| // SPDX-License-Identifier: GPL-2.0 |
| |
| #include <linux/anon_inodes.h> |
| #include <linux/atomic.h> |
| #include <linux/bitmap.h> |
| #include <linux/build_bug.h> |
| #include <linux/cdev.h> |
| #include <linux/compat.h> |
| #include <linux/compiler.h> |
| #include <linux/device.h> |
| #include <linux/err.h> |
| #include <linux/file.h> |
| #include <linux/gpio.h> |
| #include <linux/gpio/driver.h> |
| #include <linux/interrupt.h> |
| #include <linux/irqreturn.h> |
| #include <linux/kernel.h> |
| #include <linux/kfifo.h> |
| #include <linux/module.h> |
| #include <linux/mutex.h> |
| #include <linux/pinctrl/consumer.h> |
| #include <linux/poll.h> |
| #include <linux/spinlock.h> |
| #include <linux/timekeeping.h> |
| #include <linux/uaccess.h> |
| #include <linux/workqueue.h> |
| #include <linux/hte.h> |
| #include <uapi/linux/gpio.h> |
| |
| #include "gpiolib.h" |
| #include "gpiolib-cdev.h" |
| |
| /* |
| * Array sizes must ensure 64-bit alignment and not create holes in the |
| * struct packing. |
| */ |
| static_assert(IS_ALIGNED(GPIO_V2_LINES_MAX, 2)); |
| static_assert(IS_ALIGNED(GPIO_MAX_NAME_SIZE, 8)); |
| |
| /* |
| * Check that uAPI structs are 64-bit aligned for 32/64-bit compatibility |
| */ |
| static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_attribute), 8)); |
| static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_config_attribute), 8)); |
| static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_config), 8)); |
| static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_request), 8)); |
| static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_info), 8)); |
| static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_info_changed), 8)); |
| static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_event), 8)); |
| static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_values), 8)); |
| |
| /* Character device interface to GPIO. |
| * |
| * The GPIO character device, /dev/gpiochipN, provides userspace an |
| * interface to gpiolib GPIOs via ioctl()s. |
| */ |
| |
| /* |
| * GPIO line handle management |
| */ |
| |
| #ifdef CONFIG_GPIO_CDEV_V1 |
| /** |
| * 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 |
| * @num_descs: 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 num_descs; |
| }; |
| |
| #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 void linehandle_flags_to_desc_flags(u32 lflags, unsigned long *flagsp) |
| { |
| 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); |
| } |
| |
| 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; |
| |
| 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->num_descs; i++) { |
| desc = lh->descs[i]; |
| linehandle_flags_to_desc_flags(gcnf.flags, &desc->flags); |
| |
| /* |
| * 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; |
| } |
| |
| blocking_notifier_call_chain(&desc->gdev->notifier, |
| GPIO_V2_LINE_CHANGED_CONFIG, |
| desc); |
| } |
| return 0; |
| } |
| |
| static long linehandle_ioctl(struct file *file, unsigned int cmd, |
| unsigned long arg) |
| { |
| struct linehandle_state *lh = file->private_data; |
| void __user *ip = (void __user *)arg; |
| struct gpiohandle_data ghd; |
| DECLARE_BITMAP(vals, GPIOHANDLES_MAX); |
| unsigned int i; |
| int ret; |
| |
| switch (cmd) { |
| case GPIOHANDLE_GET_LINE_VALUES_IOCTL: |
| /* NOTE: It's okay to read values of output lines */ |
| ret = gpiod_get_array_value_complex(false, true, |
| lh->num_descs, lh->descs, |
| NULL, vals); |
| if (ret) |
| return ret; |
| |
| memset(&ghd, 0, sizeof(ghd)); |
| for (i = 0; i < lh->num_descs; i++) |
| ghd.values[i] = test_bit(i, vals); |
| |
| if (copy_to_user(ip, &ghd, sizeof(ghd))) |
| return -EFAULT; |
| |
| return 0; |
| case 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->num_descs; i++) |
| __assign_bit(i, vals, ghd.values[i]); |
| |
| /* Reuse the array setting function */ |
| return gpiod_set_array_value_complex(false, |
| true, |
| lh->num_descs, |
| lh->descs, |
| NULL, |
| vals); |
| case GPIOHANDLE_SET_CONFIG_IOCTL: |
| return linehandle_set_config(lh, ip); |
| default: |
| return -EINVAL; |
| } |
| } |
| |
| #ifdef CONFIG_COMPAT |
| static long linehandle_ioctl_compat(struct file *file, unsigned int cmd, |
| unsigned long arg) |
| { |
| return linehandle_ioctl(file, cmd, (unsigned long)compat_ptr(arg)); |
| } |
| #endif |
| |
| static void linehandle_free(struct linehandle_state *lh) |
| { |
| int i; |
| |
| for (i = 0; i < lh->num_descs; i++) |
| if (lh->descs[i]) |
| gpiod_free(lh->descs[i]); |
| kfree(lh->label); |
| put_device(&lh->gdev->dev); |
| kfree(lh); |
| } |
| |
| static int linehandle_release(struct inode *inode, struct file *file) |
| { |
| linehandle_free(file->private_data); |
| 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, 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); |
| |
| if (handlereq.consumer_label[0] != '\0') { |
| /* label is only initialized if consumer_label is set */ |
| lh->label = kstrndup(handlereq.consumer_label, |
| sizeof(handlereq.consumer_label) - 1, |
| GFP_KERNEL); |
| if (!lh->label) { |
| ret = -ENOMEM; |
| goto out_free_lh; |
| } |
| } |
| |
| lh->num_descs = handlereq.lines; |
| |
| /* 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_lh; |
| } |
| |
| ret = gpiod_request_user(desc, lh->label); |
| if (ret) |
| goto out_free_lh; |
| lh->descs[i] = desc; |
| linehandle_flags_to_desc_flags(handlereq.flags, &desc->flags); |
| |
| ret = gpiod_set_transitory(desc, false); |
| if (ret < 0) |
| goto out_free_lh; |
| |
| /* |
| * 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_lh; |
| } else if (lflags & GPIOHANDLE_REQUEST_INPUT) { |
| ret = gpiod_direction_input(desc); |
| if (ret) |
| goto out_free_lh; |
| } |
| |
| blocking_notifier_call_chain(&desc->gdev->notifier, |
| GPIO_V2_LINE_CHANGED_REQUESTED, desc); |
| |
| dev_dbg(&gdev->dev, "registered chardev handle for line %d\n", |
| offset); |
| } |
| |
| fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC); |
| if (fd < 0) { |
| ret = fd; |
| goto out_free_lh; |
| } |
| |
| 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->num_descs); |
| |
| return 0; |
| |
| out_put_unused_fd: |
| put_unused_fd(fd); |
| out_free_lh: |
| linehandle_free(lh); |
| return ret; |
| } |
| #endif /* CONFIG_GPIO_CDEV_V1 */ |
| |
| /** |
| * struct line - contains the state of a requested line |
| * @desc: the GPIO descriptor for this line. |
| * @req: the corresponding line request |
| * @irq: the interrupt triggered in response to events on this GPIO |
| * @eflags: the edge flags, GPIO_V2_LINE_FLAG_EDGE_RISING and/or |
| * GPIO_V2_LINE_FLAG_EDGE_FALLING, indicating the edge detection applied |
| * @timestamp_ns: cache for the timestamp storing it between hardirq and |
| * IRQ thread, used to bring the timestamp close to the actual event |
| * @req_seqno: the seqno for the current edge event in the sequence of |
| * events for the corresponding line request. This is drawn from the @req. |
| * @line_seqno: the seqno for the current edge event in the sequence of |
| * events for this line. |
| * @work: the worker that implements software debouncing |
| * @sw_debounced: flag indicating if the software debouncer is active |
| * @level: the current debounced physical level of the line |
| * @hdesc: the Hardware Timestamp Engine (HTE) descriptor |
| * @raw_level: the line level at the time of event |
