assigning the gpiochip as chip data, and using the irqchip
* stored inside the gpiochip.
*/
int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
irq_hw_number_t hwirq)
{
struct gpio_chip *gc = d->host_data;
int ret = 0;
if (!gpiochip_irqchip_irq_valid(gc, hwirq))
return -ENXIO;
irq_set_chip_data(irq, gc);
/*
* This lock class tells lockdep that GPIO irqs are in a different
* category than their parents, so it won't report false recursion.
*/
irq_set_lockdep_class(irq, gc->irq.lock_key, gc->irq.request_key);
irq_set_chip_and_handler(irq, gc->irq.chip, gc->irq.handler);
/* Chips that use nested thread handlers have them marked */
if (gc->irq.threaded)
irq_set_nested_thread(irq, 1);
irq_set_noprobe(irq);
if (gc->irq.num_parents == 1)
ret = irq_set_parent(irq, gc->irq.parents[0]);
else if (gc->irq.map)
ret = irq_set_parent(irq, gc->irq.map[hwirq]);
if (ret < 0)
return ret;
/*
* No set-up of the hardware will happen if IRQ_TYPE_NONE
* is passed as default type.
*/
if (gc->irq.default_type != IRQ_TYPE_NONE)
irq_set_irq_type(irq, gc->irq.default_type);
return 0;
}
EXPORT_SYMBOL_GPL(gpiochip_irq_map);
void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
{
struct gpio_chip *gc = d->host_data;
if (gc->irq.threaded)
irq_set_nested_thread(irq, 0);
irq_set_chip_and_handler(irq, NULL, NULL);
irq_set_chip_data(irq, NULL);
}
EXPORT_SYMBOL_GPL(gpiochip_irq_unmap);
static const struct irq_domain_ops gpiochip_domain_ops = {
.map = gpiochip_irq_map,
.unmap = gpiochip_irq_unmap,
/* Virtually all GPIO irqchips are twocell:ed */
.xlate = irq_domain_xlate_twocell,
};
/*
* TODO: move these activate/deactivate in under the hierarchicial
* irqchip implementation as static once SPMI and SSBI (all external
* users) are phased over.
*/
/**
* gpiochip_irq_domain_activate() - Lock a GPIO to be used as an IRQ
* @domain: The IRQ domain used by this IRQ chip
* @data: Outermost irq_data associated with the IRQ
* @reserve: If set, only reserve an interrupt vector instead of assigning one
*
* This function is a wrapper that calls gpiochip_lock_as_irq() and is to be
* used as the activate function for the &struct irq_domain_ops. The host_data
* for the IRQ domain must be the &struct gpio_chip.
*/
int gpiochip_irq_domain_activate(struct irq_domain *domain,
struct irq_data *data, bool reserve)
{
struct gpio_chip *gc = domain->host_data;
return gpiochip_lock_as_irq(gc, data->hwirq);
}
EXPORT_SYMBOL_GPL(gpiochip_irq_domain_activate);
/**
* gpiochip_irq_domain_deactivate() - Unlock a GPIO used as an IRQ
* @domain: The IRQ domain used by this IRQ chip
* @data: Outermost irq_data associated with the IRQ
*
* This function is a wrapper that will call gpiochip_unlock_as_irq() and is to
* be used as the deactivate function for the &struct irq_domain_ops. The
* host_data for the IRQ domain must be the &struct gpio_chip.
*/
void gpiochip_irq_domain_deactivate(struct irq_domain *domain,
struct irq_data *data)
{
struct gpio_chip *gc = domain->host_data;
return gpiochip_unlock_as_irq(gc, data->hwirq);
}
EXPORT_SYMBOL_GPL(gpiochip_irq_domain_deactivate);
static int gpiochip_to_irq(struct gpio_chip *gc, unsigned offset)
{
struct irq_domain *domain = gc->irq.domain;
if (!gpiochip_irqchip_irq_valid(gc, offset))
return -ENXIO;
#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
if (irq_domain_is_hierarchy(domain)) {
struct irq_fwspec spec;
spec.fwnode = domain->fwnode;
spec.param_count = 2;
spec.param[0] = gc->irq.child_offset_to_irq(gc, offset);
spec.param[1] = IRQ_TYPE_NONE;
return irq_create_fwspec_mapping(&spec);
}
#endif
return irq_create_mapping(domain, offset);
}
static int gpiochip_irq_reqres(struct irq_data *d)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
return gpiochip_reqres_irq(gc, d->hwirq);
}
static void gpiochip_irq_relres(struct irq_data *d)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
gpiochip_relres_irq(gc, d->hwirq);
}
static void gpiochip_irq_mask(struct irq_data *d)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
if (gc->irq.irq_mask)
gc->irq.irq_mask(d);
gpiochip_disable_irq(gc, d->hwirq);
}
static void gpiochip_irq_unmask(struct irq_data *d)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
gpiochip_enable_irq(gc, d->hwirq);
if (gc->irq.irq_unmask)
gc->irq.irq_unmask(d);
}
static void gpiochip_irq_enable(struct irq_data *d)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
gpiochip_enable_irq(gc, d->hwirq);
gc->irq.irq_enable(d);
}
static void gpiochip_irq_disable(struct irq_data *d)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
gc->irq.irq_disable(d);
gpiochip_disable_irq(gc, d->hwirq);
}
static void gpiochip_set_irq_hooks(struct gpio_chip *gc)
{
struct irq_chip *irqchip = gc->irq.chip;
if (!irqchip->irq_request_resources &&
!irqchip->irq_release_resources) {
irqchip->irq_request_resources = gpiochip_irq_reqres;
irqchip->irq_release_resources = gpiochip_irq_relres;
}
if (WARN_ON(gc->irq.irq_enable))
return;
/* Check if the irqchip already has this hook... */
if (irqchip->irq_enable == gpiochip_irq_enable) {
/*
* ...and if so, give a gentle warning that this is bad
* practice.
*/
chip_info(gc,
"detected irqchip that is shared with multiple gpiochips: please fix the driver.\n");
return;
}
if (irqchip->irq_disable) {
gc->irq.irq_disable = irqchip->irq_disable;
irqchip->irq_disable = gpiochip_irq_disable;
} else {
gc->irq.irq_mask = irqchip->irq_mask;
irqchip->irq_mask = gpiochip_irq_mask;
}
if (irqchip->irq_enable) {
gc->irq.irq_enable = irqchip->irq_enable;
irqchip->irq_enable = gpiochip_irq_enable;
} else {
gc->irq.irq_unmask = irqchip->irq_unmask;
irqchip->irq_unmask = gpiochip_irq_unmask;
}
}
/**
* gpiochip_add_irqchip() - adds an IRQ chip to a GPIO chip
* @gc: the GPIO chip to add the IRQ chip to
* @lock_key: lockdep class for IRQ lock
* @request_key: lockdep class for IRQ request
*/
static int gpiochip_add_irqchip(struct gpio_chip *gc,
struct lock_class_key *lock_key,
struct lock_class_key *request_key)
{
struct irq_chip *irqchip = gc->irq.chip;
const struct irq_domain_ops *ops = NULL;
struct device_node *np;
unsigned int type;
unsigned int i;
if (!irqchip)
return 0;
if (gc->irq.parent_handler && gc->can_sleep) {
chip_err(gc, "you cannot have chained interrupts on a chip that may sleep\n");
return -EINVAL;
}
np = gc->gpiodev->dev.of_node;
type = gc->irq.default_type;
/*
* Specifying a default trigger is a terrible idea if DT or ACPI is
* used to configure the interrupts, as you may end up with
* conflicting triggers. Tell the user, and reset to NONE.
*/
if (WARN(np && type != IRQ_TYPE_NONE,
"%s: Ignoring %u default trigger\n", np->full_name, type))
type = IRQ_TYPE_NONE;
if (has_acpi_companion(gc->parent) && type != IRQ_TYPE_NONE) {
acpi_handle_warn(ACPI_HANDLE(gc->parent),
"Ignoring %u default trigger\n", type);
type = IRQ_TYPE_NONE;
}
gc->to_irq = gpiochip_to_irq;
gc->irq.default_type = type;
gc->irq.lock_key = lock_key;
gc->irq.request_key = request_key;
/* If a parent irqdomain is provided, let's build a hierarchy */
if (gpiochip_hierarchy_is_hierarchical(gc)) {
int ret = gpiochip_hierarchy_add_domain(gc);
if (ret)
return ret;
} else {
/* Some drivers provide custom irqdomain ops */
if (gc->irq.domain_ops)
ops = gc->irq.domain_ops;
if (!ops)
ops = &gpiochip_domain_ops;
gc->irq.domain = irq_domain_add_simple(np,
gc->ngpio,
gc->irq.first,
ops, gc);
if (!gc->irq.domain)
return -EINVAL;
}
if (gc->irq.parent_handler) {
void *data = gc->irq.parent_handler_data ?: gc;
for (i = 0; i < gc->irq.num_parents; i++) {
/*
* The parent IRQ chip is already using the chip_data
* for this IRQ chip, so our callbacks simply use the
* handler_data.
*/
irq_set_chained_handler_and_data(gc->irq.parents[i],
gc->irq.parent_handler,
data);
}
}
gpiochip_set_irq_hooks(gc);
acpi_gpiochip_request_interrupts(gc);
return 0;
}
/**
* gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
* @gc: the gpiochip to remove the irqchip from
*
* This is called only from gpiochip_remove()
*/
static void gpiochip_irqchip_remove(struct gpio_chip *gc)
{
struct irq_chip *irqchip = gc->irq.chip;
unsigned int offset;
acpi_gpiochip_free_interrupts(gc);
if (irqchip && gc->irq.parent_handler) {
struct gpio_irq_chip *irq = &gc->irq;
unsigned int i;
for (i = 0; i < irq->num_parents; i++)
irq_set_chained_handler_and_data(irq->parents[i],
NULL, NULL);
}
/* Remove all IRQ mappings and delete the domain */
if (gc->irq.domain) {
unsigned int irq;
for (offset = 0; offset < gc->ngpio; offset++) {
if (!gpiochip_irqchip_irq_valid(gc, offset))
continue;
irq = irq_find_mapping(gc->irq.domain, offset);
irq_dispose_mapping(irq);
}
irq_domain_remove(gc->irq.domain);
}
if (irqchip) {
if (irqchip->irq_request_resources == gpiochip_irq_reqres) {
irqchip->irq_request_resources = NULL;
irqchip->irq_release_resources = NULL;
}
if (irqchip->irq_enable == gpiochip_irq_enable) {
irqchip->irq_enable = gc->irq.irq_enable;
irqchip->irq_disable = gc->irq.irq_disable;
}
}
gc->irq.irq_enable = NULL;
gc->irq.irq_disable = NULL;
gc->irq.chip = NULL;
gpiochip_irqchip_free_valid_mask(gc);
}
/**
* gpiochip_irqchip_add_key() - adds an irqchip to a gpiochip
* @gc: the gpiochip to add the irqchip to
* @irqchip: the irqchip to add to the gpiochip
* @first_irq: if not dynamically assigned, the base (first) IRQ to
* allocate gpiochip irqs from
* @handler: the irq handler to use (often a predefined irq core function)
* @type: the default type for IRQs on this irqchip, pass IRQ_TYPE_NONE
* to have the core avoid setting up any default type in the hardware.
* @threaded: whether this irqchip uses a nested thread handler
* @lock_key: lockdep class for IRQ lock
* @request_key: lockdep class for IRQ request
*
* This function closely associates a certain irqchip with a certain
* gpiochip, providing an irq domain to translate the local IRQs to
* global irqs in the gpiolib core, and making sure that the gpiochip
* is passed as chip data to all related functions. Driver callbacks
* need to use gpiochip_get_data() to get their local state containers back
* from the gpiochip passed as chip data. An irqdomain will be stored
* in the gpiochip that shall be used by the driver to handle IRQ number
* translation. The gpiochip will need to be initialized and registered
* before calling this function.
