// 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/skbuff.h>
#include <linux/usb.h>
#include <linux/usb/cdc.h>
#include <linux/wwan.h>
#include <asm/byteorder.h>
#include <linux/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_WWAN_IN_USE 11
#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);
enum wwan_port_type wwanp_type;
struct wwan_port *wwanp;
};
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_wwan_rx(struct wdm_device *desc, int length);
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;
}
}
if (test_bit(WDM_WWAN_IN_USE, &desc->flags)) {
wdm_wwan_rx(desc, length);
goto out;
}
/*
* 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);
}
out:
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_ratelimited(&desc->intf->dev,
"nonzero urb status received: %d\n", status);
break;
}
}
if (urb->actual_length < sizeof(struct usb_cdc_notification)) {
dev_err_ratelimited(&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;
if (test_bit(WDM_WWAN_IN_USE, &desc->flags)) {
rv = -EBUSY;
goto out;
}
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,
};
/* --- WWAN framework integration --- */
#ifdef CONFIG_WWAN
static int wdm_wwan_port_start(struct wwan_port *port)
{
struct wdm_device *desc = wwan_port_get_drvdata(port);
/* The interface is both exposed via the WWAN framework and as a
* legacy usbmisc chardev. If chardev is already open, just fail
* to prevent concurrent usage. Otherwise, switch to WWAN mode.
*/
mutex_lock(&wdm_mutex);
if (desc->count) {
mutex_unlock(&wdm_mutex);
return -EBUSY;
}
set_bit(WDM_WWAN_IN_USE, &desc->flags);
mutex_unlock(&wdm_mutex);
desc->manage_power(desc->intf, 1);
/* tx is allowed */
wwan_port_txon(port);
/* Start getting events */
return usb_submit_urb(desc->validity, GFP_KERNEL);
}
static void wdm_wwan_port_stop(struct wwan_port *port)
{
struct wdm_device *desc = wwan_port_get_drvdata(port);
/* Stop all transfers and disable WWAN mode */
poison_urbs(desc);
desc->manage_power(desc->intf, 0);
clear_bit(WDM_READ, &desc->flags);
clear_bit(WDM_WWAN_IN_USE, &desc->flags);
unpoison_urbs(desc);
}
static void wdm_wwan_port_tx_complete(struct urb *urb)
{
struct sk_buff *skb = urb->context;
struct wdm_device *desc = skb_shinfo(skb)->destructor_arg;
usb_autopm_put_interface(desc->intf);
wwan_port_txon(desc->wwanp);
kfree_skb(skb);
}
static int wdm_wwan_port_tx(struct wwan_port *port, struct sk_buff *skb)
{
struct wdm_device *desc = wwan_port_get_drvdata(port);
struct usb_interface *intf = desc->intf;
struct usb_ctrlrequest *req = desc->orq;
int rv;
rv = usb_autopm_get_interface(intf);
if (rv)
return rv;
usb_fill_control_urb(
desc->command,
interface_to_usbdev(intf),
usb_sndctrlpipe(interface_to_usbdev(intf), 0),
(unsigned char *)req,
skb->data,
skb->len,
wdm_wwan_port_tx_complete,
skb
);
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;
req->wLength = cpu_to_le16(skb->len);
skb_shinfo(skb)->destructor_arg = desc;
rv = usb_submit_urb(desc->command, GFP_KERNEL);
if (rv)
usb_autopm_put_interface(intf);
else /* One transfer at a time, stop TX until URB completion */
wwan_port_txoff(port);
return rv;
}
static const struct wwan_port_ops wdm_wwan_port_ops = {
.start = wdm_wwan_port_start,
.stop = wdm_wwan_port_stop,
.tx = wdm_wwan_port_tx,
};
static void wdm_wwan_init(struct wdm_device *desc)
{
struct usb_interface *intf = desc->intf;
struct wwan_port *port;
/* Only register to WWAN core if protocol/type is known */
if (desc->wwanp_type == WWAN_PORT_UNKNOWN) {
dev_info(&intf->dev, "Unknown control protocol\n");
return;
}
port = wwan_create_port(&intf->dev, desc->wwanp_type, &wdm_wwan_port_ops,
NULL, desc);
if (IS_ERR(port)) {
dev_err(&intf->dev, "%s: Unable to create WWAN port\n",
dev_name(intf->usb_dev));
return;
}
desc->wwanp = port;
}
static void wdm_wwan_deinit(struct wdm_device *desc)
{
if (!desc->wwanp)
return;
wwan_remove_port(desc->wwanp);
desc->wwanp = NULL;
}
static void wdm_wwan_rx(struct wdm_device *desc, int length)
{
struct wwan_port *port = desc->wwanp;
struct sk_buff *skb;
/* Forward data to WWAN port */
skb = alloc_skb(length, GFP_ATOMIC);
if (!skb)
return;
skb_put_data(skb, desc->inbuf, length);
wwan_port_rx(port, skb);
/* inbuf has been copied, it is safe to check for outstanding data */
schedule_work(&desc->service_outs_intr);
}
#else /* CONFIG_WWAN */
static void wdm_wwan_init(struct wdm_device *desc) {}
static void wdm_wwan_deinit(struct wdm_device *desc) {}
static void wdm_wwan_rx(struct wdm_device *desc, int length) {}
#endif /* CONFIG_WWAN */
/* --- 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, enum wwan_port_type type,
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;
desc->wwanp_type = type;
INIT_WORK(&desc->rxwork, wdm_rxwork);
INIT_WORK(&desc->service_outs_intr, service_interrupt_work);
if (!usb_endpoint_is_int_in(ep)) {
rv = -EINVAL;
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));
wdm_wwan_init(desc);
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, WWAN_PORT_UNKNOWN, &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
* @type: Type/protocol of the transported data (MBIM, QMI...)
* @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, enum wwan_port_type type,
int (*manage_power)(struct usb_interface *, int))
{
int rv;
rv = wdm_create(intf, ep, bufsize, type, 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);
wdm_wwan_deinit(desc);
/* 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");
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