// SPDX-License-Identifier: GPL-2.0
|
/*
|
* cdc-wdm.c
|
*
|
* This driver supports USB CDC WCM Device Management.
|
*
|
* Copyright (c) 2007-2009 Oliver Neukum
|
*
|
* Some code taken from cdc-acm.c
|
*
|
* Released under the GPLv2.
|
*
|
* Many thanks to Carl Nordbeck
|
*/
|
#include <linux/kernel.h>
|
#include <linux/errno.h>
|
#include <linux/ioctl.h>
|
#include <linux/slab.h>
|
#include <linux/module.h>
|
#include <linux/mutex.h>
|
#include <linux/uaccess.h>
|
#include <linux/bitops.h>
|
#include <linux/poll.h>
|
#include <linux/usb.h>
|
#include <linux/usb/cdc.h>
|
#include <asm/byteorder.h>
|
#include <asm/unaligned.h>
|
#include <linux/usb/cdc-wdm.h>
|
|
#define DRIVER_AUTHOR "Oliver Neukum"
|
#define DRIVER_DESC "USB Abstract Control Model driver for USB WCM Device Management"
|
|
static const struct usb_device_id wdm_ids[] = {
|
{
|
.match_flags = USB_DEVICE_ID_MATCH_INT_CLASS |
|
USB_DEVICE_ID_MATCH_INT_SUBCLASS,
|
.bInterfaceClass = USB_CLASS_COMM,
|
.bInterfaceSubClass = USB_CDC_SUBCLASS_DMM
|
},
|
{ }
|
};
|
|
MODULE_DEVICE_TABLE (usb, wdm_ids);
|
|
#define WDM_MINOR_BASE 176
|
|
|
#define WDM_IN_USE 1
|
#define WDM_DISCONNECTING 2
|
#define WDM_RESULT 3
|
#define WDM_READ 4
|
#define WDM_INT_STALL 5
|
#define WDM_POLL_RUNNING 6
|
#define WDM_RESPONDING 7
|
#define WDM_SUSPENDING 8
|
#define WDM_RESETTING 9
|
#define WDM_OVERFLOW 10
|
|
#define WDM_MAX 16
|
|
/* we cannot wait forever at flush() */
|
#define WDM_FLUSH_TIMEOUT (30 * HZ)
|
|
/* CDC-WMC r1.1 requires wMaxCommand to be "at least 256 decimal (0x100)" */
|
#define WDM_DEFAULT_BUFSIZE 256
|
|
static DEFINE_MUTEX(wdm_mutex);
|
static DEFINE_SPINLOCK(wdm_device_list_lock);
|
static LIST_HEAD(wdm_device_list);
|
|
/* --- method tables --- */
|
|
struct wdm_device {
|
u8 *inbuf; /* buffer for response */
|
u8 *outbuf; /* buffer for command */
|
u8 *sbuf; /* buffer for status */
|
u8 *ubuf; /* buffer for copy to user space */
|
|
struct urb *command;
|
struct urb *response;
|
struct urb *validity;
|
struct usb_interface *intf;
|
struct usb_ctrlrequest *orq;
|
struct usb_ctrlrequest *irq;
|
spinlock_t iuspin;
|
|
unsigned long flags;
|
u16 bufsize;
|
u16 wMaxCommand;
|
u16 wMaxPacketSize;
|
__le16 inum;
|
int reslength;
|
int length;
|
int read;
|
int count;
|
dma_addr_t shandle;
|
dma_addr_t ihandle;
|
struct mutex wlock;
|
struct mutex rlock;
|
wait_queue_head_t wait;
|
struct work_struct rxwork;
|
struct work_struct service_outs_intr;
|
int werr;
|
int rerr;
|
int resp_count;
|
|
struct list_head device_list;
|
int (*manage_power)(struct usb_interface *, int);
|
};
|
|
static struct usb_driver wdm_driver;
|
|
/* return intfdata if we own the interface, else look up intf in the list */
|
static struct wdm_device *wdm_find_device(struct usb_interface *intf)
|
{
|
struct wdm_device *desc;
|
|
spin_lock(&wdm_device_list_lock);
|
list_for_each_entry(desc, &wdm_device_list, device_list)
|
if (desc->intf == intf)
|
goto found;
|
desc = NULL;
|
found:
|
spin_unlock(&wdm_device_list_lock);
|
|
return desc;
|
}
|
|
static struct wdm_device *wdm_find_device_by_minor(int minor)
|
{
|
struct wdm_device *desc;
|
|
spin_lock(&wdm_device_list_lock);
|
list_for_each_entry(desc, &wdm_device_list, device_list)
|
if (desc->intf->minor == minor)
|
goto found;
|
desc = NULL;
|
found:
|
spin_unlock(&wdm_device_list_lock);
|
|
return desc;
|
}
|
|
/* --- callbacks --- */
|
static void wdm_out_callback(struct urb *urb)
|
{
|
struct wdm_device *desc;
|
unsigned long flags;
|
|
desc = urb->context;
|
spin_lock_irqsave(&desc->iuspin, flags);
|
desc->werr = urb->status;
|
spin_unlock_irqrestore(&desc->iuspin, flags);
|
kfree(desc->outbuf);
|
desc->outbuf = NULL;
|
clear_bit(WDM_IN_USE, &desc->flags);
|
wake_up_all(&desc->wait);
|
}
|
|
static void wdm_in_callback(struct urb *urb)
|
{
|
unsigned long flags;
|
struct wdm_device *desc = urb->context;
|
int status = urb->status;
|
int length = urb->actual_length;
|
|
spin_lock_irqsave(&desc->iuspin, flags);
|
clear_bit(WDM_RESPONDING, &desc->flags);
|
|
if (status) {
|
switch (status) {
|
case -ENOENT:
|
dev_dbg(&desc->intf->dev,
|
"nonzero urb status received: -ENOENT\n");
|
goto skip_error;
|
case -ECONNRESET:
|
dev_dbg(&desc->intf->dev,
|
"nonzero urb status received: -ECONNRESET\n");
|
goto skip_error;
|
case -ESHUTDOWN:
|
dev_dbg(&desc->intf->dev,
|
"nonzero urb status received: -ESHUTDOWN\n");
|
goto skip_error;
|
case -EPIPE:
|
dev_err(&desc->intf->dev,
|
"nonzero urb status received: -EPIPE\n");
|
break;
|
default:
|
dev_err(&desc->intf->dev,
|
"Unexpected error %d\n", status);
|
break;
|
}
|
}
|
|
/*
|
* only set a new error if there is no previous error.
