blob: 311007b1d9046566b8a155c21ef8188cca13a819 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0+
/*
* drivers/usb/class/usbtmc.c - USB Test & Measurement class driver
*
* Copyright (C) 2007 Stefan Kopp, Gechingen, Germany
* Copyright (C) 2008 Novell, Inc.
* Copyright (C) 2008 Greg Kroah-Hartman <gregkh@suse.de>
* Copyright (C) 2018 IVI Foundation, Inc.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/uaccess.h>
#include <linux/kref.h>
#include <linux/slab.h>
#include <linux/poll.h>
#include <linux/mutex.h>
#include <linux/usb.h>
#include <linux/compat.h>
#include <linux/usb/tmc.h>
/* Increment API VERSION when changing tmc.h with new flags or ioctls
* or when changing a significant behavior of the driver.
*/
#define USBTMC_API_VERSION (3)
#define USBTMC_HEADER_SIZE 12
#define USBTMC_MINOR_BASE 176
/* Minimum USB timeout (in milliseconds) */
#define USBTMC_MIN_TIMEOUT 100
/* Default USB timeout (in milliseconds) */
#define USBTMC_TIMEOUT 5000
/* Max number of urbs used in write transfers */
#define MAX_URBS_IN_FLIGHT 16
/* I/O buffer size used in generic read/write functions */
#define USBTMC_BUFSIZE (4096)
/*
* Maximum number of read cycles to empty bulk in endpoint during CLEAR and
* ABORT_BULK_IN requests. Ends the loop if (for whatever reason) a short
* packet is never read.
*/
#define USBTMC_MAX_READS_TO_CLEAR_BULK_IN 100
static const struct usb_device_id usbtmc_devices[] = {
{ USB_INTERFACE_INFO(USB_CLASS_APP_SPEC, 3, 0), },
{ USB_INTERFACE_INFO(USB_CLASS_APP_SPEC, 3, 1), },
{ 0, } /* terminating entry */
};
MODULE_DEVICE_TABLE(usb, usbtmc_devices);
/*
* This structure is the capabilities for the device
* See section 4.2.1.8 of the USBTMC specification,
* and section 4.2.2 of the USBTMC usb488 subclass
* specification for details.
*/
struct usbtmc_dev_capabilities {
__u8 interface_capabilities;
__u8 device_capabilities;
__u8 usb488_interface_capabilities;
__u8 usb488_device_capabilities;
};
/* This structure holds private data for each USBTMC device. One copy is
* allocated for each USBTMC device in the driver's probe function.
*/
struct usbtmc_device_data {
const struct usb_device_id *id;
struct usb_device *usb_dev;
struct usb_interface *intf;
struct list_head file_list;
unsigned int bulk_in;
unsigned int bulk_out;
u8 bTag;
u8 bTag_last_write; /* needed for abort */
u8 bTag_last_read; /* needed for abort */
/* packet size of IN bulk */
u16 wMaxPacketSize;
/* data for interrupt in endpoint handling */
u8 bNotify1;
u8 bNotify2;
u16 ifnum;
u8 iin_bTag;
u8 *iin_buffer;
atomic_t iin_data_valid;
unsigned int iin_ep;
int iin_ep_present;
int iin_interval;
struct urb *iin_urb;
u16 iin_wMaxPacketSize;
/* coalesced usb488_caps from usbtmc_dev_capabilities */
__u8 usb488_caps;
bool zombie; /* fd of disconnected device */
struct usbtmc_dev_capabilities capabilities;
struct kref kref;
struct mutex io_mutex; /* only one i/o function running at a time */
wait_queue_head_t waitq;
struct fasync_struct *fasync;
spinlock_t dev_lock; /* lock for file_list */
};
#define to_usbtmc_data(d) container_of(d, struct usbtmc_device_data, kref)
/*
* This structure holds private data for each USBTMC file handle.
*/
struct usbtmc_file_data {
struct usbtmc_device_data *data;
struct list_head file_elem;
u32 timeout;
u8 srq_byte;
atomic_t srq_asserted;
atomic_t closing;
u8 bmTransferAttributes; /* member of DEV_DEP_MSG_IN */
u8 eom_val;
u8 term_char;
bool term_char_enabled;
bool auto_abort;
spinlock_t err_lock; /* lock for errors */
struct usb_anchor submitted;
/* data for generic_write */
struct semaphore limit_write_sem;
u32 out_transfer_size;
int out_status;
/* data for generic_read */
u32 in_transfer_size;
int in_status;
int in_urbs_used;
struct usb_anchor in_anchor;
wait_queue_head_t wait_bulk_in;
};
/* Forward declarations */
static struct usb_driver usbtmc_driver;
static void usbtmc_draw_down(struct usbtmc_file_data *file_data);
static void usbtmc_delete(struct kref *kref)
{
struct usbtmc_device_data *data = to_usbtmc_data(kref);
usb_put_dev(data->usb_dev);
kfree(data);
}
static int usbtmc_open(struct inode *inode, struct file *filp)
{
struct usb_interface *intf;
struct usbtmc_device_data *data;
struct usbtmc_file_data *file_data;
intf = usb_find_interface(&usbtmc_driver, iminor(inode));
if (!intf) {
pr_err("can not find device for minor %d", iminor(inode));
return -ENODEV;
}
file_data = kzalloc(sizeof(*file_data), GFP_KERNEL);
if (!file_data)
return -ENOMEM;
spin_lock_init(&file_data->err_lock);
sema_init(&file_data->limit_write_sem, MAX_URBS_IN_FLIGHT);
init_usb_anchor(&file_data->submitted);
init_usb_anchor(&file_data->in_anchor);
init_waitqueue_head(&file_data->wait_bulk_in);
data = usb_get_intfdata(intf);
/* Protect reference to data from file structure until release */
kref_get(&data->kref);
mutex_lock(&data->io_mutex);
file_data->data = data;
atomic_set(&file_data->closing, 0);
file_data->timeout = USBTMC_TIMEOUT;
file_data->term_char = '\n';
file_data->term_char_enabled = 0;
file_data->auto_abort = 0;
file_data->eom_val = 1;
INIT_LIST_HEAD(&file_data->file_elem);
spin_lock_irq(&data->dev_lock);
list_add_tail(&file_data->file_elem, &data->file_list);
spin_unlock_irq(&data->dev_lock);
mutex_unlock(&data->io_mutex);
/* Store pointer in file structure's private data field */
filp->private_data = file_data;
return 0;
}
/*
* usbtmc_flush - called before file handle is closed
*/
static int usbtmc_flush(struct file *file, fl_owner_t id)
{
struct usbtmc_file_data *file_data;
struct usbtmc_device_data *data;
file_data = file->private_data;
if (file_data == NULL)
return -ENODEV;
atomic_set(&file_data->closing, 1);
data = file_data->data;
/* wait for io to stop */
mutex_lock(&data->io_mutex);
usbtmc_draw_down(file_data);
spin_lock_irq(&file_data->err_lock);
file_data->in_status = 0;
file_data->in_transfer_size = 0;
file_data->in_urbs_used = 0;
file_data->out_status = 0;
file_data->out_transfer_size = 0;
spin_unlock_irq(&file_data->err_lock);
wake_up_interruptible_all(&data->waitq);
mutex_unlock(&data->io_mutex);
return 0;
}
static int usbtmc_release(struct inode *inode, struct file *file)
{
struct usbtmc_file_data *file_data = file->private_data;
/* prevent IO _AND_ usbtmc_interrupt */
mutex_lock(&file_data->data->io_mutex);
spin_lock_irq(&file_data->data->dev_lock);
list_del(&file_data->file_elem);
spin_unlock_irq(&file_data->data->dev_lock);
mutex_unlock(&file_data->data->io_mutex);
kref_put(&file_data->data->kref, usbtmc_delete);
file_data->data = NULL;
kfree(file_data);
return 0;
}
static int usbtmc_ioctl_abort_bulk_in_tag(struct usbtmc_device_data *data,
u8 tag)
{
u8 *buffer;
struct device *dev;
int rv;
int n;
int actual;
dev = &data->intf->dev;
buffer = kmalloc(USBTMC_BUFSIZE, GFP_KERNEL);
if (!buffer)
return -ENOMEM;
rv = usb_control_msg(data->usb_dev,
usb_rcvctrlpipe(data->usb_dev, 0),
USBTMC_REQUEST_INITIATE_ABORT_BULK_IN,
USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
tag, data->bulk_in,
buffer, 2, USB_CTRL_GET_TIMEOUT);
if (rv < 0) {
dev_err(dev, "usb_control_msg returned %d\n", rv);
goto exit;
}
dev_dbg(dev, "INITIATE_ABORT_BULK_IN returned %x with tag %02x\n",
buffer[0], buffer[1]);
if (buffer[0] == USBTMC_STATUS_FAILED) {
/* No transfer in progress and the Bulk-OUT FIFO is empty. */
rv = 0;
goto exit;
}
if (buffer[0] == USBTMC_STATUS_TRANSFER_NOT_IN_PROGRESS) {
/* The device returns this status if either:
* - There is a transfer in progress, but the specified bTag
* does not match.
* - There is no transfer in progress, but the Bulk-OUT FIFO
* is not empty.
