blob: 34e6108e1d42bfd879ed28df0ed00e2d2f538425 [file] [log] [blame]
/*
* cdc-wdm.c
*
* This driver supports USB CDC WCM Device Management.
*
* Copyright (c) 2007-2008 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/slab.h>
#include <linux/module.h>
#include <linux/smp_lock.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>
/*
* Version Information
*/
#define DRIVER_VERSION "v0.03"
#define DRIVER_AUTHOR "Oliver Neukum"
#define DRIVER_DESC "USB Abstract Control Model driver for USB WCM Device Management"
static 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_MAX 16
static DEFINE_MUTEX(wdm_mutex);
/* --- 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;
u16 bMaxPacketSize0;
__le16 inum;
int reslength;
int length;
int read;
int count;
dma_addr_t shandle;
dma_addr_t ihandle;
struct mutex wlock;
struct mutex rlock;
struct mutex plock;
wait_queue_head_t wait;
struct work_struct rxwork;
int werr;
int rerr;
};
static struct usb_driver wdm_driver;
/* --- callbacks --- */
static void wdm_out_callback(struct urb *urb)
{
struct wdm_device *desc;
desc = urb->context;
spin_lock(&desc->iuspin);
desc->werr = urb->status;
spin_unlock(&desc->iuspin);
clear_bit(WDM_IN_USE, &desc->flags);
kfree(desc->outbuf);
wake_up(&desc->wait);
}
static void wdm_in_callback(struct urb *urb)
{
struct wdm_device *desc = urb->context;
int status = urb->status;
spin_lock(&desc->iuspin);
if (status) {
switch (status) {
case -ENOENT:
dev_dbg(&desc->intf->dev,
"nonzero urb status received: -ENOENT");
break;
case -ECONNRESET:
dev_dbg(&desc->intf->dev,
"nonzero urb status received: -ECONNRESET");
break;
case -ESHUTDOWN:
dev_dbg(&desc->intf->dev,
"nonzero urb status received: -ESHUTDOWN");
break;
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;
}
}
desc->rerr = status;
desc->reslength = urb->actual_length;
memmove(desc->ubuf + desc->length, desc->inbuf, desc->reslength);
desc->length += desc->reslength;
wake_up(&desc->wait);
set_bit(WDM_READ, &desc->flags);
spin_unlock(&desc->iuspin);
}
static void wdm_int_callback(struct urb *urb)
{
int rv = 0;
int status = urb->status;
struct wdm_device *desc;
struct usb_ctrlrequest *req;
struct usb_cdc_notification *dr;
desc = urb->context;
req = desc->irq;
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",
dr->wIndex, dr->wLength);
break;
case USB_CDC_NOTIFY_NETWORK_CONNECTION:
dev_dbg(&desc->intf->dev,
"NOTIFY_NETWORK_CONNECTION %s network",
dr->wValue ? "connected to" : "disconnected from");
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, dr->wIndex, dr->wLength);
goto exit;
}
req->bRequestType = (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE);
req->bRequest = USB_CDC_GET_ENCAPSULATED_RESPONSE;
req->wValue = 0;
req->wIndex = desc->inum;
req->wLength = cpu_to_le16(desc->wMaxCommand);
usb_fill_control_urb(
desc->response,
interface_to_usbdev(desc->intf),
/* using common endpoint 0 */
usb_rcvctrlpipe(interface_to_usbdev(desc->intf), 0),
(unsigned char *)req,
desc->inbuf,
desc->wMaxCommand,
wdm_in_callback,
desc
);
desc->response->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
spin_lock(&desc->iuspin);
clear_bit(WDM_READ, &desc->flags);
if (!test_bit(WDM_DISCONNECTING, &desc->flags)) {
rv = usb_submit_urb(desc->response, GFP_ATOMIC);
dev_dbg(&desc->intf->dev, "%s: usb_submit_urb %d",
__func__, rv);
}
spin_unlock(&desc->iuspin);
if (rv < 0) {
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 kill_urbs(struct wdm_device *desc)
{
/* the order here is essential */
usb_kill_urb(desc->command);
usb_kill_urb(desc->validity);
usb_kill_urb(desc->response);
}
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)
{
usb_buffer_free(interface_to_usbdev(desc->intf),
desc->wMaxPacketSize,
desc->sbuf,
desc->validity->transfer_dma);
usb_buffer_free(interface_to_usbdev(desc->intf),
desc->wMaxCommand,
desc->inbuf,
desc->response->transfer_dma);
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 -EIO;
r = mutex_lock_interruptible(&desc->wlock); /* concurrent writes */
rv = -ERESTARTSYS;
if (r)
goto outnl;
r = usb_autopm_get_interface(desc->intf);
if (r < 0)
goto outnp;
r = wait_event_interruptible(desc->wait, !test_bit(WDM_IN_USE,
&desc->flags));
if (r < 0)
goto out;
if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
rv = -ENODEV;