*
* This function will handle two cell:ed simple IRQs and assumes all
* the pins on the gpiochip can generate a unique IRQ. Everything else
* need to be open coded.
*/
int gpiochip_irqchip_add_key(struct gpio_chip *gc,
struct irq_chip *irqchip,
unsigned int first_irq,
irq_flow_handler_t handler,
unsigned int type,
bool threaded,
struct lock_class_key *lock_key,
struct lock_class_key *request_key)
{
struct device_node *of_node;
if (!gc || !irqchip)
return -EINVAL;
if (!gc->parent) {
chip_err(gc, "missing gpiochip .dev parent pointer\n");
return -EINVAL;
}
gc->irq.threaded = threaded;
of_node = gc->parent->of_node;
#ifdef CONFIG_OF_GPIO
/*
* If the gpiochip has an assigned OF node this takes precedence
* FIXME: get rid of this and use gc->parent->of_node
* everywhere
*/
if (gc->of_node)
of_node = gc->of_node;
#endif
/*
* Specifying a default trigger is a terrible idea if DT or ACPI is
* used to configure the interrupts, as you may end-up with
* conflicting triggers. Tell the user, and reset to NONE.
*/
if (WARN(of_node && type != IRQ_TYPE_NONE,
"%pOF: Ignoring %d default trigger\n", of_node, type))
type = IRQ_TYPE_NONE;
if (has_acpi_companion(gc->parent) && type != IRQ_TYPE_NONE) {
acpi_handle_warn(ACPI_HANDLE(gc->parent),
"Ignoring %d default trigger\n", type);
type = IRQ_TYPE_NONE;
}
gc->irq.chip = irqchip;
gc->irq.handler = handler;
gc->irq.default_type = type;
gc->to_irq = gpiochip_to_irq;
gc->irq.lock_key = lock_key;
gc->irq.request_key = request_key;
gc->irq.domain = irq_domain_add_simple(of_node,
gc->ngpio, first_irq,
&gpiochip_domain_ops, gc);
if (!gc->irq.domain) {
gc->irq.chip = NULL;
return -EINVAL;
}
gpiochip_set_irq_hooks(gc);
acpi_gpiochip_request_interrupts(gc);
return 0;
}
EXPORT_SYMBOL_GPL(gpiochip_irqchip_add_key);
/**
* gpiochip_irqchip_add_domain() - adds an irqdomain to a gpiochip
* @gc: the gpiochip to add the irqchip to
* @domain: the irqdomain to add to the gpiochip
*
* This function adds an IRQ domain to the gpiochip.
*/
int gpiochip_irqchip_add_domain(struct gpio_chip *gc,
struct irq_domain *domain)
{
if (!domain)
return -EINVAL;
gc->to_irq = gpiochip_to_irq;
gc->irq.domain = domain;
return 0;
}
EXPORT_SYMBOL_GPL(gpiochip_irqchip_add_domain);
#else /* CONFIG_GPIOLIB_IRQCHIP */
static inline int gpiochip_add_irqchip(struct gpio_chip *gc,
struct lock_class_key *lock_key,
struct lock_class_key *request_key)
{
return 0;
}
static void gpiochip_irqchip_remove(struct gpio_chip *gc) {}
static inline int gpiochip_irqchip_init_hw(struct gpio_chip *gc)
{
return 0;
}
static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc)
{
return 0;
}
static inline void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc)
{ }
#endif /* CONFIG_GPIOLIB_IRQCHIP */
/**
* gpiochip_generic_request() - request the gpio function for a pin
* @gc: the gpiochip owning the GPIO
* @offset: the offset of the GPIO to request for GPIO function
*/
int gpiochip_generic_request(struct gpio_chip *gc, unsigned offset)
{
#ifdef CONFIG_PINCTRL
if (list_empty(&gc->gpiodev->pin_ranges))
return 0;
#endif
return pinctrl_gpio_request(gc->gpiodev->base + offset);
}
EXPORT_SYMBOL_GPL(gpiochip_generic_request);
/**
* gpiochip_generic_free() - free the gpio function from a pin
* @gc: the gpiochip to request the gpio function for
* @offset: the offset of the GPIO to free from GPIO function
*/
void gpiochip_generic_free(struct gpio_chip *gc, unsigned offset)
{
pinctrl_gpio_free(gc->gpiodev->base + offset);
}
EXPORT_SYMBOL_GPL(gpiochip_generic_free);
/**
* gpiochip_generic_config() - apply configuration for a pin
* @gc: the gpiochip owning the GPIO
* @offset: the offset of the GPIO to apply the configuration
* @config: the configuration to be applied
*/
int gpiochip_generic_config(struct gpio_chip *gc, unsigned offset,
unsigned long config)
{
return pinctrl_gpio_set_config(gc->gpiodev->base + offset, config);
}
EXPORT_SYMBOL_GPL(gpiochip_generic_config);
#ifdef CONFIG_PINCTRL
/**
* gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
* @gc: the gpiochip to add the range for
* @pctldev: the pin controller to map to
* @gpio_offset: the start offset in the current gpio_chip number space
* @pin_group: name of the pin group inside the pin controller
*
* Calling this function directly from a DeviceTree-supported
* pinctrl driver is DEPRECATED. Please see Section 2.1 of
* Documentation/devicetree/bindings/gpio/gpio.txt on how to
* bind pinctrl and gpio drivers via the "gpio-ranges" property.
*/
int gpiochip_add_pingroup_range(struct gpio_chip *gc,
struct pinctrl_dev *pctldev,
unsigned int gpio_offset, const char *pin_group)
{
struct gpio_pin_range *pin_range;
struct gpio_device *gdev = gc->gpiodev;
int ret;
pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
if (!pin_range) {
chip_err(gc, "failed to allocate pin ranges\n");
return -ENOMEM;
}
/* Use local offset as range ID */
pin_range->range.id = gpio_offset;
pin_range->range.gc = gc;
pin_range->range.name = gc->label;
pin_range->range.base = gdev->base + gpio_offset;
pin_range->pctldev = pctldev;
ret = pinctrl_get_group_pins(pctldev, pin_group,
&pin_range->range.pins,
&pin_range->range.npins);
if (ret < 0) {
kfree(pin_range);
return ret;
}
pinctrl_add_gpio_range(pctldev, &pin_range->range);
chip_dbg(gc, "created GPIO range %d->%d ==> %s PINGRP %s\n",
gpio_offset, gpio_offset + pin_range->range.npins - 1,
pinctrl_dev_get_devname(pctldev), pin_group);
list_add_tail(&pin_range->node, &gdev->pin_ranges);
return 0;
}
EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
/**
* gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
* @gc: the gpiochip to add the range for
* @pinctl_name: the dev_name() of the pin controller to map to
* @gpio_offset: the start offset in the current gpio_chip number space
* @pin_offset: the start offset in the pin controller number space
* @npins: the number of pins from the offset of each pin space (GPIO and
* pin controller) to accumulate in this range
*
* Returns:
* 0 on success, or a negative error-code on failure.
*
* Calling this function directly from a DeviceTree-supported
* pinctrl driver is DEPRECATED. Please see Section 2.1 of
* Documentation/devicetree/bindings/gpio/gpio.txt on how to
* bind pinctrl and gpio drivers via the "gpio-ranges" property.
*/
int gpiochip_add_pin_range(struct gpio_chip *gc, const char *pinctl_name,
unsigned int gpio_offset, unsigned int pin_offset,
unsigned int npins)
{
struct gpio_pin_range *pin_range;
struct gpio_device *gdev = gc->gpiodev;
int ret;
pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
if (!pin_range) {
chip_err(gc, "failed to allocate pin ranges\n");
return -ENOMEM;
}
/* Use local offset as range ID */
pin_range->range.id = gpio_offset;
pin_range->range.gc = gc;
pin_range->range.name = gc->label;
pin_range->range.base = gdev->base + gpio_offset;
pin_range->range.pin_base = pin_offset;
pin_range->range.npins = npins;
pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
&pin_range->range);
if (IS_ERR(pin_range->pctldev)) {
ret = PTR_ERR(pin_range->pctldev);
chip_err(gc, "could not create pin range\n");
kfree(pin_range);
return ret;
}
chip_dbg(gc, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
gpio_offset, gpio_offset + npins - 1,
pinctl_name,
pin_offset, pin_offset + npins - 1);
list_add_tail(&pin_range->node, &gdev->pin_ranges);
return 0;
}
EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
/**
* gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
* @gc: the chip to remove all the mappings for
*/
void gpiochip_remove_pin_ranges(struct gpio_chip *gc)
{
struct gpio_pin_range *pin_range, *tmp;
struct gpio_device *gdev = gc->gpiodev;
list_for_each_entry_safe(pin_range, tmp, &gdev->pin_ranges, node) {
list_del(&pin_range->node);
pinctrl_remove_gpio_range(pin_range->pctldev,
&pin_range->range);
kfree(pin_range);
}
}
EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
#endif /* CONFIG_PINCTRL */
/* These "optional" allocation calls help prevent drivers from stomping
* on each other, and help provide better diagnostics in debugfs.
* They're called even less than the "set direction" calls.
*/
static int gpiod_request_commit(struct gpio_desc *desc, const char *label)
{
struct gpio_chip *gc = desc->gdev->chip;
int ret;
unsigned long flags;
unsigned offset;
if (label) {
label = kstrdup_const(label, GFP_KERNEL);
if (!label)
return -ENOMEM;
}
spin_lock_irqsave(&gpio_lock, flags);
/* NOTE: gpio_request() can be called in early boot,
* before IRQs are enabled, for non-sleeping (SOC) GPIOs.
*/
if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
desc_set_label(desc, label ? : "?");
ret = 0;
} else {
kfree_const(label);
ret = -EBUSY;
goto done;
}
if (gc->request) {
/* gc->request may sleep */
spin_unlock_irqrestore(&gpio_lock, flags);
offset = gpio_chip_hwgpio(desc);
if (gpiochip_line_is_valid(gc, offset))
ret = gc->request(gc, offset);
else
ret = -EINVAL;
spin_lock_irqsave(&gpio_lock, flags);
if (ret < 0) {
desc_set_label(desc, NULL);
kfree_const(label);
clear_bit(FLAG_REQUESTED, &desc->flags);
goto done;
}
}
if (gc->get_direction) {
/* gc->get_direction may sleep */
spin_unlock_irqrestore(&gpio_lock, flags);
gpiod_get_direction(desc);
spin_lock_irqsave(&gpio_lock, flags);
}
done:
spin_unlock_irqrestore(&gpio_lock, flags);
return ret;
}
/*
* This descriptor validation needs to be inserted verbatim into each
* function taking a descriptor, so we need to use a preprocessor
* macro to avoid endless duplication. If the desc is NULL it is an
* optional GPIO and calls should just bail out.