*/
rv = -ENOMSG;
goto exit;
}
if (buffer[0] != USBTMC_STATUS_SUCCESS) {
dev_err(dev, "INITIATE_ABORT_BULK_IN returned %x\n",
buffer[0]);
rv = -EPERM;
goto exit;
}
n = 0;
usbtmc_abort_bulk_in_status:
dev_dbg(dev, "Reading from bulk in EP\n");
/* Data must be present. So use low timeout 300 ms */
actual = 0;
rv = usb_bulk_msg(data->usb_dev,
usb_rcvbulkpipe(data->usb_dev,
data->bulk_in),
buffer, USBTMC_BUFSIZE,
&actual, 300);
print_hex_dump_debug("usbtmc ", DUMP_PREFIX_NONE, 16, 1,
buffer, actual, true);
n++;
if (rv < 0) {
dev_err(dev, "usb_bulk_msg returned %d\n", rv);
if (rv != -ETIMEDOUT)
goto exit;
}
if (actual == USBTMC_BUFSIZE)
goto usbtmc_abort_bulk_in_status;
if (n >= USBTMC_MAX_READS_TO_CLEAR_BULK_IN) {
dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
rv = -EPERM;
goto exit;
}
rv = usb_control_msg(data->usb_dev,
usb_rcvctrlpipe(data->usb_dev, 0),
USBTMC_REQUEST_CHECK_ABORT_BULK_IN_STATUS,
USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
0, data->bulk_in, buffer, 0x08,
USB_CTRL_GET_TIMEOUT);
if (rv < 0) {
dev_err(dev, "usb_control_msg returned %d\n", rv);
goto exit;
}
dev_dbg(dev, "CHECK_ABORT_BULK_IN returned %x\n", buffer[0]);
if (buffer[0] == USBTMC_STATUS_SUCCESS) {
rv = 0;
goto exit;
}
if (buffer[0] != USBTMC_STATUS_PENDING) {
dev_err(dev, "CHECK_ABORT_BULK_IN returned %x\n", buffer[0]);
rv = -EPERM;
goto exit;
}
if ((buffer[1] & 1) > 0) {
/* The device has 1 or more queued packets the Host can read */
goto usbtmc_abort_bulk_in_status;
}
/* The Host must send CHECK_ABORT_BULK_IN_STATUS at a later time. */
rv = -EAGAIN;
exit:
kfree(buffer);
return rv;
}
static int usbtmc_ioctl_abort_bulk_in(struct usbtmc_device_data *data)
{
return usbtmc_ioctl_abort_bulk_in_tag(data, data->bTag_last_read);
}
static int usbtmc_ioctl_abort_bulk_out_tag(struct usbtmc_device_data *data,
u8 tag)
{
struct device *dev;
u8 *buffer;
int rv;
int n;
dev = &data->intf->dev;
buffer = kmalloc(8, GFP_KERNEL);
if (!buffer)
return -ENOMEM;
rv = usb_control_msg(data->usb_dev,
usb_rcvctrlpipe(data->usb_dev, 0),
USBTMC_REQUEST_INITIATE_ABORT_BULK_OUT,
USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
tag, data->bulk_out,
buffer, 2, USB_CTRL_GET_TIMEOUT);
if (rv < 0) {
dev_err(dev, "usb_control_msg returned %d\n", rv);
goto exit;
}
dev_dbg(dev, "INITIATE_ABORT_BULK_OUT returned %x\n", buffer[0]);
if (buffer[0] != USBTMC_STATUS_SUCCESS) {
dev_err(dev, "INITIATE_ABORT_BULK_OUT returned %x\n",
buffer[0]);
rv = -EPERM;
goto exit;
}
n = 0;
usbtmc_abort_bulk_out_check_status:
/* do not stress device with subsequent requests */
msleep(50);
rv = usb_control_msg(data->usb_dev,
usb_rcvctrlpipe(data->usb_dev, 0),
USBTMC_REQUEST_CHECK_ABORT_BULK_OUT_STATUS,
USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
0, data->bulk_out, buffer, 0x08,
USB_CTRL_GET_TIMEOUT);
n++;
if (rv < 0) {
dev_err(dev, "usb_control_msg returned %d\n", rv);
goto exit;
}
dev_dbg(dev, "CHECK_ABORT_BULK_OUT returned %x\n", buffer[0]);
if (buffer[0] == USBTMC_STATUS_SUCCESS)
goto usbtmc_abort_bulk_out_clear_halt;
if ((buffer[0] == USBTMC_STATUS_PENDING) &&
(n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN))
goto usbtmc_abort_bulk_out_check_status;
rv = -EPERM;
goto exit;
usbtmc_abort_bulk_out_clear_halt:
rv = usb_clear_halt(data->usb_dev,
usb_sndbulkpipe(data->usb_dev, data->bulk_out));
if (rv < 0) {
dev_err(dev, "usb_control_msg returned %d\n", rv);
goto exit;
}
rv = 0;
exit:
kfree(buffer);
return rv;
}
static int usbtmc_ioctl_abort_bulk_out(struct usbtmc_device_data *data)
{
return usbtmc_ioctl_abort_bulk_out_tag(data, data->bTag_last_write);
}
static int usbtmc_get_stb(struct usbtmc_file_data *file_data, __u8 *stb)
{
struct usbtmc_device_data *data = file_data->data;
struct device *dev = &data->intf->dev;
u8 *buffer;
u8 tag;
int rv;
dev_dbg(dev, "Enter ioctl_read_stb iin_ep_present: %d\n",
data->iin_ep_present);
buffer = kmalloc(8, GFP_KERNEL);
if (!buffer)
return -ENOMEM;
atomic_set(&data->iin_data_valid, 0);
rv = usb_control_msg(data->usb_dev,
usb_rcvctrlpipe(data->usb_dev, 0),
USBTMC488_REQUEST_READ_STATUS_BYTE,
USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
data->iin_bTag,
data->ifnum,
buffer, 0x03, USB_CTRL_GET_TIMEOUT);
if (rv < 0) {
dev_err(dev, "stb usb_control_msg returned %d\n", rv);
goto exit;
}
if (buffer[0] != USBTMC_STATUS_SUCCESS) {
dev_err(dev, "control status returned %x\n", buffer[0]);
rv = -EIO;
goto exit;
}
if (data->iin_ep_present) {
rv = wait_event_interruptible_timeout(
data->waitq,
atomic_read(&data->iin_data_valid) != 0,
file_data->timeout);
if (rv < 0) {
dev_dbg(dev, "wait interrupted %d\n", rv);
goto exit;
}
if (rv == 0) {
dev_dbg(dev, "wait timed out\n");
rv = -ETIMEDOUT;
goto exit;
}
tag = data->bNotify1 & 0x7f;
if (tag != data->iin_bTag) {
dev_err(dev, "expected bTag %x got %x\n",
data->iin_bTag, tag);
}
*stb = data->bNotify2;
} else {
*stb = buffer[2];
}
dev_dbg(dev, "stb:0x%02x received %d\n", (unsigned int)*stb, rv);
exit:
/* bump interrupt bTag */
data->iin_bTag += 1;
if (data->iin_bTag > 127)
/* 1 is for SRQ see USBTMC-USB488 subclass spec section 4.3.1 */
data->iin_bTag = 2;
kfree(buffer);
return rv;
}
static int usbtmc488_ioctl_read_stb(struct usbtmc_file_data *file_data,
void __user *arg)
{
int srq_asserted = 0;
__u8 stb;
int rv;
rv = usbtmc_get_stb(file_data, &stb);
if (rv > 0) {
srq_asserted = atomic_xchg(&file_data->srq_asserted,
srq_asserted);
if (srq_asserted)
stb |= 0x40; /* Set RQS bit */
rv = put_user(stb, (__u8 __user *)arg);
}
return rv;
}
static int usbtmc_ioctl_get_srq_stb(struct usbtmc_file_data *file_data,
void __user *arg)
{
struct usbtmc_device_data *data = file_data->data;
struct device *dev = &data->intf->dev;
int srq_asserted = 0;
__u8 stb = 0;
int rv;
spin_lock_irq(&data->dev_lock);
srq_asserted = atomic_xchg(&file_data->srq_asserted, srq_asserted);
if (srq_asserted) {
stb = file_data->srq_byte;
spin_unlock_irq(&data->dev_lock);
rv = put_user(stb, (__u8 __user *)arg);
} else {
spin_unlock_irq(&data->dev_lock);
rv = -ENOMSG;
}
dev_dbg(dev, "stb:0x%02x with srq received %d\n", (unsigned int)stb, rv);
return rv;
}
static int usbtmc488_ioctl_wait_srq(struct usbtmc_file_data *file_data,
__u32 __user *arg)
{
struct usbtmc_device_data *data = file_data->data;
struct device *dev = &data->intf->dev;
int rv;
u32 timeout;
unsigned long expire;
if (!data->iin_ep_present) {
dev_dbg(dev, "no interrupt endpoint present\n");
return -EFAULT;
}
if (get_user(timeout, arg))
return -EFAULT;
expire = msecs_to_jiffies(timeout);
mutex_unlock(&data->io_mutex);
rv = wait_event_interruptible_timeout(
data->waitq,
atomic_read(&file_data->srq_asserted) != 0 ||
atomic_read(&file_data->closing),
expire);
mutex_lock(&data->io_mutex);
/* Note! disconnect or close could be called in the meantime */
if (atomic_read(&file_data->closing) || data->zombie)
rv = -ENODEV;
if (rv < 0) {
/* dev can be invalid now! */
pr_debug("%s - wait interrupted %d\n", __func__, rv);
return rv;
}
if (rv == 0) {
dev_dbg(dev, "%s - wait timed out\n", __func__);
return -ETIMEDOUT;
}
dev_dbg(dev, "%s - srq asserted\n", __func__);
return 0;
}
static int usbtmc488_ioctl_simple(struct usbtmc_device_data *data,
void __user *arg, unsigned int cmd)
{
struct device *dev = &data->intf->dev;
__u8 val;
u8 *buffer;
u16 wValue;
int rv;
if (!(data->usb488_caps & USBTMC488_CAPABILITY_SIMPLE))
return -EINVAL;
buffer = kmalloc(8, GFP_KERNEL);
if (!buffer)
return -ENOMEM;
if (cmd == USBTMC488_REQUEST_REN_CONTROL) {
rv = copy_from_user(&val, arg, sizeof(val));
if (rv) {
rv = -EFAULT;
goto exit;
}
wValue = val ? 1 : 0;
} else {
wValue = 0;
}
rv = usb_control_msg(data->usb_dev,
usb_rcvctrlpipe(data->usb_dev, 0),
cmd,
USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
wValue,
data->ifnum,
buffer, 0x01, USB_CTRL_GET_TIMEOUT);
if (rv < 0) {
dev_err(dev, "simple usb_control_msg failed %d\n", rv);
goto exit;
} else if (rv != 1) {
dev_warn(dev, "simple usb_control_msg returned %d\n", rv);
rv = -EIO;
goto exit;
}
if (buffer[0] != USBTMC_STATUS_SUCCESS) {
dev_err(dev, "simple control status returned %x\n", buffer[0]);
rv = -EIO;
goto exit;
}
rv = 0;
exit:
kfree(buffer);
return rv;
}
/*
* Sends a TRIGGER Bulk-OUT command message
* See the USBTMC-USB488 specification, Table 2.