| * @total_discard_seq: the running counter of the discarded events |
| * @last_seqno: the last sequence number before debounce period expires |
| */ |
| struct line { |
| struct gpio_desc *desc; |
| /* |
| * -- edge detector specific fields -- |
| */ |
| struct linereq *req; |
| unsigned int irq; |
| /* |
| * eflags is set by edge_detector_setup(), edge_detector_stop() and |
| * edge_detector_update(), which are themselves mutually exclusive, |
| * and is accessed by edge_irq_thread() and debounce_work_func(), |
| * which can both live with a slightly stale value. |
| */ |
| u64 eflags; |
| /* |
| * timestamp_ns and req_seqno are accessed only by |
| * edge_irq_handler() and edge_irq_thread(), which are themselves |
| * mutually exclusive, so no additional protection is necessary. |
| */ |
| u64 timestamp_ns; |
| u32 req_seqno; |
| /* |
| * line_seqno is accessed by either edge_irq_thread() or |
| * debounce_work_func(), which are themselves mutually exclusive, |
| * so no additional protection is necessary. |
| */ |
| u32 line_seqno; |
| /* |
| * -- debouncer specific fields -- |
| */ |
| struct delayed_work work; |
| /* |
| * sw_debounce is accessed by linereq_set_config(), which is the |
| * only setter, and linereq_get_values(), which can live with a |
| * slightly stale value. |
| */ |
| unsigned int sw_debounced; |
| /* |
| * level is accessed by debounce_work_func(), which is the only |
| * setter, and linereq_get_values() which can live with a slightly |
| * stale value. |
| */ |
| unsigned int level; |
| /* |
| * -- hte specific fields -- |
| */ |
| struct hte_ts_desc hdesc; |
| /* |
| * HTE provider sets line level at the time of event. The valid |
| * value is 0 or 1 and negative value for an error. |
| */ |
| int raw_level; |
| /* |
| * when sw_debounce is set on HTE enabled line, this is running |
| * counter of the discarded events. |
| */ |
| u32 total_discard_seq; |
| /* |
| * when sw_debounce is set on HTE enabled line, this variable records |
| * last sequence number before debounce period expires. |
| */ |
| u32 last_seqno; |
| }; |
| |
| /** |
| * struct linereq - contains the state of a userspace line request |
| * @gdev: the GPIO device the line request pertains to |
| * @label: consumer label used to tag GPIO descriptors |
| * @num_lines: the number of lines in the lines array |
| * @wait: wait queue that handles blocking reads of events |
| * @event_buffer_size: the number of elements allocated in @events |
| * @events: KFIFO for the GPIO events |
| * @seqno: the sequence number for edge events generated on all lines in |
| * this line request. Note that this is not used when @num_lines is 1, as |
| * the line_seqno is then the same and is cheaper to calculate. |
| * @config_mutex: mutex for serializing ioctl() calls to ensure consistency |
| * of configuration, particularly multi-step accesses to desc flags. |
| * @lines: the lines held by this line request, with @num_lines elements. |
| */ |
| struct linereq { |
| struct gpio_device *gdev; |
| const char *label; |
| u32 num_lines; |
| wait_queue_head_t wait; |
| u32 event_buffer_size; |
| DECLARE_KFIFO_PTR(events, struct gpio_v2_line_event); |
| atomic_t seqno; |
| struct mutex config_mutex; |
| struct line lines[]; |
| }; |
| |
| #define GPIO_V2_LINE_BIAS_FLAGS \ |
| (GPIO_V2_LINE_FLAG_BIAS_PULL_UP | \ |
| GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN | \ |
| GPIO_V2_LINE_FLAG_BIAS_DISABLED) |
| |
| #define GPIO_V2_LINE_DIRECTION_FLAGS \ |
| (GPIO_V2_LINE_FLAG_INPUT | \ |
| GPIO_V2_LINE_FLAG_OUTPUT) |
| |
| #define GPIO_V2_LINE_DRIVE_FLAGS \ |
| (GPIO_V2_LINE_FLAG_OPEN_DRAIN | \ |
| GPIO_V2_LINE_FLAG_OPEN_SOURCE) |
| |
| #define GPIO_V2_LINE_EDGE_FLAGS \ |
| (GPIO_V2_LINE_FLAG_EDGE_RISING | \ |
| GPIO_V2_LINE_FLAG_EDGE_FALLING) |
| |
| #define GPIO_V2_LINE_FLAG_EDGE_BOTH GPIO_V2_LINE_EDGE_FLAGS |
| |
| #define GPIO_V2_LINE_VALID_FLAGS \ |
| (GPIO_V2_LINE_FLAG_ACTIVE_LOW | \ |
| GPIO_V2_LINE_DIRECTION_FLAGS | \ |
| GPIO_V2_LINE_DRIVE_FLAGS | \ |
| GPIO_V2_LINE_EDGE_FLAGS | \ |
| GPIO_V2_LINE_FLAG_EVENT_CLOCK_REALTIME | \ |
| GPIO_V2_LINE_FLAG_EVENT_CLOCK_HTE | \ |
| GPIO_V2_LINE_BIAS_FLAGS) |
| |
| static void linereq_put_event(struct linereq *lr, |
| struct gpio_v2_line_event *le) |
| { |
| bool overflow = false; |
| |
| spin_lock(&lr->wait.lock); |
| if (kfifo_is_full(&lr->events)) { |
| overflow = true; |
| kfifo_skip(&lr->events); |
| } |
| kfifo_in(&lr->events, le, 1); |
| spin_unlock(&lr->wait.lock); |
| if (!overflow) |
| wake_up_poll(&lr->wait, EPOLLIN); |
| else |
| pr_debug_ratelimited("event FIFO is full - event dropped\n"); |
| } |
| |
| static u64 line_event_timestamp(struct line *line) |
| { |
| if (test_bit(FLAG_EVENT_CLOCK_REALTIME, &line->desc->flags)) |
| return ktime_get_real_ns(); |
| else if (test_bit(FLAG_EVENT_CLOCK_HTE, &line->desc->flags)) |
| return line->timestamp_ns; |
| |
| return ktime_get_ns(); |
| } |
| |
| static enum hte_return process_hw_ts_thread(void *p) |
| { |
| struct line *line; |
| struct linereq *lr; |
| struct gpio_v2_line_event le; |
| int level; |
| u64 eflags; |
| |
| if (!p) |
| return HTE_CB_HANDLED; |
| |
| line = p; |
| lr = line->req; |
| |
| memset(&le, 0, sizeof(le)); |
| |
| le.timestamp_ns = line->timestamp_ns; |
| eflags = READ_ONCE(line->eflags); |
| |
| if (eflags == GPIO_V2_LINE_FLAG_EDGE_BOTH) { |
| if (line->raw_level >= 0) { |
| if (test_bit(FLAG_ACTIVE_LOW, &line->desc->flags)) |
| level = !line->raw_level; |
| else |
| level = line->raw_level; |
| } else { |
| level = gpiod_get_value_cansleep(line->desc); |
| } |
| |
| if (level) |
| le.id = GPIO_V2_LINE_EVENT_RISING_EDGE; |
| else |
| le.id = GPIO_V2_LINE_EVENT_FALLING_EDGE; |
| } else if (eflags == GPIO_V2_LINE_FLAG_EDGE_RISING) { |
| /* Emit low-to-high event */ |
| le.id = GPIO_V2_LINE_EVENT_RISING_EDGE; |
| } else if (eflags == GPIO_V2_LINE_FLAG_EDGE_FALLING) { |
| /* Emit high-to-low event */ |
| le.id = GPIO_V2_LINE_EVENT_FALLING_EDGE; |
| } else { |
| return HTE_CB_HANDLED; |
| } |
| le.line_seqno = line->line_seqno; |
| le.seqno = (lr->num_lines == 1) ? le.line_seqno : line->req_seqno; |
| le.offset = gpio_chip_hwgpio(line->desc); |
| |
| linereq_put_event(lr, &le); |
| |
| return HTE_CB_HANDLED; |
| } |
| |
| static enum hte_return process_hw_ts(struct hte_ts_data *ts, void *p) |
| { |
| struct line *line; |
| struct linereq *lr; |
| int diff_seqno = 0; |
| |
| if (!ts || !p) |
| return HTE_CB_HANDLED; |
| |
| line = p; |
| line->timestamp_ns = ts->tsc; |
| line->raw_level = ts->raw_level; |
| lr = line->req; |
| |
| if (READ_ONCE(line->sw_debounced)) { |
| line->total_discard_seq++; |
| line->last_seqno = ts->seq; |
| mod_delayed_work(system_wq, &line->work, |
| usecs_to_jiffies(READ_ONCE(line->desc->debounce_period_us))); |
| } else { |
| if (unlikely(ts->seq < line->line_seqno)) |
| return HTE_CB_HANDLED; |
| |
| diff_seqno = ts->seq - line->line_seqno; |
| line->line_seqno = ts->seq; |
| if (lr->num_lines != 1) |
| line->req_seqno = atomic_add_return(diff_seqno, |
| &lr->seqno); |
| |
| return HTE_RUN_SECOND_CB; |
| } |
| |
| return HTE_CB_HANDLED; |
| } |
| |
| static irqreturn_t edge_irq_thread(int irq, void *p) |
| { |
| struct line *line = p; |
| struct linereq *lr = line->req; |
| struct gpio_v2_line_event le; |
| u64 eflags; |
| |
| /* Do not leak kernel stack to userspace */ |