|
* Errors are only cleared during read/open
|
* Avoid propagating -EPIPE (stall) to userspace since it is
|
* better handled as an empty read
|
*/
|
if (desc->rerr == 0 && status != -EPIPE)
|
desc->rerr = status;
|
|
if (length + desc->length > desc->wMaxCommand) {
|
/* The buffer would overflow */
|
set_bit(WDM_OVERFLOW, &desc->flags);
|
} else {
|
/* we may already be in overflow */
|
if (!test_bit(WDM_OVERFLOW, &desc->flags)) {
|
memmove(desc->ubuf + desc->length, desc->inbuf, length);
|
desc->length += length;
|
desc->reslength = length;
|
}
|
}
|
skip_error:
|
|
if (desc->rerr) {
|
/*
|
* Since there was an error, userspace may decide to not read
|
* any data after poll'ing.
|
* We should respond to further attempts from the device to send
|
* data, so that we can get unstuck.
|
*/
|
schedule_work(&desc->service_outs_intr);
|
} else {
|
set_bit(WDM_READ, &desc->flags);
|
wake_up(&desc->wait);
|
}
|
spin_unlock_irqrestore(&desc->iuspin, flags);
|
}
|
|
static void wdm_int_callback(struct urb *urb)
|
{
|
unsigned long flags;
|
int rv = 0;
|
int responding;
|
int status = urb->status;
|
struct wdm_device *desc;
|
struct usb_cdc_notification *dr;
|
|
desc = urb->context;
|
dr = (struct usb_cdc_notification *)desc->sbuf;
|
|
if (status) {
|
switch (status) {
|
case -ESHUTDOWN:
|
case -ENOENT:
|
case -ECONNRESET:
|
return; /* unplug */
|
case -EPIPE:
|
set_bit(WDM_INT_STALL, &desc->flags);
|
dev_err(&desc->intf->dev, "Stall on int endpoint\n");
|
goto sw; /* halt is cleared in work */
|
default:
|
dev_err(&desc->intf->dev,
|
"nonzero urb status received: %d\n", status);
|
break;
|
}
|
}
|
|
if (urb->actual_length < sizeof(struct usb_cdc_notification)) {
|
dev_err(&desc->intf->dev, "wdm_int_callback - %d bytes\n",
|
urb->actual_length);
|
goto exit;
|
}
|
|
switch (dr->bNotificationType) {
|
case USB_CDC_NOTIFY_RESPONSE_AVAILABLE:
|
dev_dbg(&desc->intf->dev,
|
"NOTIFY_RESPONSE_AVAILABLE received: index %d len %d\n",
|
le16_to_cpu(dr->wIndex), le16_to_cpu(dr->wLength));
|
break;
|
|
case USB_CDC_NOTIFY_NETWORK_CONNECTION:
|
|
dev_dbg(&desc->intf->dev,
|
"NOTIFY_NETWORK_CONNECTION %s network\n",
|
dr->wValue ? "connected to" : "disconnected from");
|
goto exit;
|
case USB_CDC_NOTIFY_SPEED_CHANGE:
|
dev_dbg(&desc->intf->dev, "SPEED_CHANGE received (len %u)\n",
|
urb->actual_length);
|
goto exit;
|
default:
|
clear_bit(WDM_POLL_RUNNING, &desc->flags);
|
dev_err(&desc->intf->dev,
|
"unknown notification %d received: index %d len %d\n",
|
dr->bNotificationType,
|
le16_to_cpu(dr->wIndex),
|
le16_to_cpu(dr->wLength));
|
goto exit;
|
}
|
|
spin_lock_irqsave(&desc->iuspin, flags);
|
responding = test_and_set_bit(WDM_RESPONDING, &desc->flags);
|
if (!desc->resp_count++ && !responding
|
&& !test_bit(WDM_DISCONNECTING, &desc->flags)
|
&& !test_bit(WDM_SUSPENDING, &desc->flags)) {
|
rv = usb_submit_urb(desc->response, GFP_ATOMIC);
|
dev_dbg(&desc->intf->dev, "submit response URB %d\n", rv);
|
}
|
spin_unlock_irqrestore(&desc->iuspin, flags);
|
if (rv < 0) {
|
clear_bit(WDM_RESPONDING, &desc->flags);
|
if (rv == -EPERM)
|
return;
|
if (rv == -ENOMEM) {
|
sw:
|
rv = schedule_work(&desc->rxwork);
|
if (rv)
|
dev_err(&desc->intf->dev,
|
"Cannot schedule work\n");
|
}
|
}
|
exit:
|
rv = usb_submit_urb(urb, GFP_ATOMIC);
|
if (rv)
|
dev_err(&desc->intf->dev,
|
"%s - usb_submit_urb failed with result %d\n",