*
* Also updates bTag_last_write.
*/
static int usbtmc488_ioctl_trigger(struct usbtmc_file_data *file_data)
{
struct usbtmc_device_data *data = file_data->data;
int retval;
u8 *buffer;
int actual;
buffer = kzalloc(USBTMC_HEADER_SIZE, GFP_KERNEL);
if (!buffer)
return -ENOMEM;
buffer[0] = 128;
buffer[1] = data->bTag;
buffer[2] = ~data->bTag;
retval = usb_bulk_msg(data->usb_dev,
usb_sndbulkpipe(data->usb_dev,
data->bulk_out),
buffer, USBTMC_HEADER_SIZE,
&actual, file_data->timeout);
/* Store bTag (in case we need to abort) */
data->bTag_last_write = data->bTag;
/* Increment bTag -- and increment again if zero */
data->bTag++;
if (!data->bTag)
data->bTag++;
kfree(buffer);
if (retval < 0) {
dev_err(&data->intf->dev, "%s returned %d\n",
__func__, retval);
return retval;
}
return 0;
}
static struct urb *usbtmc_create_urb(void)
{
const size_t bufsize = USBTMC_BUFSIZE;
u8 *dmabuf = NULL;
struct urb *urb = usb_alloc_urb(0, GFP_KERNEL);
if (!urb)
return NULL;
dmabuf = kmalloc(bufsize, GFP_KERNEL);
if (!dmabuf) {
usb_free_urb(urb);
return NULL;
}
urb->transfer_buffer = dmabuf;
urb->transfer_buffer_length = bufsize;
urb->transfer_flags |= URB_FREE_BUFFER;
return urb;
}
static void usbtmc_read_bulk_cb(struct urb *urb)
{
struct usbtmc_file_data *file_data = urb->context;
int status = urb->status;
unsigned long flags;
/* sync/async unlink faults aren't errors */
if (status) {
if (!(/* status == -ENOENT || */
status == -ECONNRESET ||
status == -EREMOTEIO || /* Short packet */
status == -ESHUTDOWN))
dev_err(&file_data->data->intf->dev,
"%s - nonzero read bulk status received: %d\n",
__func__, status);
spin_lock_irqsave(&file_data->err_lock, flags);
if (!file_data->in_status)
file_data->in_status = status;
spin_unlock_irqrestore(&file_data->err_lock, flags);
}
spin_lock_irqsave(&file_data->err_lock, flags);
file_data->in_transfer_size += urb->actual_length;
dev_dbg(&file_data->data->intf->dev,
"%s - total size: %u current: %d status: %d\n",
__func__, file_data->in_transfer_size,
urb->actual_length, status);
spin_unlock_irqrestore(&file_data->err_lock, flags);
usb_anchor_urb(urb, &file_data->in_anchor);
wake_up_interruptible(&file_data->wait_bulk_in);
wake_up_interruptible(&file_data->data->waitq);
}
static inline bool usbtmc_do_transfer(struct usbtmc_file_data *file_data)
{
bool data_or_error;
spin_lock_irq(&file_data->err_lock);
data_or_error = !usb_anchor_empty(&file_data->in_anchor)
|| file_data->in_status;
spin_unlock_irq(&file_data->err_lock);
dev_dbg(&file_data->data->intf->dev, "%s: returns %d\n", __func__,
data_or_error);
return data_or_error;
}
static ssize_t usbtmc_generic_read(struct usbtmc_file_data *file_data,
void __user *user_buffer,
u32 transfer_size,
u32 *transferred,
u32 flags)
{
struct usbtmc_device_data *data = file_data->data;
struct device *dev = &data->intf->dev;
u32 done = 0;
u32 remaining;
const u32 bufsize = USBTMC_BUFSIZE;
int retval = 0;
u32 max_transfer_size;
unsigned long expire;
int bufcount = 1;
int again = 0;
/* mutex already locked */
*transferred = done;
max_transfer_size = transfer_size;
if (flags & USBTMC_FLAG_IGNORE_TRAILER) {
/* The device may send extra alignment bytes (up to
* wMaxPacketSize – 1) to avoid sending a zero-length
* packet
*/
remaining = transfer_size;
if ((max_transfer_size % data->wMaxPacketSize) == 0)
max_transfer_size += (data->wMaxPacketSize - 1);
} else {
/* round down to bufsize to avoid truncated data left */
if (max_transfer_size > bufsize) {
max_transfer_size =
roundup(max_transfer_size + 1 - bufsize,
bufsize);
}
remaining = max_transfer_size;
}
spin_lock_irq(&file_data->err_lock);
if (file_data->in_status) {
/* return the very first error */
retval = file_data->in_status;
spin_unlock_irq(&file_data->err_lock);
goto error;
}
if (flags & USBTMC_FLAG_ASYNC) {
if (usb_anchor_empty(&file_data->in_anchor))
again = 1;
if (file_data->in_urbs_used == 0) {
file_data->in_transfer_size = 0;
file_data->in_status = 0;
}
} else {
file_data->in_transfer_size = 0;
file_data->in_status = 0;
}
if (max_transfer_size == 0) {
bufcount = 0;
} else {
bufcount = roundup(max_transfer_size, bufsize) / bufsize;
if (bufcount > file_data->in_urbs_used)
bufcount -= file_data->in_urbs_used;
else
bufcount = 0;
if (bufcount + file_data->in_urbs_used > MAX_URBS_IN_FLIGHT) {
bufcount = MAX_URBS_IN_FLIGHT -
file_data->in_urbs_used;
}
}
spin_unlock_irq(&file_data->err_lock);
dev_dbg(dev, "%s: requested=%u flags=0x%X size=%u bufs=%d used=%d\n",
__func__, transfer_size, flags,
max_transfer_size, bufcount, file_data->in_urbs_used);
while (bufcount > 0) {
u8 *dmabuf = NULL;
struct urb *urb = usbtmc_create_urb();
if (!urb) {
retval = -ENOMEM;
goto error;
}
dmabuf = urb->transfer_buffer;
usb_fill_bulk_urb(urb, data->usb_dev,
usb_rcvbulkpipe(data->usb_dev, data->bulk_in),
dmabuf, bufsize,
usbtmc_read_bulk_cb, file_data);
usb_anchor_urb(urb, &file_data->submitted);
retval = usb_submit_urb(urb, GFP_KERNEL);
/* urb is anchored. We can release our reference. */
usb_free_urb(urb);
if (unlikely(retval)) {
usb_unanchor_urb(urb);
goto error;
}
file_data->in_urbs_used++;
bufcount--;
}
if (again) {
dev_dbg(dev, "%s: ret=again\n", __func__);
return -EAGAIN;
}
if (user_buffer == NULL)
return -EINVAL;
expire = msecs_to_jiffies(file_data->timeout);
while (max_transfer_size > 0) {
u32 this_part;
struct urb *urb = NULL;
if (!(flags & USBTMC_FLAG_ASYNC)) {
dev_dbg(dev, "%s: before wait time %lu\n",
__func__, expire);
retval = wait_event_interruptible_timeout(
file_data->wait_bulk_in,
usbtmc_do_transfer(file_data),
expire);
dev_dbg(dev, "%s: wait returned %d\n",
__func__, retval);
if (retval <= 0) {
if (retval == 0)
retval = -ETIMEDOUT;
goto error;
}
}
urb = usb_get_from_anchor(&file_data->in_anchor);
if (!urb) {
if (!(flags & USBTMC_FLAG_ASYNC)) {
/* synchronous case: must not happen */
retval = -EFAULT;
goto error;
}
/* asynchronous case: ready, do not block or wait */
*transferred = done;
dev_dbg(dev, "%s: (async) done=%u ret=0\n",
__func__, done);
return 0;
}
file_data->in_urbs_used--;
if (max_transfer_size > urb->actual_length)
max_transfer_size -= urb->actual_length;
else
max_transfer_size = 0;
if (remaining > urb->actual_length)
this_part = urb->actual_length;
else
this_part = remaining;
print_hex_dump_debug("usbtmc ", DUMP_PREFIX_NONE, 16, 1,
urb->transfer_buffer, urb->actual_length, true);
if (copy_to_user(user_buffer + done,
urb->transfer_buffer, this_part)) {
usb_free_urb(urb);
retval = -EFAULT;
goto error;
}
remaining -= this_part;
done += this_part;
spin_lock_irq(&file_data->err_lock);
if (urb->status) {
/* return the very first error */
retval = file_data->in_status;
spin_unlock_irq(&file_data->err_lock);
usb_free_urb(urb);
goto error;
}
spin_unlock_irq(&file_data->err_lock);