*/
static int validate_desc(const struct gpio_desc *desc, const char *func)
{
if (!desc)
return 0;
if (IS_ERR(desc)) {
pr_warn("%s: invalid GPIO (errorpointer)\n", func);
return PTR_ERR(desc);
}
if (!desc->gdev) {
pr_warn("%s: invalid GPIO (no device)\n", func);
return -EINVAL;
}
if (!desc->gdev->chip) {
dev_warn(&desc->gdev->dev,
"%s: backing chip is gone\n", func);
return 0;
}
return 1;
}
#define VALIDATE_DESC(desc) do { \
int __valid = validate_desc(desc, __func__); \
if (__valid <= 0) \
return __valid; \
} while (0)
#define VALIDATE_DESC_VOID(desc) do { \
int __valid = validate_desc(desc, __func__); \
if (__valid <= 0) \
return; \
} while (0)
int gpiod_request(struct gpio_desc *desc, const char *label)
{
int ret = -EPROBE_DEFER;
struct gpio_device *gdev;
VALIDATE_DESC(desc);
gdev = desc->gdev;
if (try_module_get(gdev->owner)) {
ret = gpiod_request_commit(desc, label);
if (ret < 0)
module_put(gdev->owner);
else
get_device(&gdev->dev);
}
if (ret)
gpiod_dbg(desc, "%s: status %d\n", __func__, ret);
return ret;
}
static bool gpiod_free_commit(struct gpio_desc *desc)
{
bool ret = false;
unsigned long flags;
struct gpio_chip *gc;
might_sleep();
gpiod_unexport(desc);
spin_lock_irqsave(&gpio_lock, flags);
gc = desc->gdev->chip;
if (gc && test_bit(FLAG_REQUESTED, &desc->flags)) {
if (gc->free) {
spin_unlock_irqrestore(&gpio_lock, flags);
might_sleep_if(gc->can_sleep);
gc->free(gc, gpio_chip_hwgpio(desc));
spin_lock_irqsave(&gpio_lock, flags);
}
kfree_const(desc->label);
desc_set_label(desc, NULL);
clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
clear_bit(FLAG_REQUESTED, &desc->flags);
clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
clear_bit(FLAG_PULL_UP, &desc->flags);
clear_bit(FLAG_PULL_DOWN, &desc->flags);
clear_bit(FLAG_BIAS_DISABLE, &desc->flags);
clear_bit(FLAG_IS_HOGGED, &desc->flags);
#ifdef CONFIG_OF_DYNAMIC
desc->hog = NULL;
#endif
ret = true;
}
spin_unlock_irqrestore(&gpio_lock, flags);
atomic_notifier_call_chain(&desc->gdev->notifier,
GPIOLINE_CHANGED_RELEASED, desc);
return ret;
}
void gpiod_free(struct gpio_desc *desc)
{
if (desc && desc->gdev && gpiod_free_commit(desc)) {
module_put(desc->gdev->owner);
put_device(&desc->gdev->dev);
} else {
WARN_ON(extra_checks);
}
}
/**
* gpiochip_is_requested - return string iff signal was requested
* @gc: controller managing the signal
* @offset: of signal within controller's 0..(ngpio - 1) range
*
* Returns NULL if the GPIO is not currently requested, else a string.
* The string returned is the label passed to gpio_request(); if none has been
* passed it is a meaningless, non-NULL constant.
*
* This function is for use by GPIO controller drivers. The label can
* help with diagnostics, and knowing that the signal is used as a GPIO
* can help avoid accidentally multiplexing it to another controller.
*/
const char *gpiochip_is_requested(struct gpio_chip *gc, unsigned offset)
{
struct gpio_desc *desc;
if (offset >= gc->ngpio)
return NULL;
desc = gpiochip_get_desc(gc, offset);
if (IS_ERR(desc))
return NULL;
if (test_bit(FLAG_REQUESTED, &desc->flags) == 0)
return NULL;
return desc->label;
}
EXPORT_SYMBOL_GPL(gpiochip_is_requested);
/**
* gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
* @gc: GPIO chip
* @hwnum: hardware number of the GPIO for which to request the descriptor
* @label: label for the GPIO
* @lflags: lookup flags for this GPIO or 0 if default, this can be used to
* specify things like line inversion semantics with the machine flags
* such as GPIO_OUT_LOW
* @dflags: descriptor request flags for this GPIO or 0 if default, this
* can be used to specify consumer semantics such as open drain
*
* Function allows GPIO chip drivers to request and use their own GPIO
* descriptors via gpiolib API. Difference to gpiod_request() is that this
* function will not increase reference count of the GPIO chip module. This
* allows the GPIO chip module to be unloaded as needed (we assume that the
* GPIO chip driver handles freeing the GPIOs it has requested).
*
* Returns:
* A pointer to the GPIO descriptor, or an ERR_PTR()-encoded negative error
* code on failure.
*/
struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *gc,
unsigned int hwnum,
const char *label,
enum gpio_lookup_flags lflags,
enum gpiod_flags dflags)
{
struct gpio_desc *desc = gpiochip_get_desc(gc, hwnum);
int ret;
if (IS_ERR(desc)) {
chip_err(gc, "failed to get GPIO descriptor\n");
return desc;
}
ret = gpiod_request_commit(desc, label);
if (ret < 0)
return ERR_PTR(ret);
ret = gpiod_configure_flags(desc, label, lflags, dflags);
if (ret) {
chip_err(gc, "setup of own GPIO %s failed\n", label);
gpiod_free_commit(desc);
return ERR_PTR(ret);
}
return desc;
}
EXPORT_SYMBOL_GPL(gpiochip_request_own_desc);
/**
* gpiochip_free_own_desc - Free GPIO requested by the chip driver
* @desc: GPIO descriptor to free
*
* Function frees the given GPIO requested previously with
* gpiochip_request_own_desc().
*/
void gpiochip_free_own_desc(struct gpio_desc *desc)
{
if (desc)
gpiod_free_commit(desc);
}
EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
/*
* Drivers MUST set GPIO direction before making get/set calls. In
* some cases this is done in early boot, before IRQs are enabled.
*
* As a rule these aren't called more than once (except for drivers
* using the open-drain emulation idiom) so these are natural places
* to accumulate extra debugging checks. Note that we can't (yet)
* rely on gpio_request() having been called beforehand.
*/
static int gpio_do_set_config(struct gpio_chip *gc, unsigned int offset,
unsigned long config)
{
if (!gc->set_config)
return -ENOTSUPP;
return gc->set_config(gc, offset, config);
}
static int gpio_set_config(struct gpio_desc *desc, enum pin_config_param mode)
{
struct gpio_chip *gc = desc->gdev->chip;
unsigned long config;
unsigned arg;
switch (mode) {
case PIN_CONFIG_BIAS_PULL_DOWN:
case PIN_CONFIG_BIAS_PULL_UP:
arg = 1;
break;
default:
arg = 0;
}
config = PIN_CONF_PACKED(mode, arg);
return gpio_do_set_config(gc, gpio_chip_hwgpio(desc), config);
}
static int gpio_set_bias(struct gpio_desc *desc)
{
int bias = 0;
int ret = 0;
if (test_bit(FLAG_BIAS_DISABLE, &desc->flags))
bias = PIN_CONFIG_BIAS_DISABLE;
else if (test_bit(FLAG_PULL_UP, &desc->flags))
bias = PIN_CONFIG_BIAS_PULL_UP;
else if (test_bit(FLAG_PULL_DOWN, &desc->flags))
bias = PIN_CONFIG_BIAS_PULL_DOWN;
if (bias) {
ret = gpio_set_config(desc, bias);
if (ret != -ENOTSUPP)
return ret;
}
return 0;
}
/**
* gpiod_direction_input - set the GPIO direction to input
* @desc: GPIO to set to input
*
* Set the direction of the passed GPIO to input, such as gpiod_get_value() can
* be called safely on it.
*
* Return 0 in case of success, else an error code.
*/
int gpiod_direction_input(struct gpio_desc *desc)
{
struct gpio_chip *gc;
int ret = 0;
VALIDATE_DESC(desc);
gc = desc->gdev->chip;
/*
* It is legal to have no .get() and .direction_input() specified if
* the chip is output-only, but you can't specify .direction_input()
* and not support the .get() operation, that doesn't make sense.
*/
if (!gc->get && gc->direction_input) {
gpiod_warn(desc,
"%s: missing get() but have direction_input()\n",
__func__);
return -EIO;
}
/*
* If we have a .direction_input() callback, things are simple,
* just call it. Else we are some input-only chip so try to check the
* direction (if .get_direction() is supported) else we silently
* assume we are in input mode after this.
*/
if (gc->direction_input) {
ret = gc->direction_input(gc, gpio_chip_hwgpio(desc));
} else if (gc->get_direction &&
(gc->get_direction(gc, gpio_chip_hwgpio(desc)) != 1)) {
gpiod_warn(desc,
"%s: missing direction_input() operation and line is output\n",
__func__);
return -EIO;
}
if (ret == 0) {
clear_bit(FLAG_IS_OUT, &desc->flags);
ret = gpio_set_bias(desc);
}
trace_gpio_direction(desc_to_gpio(desc), 1, ret);
return ret;
}
EXPORT_SYMBOL_GPL(gpiod_direction_input);
static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value)
{
struct gpio_chip *gc = desc->gdev->chip;
int val = !!value;
int ret = 0;
/*
* It's OK not to specify .direction_output() if the gpiochip is
* output-only, but if there is then not even a .set() operation it
* is pretty tricky to drive the output line.
*/
if (!gc->set && !gc->direction_output) {
gpiod_warn(desc,
"%s: missing set() and direction_output() operations\n",
__func__);
return -EIO;
}
if (gc->direction_output) {
ret = gc->direction_output(gc, gpio_chip_hwgpio(desc), val);
} else {
/* Check that we are in output mode if we can */
if (gc->get_direction &&
gc->get_direction(gc, gpio_chip_hwgpio(desc))) {
gpiod_warn(desc,
"%s: missing direction_output() operation\n",
__func__);
return -EIO;
}
/*
* If we can't actively set the direction, we are some
* output-only chip, so just drive the output as desired.
*/
gc->set(gc, gpio_chip_hwgpio(desc), val);
}
if (!ret)
set_bit(FLAG_IS_OUT, &desc->flags);
trace_gpio_value(desc_to_gpio(desc), 0, val);
trace_gpio_direction(desc_to_gpio(desc), 0, ret);
return ret;
}
/**
* gpiod_direction_output_raw - set the GPIO direction to output
* @desc: GPIO to set to output
* @value: initial output value of the GPIO
*
* Set the direction of the passed GPIO to output, such as gpiod_set_value() can
* be called safely on it. The initial value of the output must be specified
* as raw value on the physical line without regard for the ACTIVE_LOW status.
*
* Return 0 in case of success, else an error code.
*/
int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
{
VALIDATE_DESC(desc);
return gpiod_direction_output_raw_commit(desc, value);
}
EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
/**
* gpiod_direction_output - set the GPIO direction to output
* @desc: GPIO to set to output
* @value: initial output value of the GPIO
*
* Set the direction of the passed GPIO to output, such as gpiod_set_value() can
* be called safely on it. The initial value of the output must be specified
* as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
* account.
*
* Return 0 in case of success, else an error code.
*/
int gpiod_direction_output(struct gpio_desc *desc, int value)
{
int ret;
VALIDATE_DESC(desc);
if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
value = !value;
else
value = !!value;
/* GPIOs used for enabled IRQs shall not be set as output */
if (test_bit(FLAG_USED_AS_IRQ, &desc->flags) &&
test_bit(FLAG_IRQ_IS_ENABLED, &desc->flags)) {
gpiod_err(desc,
"%s: tried to set a GPIO tied to an IRQ as output\n",
__func__);
return -EIO;
}
if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
/* First see if we can enable open drain in hardware */
ret = gpio_set_config(desc, PIN_CONFIG_DRIVE_OPEN_DRAIN);
if (!ret)
goto set_output_value;
/* Emulate open drain by not actively driving the line high */
if (value) {
ret = gpiod_direction_input(desc);
goto set_output_flag;
}
}
else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
ret = gpio_set_config(desc, PIN_CONFIG_DRIVE_OPEN_SOURCE);
if (!ret)
goto set_output_value;
/* Emulate open source by not actively driving the line low */
if (!value) {
ret = gpiod_direction_input(desc);
goto set_output_flag;
}
} else {
gpio_set_config(desc, PIN_CONFIG_DRIVE_PUSH_PULL);
}
set_output_value:
ret = gpio_set_bias(desc);
if (ret)
return ret;
return gpiod_direction_output_raw_commit(desc, value);
set_output_flag:
/*
* When emulating open-source or open-drain functionalities by not
* actively driving the line (setting mode to input) we still need to
* set the IS_OUT flag or otherwise we won't be able to set the line
* value anymore.
*/
if (ret == 0)
set_bit(FLAG_IS_OUT, &desc->flags);
return ret;
}
EXPORT_SYMBOL_GPL(gpiod_direction_output);
/**
* gpiod_set_config - sets @config for a GPIO
* @desc: descriptor of the GPIO for which to set the configuration
* @config: Same packed config format as generic pinconf
*
* Returns:
* 0 on success, %-ENOTSUPP if the controller doesn't support setting the
* configuration.
