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>
#include <linux/usb/cdc-wdm.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"

#define HUAWEI_VENDOR_ID	0x12D1

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
	},
	{
		/* 
		 * Huawei E392, E398 and possibly other Qualcomm based modems
		 * embed the Qualcomm QMI protocol inside CDC on CDC ECM like
		 * control interfaces.  Userspace access to this is required
		 * to configure the accompanying data interface
		 */
		.match_flags        = USB_DEVICE_ID_MATCH_VENDOR |
					USB_DEVICE_ID_MATCH_INT_INFO,
		.idVendor           = HUAWEI_VENDOR_ID,
		.bInterfaceClass    = USB_CLASS_VENDOR_SPEC,
		.bInterfaceSubClass = 1,
		.bInterfaceProtocol = 9, /* NOTE: CDC ECM control interface! */
	},
	{ }
};

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_MAX			16

/* 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;
	int			werr;
	int			rerr;

	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 = NULL;

	spin_lock(&wdm_device_list_lock);
	list_for_each_entry(desc, &wdm_device_list, device_list)
		if (desc->intf == intf)
			break;
	spin_unlock(&wdm_device_list_lock);

	return desc;
}

static struct wdm_device *wdm_find_device_by_minor(int minor)
{
	struct wdm_device *desc = NULL;

	spin_lock(&wdm_device_list_lock);
	list_for_each_entry(desc, &wdm_device_list, device_list)
		if (desc->intf->minor == minor)
			break;
	spin_unlock(&wdm_device_list_lock);

	return desc;
}

/* --- 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);
	kfree(desc->outbuf);
	desc->outbuf = NULL;
	clear_bit(WDM_IN_USE, &desc->flags);
	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) {