if (urb->actual_length < bufsize) {
/* short packet or ZLP received => ready */
usb_free_urb(urb);
retval = 1;
break;
}
if (!(flags & USBTMC_FLAG_ASYNC) &&
max_transfer_size > (bufsize * file_data->in_urbs_used)) {
/* resubmit, since other buffers still not enough */
usb_anchor_urb(urb, &file_data->submitted);
retval = usb_submit_urb(urb, GFP_KERNEL);
if (unlikely(retval)) {
usb_unanchor_urb(urb);
usb_free_urb(urb);
goto error;
}
file_data->in_urbs_used++;
}
usb_free_urb(urb);
retval = 0;
}
error:
*transferred = done;
dev_dbg(dev, "%s: before kill\n", __func__);
/* Attention: killing urbs can take long time (2 ms) */
usb_kill_anchored_urbs(&file_data->submitted);
dev_dbg(dev, "%s: after kill\n", __func__);
usb_scuttle_anchored_urbs(&file_data->in_anchor);
file_data->in_urbs_used = 0;
file_data->in_status = 0; /* no spinlock needed here */
dev_dbg(dev, "%s: done=%u ret=%d\n", __func__, done, retval);
return retval;
}
static ssize_t usbtmc_ioctl_generic_read(struct usbtmc_file_data *file_data,
void __user *arg)
{
struct usbtmc_message msg;
ssize_t retval = 0;
/* mutex already locked */
if (copy_from_user(&msg, arg, sizeof(struct usbtmc_message)))
return -EFAULT;
retval = usbtmc_generic_read(file_data, msg.message,
msg.transfer_size, &msg.transferred,
msg.flags);
if (put_user(msg.transferred,
&((struct usbtmc_message __user *)arg)->transferred))
return -EFAULT;
return retval;
}
static void usbtmc_write_bulk_cb(struct urb *urb)
{
struct usbtmc_file_data *file_data = urb->context;
int wakeup = 0;
unsigned long flags;
spin_lock_irqsave(&file_data->err_lock, flags);
file_data->out_transfer_size += urb->actual_length;
/* sync/async unlink faults aren't errors */
if (urb->status) {
if (!(urb->status == -ENOENT ||
urb->status == -ECONNRESET ||
urb->status == -ESHUTDOWN))
dev_err(&file_data->data->intf->dev,
"%s - nonzero write bulk status received: %d\n",
__func__, urb->status);
if (!file_data->out_status) {
file_data->out_status = urb->status;
wakeup = 1;
}
}
spin_unlock_irqrestore(&file_data->err_lock, flags);
dev_dbg(&file_data->data->intf->dev,
"%s - write bulk total size: %u\n",
__func__, file_data->out_transfer_size);
up(&file_data->limit_write_sem);
if (usb_anchor_empty(&file_data->submitted) || wakeup)
wake_up_interruptible(&file_data->data->waitq);
}
static ssize_t usbtmc_generic_write(struct usbtmc_file_data *file_data,
const void __user *user_buffer,
u32 transfer_size,
u32 *transferred,
u32 flags)
{
struct usbtmc_device_data *data = file_data->data;
struct device *dev;
u32 done = 0;
u32 remaining;
unsigned long expire;
const u32 bufsize = USBTMC_BUFSIZE;
struct urb *urb = NULL;
int retval = 0;
u32 timeout;
*transferred = 0;
/* Get pointer to private data structure */
dev = &data->intf->dev;
dev_dbg(dev, "%s: size=%u flags=0x%X sema=%u\n",
__func__, transfer_size, flags,
file_data->limit_write_sem.count);
if (flags & USBTMC_FLAG_APPEND) {
spin_lock_irq(&file_data->err_lock);
retval = file_data->out_status;
spin_unlock_irq(&file_data->err_lock);
if (retval < 0)
return retval;
} else {
spin_lock_irq(&file_data->err_lock);
file_data->out_transfer_size = 0;
file_data->out_status = 0;
spin_unlock_irq(&file_data->err_lock);
}
remaining = transfer_size;
if (remaining > INT_MAX)
remaining = INT_MAX;
timeout = file_data->timeout;
expire = msecs_to_jiffies(timeout);
while (remaining > 0) {
u32 this_part, aligned;
u8 *buffer = NULL;
if (flags & USBTMC_FLAG_ASYNC) {
if (down_trylock(&file_data->limit_write_sem)) {
retval = (done)?(0):(-EAGAIN);
goto exit;
}
} else {
retval = down_timeout(&file_data->limit_write_sem,
expire);
if (retval < 0) {
retval = -ETIMEDOUT;
goto error;
}
}
spin_lock_irq(&file_data->err_lock);
retval = file_data->out_status;
spin_unlock_irq(&file_data->err_lock);
if (retval < 0) {
up(&file_data->limit_write_sem);
goto error;
}
/* prepare next urb to send */
urb = usbtmc_create_urb();
if (!urb) {
retval = -ENOMEM;
up(&file_data->limit_write_sem);
goto error;
}
buffer = urb->transfer_buffer;
if (remaining > bufsize)
this_part = bufsize;
else
this_part = remaining;
if (copy_from_user(buffer, user_buffer + done, this_part)) {
retval = -EFAULT;
up(&file_data->limit_write_sem);
goto error;
}
print_hex_dump_debug("usbtmc ", DUMP_PREFIX_NONE,
16, 1, buffer, this_part, true);
/* fill bulk with 32 bit alignment to meet USBTMC specification
* (size + 3 & ~3) rounds up and simplifies user code
*/
aligned = (this_part + 3) & ~3;
dev_dbg(dev, "write(size:%u align:%u done:%u)\n",
(unsigned int)this_part,
(unsigned int)aligned,
(unsigned int)done);
usb_fill_bulk_urb(urb, data->usb_dev,
usb_sndbulkpipe(data->usb_dev, data->bulk_out),
urb->transfer_buffer, aligned,
usbtmc_write_bulk_cb, file_data);
usb_anchor_urb(urb, &file_data->submitted);
retval = usb_submit_urb(urb, GFP_KERNEL);
if (unlikely(retval)) {
usb_unanchor_urb(urb);
up(&file_data->limit_write_sem);
goto error;
}
usb_free_urb(urb);
urb = NULL; /* urb will be finally released by usb driver */
remaining -= this_part;
done += this_part;
}
/* All urbs are on the fly */
if (!(flags & USBTMC_FLAG_ASYNC)) {
if (!usb_wait_anchor_empty_timeout(&file_data->submitted,
timeout)) {
retval = -ETIMEDOUT;
goto error;
}
}
retval = 0;
goto exit;
error:
usb_kill_anchored_urbs(&file_data->submitted);
exit:
usb_free_urb(urb);
spin_lock_irq(&file_data->err_lock);
if (!(flags & USBTMC_FLAG_ASYNC))
done = file_data->out_transfer_size;
if (!retval && file_data->out_status)
retval = file_data->out_status;
spin_unlock_irq(&file_data->err_lock);
*transferred = done;
dev_dbg(dev, "%s: done=%u, retval=%d, urbstat=%d\n",
__func__, done, retval, file_data->out_status);
return retval;
}
static ssize_t usbtmc_ioctl_generic_write(struct usbtmc_file_data *file_data,
void __user *arg)
{
struct usbtmc_message msg;
ssize_t retval = 0;
/* mutex already locked */
if (copy_from_user(&msg, arg, sizeof(struct usbtmc_message)))
return -EFAULT;
retval = usbtmc_generic_write(file_data, msg.message,
msg.transfer_size, &msg.transferred,
msg.flags);
if (put_user(msg.transferred,
&((struct usbtmc_message __user *)arg)->transferred))
return -EFAULT;
return retval;
}
/*
* Get the generic write result
*/
static ssize_t usbtmc_ioctl_write_result(struct usbtmc_file_data *file_data,
void __user *arg)
{
u32 transferred;
int retval;
spin_lock_irq(&file_data->err_lock);
transferred = file_data->out_transfer_size;
retval = file_data->out_status;
spin_unlock_irq(&file_data->err_lock);
if (put_user(transferred, (__u32 __user *)arg))
return -EFAULT;
return retval;
}
/*
* Sends a REQUEST_DEV_DEP_MSG_IN message on the Bulk-OUT endpoint.
* @transfer_size: number of bytes to request from the device.
*
* See the USBTMC specification, Table 4.
*
* Also updates bTag_last_write.