| memset(&le, 0, sizeof(le)); |
| |
| if (line->timestamp_ns) { |
| le.timestamp_ns = line->timestamp_ns; |
| } else { |
| /* |
| * We may be running from a nested threaded interrupt in |
| * which case we didn't get the timestamp from |
| * edge_irq_handler(). |
| */ |
| le.timestamp_ns = line_event_timestamp(line); |
| if (lr->num_lines != 1) |
| line->req_seqno = atomic_inc_return(&lr->seqno); |
| } |
| line->timestamp_ns = 0; |
| |
| eflags = READ_ONCE(line->eflags); |
| if (eflags == GPIO_V2_LINE_FLAG_EDGE_BOTH) { |
| int level = gpiod_get_value_cansleep(line->desc); |
| |
| if (level) |
| /* Emit low-to-high event */ |
| le.id = GPIO_V2_LINE_EVENT_RISING_EDGE; |
| else |
| /* Emit high-to-low event */ |
| le.id = GPIO_V2_LINE_EVENT_FALLING_EDGE; |
| } else if (eflags == GPIO_V2_LINE_FLAG_EDGE_RISING) { |
| /* Emit low-to-high event */ |
| le.id = GPIO_V2_LINE_EVENT_RISING_EDGE; |
| } else if (eflags == GPIO_V2_LINE_FLAG_EDGE_FALLING) { |
| /* Emit high-to-low event */ |
| le.id = GPIO_V2_LINE_EVENT_FALLING_EDGE; |
| } else { |
| return IRQ_NONE; |
| } |
| line->line_seqno++; |
| le.line_seqno = line->line_seqno; |
| le.seqno = (lr->num_lines == 1) ? le.line_seqno : line->req_seqno; |
| le.offset = gpio_chip_hwgpio(line->desc); |
| |
| linereq_put_event(lr, &le); |
| |
| return IRQ_HANDLED; |
| } |
| |
| static irqreturn_t edge_irq_handler(int irq, void *p) |
| { |
| struct line *line = p; |
| struct linereq *lr = line->req; |
| |
| /* |
| * Just store the timestamp in hardirq context so we get it as |
| * close in time as possible to the actual event. |
| */ |
| line->timestamp_ns = line_event_timestamp(line); |
| |
| if (lr->num_lines != 1) |
| line->req_seqno = atomic_inc_return(&lr->seqno); |
| |
| return IRQ_WAKE_THREAD; |
| } |
| |
| /* |
| * returns the current debounced logical value. |
| */ |
| static bool debounced_value(struct line *line) |
| { |
| bool value; |
| |
| /* |
| * minor race - debouncer may be stopped here, so edge_detector_stop() |
| * must leave the value unchanged so the following will read the level |
| * from when the debouncer was last running. |
| */ |
| value = READ_ONCE(line->level); |
| |
| if (test_bit(FLAG_ACTIVE_LOW, &line->desc->flags)) |
| value = !value; |
| |
| return value; |
| } |
| |
| static irqreturn_t debounce_irq_handler(int irq, void *p) |
| { |
| struct line *line = p; |
| |
| mod_delayed_work(system_wq, &line->work, |
| usecs_to_jiffies(READ_ONCE(line->desc->debounce_period_us))); |
| |
| return IRQ_HANDLED; |
| } |
| |
| static void debounce_work_func(struct work_struct *work) |
| { |
| struct gpio_v2_line_event le; |
| struct line *line = container_of(work, struct line, work.work); |
| struct linereq *lr; |
| int level, diff_seqno; |
| u64 eflags; |
| |
| if (test_bit(FLAG_EVENT_CLOCK_HTE, &line->desc->flags)) { |
| level = line->raw_level; |
| if (level < 0) |
| level = gpiod_get_raw_value_cansleep(line->desc); |
| } else { |
| level = gpiod_get_raw_value_cansleep(line->desc); |
| } |
| if (level < 0) { |
| pr_debug_ratelimited("debouncer failed to read line value\n"); |
| return; |
| } |
| |
| if (READ_ONCE(line->level) == level) |
| return; |
| |
| WRITE_ONCE(line->level, level); |
| |
| /* -- edge detection -- */ |
| eflags = READ_ONCE(line->eflags); |
| if (!eflags) |
| return; |
| |
| /* switch from physical level to logical - if they differ */ |
| if (test_bit(FLAG_ACTIVE_LOW, &line->desc->flags)) |
| level = !level; |
| |
| /* ignore edges that are not being monitored */ |
| if (((eflags == GPIO_V2_LINE_FLAG_EDGE_RISING) && !level) || |
| ((eflags == GPIO_V2_LINE_FLAG_EDGE_FALLING) && level)) |
| return; |
| |
| /* Do not leak kernel stack to userspace */ |
| memset(&le, 0, sizeof(le)); |
| |
| lr = line->req; |
| le.timestamp_ns = line_event_timestamp(line); |
| le.offset = gpio_chip_hwgpio(line->desc); |
| if (test_bit(FLAG_EVENT_CLOCK_HTE, &line->desc->flags)) { |
| /* discard events except the last one */ |
| line->total_discard_seq -= 1; |
| diff_seqno = line->last_seqno - line->total_discard_seq - |
| line->line_seqno; |
| line->line_seqno = line->last_seqno - line->total_discard_seq; |
| le.line_seqno = line->line_seqno; |
| le.seqno = (lr->num_lines == 1) ? |
| le.line_seqno : atomic_add_return(diff_seqno, &lr->seqno); |
| } else { |
| line->line_seqno++; |
| le.line_seqno = line->line_seqno; |
| le.seqno = (lr->num_lines == 1) ? |
| le.line_seqno : atomic_inc_return(&lr->seqno); |
| } |
| |
| if (level) |
| /* Emit low-to-high event */ |
| le.id = GPIO_V2_LINE_EVENT_RISING_EDGE; |
| else |
| /* Emit high-to-low event */ |
| le.id = GPIO_V2_LINE_EVENT_FALLING_EDGE; |
| |
| linereq_put_event(lr, &le); |
| } |
| |
| static int hte_edge_setup(struct line *line, u64 eflags) |
| { |
| int ret; |
| unsigned long flags = 0; |
| struct hte_ts_desc *hdesc = &line->hdesc; |
| |
| if (eflags & GPIO_V2_LINE_FLAG_EDGE_RISING) |
| flags |= test_bit(FLAG_ACTIVE_LOW, &line->desc->flags) ? |
| HTE_FALLING_EDGE_TS : HTE_RISING_EDGE_TS; |
| if (eflags & GPIO_V2_LINE_FLAG_EDGE_FALLING) |
| flags |= test_bit(FLAG_ACTIVE_LOW, &line->desc->flags) ? |
| HTE_RISING_EDGE_TS : HTE_FALLING_EDGE_TS; |
| |
| line->total_discard_seq = 0; |
| |
| hte_init_line_attr(hdesc, desc_to_gpio(line->desc), flags, |
| NULL, line->desc); |
| |
| ret = hte_ts_get(NULL, hdesc, 0); |
| if (ret) |
| return ret; |
| |
| return hte_request_ts_ns(hdesc, process_hw_ts, |
| process_hw_ts_thread, line); |
| } |
| |
| static int debounce_setup(struct line *line, |
| unsigned int debounce_period_us, bool hte_req) |
| { |
| unsigned long irqflags; |
| int ret, level, irq; |
| |
| /* try hardware */ |
| ret = gpiod_set_debounce(line->desc, debounce_period_us); |
| if (!ret) { |
| WRITE_ONCE(line->desc->debounce_period_us, debounce_period_us); |
| return ret; |
| } |
| if (ret != -ENOTSUPP) |
| return ret; |
| |
| if (debounce_period_us) { |
| /* setup software debounce */ |
| level = gpiod_get_raw_value_cansleep(line->desc); |
| if (level < 0) |
| return level; |
| |
| if (!hte_req) { |
| irq = gpiod_to_irq(line->desc); |
| if (irq < 0) |
| return -ENXIO; |
| |
| irqflags = IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING; |
| ret = request_irq(irq, debounce_irq_handler, irqflags, |
| line->req->label, line); |
| if (ret) |
| return ret; |
| line->irq = irq; |
| } else { |
| ret = hte_edge_setup(line, |
| GPIO_V2_LINE_FLAG_EDGE_RISING | |
| GPIO_V2_LINE_FLAG_EDGE_FALLING); |
| if (ret) |
| return ret; |
| } |
| |
| WRITE_ONCE(line->level, level); |
| WRITE_ONCE(line->sw_debounced, 1); |
| } |
| return 0; |
| } |
| |
| static bool gpio_v2_line_config_debounced(struct gpio_v2_line_config *lc, |
| unsigned int line_idx) |
| { |
| unsigned int i; |
| u64 mask = BIT_ULL(line_idx); |
| |
| for (i = 0; i < lc->num_attrs; i++) { |
| if ((lc->attrs[i].attr.id == GPIO_V2_LINE_ATTR_ID_DEBOUNCE) && |
| (lc->attrs[i].mask & mask)) |
| return true; |
| } |
| return false; |
| } |
| |
| static u32 gpio_v2_line_config_debounce_period(struct gpio_v2_line_config *lc, |
| unsigned int line_idx) |
| { |
| unsigned int i; |
| u64 mask = BIT_ULL(line_idx); |
| |
| for (i = 0; i < lc->num_attrs; i++) { |
| if ((lc->attrs[i].attr.id == GPIO_V2_LINE_ATTR_ID_DEBOUNCE) && |
| (lc->attrs[i].mask & mask)) |
| return lc->attrs[i].attr.debounce_period_us; |
| } |
| return 0; |
| } |
| |
