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Commit afba937e authored by Oliver Neukum's avatar Oliver Neukum Committed by Greg Kroah-Hartman
Browse files

USB: CDC WDM driver 



Signed-off-by: default avatarOliver Neukum <oneukum@suse.de>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 129bd474

drivers/usb/class/Kconfig

+11 −0
Original line number Diff line number Diff line
@@ -29,3 +29,14 @@ config USB_PRINTER 
	  To compile this driver as a module, choose M here: the

	  module will be called usblp.



config USB_WDM

	tristate "USB Wireless Device Management support"

	depends on USB

	---help---

	  This driver supports the WMC Device Management functionality

	  of cell phones compliant to the CDC WMC specification. You can use

	  AT commands over this device.



	  To compile this driver as a module, choose M here: the

	  module will be called cdc-wdm.

drivers/usb/class/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -5,3 +5,4 @@ 


obj-$(CONFIG_USB_ACM)		+= cdc-acm.o

obj-$(CONFIG_USB_PRINTER)	+= usblp.o

obj-$(CONFIG_USB_WDM)		+= cdc-wdm.o

drivers/usb/class/cdc-wdm.c

0 → 100644
+740 −0
Original line number Diff line number Diff line 
/*

 * 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 "v0.02"

#define DRIVER_AUTHOR "Oliver Neukum"



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

	},

	{ }

};



#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;

	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:

			err("nonzero urb status received: -EPIPE");

			break;

		default:

			err("Unexpected error %d", 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);

			err("Stall on int endpoint");

			goto sw; /* halt is cleared in work */

		default:

			err("nonzero urb status received: %d", status);

			break;

		}

	}



	if (urb->actual_length < sizeof(struct usb_cdc_notification)) {

		err("wdm_int_callback - %d bytes", 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);

		err("unknown notification %d received: index %d len %d",

			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->bMaxPacketSize0);



	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->bMaxPacketSize0,

		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)

				err("Cannot schedule work");

		}

	}

exit:

	rv = usb_submit_urb(urb, GFP_ATOMIC);

	if (rv)

		err("%s - usb_submit_urb failed with result %d",

		     __func__, rv);



}



static void kill_urbs(struct wdm_device *desc)

{

	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->wMaxPacketSize,

			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 = 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);

	} else {

		dev_dbg(&desc->intf->dev, "Tx URB has been submitted index=%d",

			req->wIndex);

	}

out:

	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 (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);

			err("reading had resulted in %d", 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;

	rv = cntr;



err:

	mutex_unlock(&desc->rlock);

	if (rv < 0)

		err("wdm_read: exit error");

	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)

		err("Error in flush path: %d", 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;



	desc->count++;

	file->private_data = desc;



	rv = usb_submit_urb(desc->validity, GFP_KERNEL);



	if (rv < 0) {

		desc->count--;

		err("Error submitting int urb - %d", rv);

		goto out;

	}

	rv = 0;



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);

	desc->count--;

	if (!desc->count) {

		dev_dbg(&desc->intf->dev, "wdm_release: cleanup");

		kill_urbs(desc);

	}

	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) {

			err("skipping garbage");

			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:

			err("Ignoring extra header, type %d, length %d",

				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);

	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 (!usb_endpoint_is_int_in(ep)) {

		rv = -EINVAL;

		goto err;

	}



	desc->wMaxPacketSize = ep->wMaxPacketSize;

	desc->bMaxPacketSize0 = cpu_to_le16(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);

	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 struct usb_driver wdm_driver = {

	.name =		"cdc_wdm",

	.probe =	wdm_probe,

	.disconnect =	wdm_disconnect,

	.id_table =	wdm_ids,

};



/* --- 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("USB Abstract Control Model driver for "

		   "USB WCM Device Management");

MODULE_LICENSE("GPL");

include/linux/usb/cdc.h

+9 −0
Original line number Diff line number Diff line
@@ -130,6 +130,15 @@ struct usb_cdc_ether_desc { 
	__u8	bNumberPowerFilters;

} __attribute__ ((packed));



/* "Telephone Control Model Functional Descriptor" from CDC WMC spec 6.3..3 */

struct usb_cdc_dmm_desc {

	__u8	bFunctionLength;

	__u8	bDescriptorType;

	__u8	bDescriptorSubtype;

	__u16	bcdVersion;

	__le16	wMaxCommand;

} __attribute__ ((packed));



/* "MDLM Functional Descriptor" from CDC WMC spec 6.7.2.3 */

struct usb_cdc_mdlm_desc {

	__u8	bLength;