*/
int gpiod_set_config(struct gpio_desc *desc, unsigned long config)
{
struct gpio_chip *gc;
VALIDATE_DESC(desc);
gc = desc->gdev->chip;
return gpio_do_set_config(gc, gpio_chip_hwgpio(desc), config);
}
EXPORT_SYMBOL_GPL(gpiod_set_config);
/**
* gpiod_set_debounce - sets @debounce time for a GPIO
* @desc: descriptor of the GPIO for which to set debounce time
* @debounce: debounce time in microseconds
*
* Returns:
* 0 on success, %-ENOTSUPP if the controller doesn't support setting the
* debounce time.
*/
int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
{
unsigned long config;
config = pinconf_to_config_packed(PIN_CONFIG_INPUT_DEBOUNCE, debounce);
return gpiod_set_config(desc, config);
}
EXPORT_SYMBOL_GPL(gpiod_set_debounce);
/**
* gpiod_set_transitory - Lose or retain GPIO state on suspend or reset
* @desc: descriptor of the GPIO for which to configure persistence
* @transitory: True to lose state on suspend or reset, false for persistence
*
* Returns:
* 0 on success, otherwise a negative error code.
*/
int gpiod_set_transitory(struct gpio_desc *desc, bool transitory)
{
struct gpio_chip *gc;
unsigned long packed;
int gpio;
int rc;
VALIDATE_DESC(desc);
/*
* Handle FLAG_TRANSITORY first, enabling queries to gpiolib for
* persistence state.
*/
assign_bit(FLAG_TRANSITORY, &desc->flags, transitory);
/* If the driver supports it, set the persistence state now */
gc = desc->gdev->chip;
if (!gc->set_config)
return 0;
packed = pinconf_to_config_packed(PIN_CONFIG_PERSIST_STATE,
!transitory);
gpio = gpio_chip_hwgpio(desc);
rc = gpio_do_set_config(gc, gpio, packed);
if (rc == -ENOTSUPP) {
dev_dbg(&desc->gdev->dev, "Persistence not supported for GPIO %d\n",
gpio);
return 0;
}
return rc;
}
EXPORT_SYMBOL_GPL(gpiod_set_transitory);
/**
* gpiod_is_active_low - test whether a GPIO is active-low or not
* @desc: the gpio descriptor to test
*
* Returns 1 if the GPIO is active-low, 0 otherwise.
*/
int gpiod_is_active_low(const struct gpio_desc *desc)
{
VALIDATE_DESC(desc);
return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
}
EXPORT_SYMBOL_GPL(gpiod_is_active_low);
/**
* gpiod_toggle_active_low - toggle whether a GPIO is active-low or not
* @desc: the gpio descriptor to change
*/
void gpiod_toggle_active_low(struct gpio_desc *desc)
{
VALIDATE_DESC_VOID(desc);
change_bit(FLAG_ACTIVE_LOW, &desc->flags);
}
EXPORT_SYMBOL_GPL(gpiod_toggle_active_low);
/* I/O calls are only valid after configuration completed; the relevant
* "is this a valid GPIO" error checks should already have been done.
*
* "Get" operations are often inlinable as reading a pin value register,
* and masking the relevant bit in that register.
*
* When "set" operations are inlinable, they involve writing that mask to
* one register to set a low value, or a different register to set it high.
* Otherwise locking is needed, so there may be little value to inlining.
*
*------------------------------------------------------------------------
*
* IMPORTANT!!! The hot paths -- get/set value -- assume that callers
* have requested the GPIO. That can include implicit requesting by
* a direction setting call. Marking a gpio as requested locks its chip
* in memory, guaranteeing that these table lookups need no more locking
* and that gpiochip_remove() will fail.
*
* REVISIT when debugging, consider adding some instrumentation to ensure
* that the GPIO was actually requested.
*/
static int gpiod_get_raw_value_commit(const struct gpio_desc *desc)
{
struct gpio_chip *gc;
int offset;
int value;
gc = desc->gdev->chip;
offset = gpio_chip_hwgpio(desc);
value = gc->get ? gc->get(gc, offset) : -EIO;
value = value < 0 ? value : !!value;
trace_gpio_value(desc_to_gpio(desc), 1, value);
return value;
}
static int gpio_chip_get_multiple(struct gpio_chip *gc,
unsigned long *mask, unsigned long *bits)
{
if (gc->get_multiple) {
return gc->get_multiple(gc, mask, bits);
} else if (gc->get) {
int i, value;
for_each_set_bit(i, mask, gc->ngpio) {
value = gc->get(gc, i);
if (value < 0)
return value;
__assign_bit(i, bits, value);
}
return 0;
}
return -EIO;
}
int gpiod_get_array_value_complex(bool raw, bool can_sleep,
unsigned int array_size,
struct gpio_desc **desc_array,
struct gpio_array *array_info,
unsigned long *value_bitmap)
{
int ret, i = 0;
/*
* Validate array_info against desc_array and its size.
* It should immediately follow desc_array if both
* have been obtained from the same gpiod_get_array() call.
*/
if (array_info && array_info->desc == desc_array &&
array_size <= array_info->size &&
(void *)array_info == desc_array + array_info->size) {
if (!can_sleep)
WARN_ON(array_info->chip->can_sleep);
ret = gpio_chip_get_multiple(array_info->chip,
array_info->get_mask,
value_bitmap);
if (ret)
return ret;
if (!raw && !bitmap_empty(array_info->invert_mask, array_size))
bitmap_xor(value_bitmap, value_bitmap,
array_info->invert_mask, array_size);
if (bitmap_full(array_info->get_mask, array_size))
return 0;
i = find_first_zero_bit(array_info->get_mask, array_size);
} else {
array_info = NULL;
}
while (i < array_size) {
struct gpio_chip *gc = desc_array[i]->gdev->chip;
unsigned long fastpath[2 * BITS_TO_LONGS(FASTPATH_NGPIO)];
unsigned long *mask, *bits;
int first, j, ret;
if (likely(gc->ngpio <= FASTPATH_NGPIO)) {
mask = fastpath;
} else {
mask = kmalloc_array(2 * BITS_TO_LONGS(gc->ngpio),
sizeof(*mask),
can_sleep ? GFP_KERNEL : GFP_ATOMIC);
if (!mask)
return -ENOMEM;
}
bits = mask + BITS_TO_LONGS(gc->ngpio);
bitmap_zero(mask, gc->ngpio);
if (!can_sleep)
WARN_ON(gc->can_sleep);
/* collect all inputs belonging to the same chip */
first = i;
do {
const struct gpio_desc *desc = desc_array[i];
int hwgpio = gpio_chip_hwgpio(desc);
__set_bit(hwgpio, mask);
i++;
if (array_info)
i = find_next_zero_bit(array_info->get_mask,
array_size, i);
} while ((i < array_size) &&
(desc_array[i]->gdev->chip == gc));
ret = gpio_chip_get_multiple(gc, mask, bits);
if (ret) {
if (mask != fastpath)
kfree(mask);
return ret;
}
for (j = first; j < i; ) {
const struct gpio_desc *desc = desc_array[j];
int hwgpio = gpio_chip_hwgpio(desc);
int value = test_bit(hwgpio, bits);
if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
value = !value;
__assign_bit(j, value_bitmap, value);
trace_gpio_value(desc_to_gpio(desc), 1, value);
j++;
if (array_info)
j = find_next_zero_bit(array_info->get_mask, i,
j);
}
if (mask != fastpath)
kfree(mask);
}
return 0;
}
/**
* gpiod_get_raw_value() - return a gpio's raw value
* @desc: gpio whose value will be returned
*
* Return the GPIO's raw value, i.e. the value of the physical line disregarding
* its ACTIVE_LOW status, or negative errno on failure.
*
* This function can be called from contexts where we cannot sleep, and will
* complain if the GPIO chip functions potentially sleep.
*/
int gpiod_get_raw_value(const struct gpio_desc *desc)
{
VALIDATE_DESC(desc);
/* Should be using gpiod_get_raw_value_cansleep() */
WARN_ON(desc->gdev->chip->can_sleep);
return gpiod_get_raw_value_commit(desc);
}
EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
/**
* gpiod_get_value() - return a gpio's value
* @desc: gpio whose value will be returned
*
* Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
* account, or negative errno on failure.
*
* This function can be called from contexts where we cannot sleep, and will
* complain if the GPIO chip functions potentially sleep.
*/
int gpiod_get_value(const struct gpio_desc *desc)
{
int value;
VALIDATE_DESC(desc);
/* Should be using gpiod_get_value_cansleep() */
WARN_ON(desc->gdev->chip->can_sleep);
value = gpiod_get_raw_value_commit(desc);
if (value < 0)
return value;
if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
value = !value;
return value;
}
EXPORT_SYMBOL_GPL(gpiod_get_value);
/**
* gpiod_get_raw_array_value() - read raw values from an array of GPIOs
* @array_size: number of elements in the descriptor array / value bitmap
* @desc_array: array of GPIO descriptors whose values will be read
* @array_info: information on applicability of fast bitmap processing path
* @value_bitmap: bitmap to store the read values
*
* Read the raw values of the GPIOs, i.e. the values of the physical lines
* without regard for their ACTIVE_LOW status. Return 0 in case of success,
* else an error code.
*
* This function can be called from contexts where we cannot sleep,
* and it will complain if the GPIO chip functions potentially sleep.
*/
int gpiod_get_raw_array_value(unsigned int array_size,
struct gpio_desc **desc_array,
struct gpio_array *array_info,
unsigned long *value_bitmap)
{
if (!desc_array)
return -EINVAL;
return gpiod_get_array_value_complex(true, false, array_size,
desc_array, array_info,
value_bitmap);
}
EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value);
/**
* gpiod_get_array_value() - read values from an array of GPIOs
* @array_size: number of elements in the descriptor array / value bitmap
* @desc_array: array of GPIO descriptors whose values will be read
* @array_info: information on applicability of fast bitmap processing path
* @value_bitmap: bitmap to store the read values
*
* Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
* into account. Return 0 in case of success, else an error code.
*
* This function can be called from contexts where we cannot sleep,
* and it will complain if the GPIO chip functions potentially sleep.
*/
int gpiod_get_array_value(unsigned int array_size,
struct gpio_desc **desc_array,
struct gpio_array *array_info,
unsigned long *value_bitmap)
{
if (!desc_array)
return -EINVAL;
return gpiod_get_array_value_complex(false, false, array_size,
desc_array, array_info,
value_bitmap);
}
EXPORT_SYMBOL_GPL(gpiod_get_array_value);
/*
* gpio_set_open_drain_value_commit() - Set the open drain gpio's value.
* @desc: gpio descriptor whose state need to be set.
* @value: Non-zero for setting it HIGH otherwise it will set to LOW.
*/
static void gpio_set_open_drain_value_commit(struct gpio_desc *desc, bool value)
{
int ret = 0;
struct gpio_chip *gc = desc->gdev->chip;
int offset = gpio_chip_hwgpio(desc);
if (value) {
ret = gc->direction_input(gc, offset);
} else {
ret = gc->direction_output(gc, offset, 0);
if (!ret)
set_bit(FLAG_IS_OUT, &desc->flags);
}
trace_gpio_direction(desc_to_gpio(desc), value, ret);
if (ret < 0)
gpiod_err(desc,
"%s: Error in set_value for open drain err %d\n",
__func__, ret);
}
/*
* _gpio_set_open_source_value() - Set the open source gpio's value.
* @desc: gpio descriptor whose state need to be set.
* @value: Non-zero for setting it HIGH otherwise it will set to LOW.