| static void edge_detector_stop(struct line *line, bool hte_en) |
| { |
| if (line->irq && !hte_en) { |
| free_irq(line->irq, line); |
| line->irq = 0; |
| } |
| |
| if (hte_en) |
| hte_ts_put(&line->hdesc); |
| |
| cancel_delayed_work_sync(&line->work); |
| WRITE_ONCE(line->sw_debounced, 0); |
| WRITE_ONCE(line->eflags, 0); |
| if (line->desc) |
| WRITE_ONCE(line->desc->debounce_period_us, 0); |
| /* do not change line->level - see comment in debounced_value() */ |
| } |
| |
| static int edge_detector_setup(struct line *line, |
| struct gpio_v2_line_config *lc, |
| unsigned int line_idx, |
| u64 eflags, bool hte_req) |
| { |
| u32 debounce_period_us; |
| unsigned long irqflags = 0; |
| int irq, ret; |
| |
| if (eflags && !kfifo_initialized(&line->req->events)) { |
| ret = kfifo_alloc(&line->req->events, |
| line->req->event_buffer_size, GFP_KERNEL); |
| if (ret) |
| return ret; |
| } |
| WRITE_ONCE(line->eflags, eflags); |
| if (gpio_v2_line_config_debounced(lc, line_idx)) { |
| debounce_period_us = gpio_v2_line_config_debounce_period(lc, line_idx); |
| ret = debounce_setup(line, debounce_period_us, hte_req); |
| if (ret) |
| return ret; |
| WRITE_ONCE(line->desc->debounce_period_us, debounce_period_us); |
| } |
| |
| /* detection disabled or sw debouncer will provide edge detection */ |
| if (!eflags || READ_ONCE(line->sw_debounced)) |
| return 0; |
| |
| if (hte_req) |
| return hte_edge_setup(line, eflags); |
| |
| irq = gpiod_to_irq(line->desc); |
| if (irq < 0) |
| return -ENXIO; |
| |
| if (eflags & GPIO_V2_LINE_FLAG_EDGE_RISING) |
| irqflags |= test_bit(FLAG_ACTIVE_LOW, &line->desc->flags) ? |
| IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING; |
| if (eflags & GPIO_V2_LINE_FLAG_EDGE_FALLING) |
| irqflags |= test_bit(FLAG_ACTIVE_LOW, &line->desc->flags) ? |
| IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING; |
| irqflags |= IRQF_ONESHOT; |
| |
| /* Request a thread to read the events */ |
| ret = request_threaded_irq(irq, edge_irq_handler, edge_irq_thread, |
| irqflags, line->req->label, line); |
| if (ret) |
| return ret; |
| |
| line->irq = irq; |
| return 0; |
| } |
| |
| static int edge_detector_update(struct line *line, |
| struct gpio_v2_line_config *lc, |
| unsigned int line_idx, |
| u64 flags, bool polarity_change, |
| bool prev_hte_flag) |
| { |
| u64 eflags = flags & GPIO_V2_LINE_EDGE_FLAGS; |
| unsigned int debounce_period_us = |
| gpio_v2_line_config_debounce_period(lc, line_idx); |
| bool hte_change = (prev_hte_flag != |
| ((flags & GPIO_V2_LINE_FLAG_EVENT_CLOCK_HTE) != 0)); |
| |
| if ((READ_ONCE(line->eflags) == eflags) && !polarity_change && |
| (READ_ONCE(line->desc->debounce_period_us) == debounce_period_us) |
| && !hte_change) |
| return 0; |
| |
| /* sw debounced and still will be...*/ |
| if (debounce_period_us && READ_ONCE(line->sw_debounced)) { |
| WRITE_ONCE(line->eflags, eflags); |
| WRITE_ONCE(line->desc->debounce_period_us, debounce_period_us); |
| return 0; |
| } |
| |
| /* reconfiguring edge detection or sw debounce being disabled */ |
| if ((line->irq && !READ_ONCE(line->sw_debounced)) || prev_hte_flag || |
| (!debounce_period_us && READ_ONCE(line->sw_debounced))) |
| edge_detector_stop(line, prev_hte_flag); |
| |
| return edge_detector_setup(line, lc, line_idx, eflags, |
| flags & GPIO_V2_LINE_FLAG_EVENT_CLOCK_HTE); |
| } |
| |
| static u64 gpio_v2_line_config_flags(struct gpio_v2_line_config *lc, |
| unsigned int line_idx) |
| { |
| unsigned int i; |
| u64 mask = BIT_ULL(line_idx); |
| |
| for (i = 0; i < lc->num_attrs; i++) { |
| if ((lc->attrs[i].attr.id == GPIO_V2_LINE_ATTR_ID_FLAGS) && |
| (lc->attrs[i].mask & mask)) |
| return lc->attrs[i].attr.flags; |
| } |
| return lc->flags; |
| } |
| |
| static int gpio_v2_line_config_output_value(struct gpio_v2_line_config *lc, |
| unsigned int line_idx) |
| { |
| unsigned int i; |
| u64 mask = BIT_ULL(line_idx); |
| |
| for (i = 0; i < lc->num_attrs; i++) { |
| if ((lc->attrs[i].attr.id == GPIO_V2_LINE_ATTR_ID_OUTPUT_VALUES) && |
| (lc->attrs[i].mask & mask)) |
| return !!(lc->attrs[i].attr.values & mask); |
| } |
| return 0; |
| } |
| |
| static int gpio_v2_line_flags_validate(u64 flags) |
| { |
| /* Return an error if an unknown flag is set */ |
| if (flags & ~GPIO_V2_LINE_VALID_FLAGS) |
| return -EINVAL; |
| /* |
| * Do not allow both INPUT and OUTPUT flags to be set as they are |
| * contradictory. |
| */ |
| if ((flags & GPIO_V2_LINE_FLAG_INPUT) && |
| (flags & GPIO_V2_LINE_FLAG_OUTPUT)) |
| return -EINVAL; |
| |
| /* Only allow one event clock source */ |
| if ((flags & GPIO_V2_LINE_FLAG_EVENT_CLOCK_REALTIME) && |
| (flags & GPIO_V2_LINE_FLAG_EVENT_CLOCK_HTE)) |
| return -EINVAL; |
| |
| /* Edge detection requires explicit input. */ |
| if ((flags & GPIO_V2_LINE_EDGE_FLAGS) && |
| !(flags & GPIO_V2_LINE_FLAG_INPUT)) |
| return -EINVAL; |
| |
| /* |
| * Do not allow OPEN_SOURCE and 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 & GPIO_V2_LINE_FLAG_OPEN_DRAIN) && |
| (flags & GPIO_V2_LINE_FLAG_OPEN_SOURCE)) |
| return -EINVAL; |
| |
| /* Drive requires explicit output direction. */ |
| if ((flags & GPIO_V2_LINE_DRIVE_FLAGS) && |
| !(flags & GPIO_V2_LINE_FLAG_OUTPUT)) |
| return -EINVAL; |
| |
| /* Bias requires explicit direction. */ |
| if ((flags & GPIO_V2_LINE_BIAS_FLAGS) && |
| !(flags & GPIO_V2_LINE_DIRECTION_FLAGS)) |
| return -EINVAL; |
| |
| /* Only one bias flag can be set. */ |
| if (((flags & GPIO_V2_LINE_FLAG_BIAS_DISABLED) && |
| (flags & (GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN | |
| GPIO_V2_LINE_FLAG_BIAS_PULL_UP))) || |
| ((flags & GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN) && |
| (flags & GPIO_V2_LINE_FLAG_BIAS_PULL_UP))) |
| return -EINVAL; |
| |
| return 0; |
| } |
| |
| static int gpio_v2_line_config_validate(struct gpio_v2_line_config *lc, |
| unsigned int num_lines) |
| { |
| unsigned int i; |
| u64 flags; |
| int ret; |
| |
| if (lc->num_attrs > GPIO_V2_LINE_NUM_ATTRS_MAX) |
| return -EINVAL; |
| |
| if (memchr_inv(lc->padding, 0, sizeof(lc->padding))) |
| return -EINVAL; |
| |
| for (i = 0; i < num_lines; i++) { |
| flags = gpio_v2_line_config_flags(lc, i); |
| ret = gpio_v2_line_flags_validate(flags); |
| if (ret) |
| return ret; |
| |
| /* debounce requires explicit input */ |
| if (gpio_v2_line_config_debounced(lc, i) && |
| !(flags & GPIO_V2_LINE_FLAG_INPUT)) |
| return -EINVAL; |
| } |
| return 0; |
| } |
| |
| static void gpio_v2_line_config_flags_to_desc_flags(u64 flags, |
| unsigned long *flagsp) |
| { |
| assign_bit(FLAG_ACTIVE_LOW, flagsp, |
| flags & GPIO_V2_LINE_FLAG_ACTIVE_LOW); |
| |
| if (flags & GPIO_V2_LINE_FLAG_OUTPUT) |
| set_bit(FLAG_IS_OUT, flagsp); |
| else if (flags & GPIO_V2_LINE_FLAG_INPUT) |
| clear_bit(FLAG_IS_OUT, flagsp); |
| |
| assign_bit(FLAG_EDGE_RISING, flagsp, |
| flags & GPIO_V2_LINE_FLAG_EDGE_RISING); |
| assign_bit(FLAG_EDGE_FALLING, flagsp, |
| flags & GPIO_V2_LINE_FLAG_EDGE_FALLING); |
| |
| assign_bit(FLAG_OPEN_DRAIN, flagsp, |
| flags & GPIO_V2_LINE_FLAG_OPEN_DRAIN); |
| assign_bit(FLAG_OPEN_SOURCE, flagsp, |
| flags & GPIO_V2_LINE_FLAG_OPEN_SOURCE); |
| |
| assign_bit(FLAG_PULL_UP, flagsp, |
| flags & GPIO_V2_LINE_FLAG_BIAS_PULL_UP); |
| assign_bit(FLAG_PULL_DOWN, flagsp, |
| flags & GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN); |
| assign_bit(FLAG_BIAS_DISABLE, flagsp, |
| flags & GPIO_V2_LINE_FLAG_BIAS_DISABLED); |