|
__func__, rv);
|
|
}
|
|
static void poison_urbs(struct wdm_device *desc)
|
{
|
/* the order here is essential */
|
usb_poison_urb(desc->command);
|
usb_poison_urb(desc->validity);
|
usb_poison_urb(desc->response);
|
}
|
|
static void unpoison_urbs(struct wdm_device *desc)
|
{
|
/*
|
* the order here is not essential
|
* it is symmetrical just to be nice
|
*/
|
usb_unpoison_urb(desc->response);
|
usb_unpoison_urb(desc->validity);
|
usb_unpoison_urb(desc->command);
|
}
|
|
static void free_urbs(struct wdm_device *desc)
|
{
|
usb_free_urb(desc->validity);
|
usb_free_urb(desc->response);
|
usb_free_urb(desc->command);
|
}
|
|
static void cleanup(struct wdm_device *desc)
|
{
|
kfree(desc->sbuf);
|
kfree(desc->inbuf);
|
kfree(desc->orq);
|
kfree(desc->irq);
|
kfree(desc->ubuf);
|
free_urbs(desc);
|
kfree(desc);
|
}
|
|
static ssize_t wdm_write
|
(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
|
{
|
u8 *buf;
|
int rv = -EMSGSIZE, r, we;
|
struct wdm_device *desc = file->private_data;
|
struct usb_ctrlrequest *req;
|
|
if (count > desc->wMaxCommand)
|
count = desc->wMaxCommand;
|
|
spin_lock_irq(&desc->iuspin);
|
we = desc->werr;
|
desc->werr = 0;
|
spin_unlock_irq(&desc->iuspin);
|
if (we < 0)
|
return usb_translate_errors(we);
|
|
buf = memdup_user(buffer, count);
|
if (IS_ERR(buf))
|
return PTR_ERR(buf);
|
|
/* concurrent writes and disconnect */
|
r = mutex_lock_interruptible(&desc->wlock);
|
rv = -ERESTARTSYS;
|
if (r)
|
goto out_free_mem;
|
|
if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
|
rv = -ENODEV;
|
goto out_free_mem_lock;
|
}
|
|
r = usb_autopm_get_interface(desc->intf);
|
if (r < 0) {
|
rv = usb_translate_errors(r);
|
goto out_free_mem_lock;
|
}
|
|
if (!(file->f_flags & O_NONBLOCK))
|
r = wait_event_interruptible(desc->wait, !test_bit(WDM_IN_USE,
|
&desc->flags));
|
else
|
if (test_bit(WDM_IN_USE, &desc->flags))
|
r = -EAGAIN;
|
|
if (test_bit(WDM_RESETTING, &desc->flags))
|
r = -EIO;
|
|
if (test_bit(WDM_DISCONNECTING, &desc->flags))
|
r = -ENODEV;
|
|
if (r < 0) {
|
rv = r;
|
goto out_free_mem_pm;
|
}
|
|
req = desc->orq;
|
usb_fill_control_urb(
|
desc->command,
|
interface_to_usbdev(desc->intf),
|
/* using common endpoint 0 */
|
usb_sndctrlpipe(interface_to_usbdev(desc->intf), 0),
|
(unsigned char *)req,
|
buf,
|
count,
|
wdm_out_callback,
|
desc
|
);
|
|
req->bRequestType = (USB_DIR_OUT | USB_TYPE_CLASS |
|
USB_RECIP_INTERFACE);
|
req->bRequest = USB_CDC_SEND_ENCAPSULATED_COMMAND;
|
req->wValue = 0;
|
req->wIndex = desc->inum; /* already converted */
|
req->wLength = cpu_to_le16(count);
|
set_bit(WDM_IN_USE, &desc->flags);
|
desc->outbuf = buf;
|
|
rv = usb_submit_urb(desc->command, GFP_KERNEL);
|
if (rv < 0) {
|
desc->outbuf = NULL;
|
clear_bit(WDM_IN_USE, &desc->flags);
|
wake_up_all(&desc->wait); /* for wdm_wait_for_response() */
|
dev_err(&desc->intf->dev, "Tx URB error: %d\n", rv);
|
rv = usb_translate_errors(rv);
|
goto out_free_mem_pm;
|
} else {
|
dev_dbg(&desc->intf->dev, "Tx URB has been submitted index=%d\n",
|
le16_to_cpu(req->wIndex));
|
}
|
|
usb_autopm_put_interface(desc->intf);
|
mutex_unlock(&desc->wlock);
|
return count;
|
|
out_free_mem_pm:
|
usb_autopm_put_interface(desc->intf);
|
out_free_mem_lock:
|
mutex_unlock(&desc->wlock);
|
out_free_mem:
|
kfree(buf);
|
return rv;
|
}
|
|
/*
|
* Submit the read urb if resp_count is non-zero.