*/
static void gpio_set_open_source_value_commit(struct gpio_desc *desc, bool value)
{
int ret = 0;
struct gpio_chip *gc = desc->gdev->chip;
int offset = gpio_chip_hwgpio(desc);
if (value) {
ret = gc->direction_output(gc, offset, 1);
if (!ret)
set_bit(FLAG_IS_OUT, &desc->flags);
} else {
ret = gc->direction_input(gc, offset);
}
trace_gpio_direction(desc_to_gpio(desc), !value, ret);
if (ret < 0)
gpiod_err(desc,
"%s: Error in set_value for open source err %d\n",
__func__, ret);
}
static void gpiod_set_raw_value_commit(struct gpio_desc *desc, bool value)
{
struct gpio_chip *gc;
gc = desc->gdev->chip;
trace_gpio_value(desc_to_gpio(desc), 0, value);
gc->set(gc, gpio_chip_hwgpio(desc), value);
}
/*
* set multiple outputs on the same chip;
* use the chip's set_multiple function if available;
* otherwise set the outputs sequentially;
* @chip: the GPIO chip we operate on
* @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
* defines which outputs are to be changed
* @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
* defines the values the outputs specified by mask are to be set to
*/
static void gpio_chip_set_multiple(struct gpio_chip *gc,
unsigned long *mask, unsigned long *bits)
{
if (gc->set_multiple) {
gc->set_multiple(gc, mask, bits);
} else {
unsigned int i;
/* set outputs if the corresponding mask bit is set */
for_each_set_bit(i, mask, gc->ngpio)
gc->set(gc, i, test_bit(i, bits));
}
}
int gpiod_set_array_value_complex(bool raw, bool can_sleep,
unsigned int array_size,
struct gpio_desc **desc_array,
struct gpio_array *array_info,
unsigned long *value_bitmap)
{
int i = 0;
/*
* Validate array_info against desc_array and its size.
* It should immediately follow desc_array if both
* have been obtained from the same gpiod_get_array() call.
*/
if (array_info && array_info->desc == desc_array &&
array_size <= array_info->size &&
(void *)array_info == desc_array + array_info->size) {
if (!can_sleep)
WARN_ON(array_info->chip->can_sleep);
if (!raw && !bitmap_empty(array_info->invert_mask, array_size))
bitmap_xor(value_bitmap, value_bitmap,
array_info->invert_mask, array_size);
gpio_chip_set_multiple(array_info->chip, array_info->set_mask,
value_bitmap);
if (bitmap_full(array_info->set_mask, array_size))
return 0;
i = find_first_zero_bit(array_info->set_mask, array_size);
} else {
array_info = NULL;
}
while (i < array_size) {
struct gpio_chip *gc = desc_array[i]->gdev->chip;
unsigned long fastpath[2 * BITS_TO_LONGS(FASTPATH_NGPIO)];
unsigned long *mask, *bits;
int count = 0;
if (likely(gc->ngpio <= FASTPATH_NGPIO)) {
mask = fastpath;
} else {
mask = kmalloc_array(2 * BITS_TO_LONGS(gc->ngpio),
sizeof(*mask),
can_sleep ? GFP_KERNEL : GFP_ATOMIC);
if (!mask)
return -ENOMEM;
}
bits = mask + BITS_TO_LONGS(gc->ngpio);
bitmap_zero(mask, gc->ngpio);
if (!can_sleep)
WARN_ON(gc->can_sleep);
do {
struct gpio_desc *desc = desc_array[i];
int hwgpio = gpio_chip_hwgpio(desc);
int value = test_bit(i, value_bitmap);
/*
* Pins applicable for fast input but not for
* fast output processing may have been already
* inverted inside the fast path, skip them.
*/
if (!raw && !(array_info &&
test_bit(i, array_info->invert_mask)) &&
test_bit(FLAG_ACTIVE_LOW, &desc->flags))
value = !value;
trace_gpio_value(desc_to_gpio(desc), 0, value);
/*
* collect all normal outputs belonging to the same chip
* open drain and open source outputs are set individually
*/
if (test_bit(FLAG_OPEN_DRAIN, &desc->flags) && !raw) {
gpio_set_open_drain_value_commit(desc, value);
} else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags) && !raw) {
gpio_set_open_source_value_commit(desc, value);
} else {
__set_bit(hwgpio, mask);
__assign_bit(hwgpio, bits, value);
count++;
}
i++;
if (array_info)
i = find_next_zero_bit(array_info->set_mask,
array_size, i);
} while ((i < array_size) &&
(desc_array[i]->gdev->chip == gc));
/* push collected bits to outputs */
if (count != 0)
gpio_chip_set_multiple(gc, mask, bits);
if (mask != fastpath)
kfree(mask);
}
return 0;
}
/**
* gpiod_set_raw_value() - assign a gpio's raw value
* @desc: gpio whose value will be assigned
* @value: value to assign
*
* Set the raw value of the GPIO, i.e. the value of its physical line without
* regard for its ACTIVE_LOW status.
*
* This function can be called from contexts where we cannot sleep, and will
* complain if the GPIO chip functions potentially sleep.
*/
void gpiod_set_raw_value(struct gpio_desc *desc, int value)
{
VALIDATE_DESC_VOID(desc);
/* Should be using gpiod_set_raw_value_cansleep() */
WARN_ON(desc->gdev->chip->can_sleep);
gpiod_set_raw_value_commit(desc, value);
}
EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
/**
* gpiod_set_value_nocheck() - set a GPIO line value without checking
* @desc: the descriptor to set the value on
* @value: value to set
*
* This sets the value of a GPIO line backing a descriptor, applying
* different semantic quirks like active low and open drain/source
* handling.
*/
static void gpiod_set_value_nocheck(struct gpio_desc *desc, int value)
{
if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
value = !value;
if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
gpio_set_open_drain_value_commit(desc, value);
else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
gpio_set_open_source_value_commit(desc, value);
else
gpiod_set_raw_value_commit(desc, value);
}
/**
* gpiod_set_value() - assign a gpio's value
* @desc: gpio whose value will be assigned
* @value: value to assign
*
* Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW,
* OPEN_DRAIN and OPEN_SOURCE flags into account.
*
* This function can be called from contexts where we cannot sleep, and will
* complain if the GPIO chip functions potentially sleep.
*/
void gpiod_set_value(struct gpio_desc *desc, int value)
{
VALIDATE_DESC_VOID(desc);
/* Should be using gpiod_set_value_cansleep() */
WARN_ON(desc->gdev->chip->can_sleep);
gpiod_set_value_nocheck(desc, value);
}
EXPORT_SYMBOL_GPL(gpiod_set_value);
/**
* gpiod_set_raw_array_value() - assign values to an array of GPIOs
* @array_size: number of elements in the descriptor array / value bitmap
* @desc_array: array of GPIO descriptors whose values will be assigned
* @array_info: information on applicability of fast bitmap processing path
* @value_bitmap: bitmap of values to assign
*
* Set the raw values of the GPIOs, i.e. the values of the physical lines
* without regard for their ACTIVE_LOW status.
*
* This function can be called from contexts where we cannot sleep, and will
* complain if the GPIO chip functions potentially sleep.
*/
int gpiod_set_raw_array_value(unsigned int array_size,
struct gpio_desc **desc_array,
struct gpio_array *array_info,
unsigned long *value_bitmap)
{
if (!desc_array)
return -EINVAL;
return gpiod_set_array_value_complex(true, false, array_size,
desc_array, array_info, value_bitmap);
}
EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
/**
* gpiod_set_array_value() - assign values to an array of GPIOs
* @array_size: number of elements in the descriptor array / value bitmap
* @desc_array: array of GPIO descriptors whose values will be assigned
* @array_info: information on applicability of fast bitmap processing path
* @value_bitmap: bitmap of values to assign
*
* Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
* into account.
*
* This function can be called from contexts where we cannot sleep, and will
* complain if the GPIO chip functions potentially sleep.
*/
int gpiod_set_array_value(unsigned int array_size,
struct gpio_desc **desc_array,
struct gpio_array *array_info,
unsigned long *value_bitmap)
{
if (!desc_array)
return -EINVAL;
return gpiod_set_array_value_complex(false, false, array_size,
desc_array, array_info,
value_bitmap);
}
EXPORT_SYMBOL_GPL(gpiod_set_array_value);
/**
* gpiod_cansleep() - report whether gpio value access may sleep
* @desc: gpio to check
*
*/
int gpiod_cansleep(const struct gpio_desc *desc)
{
VALIDATE_DESC(desc);
return desc->gdev->chip->can_sleep;
}
EXPORT_SYMBOL_GPL(gpiod_cansleep);
/**
* gpiod_set_consumer_name() - set the consumer name for the descriptor
* @desc: gpio to set the consumer name on
* @name: the new consumer name
*/
int gpiod_set_consumer_name(struct gpio_desc *desc, const char *name)
{
VALIDATE_DESC(desc);
if (name) {
name = kstrdup_const(name, GFP_KERNEL);
if (!name)
return -ENOMEM;
}
kfree_const(desc->label);
desc_set_label(desc, name);
return 0;
}
EXPORT_SYMBOL_GPL(gpiod_set_consumer_name);
/**
* gpiod_to_irq() - return the IRQ corresponding to a GPIO
* @desc: gpio whose IRQ will be returned (already requested)
*
* Return the IRQ corresponding to the passed GPIO, or an error code in case of
* error.
*/
int gpiod_to_irq(const struct gpio_desc *desc)
{
struct gpio_chip *gc;
int offset;
/*
* Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics
* requires this function to not return zero on an invalid descriptor
* but rather a negative error number.
*/
if (!desc || IS_ERR(desc) || !desc->gdev || !desc->gdev->chip)
return -EINVAL;
gc = desc->gdev->chip;
offset = gpio_chip_hwgpio(desc);
if (gc->to_irq) {
int retirq = gc->to_irq(gc, offset);
/* Zero means NO_IRQ */
if (!retirq)
return -ENXIO;
return retirq;
}
return -ENXIO;
}
EXPORT_SYMBOL_GPL(gpiod_to_irq);
/**
* gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
* @gc: the chip the GPIO to lock belongs to
* @offset: the offset of the GPIO to lock as IRQ
*
* This is used directly by GPIO drivers that want to lock down
* a certain GPIO line to be used for IRQs.
*/
int gpiochip_lock_as_irq(struct gpio_chip *gc, unsigned int offset)
{
struct gpio_desc *desc;
desc = gpiochip_get_desc(gc, offset);
if (IS_ERR(desc))
return PTR_ERR(desc);
/*
* If it's fast: flush the direction setting if something changed
* behind our back
*/
if (!gc->can_sleep && gc->get_direction) {
int dir = gpiod_get_direction(desc);
if (dir < 0) {
chip_err(gc, "%s: cannot get GPIO direction\n",
__func__);
return dir;
}
}
/* To be valid for IRQ the line needs to be input or open drain */
if (test_bit(FLAG_IS_OUT, &desc->flags) &&
!test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
chip_err(gc,
"%s: tried to flag a GPIO set as output for IRQ\n",
__func__);
return -EIO;
}
set_bit(FLAG_USED_AS_IRQ, &desc->flags);
set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
/*
* If the consumer has not set up a label (such as when the
* IRQ is referenced from .to_irq()) we set up a label here
* so it is clear this is used as an interrupt.
*/
if (!desc->label)
desc_set_label(desc, "interrupt");
return 0;
}
EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);
/**
* gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
* @gc: the chip the GPIO to lock belongs to
* @offset: the offset of the GPIO to lock as IRQ
*
* This is used directly by GPIO drivers that want to indicate
* that a certain GPIO is no longer used exclusively for IRQ.
*/
void gpiochip_unlock_as_irq(struct gpio_chip *gc, unsigned int offset)
{
struct gpio_desc *desc;
desc = gpiochip_get_desc(gc, offset);
if (IS_ERR(desc))
return;
clear_bit(FLAG_USED_AS_IRQ, &desc->flags);
clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
/* If we only had this marking, erase it */
if (desc->label && !strcmp(desc->label, "interrupt"))
desc_set_label(desc, NULL);
}
EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq);
void gpiochip_disable_irq(struct gpio_chip *gc, unsigned int offset)
{
struct gpio_desc *desc = gpiochip_get_desc(gc, offset);
if (!IS_ERR(desc) &&
!WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags)))
clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
}
EXPORT_SYMBOL_GPL(gpiochip_disable_irq);
void gpiochip_enable_irq(struct gpio_chip *gc, unsigned int offset)
{
struct gpio_desc *desc = gpiochip_get_desc(gc, offset);
if (!IS_ERR(desc) &&
!WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags))) {
/*
* We must not be output when using IRQ UNLESS we are
* open drain.