| |
| assign_bit(FLAG_EVENT_CLOCK_REALTIME, flagsp, |
| flags & GPIO_V2_LINE_FLAG_EVENT_CLOCK_REALTIME); |
| assign_bit(FLAG_EVENT_CLOCK_HTE, flagsp, |
| flags & GPIO_V2_LINE_FLAG_EVENT_CLOCK_HTE); |
| } |
| |
| static long linereq_get_values(struct linereq *lr, void __user *ip) |
| { |
| struct gpio_v2_line_values lv; |
| DECLARE_BITMAP(vals, GPIO_V2_LINES_MAX); |
| struct gpio_desc **descs; |
| unsigned int i, didx, num_get; |
| bool val; |
| int ret; |
| |
| /* NOTE: It's ok to read values of output lines. */ |
| if (copy_from_user(&lv, ip, sizeof(lv))) |
| return -EFAULT; |
| |
| for (num_get = 0, i = 0; i < lr->num_lines; i++) { |
| if (lv.mask & BIT_ULL(i)) { |
| num_get++; |
| descs = &lr->lines[i].desc; |
| } |
| } |
| |
| if (num_get == 0) |
| return -EINVAL; |
| |
| if (num_get != 1) { |
| descs = kmalloc_array(num_get, sizeof(*descs), GFP_KERNEL); |
| if (!descs) |
| return -ENOMEM; |
| for (didx = 0, i = 0; i < lr->num_lines; i++) { |
| if (lv.mask & BIT_ULL(i)) { |
| descs[didx] = lr->lines[i].desc; |
| didx++; |
| } |
| } |
| } |
| ret = gpiod_get_array_value_complex(false, true, num_get, |
| descs, NULL, vals); |
| |
| if (num_get != 1) |
| kfree(descs); |
| if (ret) |
| return ret; |
| |
| lv.bits = 0; |
| for (didx = 0, i = 0; i < lr->num_lines; i++) { |
| if (lv.mask & BIT_ULL(i)) { |
| if (lr->lines[i].sw_debounced) |
| val = debounced_value(&lr->lines[i]); |
| else |
| val = test_bit(didx, vals); |
| if (val) |
| lv.bits |= BIT_ULL(i); |
| didx++; |
| } |
| } |
| |
| if (copy_to_user(ip, &lv, sizeof(lv))) |
| return -EFAULT; |
| |
| return 0; |
| } |
| |
| static long linereq_set_values_unlocked(struct linereq *lr, |
| struct gpio_v2_line_values *lv) |
| { |
| DECLARE_BITMAP(vals, GPIO_V2_LINES_MAX); |
| struct gpio_desc **descs; |
| unsigned int i, didx, num_set; |
| int ret; |
| |
| bitmap_zero(vals, GPIO_V2_LINES_MAX); |
| for (num_set = 0, i = 0; i < lr->num_lines; i++) { |
| if (lv->mask & BIT_ULL(i)) { |
| if (!test_bit(FLAG_IS_OUT, &lr->lines[i].desc->flags)) |
| return -EPERM; |
| if (lv->bits & BIT_ULL(i)) |
| __set_bit(num_set, vals); |
| num_set++; |
| descs = &lr->lines[i].desc; |
| } |
| } |
| if (num_set == 0) |
| return -EINVAL; |
| |
| if (num_set != 1) { |
| /* build compacted desc array and values */ |
| descs = kmalloc_array(num_set, sizeof(*descs), GFP_KERNEL); |
| if (!descs) |
| return -ENOMEM; |
| for (didx = 0, i = 0; i < lr->num_lines; i++) { |
| if (lv->mask & BIT_ULL(i)) { |
| descs[didx] = lr->lines[i].desc; |
| didx++; |
| } |
| } |
| } |
| ret = gpiod_set_array_value_complex(false, true, num_set, |
| descs, NULL, vals); |
| |
| if (num_set != 1) |
| kfree(descs); |
| return ret; |
| } |
| |
| static long linereq_set_values(struct linereq *lr, void __user *ip) |
| { |
| struct gpio_v2_line_values lv; |
| int ret; |
| |
| if (copy_from_user(&lv, ip, sizeof(lv))) |
| return -EFAULT; |
| |
| mutex_lock(&lr->config_mutex); |
| |
| ret = linereq_set_values_unlocked(lr, &lv); |
| |
| mutex_unlock(&lr->config_mutex); |
| |
| return ret; |
| } |
| |
| static long linereq_set_config_unlocked(struct linereq *lr, |
| struct gpio_v2_line_config *lc) |
| { |
| struct gpio_desc *desc; |
| unsigned int i; |
| u64 flags; |
| bool polarity_change; |
| bool prev_hte_flag; |
| int ret; |
| |
| for (i = 0; i < lr->num_lines; i++) { |
| desc = lr->lines[i].desc; |
| flags = gpio_v2_line_config_flags(lc, i); |
| polarity_change = |
| (!!test_bit(FLAG_ACTIVE_LOW, &desc->flags) != |
| ((flags & GPIO_V2_LINE_FLAG_ACTIVE_LOW) != 0)); |
| |
| prev_hte_flag = !!test_bit(FLAG_EVENT_CLOCK_HTE, &desc->flags); |
| |
| gpio_v2_line_config_flags_to_desc_flags(flags, &desc->flags); |
| /* |
| * Lines have to be requested explicitly for input |
| * or output, else the line will be treated "as is". |
| */ |
| if (flags & GPIO_V2_LINE_FLAG_OUTPUT) { |
| int val = gpio_v2_line_config_output_value(lc, i); |
| |
| edge_detector_stop(&lr->lines[i], prev_hte_flag); |
| ret = gpiod_direction_output(desc, val); |
| if (ret) |
| return ret; |
| } else if (flags & GPIO_V2_LINE_FLAG_INPUT) { |
| ret = gpiod_direction_input(desc); |
| if (ret) |
| return ret; |
| |
| ret = edge_detector_update(&lr->lines[i], lc, i, |
| flags, polarity_change, prev_hte_flag); |
| if (ret) |
| return ret; |
| } |
| |
| blocking_notifier_call_chain(&desc->gdev->notifier, |
| GPIO_V2_LINE_CHANGED_CONFIG, |
| desc); |
| } |
| return 0; |
| } |
| |
| static long linereq_set_config(struct linereq *lr, void __user *ip) |
| { |
| struct gpio_v2_line_config lc; |
| int ret; |
| |
| if (copy_from_user(&lc, ip, sizeof(lc))) |
| return -EFAULT; |
| |
| ret = gpio_v2_line_config_validate(&lc, lr->num_lines); |
| if (ret) |
| return ret; |
| |
| mutex_lock(&lr->config_mutex); |
| |
| ret = linereq_set_config_unlocked(lr, &lc); |
| |
| mutex_unlock(&lr->config_mutex); |
| |
| return ret; |
| } |
| |
| static long linereq_ioctl(struct file *file, unsigned int cmd, |
| unsigned long arg) |
| { |
| struct linereq *lr = file->private_data; |
| void __user *ip = (void __user *)arg; |
| |
| switch (cmd) { |
| case GPIO_V2_LINE_GET_VALUES_IOCTL: |
| return linereq_get_values(lr, ip); |
| case GPIO_V2_LINE_SET_VALUES_IOCTL: |
| return linereq_set_values(lr, ip); |
| case GPIO_V2_LINE_SET_CONFIG_IOCTL: |
| return linereq_set_config(lr, ip); |
| default: |
| return -EINVAL; |
| } |
| } |
| |
| #ifdef CONFIG_COMPAT |
| static long linereq_ioctl_compat(struct file *file, unsigned int cmd, |
| unsigned long arg) |
| { |
| return linereq_ioctl(file, cmd, (unsigned long)compat_ptr(arg)); |
| } |
| #endif |
| |
| static __poll_t linereq_poll(struct file *file, |
| struct poll_table_struct *wait) |
| { |
| struct linereq *lr = file->private_data; |
| __poll_t events = 0; |
| |
| poll_wait(file, &lr->wait, wait); |
| |
| if (!kfifo_is_empty_spinlocked_noirqsave(&lr->events, |
| &lr->wait.lock)) |
| events = EPOLLIN | EPOLLRDNORM; |
| |
| return events; |
| } |
| |
| static ssize_t linereq_read(struct file *file, |
| char __user *buf, |
| size_t count, |
| loff_t *f_ps) |
| { |
| struct linereq *lr = file->private_data; |
| struct gpio_v2_line_event le; |
| ssize_t bytes_read = 0; |
| int ret; |
| |
| if (count < sizeof(le)) |
| return -EINVAL; |
| |
| do { |
| spin_lock(&lr->wait.lock); |
| if (kfifo_is_empty(&lr->events)) { |
| if (bytes_read) { |
| spin_unlock(&lr->wait.lock); |
| return bytes_read; |
| } |
| |
| if (file->f_flags & O_NONBLOCK) { |
| spin_unlock(&lr->wait.lock); |
| return -EAGAIN; |
| } |
| |
| ret = wait_event_interruptible_locked(lr->wait, |
| !kfifo_is_empty(&lr->events)); |
| if (ret) { |
| spin_unlock(&lr->wait.lock); |
| return ret; |
| } |
| } |
| |
| ret = kfifo_out(&lr->events, &le, 1); |
| spin_unlock(&lr->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, &le, sizeof(le))) |
| return -EFAULT; |
| bytes_read += sizeof(le); |
| } while (count >= bytes_read + sizeof(le)); |
| |
| return bytes_read; |
| } |
| |
| static void linereq_free(struct linereq *lr) |
| { |
| unsigned int i; |
| bool hte = false; |
| |
| for (i = 0; i < lr->num_lines; i++) { |
| if (lr->lines[i].desc) |
| hte = !!test_bit(FLAG_EVENT_CLOCK_HTE, |
| &lr->lines[i].desc->flags); |
| edge_detector_stop(&lr->lines[i], hte); |
| if (lr->lines[i].desc) |
| gpiod_free(lr->lines[i].desc); |
| } |
| kfifo_free(&lr->events); |
| kfree(lr->label); |
