path: root/drivers/usb/class/cdc-wdm.c

/*
 * 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/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>

/*
 * 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 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_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		lock;
	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);
	clear_bit(WDM_RESPONDING, &desc->flags);

	if (status) {
		switch (status) {
		case -ENOENT:
			dev_dbg(&desc->intf->dev,
				"nonzero urb status received: -ENOENT");
			goto skip_error;
		case -ECONNRESET:
			dev_dbg(&desc->intf->dev,
				"nonzero urb status received: -ECONNRESET");
			goto skip_error;
		case -ESHUTDOWN:
			dev_dbg(&desc->intf->dev,
				"nonzero urb status received: -ESHUTDOWN");
			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;
		}
	}

	desc->rerr = status;
	desc->reslength = urb->actual_length;
	memmove(desc->ubuf + desc->length, desc->inbuf, desc->reslength);
	desc->length += desc->reslength;
skip_error:
	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",