|
*
|
* Called with desc->iuspin locked
|
*/
|
static int service_outstanding_interrupt(struct wdm_device *desc)
|
{
|
int rv = 0;
|
|
/* submit read urb only if the device is waiting for it */
|
if (!desc->resp_count || !--desc->resp_count)
|
goto out;
|
|
if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
|
rv = -ENODEV;
|
goto out;
|
}
|
if (test_bit(WDM_RESETTING, &desc->flags)) {
|
rv = -EIO;
|
goto out;
|
}
|
|
set_bit(WDM_RESPONDING, &desc->flags);
|
spin_unlock_irq(&desc->iuspin);
|
rv = usb_submit_urb(desc->response, GFP_KERNEL);
|
spin_lock_irq(&desc->iuspin);
|
if (rv) {
|
if (!test_bit(WDM_DISCONNECTING, &desc->flags))
|
dev_err(&desc->intf->dev,
|
"usb_submit_urb failed with result %d\n", rv);
|
|
/* make sure the next notification trigger a submit */
|
clear_bit(WDM_RESPONDING, &desc->flags);
|
desc->resp_count = 0;
|
}
|
out:
|
return rv;
|
}
|
|
static ssize_t wdm_read
|
(struct file *file, char __user *buffer, size_t count, loff_t *ppos)
|
{
|
int rv, cntr;
|
int i = 0;
|
struct wdm_device *desc = file->private_data;
|
|
|
rv = mutex_lock_interruptible(&desc->rlock); /*concurrent reads */
|
if (rv < 0)
|
return -ERESTARTSYS;
|
|
cntr = READ_ONCE(desc->length);
|
if (cntr == 0) {
|
desc->read = 0;
|
retry:
|
if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
|
rv = -ENODEV;
|
goto err;
|
}
|
if (test_bit(WDM_OVERFLOW, &desc->flags)) {
|
clear_bit(WDM_OVERFLOW, &desc->flags);
|
rv = -ENOBUFS;
|
goto err;
|
}
|
i++;
|
if (file->f_flags & O_NONBLOCK) {
|
if (!test_bit(WDM_READ, &desc->flags)) {
|
rv = -EAGAIN;
|
goto err;
|
}
|
rv = 0;
|
} else {
|
rv = wait_event_interruptible(desc->wait,
|
test_bit(WDM_READ, &desc->flags));
|
}
|
|
/* may have happened while we slept */
|
if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
|
rv = -ENODEV;
|
goto err;
|
}
|
if (test_bit(WDM_RESETTING, &desc->flags)) {
|
rv = -EIO;
|
goto err;
|
}
|
usb_mark_last_busy(interface_to_usbdev(desc->intf));
|
if (rv < 0) {
|
rv = -ERESTARTSYS;
|
goto err;
|
}
|
|
spin_lock_irq(&desc->iuspin);
|
|
if (desc->rerr) { /* read completed, error happened */
|
rv = usb_translate_errors(desc->rerr);
|
desc->rerr = 0;
|
spin_unlock_irq(&desc->iuspin);
|
goto err;
|
}
|
/*
|
* recheck whether we've lost the race
|
* against the completion handler
|
*/
|
if (!test_bit(WDM_READ, &desc->flags)) { /* lost race */
|
spin_unlock_irq(&desc->iuspin);
|
goto retry;
|
}
|
|
if (!desc->reslength) { /* zero length read */
|
dev_dbg(&desc->intf->dev, "zero length - clearing WDM_READ\n");
|
clear_bit(WDM_READ, &desc->flags);
|
rv = service_outstanding_interrupt(desc);
|
spin_unlock_irq(&desc->iuspin);
|
if (rv < 0)
|
goto err;
|
goto retry;
|
}
|
cntr = desc->length;
|
spin_unlock_irq(&desc->iuspin);
|
}
|
|
if (cntr > count)
|
cntr = count;
|
rv = copy_to_user(buffer, desc->ubuf, cntr);
|
if (rv > 0) {
|
rv = -EFAULT;
|
goto err;
|
}
|
|
spin_lock_irq(&desc->iuspin);
|
|
for (i = 0; i < desc->length - cntr; i++)
|
desc->ubuf[i] = desc->ubuf[i + cntr];
|
|
desc->length -= cntr;
|
/* in case we had outstanding data */
|
if (!desc->length) {
|
clear_bit(WDM_READ, &desc->flags);
|
service_outstanding_interrupt(desc);
|
}
|
spin_unlock_irq(&desc->iuspin);
|
rv = cntr;
|
|
err:
|
mutex_unlock(&desc->rlock);
|
return rv;
|
}
|
|
static int wdm_wait_for_response(struct file *file, long timeout)
|
{
|
struct wdm_device *desc = file->private_data;
|
long rv; /* Use long here because (int) MAX_SCHEDULE_TIMEOUT < 0. */
|
|
/*
|
* Needs both flags. We cannot do with one because resetting it would
|
* cause a race with write() yet we need to signal a disconnect.