| put_device(&lr->gdev->dev); |
| kfree(lr); |
| } |
| |
| static int linereq_release(struct inode *inode, struct file *file) |
| { |
| struct linereq *lr = file->private_data; |
| |
| linereq_free(lr); |
| return 0; |
| } |
| |
| static const struct file_operations line_fileops = { |
| .release = linereq_release, |
| .read = linereq_read, |
| .poll = linereq_poll, |
| .owner = THIS_MODULE, |
| .llseek = noop_llseek, |
| .unlocked_ioctl = linereq_ioctl, |
| #ifdef CONFIG_COMPAT |
| .compat_ioctl = linereq_ioctl_compat, |
| #endif |
| }; |
| |
| static int linereq_create(struct gpio_device *gdev, void __user *ip) |
| { |
| struct gpio_v2_line_request ulr; |
| struct gpio_v2_line_config *lc; |
| struct linereq *lr; |
| struct file *file; |
| u64 flags; |
| unsigned int i; |
| int fd, ret; |
| |
| if (copy_from_user(&ulr, ip, sizeof(ulr))) |
| return -EFAULT; |
| |
| if ((ulr.num_lines == 0) || (ulr.num_lines > GPIO_V2_LINES_MAX)) |
| return -EINVAL; |
| |
| if (memchr_inv(ulr.padding, 0, sizeof(ulr.padding))) |
| return -EINVAL; |
| |
| lc = &ulr.config; |
| ret = gpio_v2_line_config_validate(lc, ulr.num_lines); |
| if (ret) |
| return ret; |
| |
| lr = kzalloc(struct_size(lr, lines, ulr.num_lines), GFP_KERNEL); |
| if (!lr) |
| return -ENOMEM; |
| |
| lr->gdev = gdev; |
| get_device(&gdev->dev); |
| |
| for (i = 0; i < ulr.num_lines; i++) { |
| lr->lines[i].req = lr; |
| WRITE_ONCE(lr->lines[i].sw_debounced, 0); |
| INIT_DELAYED_WORK(&lr->lines[i].work, debounce_work_func); |
| } |
| |
| if (ulr.consumer[0] != '\0') { |
| /* label is only initialized if consumer is set */ |
| lr->label = kstrndup(ulr.consumer, sizeof(ulr.consumer) - 1, |
| GFP_KERNEL); |
| if (!lr->label) { |
| ret = -ENOMEM; |
| goto out_free_linereq; |
| } |
| } |
| |
| mutex_init(&lr->config_mutex); |
| init_waitqueue_head(&lr->wait); |
| lr->event_buffer_size = ulr.event_buffer_size; |
| if (lr->event_buffer_size == 0) |
| lr->event_buffer_size = ulr.num_lines * 16; |
| else if (lr->event_buffer_size > GPIO_V2_LINES_MAX * 16) |
| lr->event_buffer_size = GPIO_V2_LINES_MAX * 16; |
| |
| atomic_set(&lr->seqno, 0); |
| lr->num_lines = ulr.num_lines; |
| |
| /* Request each GPIO */ |
| for (i = 0; i < ulr.num_lines; i++) { |
| u32 offset = ulr.offsets[i]; |
| struct gpio_desc *desc = gpiochip_get_desc(gdev->chip, offset); |
| |
| if (IS_ERR(desc)) { |
| ret = PTR_ERR(desc); |
| goto out_free_linereq; |
| } |
| |
| ret = gpiod_request_user(desc, lr->label); |
| if (ret) |
| goto out_free_linereq; |
| |
| lr->lines[i].desc = desc; |
| flags = gpio_v2_line_config_flags(lc, i); |
| gpio_v2_line_config_flags_to_desc_flags(flags, &desc->flags); |
| |
| ret = gpiod_set_transitory(desc, false); |
| if (ret < 0) |
| goto out_free_linereq; |
| |
| /* |
| * Lines have to be requested explicitly for input |
| * or output, else the line will be treated "as is". |
| */ |
| if (flags & GPIO_V2_LINE_FLAG_OUTPUT) { |
| int val = gpio_v2_line_config_output_value(lc, i); |
| |
| ret = gpiod_direction_output(desc, val); |
| if (ret) |
| goto out_free_linereq; |
| } else if (flags & GPIO_V2_LINE_FLAG_INPUT) { |
| ret = gpiod_direction_input(desc); |
| if (ret) |
| goto out_free_linereq; |
| |
| ret = edge_detector_setup(&lr->lines[i], lc, i, |
| flags & GPIO_V2_LINE_EDGE_FLAGS, |
| flags & GPIO_V2_LINE_FLAG_EVENT_CLOCK_HTE); |
| if (ret) |
| goto out_free_linereq; |
| } |
| |
| blocking_notifier_call_chain(&desc->gdev->notifier, |
| GPIO_V2_LINE_CHANGED_REQUESTED, desc); |
| |
| dev_dbg(&gdev->dev, "registered chardev handle for line %d\n", |
| offset); |
| } |
| |
| fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC); |
| if (fd < 0) { |
| ret = fd; |
| goto out_free_linereq; |
| } |
| |
| file = anon_inode_getfile("gpio-line", &line_fileops, lr, |
| O_RDONLY | O_CLOEXEC); |
| if (IS_ERR(file)) { |
| ret = PTR_ERR(file); |
| goto out_put_unused_fd; |
| } |
| |
| ulr.fd = fd; |
| if (copy_to_user(ip, &ulr, sizeof(ulr))) { |
| /* |
| * 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", |
| lr->num_lines); |
| |
| return 0; |
| |
| out_put_unused_fd: |
| put_unused_fd(fd); |
| out_free_linereq: |
| linereq_free(lr); |
| return ret; |
| } |
| |
| #ifdef CONFIG_GPIO_CDEV_V1 |
| |
| /* |
| * 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 *file, |
| struct poll_table_struct *wait) |
| { |
| struct lineevent_state *le = file->private_data; |
| __poll_t events = 0; |
| |
| poll_wait(file, &le->wait, wait); |
| |
| if (!kfifo_is_empty_spinlocked_noirqsave(&le->events, &le->wait.lock)) |
| events = EPOLLIN | EPOLLRDNORM; |
| |
| return events; |
| } |
| |
| struct compat_gpioeevent_data { |
| compat_u64 timestamp; |
| u32 id; |
| }; |
| |
| static ssize_t lineevent_read(struct file *file, |
| char __user *buf, |
| size_t count, |
| loff_t *f_ps) |
| { |
| struct lineevent_state *le = file->private_data; |
| struct gpioevent_data ge; |
| ssize_t bytes_read = 0; |
| ssize_t ge_size; |
| int ret; |
| |
| /* |
| * When compatible system call is being used the struct gpioevent_data, |
| * in case of at least ia32, has different size due to the alignment |
| * differences. Because we have first member 64 bits followed by one of |
| * 32 bits there is no gap between them. The only difference is the |
| * padding at the end of the data structure. Hence, we calculate the |
| * actual sizeof() and pass this as an argument to copy_to_user() to |
| * drop unneeded bytes from the output. |
| */ |
| if (compat_need_64bit_alignment_fixup()) |
| ge_size = sizeof(struct compat_gpioeevent_data); |
| else |
| ge_size = sizeof(struct gpioevent_data); |
| if (count < ge_size) |
| 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 (file->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, ge_size)) |
| return -EFAULT; |
| bytes_read += ge_size; |
| } while (count >= bytes_read + ge_size); |
| |
| return bytes_read; |
| } |
| |
| static void lineevent_free(struct lineevent_state *le) |
| { |
| if (le->irq) |
| free_irq(le->irq, le); |
| if (le->desc) |
| gpiod_free(le->desc); |
| kfree(le->label); |
| put_device(&le->gdev->dev); |
| kfree(le); |
| } |
| |
| static int lineevent_release(struct inode *inode, struct file *file) |
| { |
| lineevent_free(file->private_data); |
| return 0; |
| } |
| |
| static long lineevent_ioctl(struct file *file, unsigned int cmd, |
| unsigned long arg) |
| { |
| struct lineevent_state *le = file->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 *file, unsigned int cmd, |
| unsigned long arg) |
| { |
| return lineevent_ioctl(file, 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 irq, 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); |
| |
| if (eventreq.consumer_label[0] != '\0') { |
| /* label is only initialized if consumer_label is set */ |
| le->label = kstrndup(eventreq.consumer_label, |
| sizeof(eventreq.consumer_label) - 1, |
| GFP_KERNEL); |
| if (!le->label) { |
| ret = -ENOMEM; |
| goto out_free_le; |
| } |
| } |
| |
| ret = gpiod_request_user(desc, le->label); |
| if (ret) |
| goto out_free_le; |
| le->desc = desc; |
| le->eflags = eflags; |
| |
| linehandle_flags_to_desc_flags(lflags, &desc->flags); |
| |
| ret = gpiod_direction_input(desc); |
| if (ret) |
| goto out_free_le; |
| |
| blocking_notifier_call_chain(&desc->gdev->notifier, |
| GPIO_V2_LINE_CHANGED_REQUESTED, desc); |
| |
| irq = gpiod_to_irq(desc); |