goto out;
}
desc->outbuf = buf = kmalloc(count, GFP_KERNEL);
if (!buf) {
rv = -ENOMEM;
goto out;
}
r = copy_from_user(buf, buffer, count);
if (r > 0) {
kfree(buf);
rv = -EFAULT;
goto out;
}
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;
req->wLength = cpu_to_le16(count);
set_bit(WDM_IN_USE, &desc->flags);
rv = usb_submit_urb(desc->command, GFP_KERNEL);
if (rv < 0) {
kfree(buf);
clear_bit(WDM_IN_USE, &desc->flags);
dev_err(&desc->intf->dev, "Tx URB error: %d\n", rv);
} else {
dev_dbg(&desc->intf->dev, "Tx URB has been submitted index=%d",
req->wIndex);
}
out:
usb_autopm_put_interface(desc->intf);
outnp:
mutex_unlock(&desc->wlock);
outnl:
return rv < 0 ? rv : count;
}
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;
if (desc->length == 0) {
desc->read = 0;
retry:
i++;
rv = wait_event_interruptible(desc->wait,
test_bit(WDM_READ, &desc->flags));
if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
rv = -ENODEV;
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 */
int t = desc->rerr;
desc->rerr = 0;
spin_unlock_irq(&desc->iuspin);
dev_err(&desc->intf->dev,
"reading had resulted in %d\n", t);
rv = -EIO;
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 */
spin_unlock_irq(&desc->iuspin);
goto retry;
}
clear_bit(WDM_READ, &desc->flags);
spin_unlock_irq(&desc->iuspin);
}
cntr = count > desc->length ? desc->length : count;
rv = copy_to_user(buffer, desc->ubuf, cntr);
if (rv > 0) {
rv = -EFAULT;
goto err;
}
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);
rv = cntr;
err:
mutex_unlock(&desc->rlock);
if (rv < 0)
dev_err(&desc->intf->dev, "wdm_read: exit error\n");
return rv;
}
static int wdm_flush(struct file *file, fl_owner_t id)
{
struct wdm_device *desc = file->private_data;
wait_event(desc->wait, !test_bit(WDM_IN_USE, &desc->flags));
if (desc->werr < 0)
dev_err(&desc->intf->dev, "Error in flush path: %d\n",
desc->werr);
return desc->werr;
}
static unsigned int wdm_poll(struct file *file, struct poll_table_struct *wait)
{
struct wdm_device *desc = file->private_data;
unsigned long flags;
unsigned int mask = 0;
spin_lock_irqsave(&desc->iuspin, flags);
if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
mask = POLLERR;
spin_unlock_irqrestore(&desc->iuspin, flags);
goto desc_out;
}
if (test_bit(WDM_READ, &desc->flags))
mask = POLLIN | POLLRDNORM;
if (desc->rerr || desc->werr)
mask |= POLLERR;
if (!test_bit(WDM_IN_USE, &desc->flags))
mask |= POLLOUT | POLLWRNORM;
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);
intf = usb_find_interface(&wdm_driver, minor);
if (!intf)
goto out;
desc = usb_get_intfdata(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;
}
intf->needs_remote_wakeup = 1;
mutex_lock(&desc->plock);
if (!desc->count++) {
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);
}
} else {
rv = 0;
}
mutex_unlock(&desc->plock);
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);
mutex_lock(&desc->plock);
desc->count--;
mutex_unlock(&desc->plock);
if (!desc->count) {
dev_dbg(&desc->intf->dev, "wdm_release: cleanup");
kill_urbs(desc);
if (!test_bit(WDM_DISCONNECTING, &desc->flags))
desc->intf->needs_remote_wakeup = 0;
}
mutex_unlock(&wdm_mutex);
return 0;
}
static const struct file_operations wdm_fops = {
.owner = THIS_MODULE,
.read = wdm_read,
.write = wdm_write,
.open = wdm_open,
.flush = wdm_flush,
.release = wdm_release,
.poll = wdm_poll
};
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;
spin_lock_irqsave(&desc->iuspin, flags);
if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
spin_unlock_irqrestore(&desc->iuspin, flags);
} else {
spin_unlock_irqrestore(&desc->iuspin, flags);
rv = usb_submit_urb(desc->response, GFP_KERNEL);
if (rv < 0 && rv != -EPERM) {
spin_lock_irqsave(&desc->iuspin, flags);
if (!test_bit(WDM_DISCONNECTING, &desc->flags))
schedule_work(&desc->rxwork);
spin_unlock_irqrestore(&desc->iuspin, flags);
}
}
}
/* --- hotplug --- */
static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id)
{
int rv = -EINVAL;
struct usb_device *udev = interface_to_usbdev(intf);
struct wdm_device *desc;
struct usb_host_interface *iface;
struct usb_endpoint_descriptor *ep;
struct usb_cdc_dmm_desc *dmhd;
u8 *buffer = intf->altsetting->extra;
int buflen = intf->altsetting->extralen;
u16 maxcom = 0;
if (!buffer)
goto out;