|
*/
|
rv = wait_event_interruptible_timeout(desc->wait,
|
!test_bit(WDM_IN_USE, &desc->flags) ||
|
test_bit(WDM_DISCONNECTING, &desc->flags),
|
timeout);
|
|
/*
|
* To report the correct error. This is best effort.
|
* We are inevitably racing with the hardware.
|
*/
|
if (test_bit(WDM_DISCONNECTING, &desc->flags))
|
return -ENODEV;
|
if (!rv)
|
return -EIO;
|
if (rv < 0)
|
return -EINTR;
|
|
spin_lock_irq(&desc->iuspin);
|
rv = desc->werr;
|
desc->werr = 0;
|
spin_unlock_irq(&desc->iuspin);
|
|
return usb_translate_errors(rv);
|
|
}
|
|
/*
|
* You need to send a signal when you react to malicious or defective hardware.
|
* Also, don't abort when fsync() returned -EINVAL, for older kernels which do
|
* not implement wdm_flush() will return -EINVAL.
|
*/
|
static int wdm_fsync(struct file *file, loff_t start, loff_t end, int datasync)
|
{
|
return wdm_wait_for_response(file, MAX_SCHEDULE_TIMEOUT);
|
}
|
|
/*
|
* Same with wdm_fsync(), except it uses finite timeout in order to react to
|
* malicious or defective hardware which ceased communication after close() was
|
* implicitly called due to process termination.
|
*/
|
static int wdm_flush(struct file *file, fl_owner_t id)
|
{
|
return wdm_wait_for_response(file, WDM_FLUSH_TIMEOUT);
|
}
|
|
static __poll_t wdm_poll(struct file *file, struct poll_table_struct *wait)
|
{
|
struct wdm_device *desc = file->private_data;
|
unsigned long flags;
|
__poll_t mask = 0;
|
|
spin_lock_irqsave(&desc->iuspin, flags);
|
if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
|
mask = EPOLLHUP | EPOLLERR;
|
spin_unlock_irqrestore(&desc->iuspin, flags);
|
goto desc_out;
|
}
|
if (test_bit(WDM_READ, &desc->flags))
|
mask = EPOLLIN | EPOLLRDNORM;
|
if (desc->rerr || desc->werr)
|
mask |= EPOLLERR;
|
if (!test_bit(WDM_IN_USE, &desc->flags))
|
mask |= EPOLLOUT | EPOLLWRNORM;
|
spin_unlock_irqrestore(&desc->iuspin, flags);
|
|
poll_wait(file, &desc->wait, wait);
|
|
desc_out:
|
return mask;
|
}
|
|
static int wdm_open(struct inode *inode, struct file *file)
|
{
|
int minor = iminor(inode);
|
int rv = -ENODEV;
|
struct usb_interface *intf;
|
struct wdm_device *desc;
|
|
mutex_lock(&wdm_mutex);
|
desc = wdm_find_device_by_minor(minor);
|
if (!desc)
|
goto out;
|
|
intf = desc->intf;
|
if (test_bit(WDM_DISCONNECTING, &desc->flags))
|
goto out;
|
file->private_data = desc;
|
|
rv = usb_autopm_get_interface(desc->intf);
|
if (rv < 0) {
|
dev_err(&desc->intf->dev, "Error autopm - %d\n", rv);
|
goto out;
|
}
|
|
/* using write lock to protect desc->count */
|
mutex_lock(&desc->wlock);
|
if (!desc->count++) {
|
desc->werr = 0;
|
desc->rerr = 0;
|
rv = usb_submit_urb(desc->validity, GFP_KERNEL);
|
if (rv < 0) {
|
desc->count--;
|
dev_err(&desc->intf->dev,
|
"Error submitting int urb - %d\n", rv);
|
rv = usb_translate_errors(rv);
|
}
|
} else {
|
rv = 0;
|
}
|
mutex_unlock(&desc->wlock);
|
if (desc->count == 1)
|
desc->manage_power(intf, 1);
|
usb_autopm_put_interface(desc->intf);
|
out:
|
mutex_unlock(&wdm_mutex);
|
return rv;
|
}
|
|
static int wdm_release(struct inode *inode, struct file *file)
|
{
|
struct wdm_device *desc = file->private_data;
|
|
mutex_lock(&wdm_mutex);
|
|
/* using write lock to protect desc->count */
|
mutex_lock(&desc->wlock);
|
desc->count--;
|
mutex_unlock(&desc->wlock);
|
|
if (!desc->count) {
|
if (!test_bit(WDM_DISCONNECTING, &desc->flags)) {
|
dev_dbg(&desc->intf->dev, "wdm_release: cleanup\n");
|
poison_urbs(desc);
|
spin_lock_irq(&desc->iuspin);
|
desc->resp_count = 0;
|
clear_bit(WDM_RESPONDING, &desc->flags);
|
spin_unlock_irq(&desc->iuspin);