| if (irq <= 0) { |
| ret = -ENODEV; |
| goto out_free_le; |
| } |
| le->irq = irq; |
| |
| 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_le; |
| |
| fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC); |
| if (fd < 0) { |
| ret = fd; |
| goto out_free_le; |
| } |
| |
| 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_le: |
| lineevent_free(le); |
| return ret; |
| } |
| |
| static void gpio_v2_line_info_to_v1(struct gpio_v2_line_info *info_v2, |
| struct gpioline_info *info_v1) |
| { |
| u64 flagsv2 = info_v2->flags; |
| |
| memcpy(info_v1->name, info_v2->name, sizeof(info_v1->name)); |
| memcpy(info_v1->consumer, info_v2->consumer, sizeof(info_v1->consumer)); |
| info_v1->line_offset = info_v2->offset; |
| info_v1->flags = 0; |
| |
| if (flagsv2 & GPIO_V2_LINE_FLAG_USED) |
| info_v1->flags |= GPIOLINE_FLAG_KERNEL; |
| |
| if (flagsv2 & GPIO_V2_LINE_FLAG_OUTPUT) |
| info_v1->flags |= GPIOLINE_FLAG_IS_OUT; |
| |
| if (flagsv2 & GPIO_V2_LINE_FLAG_ACTIVE_LOW) |
| info_v1->flags |= GPIOLINE_FLAG_ACTIVE_LOW; |
| |
| if (flagsv2 & GPIO_V2_LINE_FLAG_OPEN_DRAIN) |
| info_v1->flags |= GPIOLINE_FLAG_OPEN_DRAIN; |
| if (flagsv2 & GPIO_V2_LINE_FLAG_OPEN_SOURCE) |
| info_v1->flags |= GPIOLINE_FLAG_OPEN_SOURCE; |
| |
| if (flagsv2 & GPIO_V2_LINE_FLAG_BIAS_PULL_UP) |
| info_v1->flags |= GPIOLINE_FLAG_BIAS_PULL_UP; |
| if (flagsv2 & GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN) |
| info_v1->flags |= GPIOLINE_FLAG_BIAS_PULL_DOWN; |
| if (flagsv2 & GPIO_V2_LINE_FLAG_BIAS_DISABLED) |
| info_v1->flags |= GPIOLINE_FLAG_BIAS_DISABLE; |
| } |
| |
| static void gpio_v2_line_info_changed_to_v1( |
| struct gpio_v2_line_info_changed *lic_v2, |
| struct gpioline_info_changed *lic_v1) |
| { |
| memset(lic_v1, 0, sizeof(*lic_v1)); |
| gpio_v2_line_info_to_v1(&lic_v2->info, &lic_v1->info); |
| lic_v1->timestamp = lic_v2->timestamp_ns; |
| lic_v1->event_type = lic_v2->event_type; |
| } |
| |
| #endif /* CONFIG_GPIO_CDEV_V1 */ |
| |
| static void gpio_desc_to_lineinfo(struct gpio_desc *desc, |
| struct gpio_v2_line_info *info) |
| { |
| struct gpio_chip *gc = desc->gdev->chip; |
| bool ok_for_pinctrl; |
| unsigned long flags; |
| u32 debounce_period_us; |
| unsigned int num_attrs = 0; |
| |
| memset(info, 0, sizeof(*info)); |
| info->offset = gpio_chip_hwgpio(desc); |
| |
| /* |
| * 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->offset); |
| |
| spin_lock_irqsave(&gpio_lock, flags); |
| |
| if (desc->name) |
| strscpy(info->name, desc->name, sizeof(info->name)); |
| |
| if (desc->label) |
| strscpy(info->consumer, desc->label, sizeof(info->consumer)); |
| |
| /* |
| * 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) || |
| !gpiochip_line_is_valid(gc, info->offset) || |
| !ok_for_pinctrl) |
| info->flags |= GPIO_V2_LINE_FLAG_USED; |
| |
| if (test_bit(FLAG_IS_OUT, &desc->flags)) |
| info->flags |= GPIO_V2_LINE_FLAG_OUTPUT; |
| else |
| info->flags |= GPIO_V2_LINE_FLAG_INPUT; |
| |
| if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) |
| info->flags |= GPIO_V2_LINE_FLAG_ACTIVE_LOW; |
| |
| if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) |
| info->flags |= GPIO_V2_LINE_FLAG_OPEN_DRAIN; |
| if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) |
| info->flags |= GPIO_V2_LINE_FLAG_OPEN_SOURCE; |
| |
| if (test_bit(FLAG_BIAS_DISABLE, &desc->flags)) |
| info->flags |= GPIO_V2_LINE_FLAG_BIAS_DISABLED; |
| if (test_bit(FLAG_PULL_DOWN, &desc->flags)) |
| info->flags |= GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN; |
| if (test_bit(FLAG_PULL_UP, &desc->flags)) |
| info->flags |= GPIO_V2_LINE_FLAG_BIAS_PULL_UP; |
| |
| if (test_bit(FLAG_EDGE_RISING, &desc->flags)) |
| info->flags |= GPIO_V2_LINE_FLAG_EDGE_RISING; |
| if (test_bit(FLAG_EDGE_FALLING, &desc->flags)) |
| info->flags |= GPIO_V2_LINE_FLAG_EDGE_FALLING; |
| |
| if (test_bit(FLAG_EVENT_CLOCK_REALTIME, &desc->flags)) |
| info->flags |= GPIO_V2_LINE_FLAG_EVENT_CLOCK_REALTIME; |
| else if (test_bit(FLAG_EVENT_CLOCK_HTE, &desc->flags)) |
| info->flags |= GPIO_V2_LINE_FLAG_EVENT_CLOCK_HTE; |
| |
| debounce_period_us = READ_ONCE(desc->debounce_period_us); |
| if (debounce_period_us) { |
| info->attrs[num_attrs].id = GPIO_V2_LINE_ATTR_ID_DEBOUNCE; |
| info->attrs[num_attrs].debounce_period_us = debounce_period_us; |
| num_attrs++; |
| } |
| info->num_attrs = num_attrs; |
| |
| spin_unlock_irqrestore(&gpio_lock, flags); |
| } |
| |
| struct gpio_chardev_data { |
| struct gpio_device *gdev; |
| wait_queue_head_t wait; |
| DECLARE_KFIFO(events, struct gpio_v2_line_info_changed, 32); |
| struct notifier_block lineinfo_changed_nb; |
| unsigned long *watched_lines; |
| #ifdef CONFIG_GPIO_CDEV_V1 |
| atomic_t watch_abi_version; |
| #endif |
| }; |
| |
| static int chipinfo_get(struct gpio_chardev_data *cdev, void __user *ip) |
| { |
| struct gpio_device *gdev = cdev->gdev; |
| struct gpiochip_info chipinfo; |
| |
| memset(&chipinfo, 0, sizeof(chipinfo)); |
| |
| strscpy(chipinfo.name, dev_name(&gdev->dev), sizeof(chipinfo.name)); |
| strscpy(chipinfo.label, gdev->label, sizeof(chipinfo.label)); |
| chipinfo.lines = gdev->ngpio; |
| if (copy_to_user(ip, &chipinfo, sizeof(chipinfo))) |
| return -EFAULT; |
| return 0; |
| } |
| |
| #ifdef CONFIG_GPIO_CDEV_V1 |
| /* |
| * returns 0 if the versions match, else the previously selected ABI version |
| */ |
| static int lineinfo_ensure_abi_version(struct gpio_chardev_data *cdata, |
| unsigned int version) |
| { |
| int abiv = atomic_cmpxchg(&cdata->watch_abi_version, 0, version); |
| |
| if (abiv == version) |
| return 0; |
| |
| return abiv; |
| } |
| |
| static int lineinfo_get_v1(struct gpio_chardev_data *cdev, void __user *ip, |
| bool watch) |
| { |
| struct gpio_desc *desc; |
| struct gpioline_info lineinfo; |
| struct gpio_v2_line_info lineinfo_v2; |
| |
| if (copy_from_user(&lineinfo, ip, sizeof(lineinfo))) |
| return -EFAULT; |
| |
| /* this doubles as a range check on line_offset */ |
| desc = gpiochip_get_desc(cdev->gdev->chip, lineinfo.line_offset); |
| if (IS_ERR(desc)) |
| return PTR_ERR(desc); |
| |
| if (watch) { |
| if (lineinfo_ensure_abi_version(cdev, 1)) |
| return -EPERM; |
| |
| if (test_and_set_bit(lineinfo.line_offset, cdev->watched_lines)) |
| return -EBUSY; |
| } |
| |
| gpio_desc_to_lineinfo(desc, &lineinfo_v2); |
| gpio_v2_line_info_to_v1(&lineinfo_v2, &lineinfo); |
| |
| if (copy_to_user(ip, &lineinfo, sizeof(lineinfo))) { |
| if (watch) |
| clear_bit(lineinfo.line_offset, cdev->watched_lines); |
| return -EFAULT; |
| } |
| |
| return 0; |
| } |
| #endif |
| |
| static int lineinfo_get(struct gpio_chardev_data *cdev, void __user *ip, |
| bool watch) |
| { |
| struct gpio_desc *desc; |
| struct gpio_v2_line_info lineinfo; |
| |
| if (copy_from_user(&lineinfo, ip, sizeof(lineinfo))) |
| return -EFAULT; |
| |
| if (memchr_inv(lineinfo.padding, 0, sizeof(lineinfo.padding))) |
| return -EINVAL; |
| |
| desc = gpiochip_get_desc(cdev->gdev->chip, lineinfo.offset); |
| if (IS_ERR(desc)) |
| return PTR_ERR(desc); |
| |
| if (watch) { |
| #ifdef CONFIG_GPIO_CDEV_V1 |
| if (lineinfo_ensure_abi_version(cdev, 2)) |
| return -EPERM; |
| #endif |
| if (test_and_set_bit(lineinfo.offset, cdev->watched_lines)) |
| return -EBUSY; |
| } |
| gpio_desc_to_lineinfo(desc, &lineinfo); |
| |
| if (copy_to_user(ip, &lineinfo, sizeof(lineinfo))) { |
| if (watch) |
| clear_bit(lineinfo.offset, cdev->watched_lines); |
