drivers/usb/misc/isight_firmware.c

   1 /*
   2  * Driver for loading USB isight firmware
   3  *
   4  * Copyright (C) 2008 Matthew Garrett <mjg@redhat.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License as published by the Free
   8  * Software Foundation, version 2.
   9  *
  10  * The USB isight cameras in recent Apples are roughly compatible with the USB
  11  * video class specification, and can be driven by uvcvideo. However, they
  12  * need firmware to be loaded beforehand. After firmware loading, the device
  13  * detaches from the USB bus and reattaches with a new device ID. It can then
  14  * be claimed by the uvc driver.
  15  *
  16  * The firmware is non-free and must be extracted by the user. Tools to do this
  17  * are available at http://bersace03.free.fr/ift/
  18  *
  19  * The isight firmware loading was reverse engineered by Johannes Berg
  20  * <johannes@sipsolutions.de>, and this driver is based on code by Ronald
  21  * Bultje <rbultje@ronald.bitfreak.net>
  22  */
  23
  24 #include <linux/usb.h>
  25 #include <linux/firmware.h>
  26 #include <linux/errno.h>
  27 #include <linux/module.h>
  28
  29 static struct usb_device_id id_table[] = {
  30         {USB_DEVICE(0x05ac, 0x8300)},
  31         {},
  32 };
  33
  34 MODULE_DEVICE_TABLE(usb, id_table);
  35
  36 static int isight_firmware_load(struct usb_interface *intf,
  37                                 const struct usb_device_id *id)
  38 {
  39         struct usb_device *dev = interface_to_usbdev(intf);
  40         int llen, len, req, ret = 0;
  41         const struct firmware *firmware;
  42         unsigned char *buf = kmalloc(50, GFP_KERNEL);
  43         unsigned char data[4];
  44         const u8 *ptr;
  45
  46         if (!buf)
  47                 return -ENOMEM;
  48
  49         if (request_firmware(&firmware, "isight.fw", &dev->dev) != 0) {
  50                 printk(KERN_ERR "Unable to load isight firmware\n");
  51                 ret = -ENODEV;
  52                 goto out;
  53         }
  54
  55         ptr = firmware->data;
  56
  57         if (usb_control_msg
  58             (dev, usb_sndctrlpipe(dev, 0), 0xa0, 0x40, 0xe600, 0, "\1", 1,
  59              300) != 1) {
  60                 printk(KERN_ERR
  61                        "Failed to initialise isight firmware loader\n");
  62                 ret = -ENODEV;
  63                 goto out;
  64         }
  65
  66         while (ptr+4 <= firmware->data+firmware->size) {
  67                 memcpy(data, ptr, 4);
  68                 len = (data[0] << 8 | data[1]);
  69                 req = (data[2] << 8 | data[3]);
  70                 ptr += 4;
  71
  72                 if (len == 0x8001)
  73                         break;  /* success */
  74                 else if (len == 0)
  75                         continue;
  76
  77                 for (; len > 0; req += 50) {
  78                         llen = min(len, 50);
  79                         len -= llen;
  80                         if (ptr+llen > firmware->data+firmware->size) {
  81                                 printk(KERN_ERR
  82                                        "Malformed isight firmware");
  83                                 ret = -ENODEV;
  84                                 goto out;
  85                         }
  86                         memcpy(buf, ptr, llen);
  87
  88                         ptr += llen;
  89
  90                         if (usb_control_msg
  91                             (dev, usb_sndctrlpipe(dev, 0), 0xa0, 0x40, req, 0,
  92                              buf, llen, 300) != llen) {
  93                                 printk(KERN_ERR
  94                                        "Failed to load isight firmware\n");
  95                                 ret = -ENODEV;
  96                                 goto out;
  97                         }
  98
  99                 }
 100         }
 101
 102         if (usb_control_msg
 103             (dev, usb_sndctrlpipe(dev, 0), 0xa0, 0x40, 0xe600, 0, "\0", 1,
 104              300) != 1) {
 105                 printk(KERN_ERR "isight firmware loading completion failed\n");
 106                 ret = -ENODEV;
 107         }
 108
 109 out:
 110         kfree(buf);
 111         release_firmware(firmware);
 112         return ret;
 113 }
 114
 115 static void isight_firmware_disconnect(struct usb_interface *intf)
 116 {
 117 }
 118
 119 static struct usb_driver isight_firmware_driver = {
 120         .name = "isight_firmware",
 121         .probe = isight_firmware_load,
 122         .disconnect = isight_firmware_disconnect,
 123         .id_table = id_table,
 124 };
 125
 126 static int __init isight_firmware_init(void)
 127 {
 128         return usb_register(&isight_firmware_driver);
 129 }
 130
 131 static void __exit isight_firmware_exit(void)
 132 {
 133         usb_deregister(&isight_firmware_driver);
 134 }
 135
 136 module_init(isight_firmware_init);
 137 module_exit(isight_firmware_exit);
 138
 139 MODULE_LICENSE("GPL");
 140 MODULE_AUTHOR("Matthew Garrett <mjg@redhat.com>");