*/
static int send_request_dev_dep_msg_in(struct usbtmc_file_data *file_data,
u32 transfer_size)
{
struct usbtmc_device_data *data = file_data->data;
int retval;
u8 *buffer;
int actual;
buffer = kmalloc(USBTMC_HEADER_SIZE, GFP_KERNEL);
if (!buffer)
return -ENOMEM;
/* Setup IO buffer for REQUEST_DEV_DEP_MSG_IN message
* Refer to class specs for details
*/
buffer[0] = 2;
buffer[1] = data->bTag;
buffer[2] = ~data->bTag;
buffer[3] = 0; /* Reserved */
buffer[4] = transfer_size >> 0;
buffer[5] = transfer_size >> 8;
buffer[6] = transfer_size >> 16;
buffer[7] = transfer_size >> 24;
buffer[8] = file_data->term_char_enabled * 2;
/* Use term character? */
buffer[9] = file_data->term_char;
buffer[10] = 0; /* Reserved */
buffer[11] = 0; /* Reserved */
/* Send bulk URB */
retval = usb_bulk_msg(data->usb_dev,
usb_sndbulkpipe(data->usb_dev,
data->bulk_out),
buffer, USBTMC_HEADER_SIZE,
&actual, file_data->timeout);
/* Store bTag (in case we need to abort) */
data->bTag_last_write = data->bTag;
/* Increment bTag -- and increment again if zero */
data->bTag++;
if (!data->bTag)
data->bTag++;
kfree(buffer);
if (retval < 0)
dev_err(&data->intf->dev, "%s returned %d\n",
__func__, retval);
return retval;
}
static ssize_t usbtmc_read(struct file *filp, char __user *buf,
size_t count, loff_t *f_pos)
{
struct usbtmc_file_data *file_data;
struct usbtmc_device_data *data;
struct device *dev;
const u32 bufsize = USBTMC_BUFSIZE;
u32 n_characters;
u8 *buffer;
int actual;
u32 done = 0;
u32 remaining;
int retval;
/* Get pointer to private data structure */
file_data = filp->private_data;
data = file_data->data;
dev = &data->intf->dev;
buffer = kmalloc(bufsize, GFP_KERNEL);
if (!buffer)
return -ENOMEM;
mutex_lock(&data->io_mutex);
if (data->zombie) {
retval = -ENODEV;
goto exit;
}
if (count > INT_MAX)
count = INT_MAX;
dev_dbg(dev, "%s(count:%zu)\n", __func__, count);
retval = send_request_dev_dep_msg_in(file_data, count);
if (retval < 0) {
if (file_data->auto_abort)
usbtmc_ioctl_abort_bulk_out(data);
goto exit;
}
/* Loop until we have fetched everything we requested */
remaining = count;
actual = 0;
/* Send bulk URB */
retval = usb_bulk_msg(data->usb_dev,
usb_rcvbulkpipe(data->usb_dev,
data->bulk_in),
buffer, bufsize, &actual,
file_data->timeout);
dev_dbg(dev, "%s: bulk_msg retval(%u), actual(%d)\n",
__func__, retval, actual);
/* Store bTag (in case we need to abort) */
data->bTag_last_read = data->bTag;
if (retval < 0) {
if (file_data->auto_abort)
usbtmc_ioctl_abort_bulk_in(data);
goto exit;
}
/* Sanity checks for the header */
if (actual < USBTMC_HEADER_SIZE) {
dev_err(dev, "Device sent too small first packet: %u < %u\n",
actual, USBTMC_HEADER_SIZE);
if (file_data->auto_abort)
usbtmc_ioctl_abort_bulk_in(data);
goto exit;
}
if (buffer[0] != 2) {
dev_err(dev, "Device sent reply with wrong MsgID: %u != 2\n",
buffer[0]);
if (file_data->auto_abort)
usbtmc_ioctl_abort_bulk_in(data);
goto exit;
}
if (buffer[1] != data->bTag_last_write) {
dev_err(dev, "Device sent reply with wrong bTag: %u != %u\n",
buffer[1], data->bTag_last_write);
if (file_data->auto_abort)
usbtmc_ioctl_abort_bulk_in(data);
goto exit;
}
/* How many characters did the instrument send? */
n_characters = buffer[4] +
(buffer[5] << 8) +
(buffer[6] << 16) +
(buffer[7] << 24);
file_data->bmTransferAttributes = buffer[8];
dev_dbg(dev, "Bulk-IN header: N_characters(%u), bTransAttr(%u)\n",
n_characters, buffer[8]);
if (n_characters > remaining) {
dev_err(dev, "Device wants to return more data than requested: %u > %zu\n",
n_characters, count);
if (file_data->auto_abort)
usbtmc_ioctl_abort_bulk_in(data);
goto exit;
}
print_hex_dump_debug("usbtmc ", DUMP_PREFIX_NONE,
16, 1, buffer, actual, true);
remaining = n_characters;
/* Remove the USBTMC header */
actual -= USBTMC_HEADER_SIZE;
/* Remove padding if it exists */
if (actual > remaining)
actual = remaining;
remaining -= actual;
/* Copy buffer to user space */
if (copy_to_user(buf, &buffer[USBTMC_HEADER_SIZE], actual)) {
/* There must have been an addressing problem */
retval = -EFAULT;
goto exit;
}
if ((actual + USBTMC_HEADER_SIZE) == bufsize) {
retval = usbtmc_generic_read(file_data, buf + actual,
remaining,
&done,
USBTMC_FLAG_IGNORE_TRAILER);
if (retval < 0)
goto exit;
}
done += actual;
/* Update file position value */
*f_pos = *f_pos + done;
retval = done;
exit:
mutex_unlock(&data->io_mutex);
kfree(buffer);
return retval;
}
static ssize_t usbtmc_write(struct file *filp, const char __user *buf,
size_t count, loff_t *f_pos)
{
struct usbtmc_file_data *file_data;
struct usbtmc_device_data *data;
struct urb *urb = NULL;
ssize_t retval = 0;
u8 *buffer;
u32 remaining, done;
u32 transfersize, aligned, buflen;
file_data = filp->private_data;
data = file_data->data;
mutex_lock(&data->io_mutex);
if (data->zombie) {
retval = -ENODEV;
goto exit;
}
done = 0;
spin_lock_irq(&file_data->err_lock);
file_data->out_transfer_size = 0;
file_data->out_status = 0;
spin_unlock_irq(&file_data->err_lock);
if (!count)
goto exit;
if (down_trylock(&file_data->limit_write_sem)) {
/* previous calls were async */
retval = -EBUSY;
goto exit;
}
urb = usbtmc_create_urb();
if (!urb) {
retval = -ENOMEM;
up(&file_data->limit_write_sem);
goto exit;
}
buffer = urb->transfer_buffer;
buflen = urb->transfer_buffer_length;
if (count > INT_MAX) {
transfersize = INT_MAX;
buffer[8] = 0;
} else {
transfersize = count;
buffer[8] = file_data->eom_val;
}
/* Setup IO buffer for DEV_DEP_MSG_OUT message */
buffer[0] = 1;
buffer[1] = data->bTag;
buffer[2] = ~data->bTag;
buffer[3] = 0; /* Reserved */
buffer[4] = transfersize >> 0;
buffer[5] = transfersize >> 8;
buffer[6] = transfersize >> 16;
buffer[7] = transfersize >> 24;
/* buffer[8] is set above... */
buffer[9] = 0; /* Reserved */
buffer[10] = 0; /* Reserved */
buffer[11] = 0; /* Reserved */
remaining = transfersize;
if (transfersize + USBTMC_HEADER_SIZE > buflen) {
transfersize = buflen - USBTMC_HEADER_SIZE;
aligned = buflen;
} else {
aligned = (transfersize + (USBTMC_HEADER_SIZE + 3)) & ~3;
}
if (copy_from_user(&buffer[USBTMC_HEADER_SIZE], buf, transfersize)) {
retval = -EFAULT;
up(&file_data->limit_write_sem);
goto exit;
}
dev_dbg(&data->intf->dev, "%s(size:%u align:%u)\n", __func__,
(unsigned int)transfersize, (unsigned int)aligned);
print_hex_dump_debug("usbtmc ", DUMP_PREFIX_NONE,
16, 1, buffer, aligned, true);
usb_fill_bulk_urb(urb, data->usb_dev,
usb_sndbulkpipe(data->usb_dev, data->bulk_out),
urb->transfer_buffer, aligned,
usbtmc_write_bulk_cb, file_data);
usb_anchor_urb(urb, &file_data->submitted);
retval = usb_submit_urb(urb, GFP_KERNEL);
if (unlikely(retval)) {
usb_unanchor_urb(urb);
up(&file_data->limit_write_sem);
goto exit;
}
remaining -= transfersize;
data->bTag_last_write = data->bTag;
data->bTag++;
if (!data->bTag)
data->bTag++;
/* call generic_write even when remaining = 0 */