*/
WARN_ON(test_bit(FLAG_IS_OUT, &desc->flags) &&
!test_bit(FLAG_OPEN_DRAIN, &desc->flags));
set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
}
}
EXPORT_SYMBOL_GPL(gpiochip_enable_irq);
bool gpiochip_line_is_irq(struct gpio_chip *gc, unsigned int offset)
{
if (offset >= gc->ngpio)
return false;
return test_bit(FLAG_USED_AS_IRQ, &gc->gpiodev->descs[offset].flags);
}
EXPORT_SYMBOL_GPL(gpiochip_line_is_irq);
int gpiochip_reqres_irq(struct gpio_chip *gc, unsigned int offset)
{
int ret;
if (!try_module_get(gc->gpiodev->owner))
return -ENODEV;
ret = gpiochip_lock_as_irq(gc, offset);
if (ret) {
chip_err(gc, "unable to lock HW IRQ %u for IRQ\n", offset);
module_put(gc->gpiodev->owner);
return ret;
}
return 0;
}
EXPORT_SYMBOL_GPL(gpiochip_reqres_irq);
void gpiochip_relres_irq(struct gpio_chip *gc, unsigned int offset)
{
gpiochip_unlock_as_irq(gc, offset);
module_put(gc->gpiodev->owner);
}
EXPORT_SYMBOL_GPL(gpiochip_relres_irq);
bool gpiochip_line_is_open_drain(struct gpio_chip *gc, unsigned int offset)
{
if (offset >= gc->ngpio)
return false;
return test_bit(FLAG_OPEN_DRAIN, &gc->gpiodev->descs[offset].flags);
}
EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain);
bool gpiochip_line_is_open_source(struct gpio_chip *gc, unsigned int offset)
{
if (offset >= gc->ngpio)
return false;
return test_bit(FLAG_OPEN_SOURCE, &gc->gpiodev->descs[offset].flags);
}
EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source);
bool gpiochip_line_is_persistent(struct gpio_chip *gc, unsigned int offset)
{
if (offset >= gc->ngpio)
return false;
return !test_bit(FLAG_TRANSITORY, &gc->gpiodev->descs[offset].flags);
}
EXPORT_SYMBOL_GPL(gpiochip_line_is_persistent);
/**
* gpiod_get_raw_value_cansleep() - return a gpio's raw value
* @desc: gpio whose value will be returned
*
* Return the GPIO's raw value, i.e. the value of the physical line disregarding
* its ACTIVE_LOW status, or negative errno on failure.
*
* This function is to be called from contexts that can sleep.
*/
int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
{
might_sleep_if(extra_checks);
VALIDATE_DESC(desc);
return gpiod_get_raw_value_commit(desc);
}
EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
/**
* gpiod_get_value_cansleep() - return a gpio's value
* @desc: gpio whose value will be returned
*
* Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
* account, or negative errno on failure.
*
* This function is to be called from contexts that can sleep.
*/
int gpiod_get_value_cansleep(const struct gpio_desc *desc)
{
int value;
might_sleep_if(extra_checks);
VALIDATE_DESC(desc);
value = gpiod_get_raw_value_commit(desc);
if (value < 0)
return value;
if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
value = !value;
return value;
}
EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
/**
* gpiod_get_raw_array_value_cansleep() - read raw values from an array of GPIOs
* @array_size: number of elements in the descriptor array / value bitmap
* @desc_array: array of GPIO descriptors whose values will be read
* @array_info: information on applicability of fast bitmap processing path
* @value_bitmap: bitmap to store the read values
*
* Read the raw values of the GPIOs, i.e. the values of the physical lines
* without regard for their ACTIVE_LOW status. Return 0 in case of success,
* else an error code.
*
* This function is to be called from contexts that can sleep.
*/
int gpiod_get_raw_array_value_cansleep(unsigned int array_size,
struct gpio_desc **desc_array,
struct gpio_array *array_info,
unsigned long *value_bitmap)
{
might_sleep_if(extra_checks);
if (!desc_array)
return -EINVAL;
return gpiod_get_array_value_complex(true, true, array_size,
desc_array, array_info,
value_bitmap);
}
EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value_cansleep);
/**
* gpiod_get_array_value_cansleep() - read values from an array of GPIOs
* @array_size: number of elements in the descriptor array / value bitmap
* @desc_array: array of GPIO descriptors whose values will be read
* @array_info: information on applicability of fast bitmap processing path
* @value_bitmap: bitmap to store the read values
*
* Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
* into account. Return 0 in case of success, else an error code.
*
* This function is to be called from contexts that can sleep.
*/
int gpiod_get_array_value_cansleep(unsigned int array_size,
struct gpio_desc **desc_array,
struct gpio_array *array_info,
unsigned long *value_bitmap)
{
might_sleep_if(extra_checks);
if (!desc_array)
return -EINVAL;
return gpiod_get_array_value_complex(false, true, array_size,
desc_array, array_info,
value_bitmap);
}
EXPORT_SYMBOL_GPL(gpiod_get_array_value_cansleep);
/**
* gpiod_set_raw_value_cansleep() - assign a gpio's raw value
* @desc: gpio whose value will be assigned
* @value: value to assign
*
* Set the raw value of the GPIO, i.e. the value of its physical line without
* regard for its ACTIVE_LOW status.
*
* This function is to be called from contexts that can sleep.
*/
void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
{
might_sleep_if(extra_checks);
VALIDATE_DESC_VOID(desc);
gpiod_set_raw_value_commit(desc, value);
}
EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
/**
* gpiod_set_value_cansleep() - assign a gpio's value
* @desc: gpio whose value will be assigned
* @value: value to assign
*
* Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
* account
*
* This function is to be called from contexts that can sleep.
*/
void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
{
might_sleep_if(extra_checks);
VALIDATE_DESC_VOID(desc);
gpiod_set_value_nocheck(desc, value);
}
EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
/**
* gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
* @array_size: number of elements in the descriptor array / value bitmap
* @desc_array: array of GPIO descriptors whose values will be assigned
* @array_info: information on applicability of fast bitmap processing path
* @value_bitmap: bitmap of values to assign
*
* Set the raw values of the GPIOs, i.e. the values of the physical lines
* without regard for their ACTIVE_LOW status.
*
* This function is to be called from contexts that can sleep.
*/
int gpiod_set_raw_array_value_cansleep(unsigned int array_size,
struct gpio_desc **desc_array,
struct gpio_array *array_info,
unsigned long *value_bitmap)
{
might_sleep_if(extra_checks);
if (!desc_array)
return -EINVAL;
return gpiod_set_array_value_complex(true, true, array_size, desc_array,
array_info, value_bitmap);
}
EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep);
/**
* gpiod_add_lookup_tables() - register GPIO device consumers
* @tables: list of tables of consumers to register
* @n: number of tables in the list
*/
void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n)
{
unsigned int i;
mutex_lock(&gpio_lookup_lock);
for (i = 0; i < n; i++)
list_add_tail(&tables[i]->list, &gpio_lookup_list);
mutex_unlock(&gpio_lookup_lock);
}
/**
* gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
* @array_size: number of elements in the descriptor array / value bitmap
* @desc_array: array of GPIO descriptors whose values will be assigned
* @array_info: information on applicability of fast bitmap processing path
* @value_bitmap: bitmap of values to assign
*
* Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
* into account.
*
* This function is to be called from contexts that can sleep.
*/
int gpiod_set_array_value_cansleep(unsigned int array_size,
struct gpio_desc **desc_array,
struct gpio_array *array_info,
unsigned long *value_bitmap)
{
might_sleep_if(extra_checks);
if (!desc_array)
return -EINVAL;
return gpiod_set_array_value_complex(false, true, array_size,
desc_array, array_info,
value_bitmap);
}
EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep);
/**
* gpiod_add_lookup_table() - register GPIO device consumers
* @table: table of consumers to register
*/
void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
{
mutex_lock(&gpio_lookup_lock);
list_add_tail(&table->list, &gpio_lookup_list);
mutex_unlock(&gpio_lookup_lock);
}
EXPORT_SYMBOL_GPL(gpiod_add_lookup_table);
/**
* gpiod_remove_lookup_table() - unregister GPIO device consumers
* @table: table of consumers to unregister
*/
void gpiod_remove_lookup_table(struct gpiod_lookup_table *table)
{
mutex_lock(&gpio_lookup_lock);
list_del(&table->list);
mutex_unlock(&gpio_lookup_lock);
}
EXPORT_SYMBOL_GPL(gpiod_remove_lookup_table);
/**
* gpiod_add_hogs() - register a set of GPIO hogs from machine code
* @hogs: table of gpio hog entries with a zeroed sentinel at the end
*/
void gpiod_add_hogs(struct gpiod_hog *hogs)
{
struct gpio_chip *gc;
struct gpiod_hog *hog;
mutex_lock(&gpio_machine_hogs_mutex);
for (hog = &hogs[0]; hog->chip_label; hog++) {
list_add_tail(&hog->list, &gpio_machine_hogs);
/*
* The chip may have been registered earlier, so check if it
* exists and, if so, try to hog the line now.
*/
gc = find_chip_by_name(hog->chip_label);
if (gc)
gpiochip_machine_hog(gc, hog);
}
mutex_unlock(&gpio_machine_hogs_mutex);
}
EXPORT_SYMBOL_GPL(gpiod_add_hogs);
static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
{
const char *dev_id = dev ? dev_name(dev) : NULL;
struct gpiod_lookup_table *table;
mutex_lock(&gpio_lookup_lock);
list_for_each_entry(table, &gpio_lookup_list, list) {
if (table->dev_id && dev_id) {
/*
* Valid strings on both ends, must be identical to have
* a match
*/
if (!strcmp(table->dev_id, dev_id))
goto found;
} else {
/*
* One of the pointers is NULL, so both must be to have
* a match
*/
if (dev_id == table->dev_id)
goto found;
}
}
table = NULL;
found:
mutex_unlock(&gpio_lookup_lock);
return table;
}
static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
unsigned int idx, unsigned long *flags)
{
struct gpio_desc *desc = ERR_PTR(-ENOENT);
struct gpiod_lookup_table *table;
struct gpiod_lookup *p;
table = gpiod_find_lookup_table(dev);
if (!table)
return desc;
for (p = &table->table[0]; p->key; p++) {
struct gpio_chip *gc;
/* idx must always match exactly */
if (p->idx != idx)
continue;
/* If the lookup entry has a con_id, require exact match */
if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
continue;
if (p->chip_hwnum == U16_MAX) {
desc = gpio_name_to_desc(p->key);
if (desc) {
*flags = p->flags;
return desc;
}
dev_warn(dev, "cannot find GPIO line %s, deferring\n",
p->key);
return ERR_PTR(-EPROBE_DEFER);
}
gc = find_chip_by_name(p->key);
if (!gc) {
/*
* As the lookup table indicates a chip with
* p->key should exist, assume it may
* still appear later and let the interested
* consumer be probed again or let the Deferred
* Probe infrastructure handle the error.