while (buflen > 0) {
if (buffer [1] != USB_DT_CS_INTERFACE) {
dev_err(&intf->dev, "skipping garbage\n");
goto next_desc;
}
switch (buffer [2]) {
case USB_CDC_HEADER_TYPE:
break;
case USB_CDC_DMM_TYPE:
dmhd = (struct usb_cdc_dmm_desc *)buffer;
maxcom = le16_to_cpu(dmhd->wMaxCommand);
dev_dbg(&intf->dev,
"Finding maximum buffer length: %d", maxcom);
break;
default:
dev_err(&intf->dev,
"Ignoring extra header, type %d, length %d\n",
buffer[2], buffer[0]);
break;
}
next_desc:
buflen -= buffer[0];
buffer += buffer[0];
}
rv = -ENOMEM;
desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL);
if (!desc)
goto out;
mutex_init(&desc->wlock);
mutex_init(&desc->rlock);
mutex_init(&desc->plock);
spin_lock_init(&desc->iuspin);
init_waitqueue_head(&desc->wait);
desc->wMaxCommand = maxcom;
desc->inum = cpu_to_le16((u16)intf->cur_altsetting->desc.bInterfaceNumber);
desc->intf = intf;
INIT_WORK(&desc->rxwork, wdm_rxwork);
iface = &intf->altsetting[0];
ep = &iface->endpoint[0].desc;
if (!ep || !usb_endpoint_is_int_in(ep)) {
rv = -EINVAL;
goto err;
}
desc->wMaxPacketSize = le16_to_cpu(ep->wMaxPacketSize);
desc->bMaxPacketSize0 = udev->descriptor.bMaxPacketSize0;
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 = usb_buffer_alloc(interface_to_usbdev(intf),
desc->wMaxPacketSize,
GFP_KERNEL,
&desc->validity->transfer_dma);
if (!desc->sbuf)
goto err;
desc->inbuf = usb_buffer_alloc(interface_to_usbdev(intf),
desc->bMaxPacketSize0,
GFP_KERNEL,
&desc->response->transfer_dma);
if (!desc->inbuf)
goto err2;
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->validity->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
usb_set_intfdata(intf, desc);
rv = usb_register_dev(intf, &wdm_class);
dev_info(&intf->dev, "cdc-wdm%d: USB WDM device\n",
intf->minor - WDM_MINOR_BASE);
if (rv < 0)
goto err;
out:
return rv;
err2:
usb_buffer_free(interface_to_usbdev(desc->intf),
desc->wMaxPacketSize,
desc->sbuf,
desc->validity->transfer_dma);
err:
free_urbs(desc);
kfree(desc->ubuf);
kfree(desc->orq);
kfree(desc->irq);
kfree(desc);
return rv;
}
static void wdm_disconnect(struct usb_interface *intf)
{
struct wdm_device *desc;
unsigned long flags;
usb_deregister_dev(intf, &wdm_class);
mutex_lock(&wdm_mutex);
desc = usb_get_intfdata(intf);
/* 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);
/* to terminate pending flushes */
clear_bit(WDM_IN_USE, &desc->flags);
spin_unlock_irqrestore(&desc->iuspin, flags);
cancel_work_sync(&desc->rxwork);
kill_urbs(desc);
wake_up_all(&desc->wait);
if (!desc->count)
cleanup(desc);
mutex_unlock(&wdm_mutex);
}
static int wdm_suspend(struct usb_interface *intf, pm_message_t message)
{
struct wdm_device *desc = usb_get_intfdata(intf);
int rv = 0;
dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor);
mutex_lock(&desc->plock);
#ifdef CONFIG_PM
if ((message.event & PM_EVENT_AUTO) &&
test_bit(WDM_IN_USE, &desc->flags)) {
rv = -EBUSY;
} else {
#endif
cancel_work_sync(&desc->rxwork);
kill_urbs(desc);
#ifdef CONFIG_PM
}
#endif
mutex_unlock(&desc->plock);
return rv;
}
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;
}
static int wdm_resume(struct usb_interface *intf)
{
struct wdm_device *desc = usb_get_intfdata(intf);
int rv;
dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor);
mutex_lock(&desc->plock);
rv = recover_from_urb_loss(desc);
mutex_unlock(&desc->plock);
return rv;
}
static int wdm_pre_reset(struct usb_interface *intf)
{
struct wdm_device *desc = usb_get_intfdata(intf);
mutex_lock(&desc->plock);
return 0;
}
static int wdm_post_reset(struct usb_interface *intf)
{
struct wdm_device *desc = usb_get_intfdata(intf);
int rv;
rv = recover_from_urb_loss(desc);
mutex_unlock(&desc->plock);
return 0;
}
static struct usb_driver wdm_driver = {
.name = "cdc_wdm",
.probe = wdm_probe,
.disconnect = wdm_disconnect,
.suspend = wdm_suspend,
.resume = wdm_resume,
.reset_resume = wdm_resume,
.pre_reset = wdm_pre_reset,
.post_reset = wdm_post_reset,
.id_table = wdm_ids,
.supports_autosuspend = 1,
};
/* --- low level module stuff --- */
static int __init wdm_init(void)
{
int rv;
rv = usb_register(&wdm_driver);
return rv;
}
static void __exit wdm_exit(void)
{
usb_deregister(&wdm_driver);
}
module_init(wdm_init);
module_exit(wdm_exit);
MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");