|
desc->manage_power(desc->intf, 0);
|
unpoison_urbs(desc);
|
} else {
|
/* must avoid dev_printk here as desc->intf is invalid */
|
pr_debug(KBUILD_MODNAME " %s: device gone - cleaning up\n", __func__);
|
cleanup(desc);
|
}
|
}
|
mutex_unlock(&wdm_mutex);
|
return 0;
|
}
|
|
static long wdm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
|
{
|
struct wdm_device *desc = file->private_data;
|
int rv = 0;
|
|
switch (cmd) {
|
case IOCTL_WDM_MAX_COMMAND:
|
if (copy_to_user((void __user *)arg, &desc->wMaxCommand, sizeof(desc->wMaxCommand)))
|
rv = -EFAULT;
|
break;
|
default:
|
rv = -ENOTTY;
|
}
|
return rv;
|
}
|
|
static const struct file_operations wdm_fops = {
|
.owner = THIS_MODULE,
|
.read = wdm_read,
|
.write = wdm_write,
|
.fsync = wdm_fsync,
|
.open = wdm_open,
|
.flush = wdm_flush,
|
.release = wdm_release,
|
.poll = wdm_poll,
|
.unlocked_ioctl = wdm_ioctl,
|
.compat_ioctl = compat_ptr_ioctl,
|
.llseek = noop_llseek,
|
};
|
|
static struct usb_class_driver wdm_class = {
|
.name = "cdc-wdm%d",
|
.fops = &wdm_fops,
|
.minor_base = WDM_MINOR_BASE,
|
};
|
|
/* --- error handling --- */
|
static void wdm_rxwork(struct work_struct *work)
|
{
|
struct wdm_device *desc = container_of(work, struct wdm_device, rxwork);
|
unsigned long flags;
|
int rv = 0;
|
int responding;
|
|
spin_lock_irqsave(&desc->iuspin, flags);
|
if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
|
spin_unlock_irqrestore(&desc->iuspin, flags);
|
} else {
|
responding = test_and_set_bit(WDM_RESPONDING, &desc->flags);
|
spin_unlock_irqrestore(&desc->iuspin, flags);
|
if (!responding)
|
rv = usb_submit_urb(desc->response, GFP_KERNEL);
|
if (rv < 0 && rv != -EPERM) {
|
spin_lock_irqsave(&desc->iuspin, flags);
|
clear_bit(WDM_RESPONDING, &desc->flags);
|
if (!test_bit(WDM_DISCONNECTING, &desc->flags))
|
schedule_work(&desc->rxwork);
|
spin_unlock_irqrestore(&desc->iuspin, flags);
|
}
|
}
|
}
|
|
static void service_interrupt_work(struct work_struct *work)
|
{
|
struct wdm_device *desc;
|
|
desc = container_of(work, struct wdm_device, service_outs_intr);
|
|
spin_lock_irq(&desc->iuspin);
|
service_outstanding_interrupt(desc);
|
if (!desc->resp_count) {
|
set_bit(WDM_READ, &desc->flags);
|
wake_up(&desc->wait);
|
}
|
spin_unlock_irq(&desc->iuspin);
|
}
|
|
/* --- hotplug --- */
|
|
static int wdm_create(struct usb_interface *intf, struct usb_endpoint_descriptor *ep,
|
u16 bufsize, int (*manage_power)(struct usb_interface *, int))
|
{
|
int rv = -ENOMEM;
|
struct wdm_device *desc;
|
|
desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL);
|
if (!desc)
|
goto out;
|
INIT_LIST_HEAD(&desc->device_list);
|
mutex_init(&desc->rlock);
|
mutex_init(&desc->wlock);
|
spin_lock_init(&desc->iuspin);
|
init_waitqueue_head(&desc->wait);
|
desc->wMaxCommand = bufsize;
|
/* this will be expanded and needed in hardware endianness */
|
desc->inum = cpu_to_le16((u16)intf->cur_altsetting->desc.bInterfaceNumber);
|
desc->intf = intf;
|
INIT_WORK(&desc->rxwork, wdm_rxwork);
|
INIT_WORK(&desc->service_outs_intr, service_interrupt_work);
|
|
rv = -EINVAL;
|
if (!usb_endpoint_is_int_in(ep))
|
goto err;
|
|
desc->wMaxPacketSize = usb_endpoint_maxp(ep);
|
|
desc->orq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
|
if (!desc->orq)
|
goto err;
|
desc->irq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
|
if (!desc->irq)
|
goto err;
|
|
desc->validity = usb_alloc_urb(0, GFP_KERNEL);
|
if (!desc->validity)
|
goto err;
|
|
desc->response = usb_alloc_urb(0, GFP_KERNEL);
|
if (!desc->response)
|
goto err;
|
|