retval = usbtmc_generic_write(file_data, buf + transfersize, remaining,
&done, USBTMC_FLAG_APPEND);
/* truncate alignment bytes */
if (done > remaining)
done = remaining;
/*add size of first urb*/
done += transfersize;
if (retval < 0) {
usb_kill_anchored_urbs(&file_data->submitted);
dev_err(&data->intf->dev,
"Unable to send data, error %d\n", (int)retval);
if (file_data->auto_abort)
usbtmc_ioctl_abort_bulk_out(data);
goto exit;
}
retval = done;
exit:
usb_free_urb(urb);
mutex_unlock(&data->io_mutex);
return retval;
}
static int usbtmc_ioctl_clear(struct usbtmc_device_data *data)
{
struct device *dev;
u8 *buffer;
int rv;
int n;
int actual = 0;
dev = &data->intf->dev;
dev_dbg(dev, "Sending INITIATE_CLEAR request\n");
buffer = kmalloc(USBTMC_BUFSIZE, GFP_KERNEL);
if (!buffer)
return -ENOMEM;
rv = usb_control_msg(data->usb_dev,
usb_rcvctrlpipe(data->usb_dev, 0),
USBTMC_REQUEST_INITIATE_CLEAR,
USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
0, 0, buffer, 1, USB_CTRL_GET_TIMEOUT);
if (rv < 0) {
dev_err(dev, "usb_control_msg returned %d\n", rv);
goto exit;
}
dev_dbg(dev, "INITIATE_CLEAR returned %x\n", buffer[0]);
if (buffer[0] != USBTMC_STATUS_SUCCESS) {
dev_err(dev, "INITIATE_CLEAR returned %x\n", buffer[0]);
rv = -EPERM;
goto exit;
}
n = 0;
usbtmc_clear_check_status:
dev_dbg(dev, "Sending CHECK_CLEAR_STATUS request\n");
rv = usb_control_msg(data->usb_dev,
usb_rcvctrlpipe(data->usb_dev, 0),
USBTMC_REQUEST_CHECK_CLEAR_STATUS,
USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
0, 0, buffer, 2, USB_CTRL_GET_TIMEOUT);
if (rv < 0) {
dev_err(dev, "usb_control_msg returned %d\n", rv);
goto exit;
}
dev_dbg(dev, "CHECK_CLEAR_STATUS returned %x\n", buffer[0]);
if (buffer[0] == USBTMC_STATUS_SUCCESS)
goto usbtmc_clear_bulk_out_halt;
if (buffer[0] != USBTMC_STATUS_PENDING) {
dev_err(dev, "CHECK_CLEAR_STATUS returned %x\n", buffer[0]);
rv = -EPERM;
goto exit;
}
if ((buffer[1] & 1) != 0) {
do {
dev_dbg(dev, "Reading from bulk in EP\n");
actual = 0;
rv = usb_bulk_msg(data->usb_dev,
usb_rcvbulkpipe(data->usb_dev,
data->bulk_in),
buffer, USBTMC_BUFSIZE,
&actual, USB_CTRL_GET_TIMEOUT);
print_hex_dump_debug("usbtmc ", DUMP_PREFIX_NONE,
16, 1, buffer, actual, true);
n++;
if (rv < 0) {
dev_err(dev, "usb_control_msg returned %d\n",
rv);
goto exit;
}
} while ((actual == USBTMC_BUFSIZE) &&
(n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
} else {
/* do not stress device with subsequent requests */
msleep(50);
n++;
}
if (n >= USBTMC_MAX_READS_TO_CLEAR_BULK_IN) {
dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
rv = -EPERM;
goto exit;
}
goto usbtmc_clear_check_status;
usbtmc_clear_bulk_out_halt:
rv = usb_clear_halt(data->usb_dev,
usb_sndbulkpipe(data->usb_dev, data->bulk_out));
if (rv < 0) {
dev_err(dev, "usb_clear_halt returned %d\n", rv);
goto exit;
}
rv = 0;
exit:
kfree(buffer);
return rv;
}
static int usbtmc_ioctl_clear_out_halt(struct usbtmc_device_data *data)
{
int rv;
rv = usb_clear_halt(data->usb_dev,
usb_sndbulkpipe(data->usb_dev, data->bulk_out));
if (rv < 0)
dev_err(&data->usb_dev->dev, "%s returned %d\n", __func__, rv);
return rv;
}
static int usbtmc_ioctl_clear_in_halt(struct usbtmc_device_data *data)
{
int rv;
rv = usb_clear_halt(data->usb_dev,
usb_rcvbulkpipe(data->usb_dev, data->bulk_in));
if (rv < 0)
dev_err(&data->usb_dev->dev, "%s returned %d\n", __func__, rv);
return rv;
}
static int usbtmc_ioctl_cancel_io(struct usbtmc_file_data *file_data)
{
spin_lock_irq(&file_data->err_lock);
file_data->in_status = -ECANCELED;
file_data->out_status = -ECANCELED;
spin_unlock_irq(&file_data->err_lock);
usb_kill_anchored_urbs(&file_data->submitted);
return 0;
}
static int usbtmc_ioctl_cleanup_io(struct usbtmc_file_data *file_data)
{
usb_kill_anchored_urbs(&file_data->submitted);
usb_scuttle_anchored_urbs(&file_data->in_anchor);
spin_lock_irq(&file_data->err_lock);
file_data->in_status = 0;
file_data->in_transfer_size = 0;
file_data->out_status = 0;
file_data->out_transfer_size = 0;
spin_unlock_irq(&file_data->err_lock);
file_data->in_urbs_used = 0;
return 0;
}
static int get_capabilities(struct usbtmc_device_data *data)
{
struct device *dev = &data->usb_dev->dev;
char *buffer;
int rv = 0;
buffer = kmalloc(0x18, GFP_KERNEL);
if (!buffer)
return -ENOMEM;
rv = usb_control_msg(data->usb_dev, usb_rcvctrlpipe(data->usb_dev, 0),
USBTMC_REQUEST_GET_CAPABILITIES,
USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
0, 0, buffer, 0x18, USB_CTRL_GET_TIMEOUT);
if (rv < 0) {
dev_err(dev, "usb_control_msg returned %d\n", rv);
goto err_out;
}
dev_dbg(dev, "GET_CAPABILITIES returned %x\n", buffer[0]);
if (buffer[0] != USBTMC_STATUS_SUCCESS) {
dev_err(dev, "GET_CAPABILITIES returned %x\n", buffer[0]);
rv = -EPERM;
goto err_out;
}
dev_dbg(dev, "Interface capabilities are %x\n", buffer[4]);
dev_dbg(dev, "Device capabilities are %x\n", buffer[5]);
dev_dbg(dev, "USB488 interface capabilities are %x\n", buffer[14]);
dev_dbg(dev, "USB488 device capabilities are %x\n", buffer[15]);
data->capabilities.interface_capabilities = buffer[4];
data->capabilities.device_capabilities = buffer[5];
data->capabilities.usb488_interface_capabilities = buffer[14];
data->capabilities.usb488_device_capabilities = buffer[15];
data->usb488_caps = (buffer[14] & 0x07) | ((buffer[15] & 0x0f) << 4);
rv = 0;
err_out:
kfree(buffer);
return rv;
}
#define capability_attribute(name) \
static ssize_t name##_show(struct device *dev, \
struct device_attribute *attr, char *buf) \
{ \
struct usb_interface *intf = to_usb_interface(dev); \
struct usbtmc_device_data *data = usb_get_intfdata(intf); \
\
return sprintf(buf, "%d\n", data->capabilities.name); \
} \
static DEVICE_ATTR_RO(name)
capability_attribute(interface_capabilities);
capability_attribute(device_capabilities);
capability_attribute(usb488_interface_capabilities);
capability_attribute(usb488_device_capabilities);
static struct attribute *usbtmc_attrs[] = {
&dev_attr_interface_capabilities.attr,
&dev_attr_device_capabilities.attr,
&dev_attr_usb488_interface_capabilities.attr,
&dev_attr_usb488_device_capabilities.attr,
NULL,
};
ATTRIBUTE_GROUPS(usbtmc);
static int usbtmc_ioctl_indicator_pulse(struct usbtmc_device_data *data)
{
struct device *dev;
u8 *buffer;
int rv;
dev = &data->intf->dev;
buffer = kmalloc(2, GFP_KERNEL);
if (!buffer)
return -ENOMEM;
rv = usb_control_msg(data->usb_dev,
usb_rcvctrlpipe(data->usb_dev, 0),
USBTMC_REQUEST_INDICATOR_PULSE,
USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
0, 0, buffer, 0x01, USB_CTRL_GET_TIMEOUT);
if (rv < 0) {
dev_err(dev, "usb_control_msg returned %d\n", rv);
goto exit;
}
dev_dbg(dev, "INDICATOR_PULSE returned %x\n", buffer[0]);
if (buffer[0] != USBTMC_STATUS_SUCCESS) {
dev_err(dev, "INDICATOR_PULSE returned %x\n", buffer[0]);
rv = -EPERM;
goto exit;
}
rv = 0;
exit:
kfree(buffer);
return rv;
}