*/
dev_warn(dev, "cannot find GPIO chip %s, deferring\n",
p->key);
return ERR_PTR(-EPROBE_DEFER);
}
if (gc->ngpio <= p->chip_hwnum) {
dev_err(dev,
"requested GPIO %u (%u) is out of range [0..%u] for chip %s\n",
idx, p->chip_hwnum, gc->ngpio - 1,
gc->label);
return ERR_PTR(-EINVAL);
}
desc = gpiochip_get_desc(gc, p->chip_hwnum);
*flags = p->flags;
return desc;
}
return desc;
}
static int platform_gpio_count(struct device *dev, const char *con_id)
{
struct gpiod_lookup_table *table;
struct gpiod_lookup *p;
unsigned int count = 0;
table = gpiod_find_lookup_table(dev);
if (!table)
return -ENOENT;
for (p = &table->table[0]; p->key; p++) {
if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) ||
(!con_id && !p->con_id))
count++;
}
if (!count)
return -ENOENT;
return count;
}
/**
* fwnode_gpiod_get_index - obtain a GPIO from firmware node
* @fwnode: handle of the firmware node
* @con_id: function within the GPIO consumer
* @index: index of the GPIO to obtain for the consumer
* @flags: GPIO initialization flags
* @label: label to attach to the requested GPIO
*
* This function can be used for drivers that get their configuration
* from opaque firmware.
*
* The function properly finds the corresponding GPIO using whatever is the
* underlying firmware interface and then makes sure that the GPIO
* descriptor is requested before it is returned to the caller.
*
* Returns:
* On successful request the GPIO pin is configured in accordance with
* provided @flags.
*
* In case of error an ERR_PTR() is returned.
*/
struct gpio_desc *fwnode_gpiod_get_index(struct fwnode_handle *fwnode,
const char *con_id, int index,
enum gpiod_flags flags,
const char *label)
{
struct gpio_desc *desc;
char prop_name[32]; /* 32 is max size of property name */
unsigned int i;
for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
if (con_id)
snprintf(prop_name, sizeof(prop_name), "%s-%s",
con_id, gpio_suffixes[i]);
else
snprintf(prop_name, sizeof(prop_name), "%s",
gpio_suffixes[i]);
desc = fwnode_get_named_gpiod(fwnode, prop_name, index, flags,
label);
if (!IS_ERR(desc) || (PTR_ERR(desc) != -ENOENT))
break;
}
return desc;
}
EXPORT_SYMBOL_GPL(fwnode_gpiod_get_index);
/**
* gpiod_count - return the number of GPIOs associated with a device / function
* or -ENOENT if no GPIO has been assigned to the requested function
* @dev: GPIO consumer, can be NULL for system-global GPIOs
* @con_id: function within the GPIO consumer
*/
int gpiod_count(struct device *dev, const char *con_id)
{
int count = -ENOENT;
if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node)
count = of_gpio_get_count(dev, con_id);
else if (IS_ENABLED(CONFIG_ACPI) && dev && ACPI_HANDLE(dev))
count = acpi_gpio_count(dev, con_id);
if (count < 0)
count = platform_gpio_count(dev, con_id);
return count;
}
EXPORT_SYMBOL_GPL(gpiod_count);
/**
* gpiod_get - obtain a GPIO for a given GPIO function
* @dev: GPIO consumer, can be NULL for system-global GPIOs
* @con_id: function within the GPIO consumer
* @flags: optional GPIO initialization flags
*
* Return the GPIO descriptor corresponding to the function con_id of device
* dev, -ENOENT if no GPIO has been assigned to the requested function, or
* another IS_ERR() code if an error occurred while trying to acquire the GPIO.
*/
struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id,
enum gpiod_flags flags)
{
return gpiod_get_index(dev, con_id, 0, flags);
}
EXPORT_SYMBOL_GPL(gpiod_get);
/**
* gpiod_get_optional - obtain an optional GPIO for a given GPIO function
* @dev: GPIO consumer, can be NULL for system-global GPIOs
* @con_id: function within the GPIO consumer
* @flags: optional GPIO initialization flags
*
* This is equivalent to gpiod_get(), except that when no GPIO was assigned to
* the requested function it will return NULL. This is convenient for drivers
* that need to handle optional GPIOs.
*/
struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
const char *con_id,
enum gpiod_flags flags)
{
return gpiod_get_index_optional(dev, con_id, 0, flags);
}
EXPORT_SYMBOL_GPL(gpiod_get_optional);
/**
* gpiod_configure_flags - helper function to configure a given GPIO
* @desc: gpio whose value will be assigned
* @con_id: function within the GPIO consumer
* @lflags: bitmask of gpio_lookup_flags GPIO_* values - returned from
* of_find_gpio() or of_get_gpio_hog()
* @dflags: gpiod_flags - optional GPIO initialization flags
*
* Return 0 on success, -ENOENT if no GPIO has been assigned to the
* requested function and/or index, or another IS_ERR() code if an error
* occurred while trying to acquire the GPIO.
*/
int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
unsigned long lflags, enum gpiod_flags dflags)
{
int ret;
if (lflags & GPIO_ACTIVE_LOW)
set_bit(FLAG_ACTIVE_LOW, &desc->flags);
if (lflags & GPIO_OPEN_DRAIN)
set_bit(FLAG_OPEN_DRAIN, &desc->flags);
else if (dflags & GPIOD_FLAGS_BIT_OPEN_DRAIN) {
/*
* This enforces open drain mode from the consumer side.
* This is necessary for some busses like I2C, but the lookup
* should *REALLY* have specified them as open drain in the
* first place, so print a little warning here.
*/
set_bit(FLAG_OPEN_DRAIN, &desc->flags);
gpiod_warn(desc,
"enforced open drain please flag it properly in DT/ACPI DSDT/board file\n");
}
if (lflags & GPIO_OPEN_SOURCE)
set_bit(FLAG_OPEN_SOURCE, &desc->flags);
if ((lflags & GPIO_PULL_UP) && (lflags & GPIO_PULL_DOWN)) {
gpiod_err(desc,
"both pull-up and pull-down enabled, invalid configuration\n");
return -EINVAL;
}
if (lflags & GPIO_PULL_UP)
set_bit(FLAG_PULL_UP, &desc->flags);
else if (lflags & GPIO_PULL_DOWN)
set_bit(FLAG_PULL_DOWN, &desc->flags);
ret = gpiod_set_transitory(desc, (lflags & GPIO_TRANSITORY));
if (ret < 0)
return ret;
/* No particular flag request, return here... */
if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
gpiod_dbg(desc, "no flags found for %s\n", con_id);
return 0;
}
/* Process flags */
if (dflags & GPIOD_FLAGS_BIT_DIR_OUT)
ret = gpiod_direction_output(desc,
!!(dflags & GPIOD_FLAGS_BIT_DIR_VAL));
else
ret = gpiod_direction_input(desc);
return ret;
}
/**
* gpiod_get_index - obtain a GPIO from a multi-index GPIO function
* @dev: GPIO consumer, can be NULL for system-global GPIOs
* @con_id: function within the GPIO consumer
* @idx: index of the GPIO to obtain in the consumer
* @flags: optional GPIO initialization flags
*
* This variant of gpiod_get() allows to access GPIOs other than the first
* defined one for functions that define several GPIOs.
*
* Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
* requested function and/or index, or another IS_ERR() code if an error
* occurred while trying to acquire the GPIO.
*/
struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
const char *con_id,
unsigned int idx,
enum gpiod_flags flags)
{
unsigned long lookupflags = GPIO_LOOKUP_FLAGS_DEFAULT;
struct gpio_desc *desc = NULL;
int ret;
/* Maybe we have a device name, maybe not */
const char *devname = dev ? dev_name(dev) : "?";
dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id);
if (dev) {
/* Using device tree? */
if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
dev_dbg(dev, "using device tree for GPIO lookup\n");
desc = of_find_gpio(dev, con_id, idx, &lookupflags);
} else if (ACPI_COMPANION(dev)) {
dev_dbg(dev, "using ACPI for GPIO lookup\n");
desc = acpi_find_gpio(dev, con_id, idx, &flags, &lookupflags);
}
}
/*
* Either we are not using DT or ACPI, or their lookup did not return
* a result. In that case, use platform lookup as a fallback.
*/
if (!desc || desc == ERR_PTR(-ENOENT)) {
dev_dbg(dev, "using lookup tables for GPIO lookup\n");
desc = gpiod_find(dev, con_id, idx, &lookupflags);
}
if (IS_ERR(desc)) {
dev_dbg(dev, "No GPIO consumer %s found\n", con_id);
return desc;
}
/*
* If a connection label was passed use that, else attempt to use
* the device name as label
*/
ret = gpiod_request(desc, con_id ? con_id : devname);
if (ret < 0) {
if (ret == -EBUSY && flags & GPIOD_FLAGS_BIT_NONEXCLUSIVE) {
/*
* This happens when there are several consumers for
* the same GPIO line: we just return here without
* further initialization. It is a bit if a hack.
* This is necessary to support fixed regulators.
*
* FIXME: Make this more sane and safe.
*/
dev_info(dev, "nonexclusive access to GPIO for %s\n",
con_id ? con_id : devname);
return desc;
} else {
return ERR_PTR(ret);
}
}
ret = gpiod_configure_flags(desc, con_id, lookupflags, flags);
if (ret < 0) {
dev_dbg(dev, "setup of GPIO %s failed\n", con_id);
gpiod_put(desc);
return ERR_PTR(ret);
}
atomic_notifier_call_chain(&desc->gdev->notifier,
GPIOLINE_CHANGED_REQUESTED, desc);
return desc;
}
EXPORT_SYMBOL_GPL(gpiod_get_index);
/**
* fwnode_get_named_gpiod - obtain a GPIO from firmware node
* @fwnode: handle of the firmware node
* @propname: name of the firmware property representing the GPIO
* @index: index of the GPIO to obtain for the consumer
* @dflags: GPIO initialization flags
* @label: label to attach to the requested GPIO
*
* This function can be used for drivers that get their configuration
* from opaque firmware.
*
* The function properly finds the corresponding GPIO using whatever is the
* underlying firmware interface and then makes sure that the GPIO
* descriptor is requested before it is returned to the caller.
*
* Returns:
* On successful request the GPIO pin is configured in accordance with
* provided @dflags.
*
* In case of error an ERR_PTR() is returned.
*/
struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
const char *propname, int index,
enum gpiod_flags dflags,
const char *label)
{
unsigned long lflags = GPIO_LOOKUP_FLAGS_DEFAULT;
struct gpio_desc *desc = ERR_PTR(-ENODEV);
int ret;
if (!fwnode)
return ERR_PTR(-EINVAL);
if (is_of_node(fwnode)) {
desc = gpiod_get_from_of_node(to_of_node(fwnode),
propname, index,
dflags,
label);
return desc;
} else if (is_acpi_node(fwnode)) {
struct acpi_gpio_info info;
desc = acpi_node_get_gpiod(fwnode, propname, index, &info);
if (IS_ERR(desc))
return desc;
acpi_gpio_update_gpiod_flags(&dflags, &info);
acpi_gpio_update_gpiod_lookup_flags(&lflags, &info);
}
/* Currently only ACPI takes this path */
ret = gpiod_request(desc, label);
if (ret)
return ERR_PTR(ret);
ret = gpiod_configure_flags(desc, propname, lflags, dflags);
if (ret < 0) {
gpiod_put(desc);
return ERR_PTR(ret);
}
atomic_notifier_call_chain(&desc->gdev->notifier,
GPIOLINE_CHANGED_REQUESTED, desc);
return desc;
}
EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod);
/**
* gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
* function
* @dev: GPIO consumer, can be NULL for system-global GPIOs
* @con_id: function within the GPIO consumer
* @index: index of the GPIO to obtain in the consumer
* @flags: optional GPIO initialization flags
*
* This is equivalent to gpiod_get_index(), except that when no GPIO with the
* specified index was assigned to the requested function it will return NULL.
* This is convenient for drivers that need to handle optional GPIOs.