| return -EFAULT; |
| } |
| |
| return 0; |
| } |
| |
| static int lineinfo_unwatch(struct gpio_chardev_data *cdev, void __user *ip) |
| { |
| __u32 offset; |
| |
| if (copy_from_user(&offset, ip, sizeof(offset))) |
| return -EFAULT; |
| |
| if (offset >= cdev->gdev->ngpio) |
| return -EINVAL; |
| |
| if (!test_and_clear_bit(offset, cdev->watched_lines)) |
| return -EBUSY; |
| |
| return 0; |
| } |
| |
| /* |
| * gpio_ioctl() - ioctl handler for the GPIO chardev |
| */ |
| static long gpio_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
| { |
| struct gpio_chardev_data *cdev = file->private_data; |
| struct gpio_device *gdev = cdev->gdev; |
| void __user *ip = (void __user *)arg; |
| |
| /* We fail any subsequent ioctl():s when the chip is gone */ |
| if (!gdev->chip) |
| return -ENODEV; |
| |
| /* Fill in the struct and pass to userspace */ |
| switch (cmd) { |
| case GPIO_GET_CHIPINFO_IOCTL: |
| return chipinfo_get(cdev, ip); |
| #ifdef CONFIG_GPIO_CDEV_V1 |
| case GPIO_GET_LINEHANDLE_IOCTL: |
| return linehandle_create(gdev, ip); |
| case GPIO_GET_LINEEVENT_IOCTL: |
| return lineevent_create(gdev, ip); |
| case GPIO_GET_LINEINFO_IOCTL: |
| return lineinfo_get_v1(cdev, ip, false); |
| case GPIO_GET_LINEINFO_WATCH_IOCTL: |
| return lineinfo_get_v1(cdev, ip, true); |
| #endif /* CONFIG_GPIO_CDEV_V1 */ |
| case GPIO_V2_GET_LINEINFO_IOCTL: |
| return lineinfo_get(cdev, ip, false); |
| case GPIO_V2_GET_LINEINFO_WATCH_IOCTL: |
| return lineinfo_get(cdev, ip, true); |
| case GPIO_V2_GET_LINE_IOCTL: |
| return linereq_create(gdev, ip); |
| case GPIO_GET_LINEINFO_UNWATCH_IOCTL: |
| return lineinfo_unwatch(cdev, ip); |
| default: |
| return -EINVAL; |
| } |
| } |
| |
| #ifdef CONFIG_COMPAT |
| static long gpio_ioctl_compat(struct file *file, unsigned int cmd, |
| unsigned long arg) |
| { |
| return gpio_ioctl(file, 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 *cdev = to_gpio_chardev_data(nb); |
| struct gpio_v2_line_info_changed chg; |
| struct gpio_desc *desc = data; |
| int ret; |
| |
| if (!test_bit(gpio_chip_hwgpio(desc), cdev->watched_lines)) |
| return NOTIFY_DONE; |
| |
| memset(&chg, 0, sizeof(chg)); |
| chg.event_type = action; |
| chg.timestamp_ns = ktime_get_ns(); |
| gpio_desc_to_lineinfo(desc, &chg.info); |
| |
| ret = kfifo_in_spinlocked(&cdev->events, &chg, 1, &cdev->wait.lock); |
| if (ret) |
| wake_up_poll(&cdev->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 *file, |
| struct poll_table_struct *pollt) |
| { |
| struct gpio_chardev_data *cdev = file->private_data; |
| __poll_t events = 0; |
| |
| poll_wait(file, &cdev->wait, pollt); |
| |
| if (!kfifo_is_empty_spinlocked_noirqsave(&cdev->events, |
| &cdev->wait.lock)) |
| events = EPOLLIN | EPOLLRDNORM; |
| |
| return events; |
| } |
| |
| static ssize_t lineinfo_watch_read(struct file *file, char __user *buf, |
| size_t count, loff_t *off) |
| { |
| struct gpio_chardev_data *cdev = file->private_data; |
| struct gpio_v2_line_info_changed event; |
| ssize_t bytes_read = 0; |
| int ret; |
| size_t event_size; |
| |
| #ifndef CONFIG_GPIO_CDEV_V1 |
| event_size = sizeof(struct gpio_v2_line_info_changed); |
| if (count < event_size) |
| return -EINVAL; |
| #endif |
| |
| do { |
| spin_lock(&cdev->wait.lock); |
| if (kfifo_is_empty(&cdev->events)) { |
| if (bytes_read) { |
| spin_unlock(&cdev->wait.lock); |
| return bytes_read; |
| } |
| |
| if (file->f_flags & O_NONBLOCK) { |
| spin_unlock(&cdev->wait.lock); |
| return -EAGAIN; |
| } |
| |
| ret = wait_event_interruptible_locked(cdev->wait, |
| !kfifo_is_empty(&cdev->events)); |
| if (ret) { |
| spin_unlock(&cdev->wait.lock); |
| return ret; |
| } |
| } |
| #ifdef CONFIG_GPIO_CDEV_V1 |
| /* must be after kfifo check so watch_abi_version is set */ |
| if (atomic_read(&cdev->watch_abi_version) == 2) |
| event_size = sizeof(struct gpio_v2_line_info_changed); |
| else |
| event_size = sizeof(struct gpioline_info_changed); |
| if (count < event_size) { |
| spin_unlock(&cdev->wait.lock); |
| return -EINVAL; |
| } |
| #endif |
| ret = kfifo_out(&cdev->events, &event, 1); |
| spin_unlock(&cdev->wait.lock); |
| if (ret != 1) { |
| ret = -EIO; |
| break; |
| /* We should never get here. See lineevent_read(). */ |
| } |
| |
| #ifdef CONFIG_GPIO_CDEV_V1 |
| if (event_size == sizeof(struct gpio_v2_line_info_changed)) { |
| if (copy_to_user(buf + bytes_read, &event, event_size)) |
| return -EFAULT; |
| } else { |
| struct gpioline_info_changed event_v1; |
| |
| gpio_v2_line_info_changed_to_v1(&event, &event_v1); |
| if (copy_to_user(buf + bytes_read, &event_v1, |
| event_size)) |
| return -EFAULT; |
| } |
| #else |
| if (copy_to_user(buf + bytes_read, &event, event_size)) |
| return -EFAULT; |
| #endif |
| bytes_read += event_size; |
| } while (count >= bytes_read + sizeof(event)); |
| |
| return bytes_read; |
| } |
| |
| /** |
| * gpio_chrdev_open() - open the chardev for ioctl operations |
| * @inode: inode for this chardev |
| * @file: file struct for storing private data |
| * Returns 0 on success |
| */ |
| static int gpio_chrdev_open(struct inode *inode, struct file *file) |
| { |
| struct gpio_device *gdev = container_of(inode->i_cdev, |
| struct gpio_device, chrdev); |
| struct gpio_chardev_data *cdev; |
| int ret = -ENOMEM; |
| |
| /* Fail on open if the backing gpiochip is gone */ |
| if (!gdev->chip) |
| return -ENODEV; |
| |
| cdev = kzalloc(sizeof(*cdev), GFP_KERNEL); |
| if (!cdev) |
| return -ENOMEM; |
| |
| cdev->watched_lines = bitmap_zalloc(gdev->chip->ngpio, GFP_KERNEL); |
| if (!cdev->watched_lines) |
| goto out_free_cdev; |
| |
| init_waitqueue_head(&cdev->wait); |
| INIT_KFIFO(cdev->events); |
| cdev->gdev = gdev; |
| |
| cdev->lineinfo_changed_nb.notifier_call = lineinfo_changed_notify; |
| ret = blocking_notifier_chain_register(&gdev->notifier, |
| &cdev->lineinfo_changed_nb); |
| if (ret) |
| goto out_free_bitmap; |
| |
| get_device(&gdev->dev); |
| file->private_data = cdev; |
| |
| ret = nonseekable_open(inode, file); |
| if (ret) |
| goto out_unregister_notifier; |
| |
| return ret; |
| |
| out_unregister_notifier: |
| blocking_notifier_chain_unregister(&gdev->notifier, |
| &cdev->lineinfo_changed_nb); |
| out_free_bitmap: |
| bitmap_free(cdev->watched_lines); |
| out_free_cdev: |
| kfree(cdev); |
| return ret; |
| } |
| |
| /** |
| * gpio_chrdev_release() - close chardev after ioctl operations |
| * @inode: inode for this chardev |
| * @file: file struct for storing private data |
| * Returns 0 on success |
| */ |
| static int gpio_chrdev_release(struct inode *inode, struct file *file) |
| { |
| struct gpio_chardev_data *cdev = file->private_data; |
| struct gpio_device *gdev = cdev->gdev; |
| |
| bitmap_free(cdev->watched_lines); |
| blocking_notifier_chain_unregister(&gdev->notifier, |
| &cdev->lineinfo_changed_nb); |
| put_device(&gdev->dev); |
| kfree(cdev); |
| |
| 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 |
| }; |
| |
| int gpiolib_cdev_register(struct gpio_device *gdev, dev_t devt) |
| { |
| int ret; |
| |
| cdev_init(&gdev->chrdev, &gpio_fileops); |
| gdev->chrdev.owner = THIS_MODULE; |
| gdev->dev.devt = MKDEV(MAJOR(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(devt), gdev->id); |
| |
| return 0; |
| } |
| |
| void gpiolib_cdev_unregister(struct gpio_device *gdev) |
| { |
| cdev_device_del(&gdev->chrdev, &gdev->dev); |
| } |