desc->command = usb_alloc_urb(0, GFP_KERNEL);
|
if (!desc->command)
|
goto err;
|
|
desc->ubuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
|
if (!desc->ubuf)
|
goto err;
|
|
desc->sbuf = kmalloc(desc->wMaxPacketSize, GFP_KERNEL);
|
if (!desc->sbuf)
|
goto err;
|
|
desc->inbuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
|
if (!desc->inbuf)
|
goto err;
|
|
usb_fill_int_urb(
|
desc->validity,
|
interface_to_usbdev(intf),
|
usb_rcvintpipe(interface_to_usbdev(intf), ep->bEndpointAddress),
|
desc->sbuf,
|
desc->wMaxPacketSize,
|
wdm_int_callback,
|
desc,
|
ep->bInterval
|
);
|
|
desc->irq->bRequestType = (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE);
|
desc->irq->bRequest = USB_CDC_GET_ENCAPSULATED_RESPONSE;
|
desc->irq->wValue = 0;
|
desc->irq->wIndex = desc->inum; /* already converted */
|
desc->irq->wLength = cpu_to_le16(desc->wMaxCommand);
|
|
usb_fill_control_urb(
|
desc->response,
|
interface_to_usbdev(intf),
|
/* using common endpoint 0 */
|
usb_rcvctrlpipe(interface_to_usbdev(desc->intf), 0),
|
(unsigned char *)desc->irq,
|
desc->inbuf,
|
desc->wMaxCommand,
|
wdm_in_callback,
|
desc
|
);
|
|
desc->manage_power = manage_power;
|
|
spin_lock(&wdm_device_list_lock);
|
list_add(&desc->device_list, &wdm_device_list);
|
spin_unlock(&wdm_device_list_lock);
|
|
rv = usb_register_dev(intf, &wdm_class);
|
if (rv < 0)
|
goto err;
|
else
|
dev_info(&intf->dev, "%s: USB WDM device\n", dev_name(intf->usb_dev));
|
out:
|
return rv;
|
err:
|
spin_lock(&wdm_device_list_lock);
|
list_del(&desc->device_list);
|
spin_unlock(&wdm_device_list_lock);
|
cleanup(desc);
|
return rv;
|
}
|
|
static int wdm_manage_power(struct usb_interface *intf, int on)
|
{
|
/* need autopm_get/put here to ensure the usbcore sees the new value */
|
int rv = usb_autopm_get_interface(intf);
|
|
intf->needs_remote_wakeup = on;
|
if (!rv)
|
usb_autopm_put_interface(intf);
|
return 0;
|
}
|
|
static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id)
|
{
|
int rv = -EINVAL;
|
struct usb_host_interface *iface;
|
struct usb_endpoint_descriptor *ep;
|
struct usb_cdc_parsed_header hdr;
|
u8 *buffer = intf->altsetting->extra;
|
int buflen = intf->altsetting->extralen;
|
u16 maxcom = WDM_DEFAULT_BUFSIZE;
|
|
if (!buffer)
|
goto err;
|
|
cdc_parse_cdc_header(&hdr, intf, buffer, buflen);
|
|
if (hdr.usb_cdc_dmm_desc)
|
maxcom = le16_to_cpu(hdr.usb_cdc_dmm_desc->wMaxCommand);
|
|
iface = intf->cur_altsetting;
|
if (iface->desc.bNumEndpoints != 1)
|
goto err;
|
ep = &iface->endpoint[0].desc;
|
|
rv = wdm_create(intf, ep, maxcom, &wdm_manage_power);
|
|
err:
|
return rv;
|
}
|
|
/**
|
* usb_cdc_wdm_register - register a WDM subdriver
|
* @intf: usb interface the subdriver will associate with
|
* @ep: interrupt endpoint to monitor for notifications
|
* @bufsize: maximum message size to support for read/write
|
* @manage_power: call-back invoked during open and release to
|
* manage the device's power
|
* Create WDM usb class character device and associate it with intf
|
* without binding, allowing another driver to manage the interface.
|
*
|
* The subdriver will manage the given interrupt endpoint exclusively
|
* and will issue control requests referring to the given intf. It
|
* will otherwise avoid interferring, and in particular not do
|
* usb_set_intfdata/usb_get_intfdata on intf.
|
*
|
* The return value is a pointer to the subdriver's struct usb_driver.
|
* The registering driver is responsible for calling this subdriver's
|
* disconnect, suspend, resume, pre_reset and post_reset methods from
|
* its own.