*/
struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
const char *con_id,
unsigned int index,
enum gpiod_flags flags)
{
struct gpio_desc *desc;
desc = gpiod_get_index(dev, con_id, index, flags);
if (IS_ERR(desc)) {
if (PTR_ERR(desc) == -ENOENT)
return NULL;
}
return desc;
}
EXPORT_SYMBOL_GPL(gpiod_get_index_optional);
/**
* gpiod_hog - Hog the specified GPIO desc given the provided flags
* @desc: gpio whose value will be assigned
* @name: gpio line name
* @lflags: bitmask of gpio_lookup_flags GPIO_* values - returned from
* of_find_gpio() or of_get_gpio_hog()
* @dflags: gpiod_flags - optional GPIO initialization flags
*/
int gpiod_hog(struct gpio_desc *desc, const char *name,
unsigned long lflags, enum gpiod_flags dflags)
{
struct gpio_chip *gc;
struct gpio_desc *local_desc;
int hwnum;
int ret;
gc = gpiod_to_chip(desc);
hwnum = gpio_chip_hwgpio(desc);
local_desc = gpiochip_request_own_desc(gc, hwnum, name,
lflags, dflags);
if (IS_ERR(local_desc)) {
ret = PTR_ERR(local_desc);
pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n",
name, gc->label, hwnum, ret);
return ret;
}
/* Mark GPIO as hogged so it can be identified and removed later */
set_bit(FLAG_IS_HOGGED, &desc->flags);
gpiod_info(desc, "hogged as %s%s\n",
(dflags & GPIOD_FLAGS_BIT_DIR_OUT) ? "output" : "input",
(dflags & GPIOD_FLAGS_BIT_DIR_OUT) ?
(dflags & GPIOD_FLAGS_BIT_DIR_VAL) ? "/high" : "/low" : "");
return 0;
}
/**
* gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
* @gc: gpio chip to act on
*/
static void gpiochip_free_hogs(struct gpio_chip *gc)
{
int id;
for (id = 0; id < gc->ngpio; id++) {
if (test_bit(FLAG_IS_HOGGED, &gc->gpiodev->descs[id].flags))
gpiochip_free_own_desc(&gc->gpiodev->descs[id]);
}
}
/**
* gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
* @dev: GPIO consumer, can be NULL for system-global GPIOs
* @con_id: function within the GPIO consumer
* @flags: optional GPIO initialization flags
*
* This function acquires all the GPIOs defined under a given function.
*
* Return a struct gpio_descs containing an array of descriptors, -ENOENT if
* no GPIO has been assigned to the requested function, or another IS_ERR()
* code if an error occurred while trying to acquire the GPIOs.
*/
struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
const char *con_id,
enum gpiod_flags flags)
{
struct gpio_desc *desc;
struct gpio_descs *descs;
struct gpio_array *array_info = NULL;
struct gpio_chip *gc;
int count, bitmap_size;
count = gpiod_count(dev, con_id);
if (count < 0)
return ERR_PTR(count);
descs = kzalloc(struct_size(descs, desc, count), GFP_KERNEL);
if (!descs)
return ERR_PTR(-ENOMEM);
for (descs->ndescs = 0; descs->ndescs < count; ) {
desc = gpiod_get_index(dev, con_id, descs->ndescs, flags);
if (IS_ERR(desc)) {
gpiod_put_array(descs);
return ERR_CAST(desc);
}
descs->desc[descs->ndescs] = desc;
gc = gpiod_to_chip(desc);
/*
* If pin hardware number of array member 0 is also 0, select
* its chip as a candidate for fast bitmap processing path.
*/
if (descs->ndescs == 0 && gpio_chip_hwgpio(desc) == 0) {
struct gpio_descs *array;
bitmap_size = BITS_TO_LONGS(gc->ngpio > count ?
gc->ngpio : count);
array = kzalloc(struct_size(descs, desc, count) +
struct_size(array_info, invert_mask,
3 * bitmap_size), GFP_KERNEL);
if (!array) {
gpiod_put_array(descs);
return ERR_PTR(-ENOMEM);
}
memcpy(array, descs,
struct_size(descs, desc, descs->ndescs + 1));
kfree(descs);
descs = array;
array_info = (void *)(descs->desc + count);
array_info->get_mask = array_info->invert_mask +
bitmap_size;
array_info->set_mask = array_info->get_mask +
bitmap_size;
array_info->desc = descs->desc;
array_info->size = count;
array_info->chip = gc;
bitmap_set(array_info->get_mask, descs->ndescs,
count - descs->ndescs);
bitmap_set(array_info->set_mask, descs->ndescs,
count - descs->ndescs);
descs->info = array_info;
}
/* Unmark array members which don't belong to the 'fast' chip */
if (array_info && array_info->chip != gc) {
__clear_bit(descs->ndescs, array_info->get_mask);
__clear_bit(descs->ndescs, array_info->set_mask);
}
/*
* Detect array members which belong to the 'fast' chip
* but their pins are not in hardware order.
*/
else if (array_info &&
gpio_chip_hwgpio(desc) != descs->ndescs) {
/*
* Don't use fast path if all array members processed so
* far belong to the same chip as this one but its pin
* hardware number is different from its array index.
*/
if (bitmap_full(array_info->get_mask, descs->ndescs)) {
array_info = NULL;
} else {
__clear_bit(descs->ndescs,
array_info->get_mask);
__clear_bit(descs->ndescs,
array_info->set_mask);
}
} else if (array_info) {
/* Exclude open drain or open source from fast output */
if (gpiochip_line_is_open_drain(gc, descs->ndescs) ||
gpiochip_line_is_open_source(gc, descs->ndescs))
__clear_bit(descs->ndescs,
array_info->set_mask);
/* Identify 'fast' pins which require invertion */
if (gpiod_is_active_low(desc))
__set_bit(descs->ndescs,
array_info->invert_mask);
}
descs->ndescs++;
}
if (array_info)
dev_dbg(dev,
"GPIO array info: chip=%s, size=%d, get_mask=%lx, set_mask=%lx, invert_mask=%lx\n",
array_info->chip->label, array_info->size,
*array_info->get_mask, *array_info->set_mask,
*array_info->invert_mask);
return descs;
}
EXPORT_SYMBOL_GPL(gpiod_get_array);
/**
* gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
* function
* @dev: GPIO consumer, can be NULL for system-global GPIOs
* @con_id: function within the GPIO consumer
* @flags: optional GPIO initialization flags
*
* This is equivalent to gpiod_get_array(), except that when no GPIO was
* assigned to the requested function it will return NULL.
*/
struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev,
const char *con_id,
enum gpiod_flags flags)
{
struct gpio_descs *descs;
descs = gpiod_get_array(dev, con_id, flags);
if (PTR_ERR(descs) == -ENOENT)
return NULL;
return descs;
}
EXPORT_SYMBOL_GPL(gpiod_get_array_optional);
/**
* gpiod_put - dispose of a GPIO descriptor
* @desc: GPIO descriptor to dispose of
*
* No descriptor can be used after gpiod_put() has been called on it.
*/
void gpiod_put(struct gpio_desc *desc)
{
if (desc)
gpiod_free(desc);
}
EXPORT_SYMBOL_GPL(gpiod_put);
/**
* gpiod_put_array - dispose of multiple GPIO descriptors
* @descs: struct gpio_descs containing an array of descriptors
*/
void gpiod_put_array(struct gpio_descs *descs)
{
unsigned int i;
for (i = 0; i < descs->ndescs; i++)
gpiod_put(descs->desc[i]);
kfree(descs);
}
EXPORT_SYMBOL_GPL(gpiod_put_array);
static int __init gpiolib_dev_init(void)
{
int ret;
/* Register GPIO sysfs bus */
ret = bus_register(&gpio_bus_type);
if (ret < 0) {
pr_err("gpiolib: could not register GPIO bus type\n");
return ret;
}
ret = alloc_chrdev_region(&gpio_devt, 0, GPIO_DEV_MAX, GPIOCHIP_NAME);
if (ret < 0) {
pr_err("gpiolib: failed to allocate char dev region\n");
bus_unregister(&gpio_bus_type);
return ret;
}
gpiolib_initialized = true;
gpiochip_setup_devs();
#if IS_ENABLED(CONFIG_OF_DYNAMIC) && IS_ENABLED(CONFIG_OF_GPIO)
WARN_ON(of_reconfig_notifier_register(&gpio_of_notifier));
#endif /* CONFIG_OF_DYNAMIC && CONFIG_OF_GPIO */
return ret;
}
core_initcall(gpiolib_dev_init);
#ifdef CONFIG_DEBUG_FS
static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev)
{
unsigned i;
struct gpio_chip *gc = gdev->chip;
unsigned gpio = gdev->base;
struct gpio_desc *gdesc = &gdev->descs[0];
bool is_out;
bool is_irq;
bool active_low;
for (i = 0; i < gdev->ngpio; i++, gpio++, gdesc++) {
if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) {
if (gdesc->name) {
seq_printf(s, " gpio-%-3d (%-20.20s)\n",
gpio, gdesc->name);
}
continue;
}
gpiod_get_direction(gdesc);
is_out = test_bit(FLAG_IS_OUT, &gdesc->flags);
is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags);
active_low = test_bit(FLAG_ACTIVE_LOW, &gdesc->flags);
seq_printf(s, " gpio-%-3d (%-20.20s|%-20.20s) %s %s %s%s",
gpio, gdesc->name ? gdesc->name : "", gdesc->label,
is_out ? "out" : "in ",
gc->get ? (gc->get(gc, i) ? "hi" : "lo") : "? ",
is_irq ? "IRQ " : "",
active_low ? "ACTIVE LOW" : "");
seq_printf(s, "\n");
}
}
static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
{
unsigned long flags;
struct gpio_device *gdev = NULL;
loff_t index = *pos;
s->private = "";
spin_lock_irqsave(&gpio_lock, flags);
list_for_each_entry(gdev, &gpio_devices, list)
if (index-- == 0) {
spin_unlock_irqrestore(&gpio_lock, flags);
return gdev;
}
spin_unlock_irqrestore(&gpio_lock, flags);
return NULL;
}
static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
{
unsigned long flags;
struct gpio_device *gdev = v;
void *ret = NULL;
spin_lock_irqsave(&gpio_lock, flags);
if (list_is_last(&gdev->list, &gpio_devices))
ret = NULL;
else
ret = list_entry(gdev->list.next, struct gpio_device, list);
spin_unlock_irqrestore(&gpio_lock, flags);
s->private = "\n";
++*pos;
return ret;
}
static void gpiolib_seq_stop(struct seq_file *s, void *v)
{
}
static int gpiolib_seq_show(struct seq_file *s, void *v)
{
struct gpio_device *gdev = v;
struct gpio_chip *gc = gdev->chip;
struct device *parent;
if (!gc) {
seq_printf(s, "%s%s: (dangling chip)", (char *)s->private,
dev_name(&gdev->dev));
return 0;
}
seq_printf(s, "%s%s: GPIOs %d-%d", (char *)s->private,
dev_name(&gdev->dev),
gdev->base, gdev->base + gdev->ngpio - 1);
parent = gc->parent;
if (parent)
seq_printf(s, ", parent: %s/%s",
parent->bus ? parent->bus->name : "no-bus",
dev_name(parent));
if (gc->label)
seq_printf(s, ", %s", gc->label);
if (gc->can_sleep)
seq_printf(s, ", can sleep");
seq_printf(s, ":\n");
if (gc->dbg_show)
gc->dbg_show(s, gc);
else
gpiolib_dbg_show(s, gdev);
return 0;
}
static const struct seq_operations gpiolib_seq_ops = {
.start = gpiolib_seq_start,
.next = gpiolib_seq_next,
.stop = gpiolib_seq_stop,
.show = gpiolib_seq_show,
};
static int gpiolib_open(struct inode *inode, struct file *file)
{
return seq_open(file, &gpiolib_seq_ops);
}
static const struct file_operations gpiolib_operations = {
.owner = THIS_MODULE,
.open = gpiolib_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
};
static int __init gpiolib_debugfs_init(void)
{
/* /sys/kernel/debug/gpio */
debugfs_create_file("gpio", S_IFREG | S_IRUGO, NULL, NULL,
&gpiolib_operations);
return 0;
}
subsys_initcall(gpiolib_debugfs_init);
#endif /* DEBUG_FS */