static int usbtmc_ioctl_request(struct usbtmc_device_data *data,
void __user *arg)
{
struct device *dev = &data->intf->dev;
struct usbtmc_ctrlrequest request;
u8 *buffer = NULL;
int rv;
unsigned int is_in, pipe;
unsigned long res;
res = copy_from_user(&request, arg, sizeof(struct usbtmc_ctrlrequest));
if (res)
return -EFAULT;
if (request.req.wLength > USBTMC_BUFSIZE)
return -EMSGSIZE;
if (request.req.wLength == 0) /* Length-0 requests are never IN */
request.req.bRequestType &= ~USB_DIR_IN;
is_in = request.req.bRequestType & USB_DIR_IN;
if (request.req.wLength) {
buffer = kmalloc(request.req.wLength, GFP_KERNEL);
if (!buffer)
return -ENOMEM;
if (!is_in) {
/* Send control data to device */
res = copy_from_user(buffer, request.data,
request.req.wLength);
if (res) {
rv = -EFAULT;
goto exit;
}
}
}
if (is_in)
pipe = usb_rcvctrlpipe(data->usb_dev, 0);
else
pipe = usb_sndctrlpipe(data->usb_dev, 0);
rv = usb_control_msg(data->usb_dev,
pipe,
request.req.bRequest,
request.req.bRequestType,
request.req.wValue,
request.req.wIndex,
buffer, request.req.wLength, USB_CTRL_GET_TIMEOUT);
if (rv < 0) {
dev_err(dev, "%s failed %d\n", __func__, rv);
goto exit;
}
if (rv && is_in) {
/* Read control data from device */
res = copy_to_user(request.data, buffer, rv);
if (res)
rv = -EFAULT;
}
exit:
kfree(buffer);
return rv;
}
/*
* Get the usb timeout value
*/
static int usbtmc_ioctl_get_timeout(struct usbtmc_file_data *file_data,
void __user *arg)
{
u32 timeout;
timeout = file_data->timeout;
return put_user(timeout, (__u32 __user *)arg);
}
/*
* Set the usb timeout value
*/
static int usbtmc_ioctl_set_timeout(struct usbtmc_file_data *file_data,
void __user *arg)
{
u32 timeout;
if (get_user(timeout, (__u32 __user *)arg))
return -EFAULT;
/* Note that timeout = 0 means
* MAX_SCHEDULE_TIMEOUT in usb_control_msg
*/
if (timeout < USBTMC_MIN_TIMEOUT)
return -EINVAL;
file_data->timeout = timeout;
return 0;
}
/*
* enables/disables sending EOM on write
*/
static int usbtmc_ioctl_eom_enable(struct usbtmc_file_data *file_data,
void __user *arg)
{
u8 eom_enable;
if (copy_from_user(&eom_enable, arg, sizeof(eom_enable)))
return -EFAULT;
if (eom_enable > 1)
return -EINVAL;
file_data->eom_val = eom_enable;
return 0;
}
/*
* Configure termination character for read()
*/
static int usbtmc_ioctl_config_termc(struct usbtmc_file_data *file_data,
void __user *arg)
{
struct usbtmc_termchar termc;
if (copy_from_user(&termc, arg, sizeof(termc)))
return -EFAULT;
if ((termc.term_char_enabled > 1) ||
(termc.term_char_enabled &&
!(file_data->data->capabilities.device_capabilities & 1)))
return -EINVAL;
file_data->term_char = termc.term_char;
file_data->term_char_enabled = termc.term_char_enabled;
return 0;
}
static long usbtmc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
struct usbtmc_file_data *file_data;
struct usbtmc_device_data *data;
int retval = -EBADRQC;
__u8 tmp_byte;
file_data = file->private_data;
data = file_data->data;
mutex_lock(&data->io_mutex);
if (data->zombie) {
retval = -ENODEV;
goto skip_io_on_zombie;
}
switch (cmd) {
case USBTMC_IOCTL_CLEAR_OUT_HALT:
retval = usbtmc_ioctl_clear_out_halt(data);
break;
case USBTMC_IOCTL_CLEAR_IN_HALT:
retval = usbtmc_ioctl_clear_in_halt(data);
break;
case USBTMC_IOCTL_INDICATOR_PULSE:
retval = usbtmc_ioctl_indicator_pulse(data);
break;
case USBTMC_IOCTL_CLEAR:
retval = usbtmc_ioctl_clear(data);
break;
case USBTMC_IOCTL_ABORT_BULK_OUT:
retval = usbtmc_ioctl_abort_bulk_out(data);
break;
case USBTMC_IOCTL_ABORT_BULK_IN:
retval = usbtmc_ioctl_abort_bulk_in(data);
break;
case USBTMC_IOCTL_CTRL_REQUEST:
retval = usbtmc_ioctl_request(data, (void __user *)arg);
break;
case USBTMC_IOCTL_GET_TIMEOUT:
retval = usbtmc_ioctl_get_timeout(file_data,
(void __user *)arg);
break;
case USBTMC_IOCTL_SET_TIMEOUT:
retval = usbtmc_ioctl_set_timeout(file_data,
(void __user *)arg);
break;
case USBTMC_IOCTL_EOM_ENABLE:
retval = usbtmc_ioctl_eom_enable(file_data,
(void __user *)arg);
break;
case USBTMC_IOCTL_CONFIG_TERMCHAR:
retval = usbtmc_ioctl_config_termc(file_data,
(void __user *)arg);
break;
case USBTMC_IOCTL_WRITE:
retval = usbtmc_ioctl_generic_write(file_data,
(void __user *)arg);
break;
case USBTMC_IOCTL_READ:
retval = usbtmc_ioctl_generic_read(file_data,
(void __user *)arg);
break;
case USBTMC_IOCTL_WRITE_RESULT:
retval = usbtmc_ioctl_write_result(file_data,
(void __user *)arg);
break;
case USBTMC_IOCTL_API_VERSION:
retval = put_user(USBTMC_API_VERSION,
(__u32 __user *)arg);
break;
case USBTMC488_IOCTL_GET_CAPS:
retval = put_user(data->usb488_caps,
(unsigned char __user *)arg);
break;
case USBTMC488_IOCTL_READ_STB:
retval = usbtmc488_ioctl_read_stb(file_data,
(void __user *)arg);
break;
case USBTMC488_IOCTL_REN_CONTROL:
retval = usbtmc488_ioctl_simple(data, (void __user *)arg,
USBTMC488_REQUEST_REN_CONTROL);
break;
case USBTMC488_IOCTL_GOTO_LOCAL:
retval = usbtmc488_ioctl_simple(data, (void __user *)arg,
USBTMC488_REQUEST_GOTO_LOCAL);
break;
case USBTMC488_IOCTL_LOCAL_LOCKOUT:
retval = usbtmc488_ioctl_simple(data, (void __user *)arg,
USBTMC488_REQUEST_LOCAL_LOCKOUT);
break;
case USBTMC488_IOCTL_TRIGGER:
retval = usbtmc488_ioctl_trigger(file_data);
break;
case USBTMC488_IOCTL_WAIT_SRQ:
retval = usbtmc488_ioctl_wait_srq(file_data,
(__u32 __user *)arg);
break;
case USBTMC_IOCTL_MSG_IN_ATTR:
retval = put_user(file_data->bmTransferAttributes,
(__u8 __user *)arg);
break;
case USBTMC_IOCTL_AUTO_ABORT:
retval = get_user(tmp_byte, (unsigned char __user *)arg);
if (retval == 0)
file_data->auto_abort = !!tmp_byte;
break;
case USBTMC_IOCTL_GET_STB:
retval = usbtmc_get_stb(file_data, &tmp_byte);
if (retval > 0)
retval = put_user(tmp_byte, (__u8 __user *)arg);
break;
case USBTMC_IOCTL_GET_SRQ_STB:
retval = usbtmc_ioctl_get_srq_stb(file_data,
(void __user *)arg);
break;
case USBTMC_IOCTL_CANCEL_IO:
retval = usbtmc_ioctl_cancel_io(file_data);
break;
case USBTMC_IOCTL_CLEANUP_IO:
retval = usbtmc_ioctl_cleanup_io(file_data);
break;
}
skip_io_on_zombie:
mutex_unlock(&data->io_mutex);
return retval;
}
static int usbtmc_fasync(int fd, struct file *file, int on)
{
struct usbtmc_file_data *file_data = file->private_data;
return fasync_helper(fd, file, on, &file_data->data->fasync);
}
static __poll_t usbtmc_poll(struct file *file, poll_table *wait)
{
struct usbtmc_file_data *file_data = file->private_data;
struct usbtmc_device_data *data = file_data->data;
__poll_t mask;
mutex_lock(&data->io_mutex);
if (data->zombie) {
mask = EPOLLHUP | EPOLLERR;
goto no_poll;
}
poll_wait(file, &data->waitq, wait);
/* Note that EPOLLPRI is now assigned to SRQ, and
* EPOLLIN|EPOLLRDNORM to normal read data.
*/
mask = 0;
if (atomic_read(&file_data->srq_asserted))
mask |= EPOLLPRI;
/* Note that the anchor submitted includes all urbs for BULK IN
* and OUT. So EPOLLOUT is signaled when BULK OUT is empty and
* all BULK IN urbs are completed and moved to in_anchor.