|
*/
|
struct usb_driver *usb_cdc_wdm_register(struct usb_interface *intf,
|
struct usb_endpoint_descriptor *ep,
|
int bufsize,
|
int (*manage_power)(struct usb_interface *, int))
|
{
|
int rv;
|
|
rv = wdm_create(intf, ep, bufsize, manage_power);
|
if (rv < 0)
|
goto err;
|
|
return &wdm_driver;
|
err:
|
return ERR_PTR(rv);
|
}
|
EXPORT_SYMBOL(usb_cdc_wdm_register);
|
|
static void wdm_disconnect(struct usb_interface *intf)
|
{
|
struct wdm_device *desc;
|
unsigned long flags;
|
|
usb_deregister_dev(intf, &wdm_class);
|
desc = wdm_find_device(intf);
|
mutex_lock(&wdm_mutex);
|
|
/* the spinlock makes sure no new urbs are generated in the callbacks */
|
spin_lock_irqsave(&desc->iuspin, flags);
|
set_bit(WDM_DISCONNECTING, &desc->flags);
|
set_bit(WDM_READ, &desc->flags);
|
spin_unlock_irqrestore(&desc->iuspin, flags);
|
wake_up_all(&desc->wait);
|
mutex_lock(&desc->rlock);
|
mutex_lock(&desc->wlock);
|
poison_urbs(desc);
|
cancel_work_sync(&desc->rxwork);
|
cancel_work_sync(&desc->service_outs_intr);
|
mutex_unlock(&desc->wlock);
|
mutex_unlock(&desc->rlock);
|
|
/* the desc->intf pointer used as list key is now invalid */
|
spin_lock(&wdm_device_list_lock);
|
list_del(&desc->device_list);
|
spin_unlock(&wdm_device_list_lock);
|
|
if (!desc->count)
|
cleanup(desc);
|
else
|
dev_dbg(&intf->dev, "%d open files - postponing cleanup\n", desc->count);
|
mutex_unlock(&wdm_mutex);
|
}
|
|
#ifdef CONFIG_PM
|
static int wdm_suspend(struct usb_interface *intf, pm_message_t message)
|
{
|
struct wdm_device *desc = wdm_find_device(intf);
|
int rv = 0;
|
|
dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor);
|
|
/* if this is an autosuspend the caller does the locking */
|
if (!PMSG_IS_AUTO(message)) {
|
mutex_lock(&desc->rlock);
|
mutex_lock(&desc->wlock);
|
}
|
spin_lock_irq(&desc->iuspin);
|
|
if (PMSG_IS_AUTO(message) &&
|
(test_bit(WDM_IN_USE, &desc->flags)
|
|| test_bit(WDM_RESPONDING, &desc->flags))) {
|
spin_unlock_irq(&desc->iuspin);
|
rv = -EBUSY;
|
} else {
|
|
set_bit(WDM_SUSPENDING, &desc->flags);
|
spin_unlock_irq(&desc->iuspin);
|
/* callback submits work - order is essential */
|
poison_urbs(desc);
|
cancel_work_sync(&desc->rxwork);
|
cancel_work_sync(&desc->service_outs_intr);
|
unpoison_urbs(desc);
|
}
|
if (!PMSG_IS_AUTO(message)) {
|
mutex_unlock(&desc->wlock);
|
mutex_unlock(&desc->rlock);
|
}
|
|
return rv;
|
}
|
#endif
|
|
static int recover_from_urb_loss(struct wdm_device *desc)
|
{
|
int rv = 0;
|
|
if (desc->count) {
|
rv = usb_submit_urb(desc->validity, GFP_NOIO);
|
if (rv < 0)
|
dev_err(&desc->intf->dev,
|
"Error resume submitting int urb - %d\n", rv);
|
}
|
return rv;
|
}
|
|
#ifdef CONFIG_PM
|
static int wdm_resume(struct usb_interface *intf)
|
{
|
struct wdm_device *desc = wdm_find_device(intf);
|
int rv;
|
|
dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor);
|
|
clear_bit(WDM_SUSPENDING, &desc->flags);
|
rv = recover_from_urb_loss(desc);
|
|
return rv;
|
}
|
#endif
|
|
static int wdm_pre_reset(struct usb_interface *intf)
|
{
|
struct wdm_device *desc = wdm_find_device(intf);
|
|
/*
|
* we notify everybody using poll of
|
* an exceptional situation
|
* must be done before recovery lest a spontaneous
|
* message from the device is lost
|
*/
|
spin_lock_irq(&desc->iuspin);
|
set_bit(WDM_RESETTING, &desc->flags); /* inform read/write */
|
set_bit(WDM_READ, &desc->flags); /* unblock read */
|
clear_bit(WDM_IN_USE, &desc->flags); /* unblock write */
|
desc->rerr = -EINTR;
|
spin_unlock_irq(&desc->iuspin);
|
wake_up_all(&desc->wait);
|
mutex_lock(&desc->rlock);
|
mutex_lock(&desc->wlock);
|
poison_urbs(desc);
|
cancel_work_sync(&desc->rxwork);
|
cancel_work_sync(&desc->service_outs_intr);
|
return 0;
|
}
|
|
static int wdm_post_reset(struct usb_interface *intf)
|
{
|
struct wdm_device *desc = wdm_find_device(intf);
|
int rv;
|
|
unpoison_urbs(desc);
|
clear_bit(WDM_OVERFLOW, &desc->flags);
|
clear_bit(WDM_RESETTING, &desc->flags);
|
rv = recover_from_urb_loss(desc);
|
mutex_unlock(&desc->wlock);
|
mutex_unlock(&desc->rlock);
|
return rv;
|
}
|
|
static struct usb_driver wdm_driver = {
|
.name = "cdc_wdm",
|
.probe = wdm_probe,
|
.disconnect = wdm_disconnect,
|
#ifdef CONFIG_PM
|
.suspend = wdm_suspend,
|
.resume = wdm_resume,
|
.reset_resume = wdm_resume,
|
#endif
|
.pre_reset = wdm_pre_reset,
|
.post_reset = wdm_post_reset,
|
.id_table = wdm_ids,
|
.supports_autosuspend = 1,
|
.disable_hub_initiated_lpm = 1,
|
};
|
|
module_usb_driver(wdm_driver);
|
|
MODULE_AUTHOR(DRIVER_AUTHOR);
|
MODULE_DESCRIPTION(DRIVER_DESC);
|
MODULE_LICENSE("GPL");
|