*/
if (usb_anchor_empty(&file_data->submitted))
mask |= (EPOLLOUT | EPOLLWRNORM);
if (!usb_anchor_empty(&file_data->in_anchor))
mask |= (EPOLLIN | EPOLLRDNORM);
spin_lock_irq(&file_data->err_lock);
if (file_data->in_status || file_data->out_status)
mask |= EPOLLERR;
spin_unlock_irq(&file_data->err_lock);
dev_dbg(&data->intf->dev, "poll mask = %x\n", mask);
no_poll:
mutex_unlock(&data->io_mutex);
return mask;
}
static const struct file_operations fops = {
.owner = THIS_MODULE,
.read = usbtmc_read,
.write = usbtmc_write,
.open = usbtmc_open,
.release = usbtmc_release,
.flush = usbtmc_flush,
.unlocked_ioctl = usbtmc_ioctl,
.compat_ioctl = compat_ptr_ioctl,
.fasync = usbtmc_fasync,
.poll = usbtmc_poll,
.llseek = default_llseek,
};
static struct usb_class_driver usbtmc_class = {
.name = "usbtmc%d",
.fops = &fops,
.minor_base = USBTMC_MINOR_BASE,
};
static void usbtmc_interrupt(struct urb *urb)
{
struct usbtmc_device_data *data = urb->context;
struct device *dev = &data->intf->dev;
int status = urb->status;
int rv;
dev_dbg(&data->intf->dev, "int status: %d len %d\n",
status, urb->actual_length);
switch (status) {
case 0: /* SUCCESS */
/* check for valid STB notification */
if (data->iin_buffer[0] > 0x81) {
data->bNotify1 = data->iin_buffer[0];
data->bNotify2 = data->iin_buffer[1];
atomic_set(&data->iin_data_valid, 1);
wake_up_interruptible(&data->waitq);
goto exit;
}
/* check for SRQ notification */
if (data->iin_buffer[0] == 0x81) {
unsigned long flags;
struct list_head *elem;
if (data->fasync)
kill_fasync(&data->fasync,
SIGIO, POLL_PRI);
spin_lock_irqsave(&data->dev_lock, flags);
list_for_each(elem, &data->file_list) {
struct usbtmc_file_data *file_data;
file_data = list_entry(elem,
struct usbtmc_file_data,
file_elem);
file_data->srq_byte = data->iin_buffer[1];
atomic_set(&file_data->srq_asserted, 1);
}
spin_unlock_irqrestore(&data->dev_lock, flags);
dev_dbg(dev, "srq received bTag %x stb %x\n",
(unsigned int)data->iin_buffer[0],
(unsigned int)data->iin_buffer[1]);
wake_up_interruptible_all(&data->waitq);
goto exit;
}
dev_warn(dev, "invalid notification: %x\n",
data->iin_buffer[0]);
break;
case -EOVERFLOW:
dev_err(dev, "overflow with length %d, actual length is %d\n",
data->iin_wMaxPacketSize, urb->actual_length);
fallthrough;
default:
/* urb terminated, clean up */
dev_dbg(dev, "urb terminated, status: %d\n", status);
return;
}
exit:
rv = usb_submit_urb(urb, GFP_ATOMIC);
if (rv)
dev_err(dev, "usb_submit_urb failed: %d\n", rv);
}
static void usbtmc_free_int(struct usbtmc_device_data *data)
{
if (!data->iin_ep_present || !data->iin_urb)
return;
usb_kill_urb(data->iin_urb);
kfree(data->iin_buffer);
data->iin_buffer = NULL;
usb_free_urb(data->iin_urb);
data->iin_urb = NULL;
kref_put(&data->kref, usbtmc_delete);
}
static int usbtmc_probe(struct usb_interface *intf,
const struct usb_device_id *id)
{
struct usbtmc_device_data *data;
struct usb_host_interface *iface_desc;
struct usb_endpoint_descriptor *bulk_in, *bulk_out, *int_in;
int retcode;
dev_dbg(&intf->dev, "%s called\n", __func__);
data = kzalloc(sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;
data->intf = intf;
data->id = id;
data->usb_dev = usb_get_dev(interface_to_usbdev(intf));
usb_set_intfdata(intf, data);
kref_init(&data->kref);
mutex_init(&data->io_mutex);
init_waitqueue_head(&data->waitq);
atomic_set(&data->iin_data_valid, 0);
INIT_LIST_HEAD(&data->file_list);
spin_lock_init(&data->dev_lock);
data->zombie = 0;
/* Initialize USBTMC bTag and other fields */
data->bTag = 1;
/* 2 <= bTag <= 127 USBTMC-USB488 subclass specification 4.3.1 */
data->iin_bTag = 2;
/* USBTMC devices have only one setting, so use that */
iface_desc = data->intf->cur_altsetting;
data->ifnum = iface_desc->desc.bInterfaceNumber;
/* Find bulk endpoints */
retcode = usb_find_common_endpoints(iface_desc,
&bulk_in, &bulk_out, NULL, NULL);
if (retcode) {
dev_err(&intf->dev, "bulk endpoints not found\n");
goto err_put;
}
retcode = -EINVAL;
data->bulk_in = bulk_in->bEndpointAddress;
data->wMaxPacketSize = usb_endpoint_maxp(bulk_in);
if (!data->wMaxPacketSize)
goto err_put;
dev_dbg(&intf->dev, "Found bulk in endpoint at %u\n", data->bulk_in);
data->bulk_out = bulk_out->bEndpointAddress;
dev_dbg(&intf->dev, "Found Bulk out endpoint at %u\n", data->bulk_out);
/* Find int endpoint */
retcode = usb_find_int_in_endpoint(iface_desc, &int_in);
if (!retcode) {
data->iin_ep_present = 1;
data->iin_ep = int_in->bEndpointAddress;
data->iin_wMaxPacketSize = usb_endpoint_maxp(int_in);
data->iin_interval = int_in->bInterval;
dev_dbg(&intf->dev, "Found Int in endpoint at %u\n",
data->iin_ep);
}
retcode = get_capabilities(data);
if (retcode)
dev_err(&intf->dev, "can't read capabilities\n");
if (data->iin_ep_present) {
/* allocate int urb */
data->iin_urb = usb_alloc_urb(0, GFP_KERNEL);
if (!data->iin_urb) {
retcode = -ENOMEM;
goto error_register;
}
/* Protect interrupt in endpoint data until iin_urb is freed */
kref_get(&data->kref);
/* allocate buffer for interrupt in */
data->iin_buffer = kmalloc(data->iin_wMaxPacketSize,
GFP_KERNEL);
if (!data->iin_buffer) {
retcode = -ENOMEM;
goto error_register;
}
/* fill interrupt urb */
usb_fill_int_urb(data->iin_urb, data->usb_dev,
usb_rcvintpipe(data->usb_dev, data->iin_ep),
data->iin_buffer, data->iin_wMaxPacketSize,
usbtmc_interrupt,
data, data->iin_interval);
retcode = usb_submit_urb(data->iin_urb, GFP_KERNEL);
if (retcode) {
dev_err(&intf->dev, "Failed to submit iin_urb\n");
goto error_register;
}
}
retcode = usb_register_dev(intf, &usbtmc_class);
if (retcode) {
dev_err(&intf->dev, "Not able to get a minor (base %u, slice default): %d\n",
USBTMC_MINOR_BASE,
retcode);
goto error_register;
}
dev_dbg(&intf->dev, "Using minor number %d\n", intf->minor);
return 0;
error_register:
usbtmc_free_int(data);
err_put:
kref_put(&data->kref, usbtmc_delete);
return retcode;
}
static void usbtmc_disconnect(struct usb_interface *intf)
{
struct usbtmc_device_data *data = usb_get_intfdata(intf);
struct list_head *elem;
usb_deregister_dev(intf, &usbtmc_class);
mutex_lock(&data->io_mutex);
data->zombie = 1;
wake_up_interruptible_all(&data->waitq);
list_for_each(elem, &data->file_list) {
struct usbtmc_file_data *file_data;
file_data = list_entry(elem,
struct usbtmc_file_data,
file_elem);
usb_kill_anchored_urbs(&file_data->submitted);
usb_scuttle_anchored_urbs(&file_data->in_anchor);
}
mutex_unlock(&data->io_mutex);
usbtmc_free_int(data);
kref_put(&data->kref, usbtmc_delete);
}
static void usbtmc_draw_down(struct usbtmc_file_data *file_data)
{
int time;
time = usb_wait_anchor_empty_timeout(&file_data->submitted, 1000);
if (!time)
usb_kill_anchored_urbs(&file_data->submitted);
usb_scuttle_anchored_urbs(&file_data->in_anchor);
}
static int usbtmc_suspend(struct usb_interface *intf, pm_message_t message)
{
struct usbtmc_device_data *data = usb_get_intfdata(intf);
struct list_head *elem;
if (!data)
return 0;
mutex_lock(&data->io_mutex);
list_for_each(elem, &data->file_list) {
struct usbtmc_file_data *file_data;
file_data = list_entry(elem,
struct usbtmc_file_data,
file_elem);
usbtmc_draw_down(file_data);
}
if (data->iin_ep_present && data->iin_urb)
usb_kill_urb(data->iin_urb);
mutex_unlock(&data->io_mutex);
return 0;
}
static int usbtmc_resume(struct usb_interface *intf)
{
struct usbtmc_device_data *data = usb_get_intfdata(intf);
int retcode = 0;
if (data->iin_ep_present && data->iin_urb)
retcode = usb_submit_urb(data->iin_urb, GFP_KERNEL);
if (retcode)
dev_err(&intf->dev, "Failed to submit iin_urb\n");
return retcode;
}
static int usbtmc_pre_reset(struct usb_interface *intf)
{
struct usbtmc_device_data *data = usb_get_intfdata(intf);
struct list_head *elem;
if (!data)
return 0;
mutex_lock(&data->io_mutex);
list_for_each(elem, &data->file_list) {
struct usbtmc_file_data *file_data;
file_data = list_entry(elem,
struct usbtmc_file_data,
file_elem);
usbtmc_ioctl_cancel_io(file_data);
}
return 0;
}
static int usbtmc_post_reset(struct usb_interface *intf)
{
struct usbtmc_device_data *data = usb_get_intfdata(intf);
mutex_unlock(&data->io_mutex);
return 0;
}
static struct usb_driver usbtmc_driver = {
.name = "usbtmc",
.id_table = usbtmc_devices,
.probe = usbtmc_probe,
.disconnect = usbtmc_disconnect,
.suspend = usbtmc_suspend,
.resume = usbtmc_resume,
.pre_reset = usbtmc_pre_reset,
.post_reset = usbtmc_post_reset,
.dev_groups = usbtmc_groups,
};
module_usb_driver(usbtmc_driver);
MODULE_LICENSE("GPL");