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;
  43         unsigned char data[4];
  44         char *ptr;
  45
  46         if (request_firmware(&firmware, "isight.fw", &dev->dev) != 0) {
  47                 printk(KERN_ERR "Unable to load isight firmware\n");
  48                 return -ENODEV;
  49         }
  50
  51         ptr = firmware->data;
  52
  53         if (usb_control_msg
  54             (dev, usb_sndctrlpipe(dev, 0), 0xa0, 0x40, 0xe600, 0, "\1", 1,
  55              300) != 1) {
  56                 printk(KERN_ERR
  57                        "Failed to initialise isight firmware loader\n");
  58                 ret = -ENODEV;
  59                 goto out;
  60         }
  61
  62         while (1) {
  63                 memcpy(data, ptr, 4);
  64                 len = (data[0] << 8 | data[1]);
  65                 req = (data[2] << 8 | data[3]);
  66                 ptr += 4;
  67
  68                 if (len == 0x8001)
  69                         break;  /* success */
  70                 else if (len == 0)
  71                         continue;
  72
  73                 for (; len > 0; req += 50) {
  74                         llen = len > 50 ? 50 : len;
  75                         len -= llen;
  76
  77                         buf = kmalloc(llen, GFP_KERNEL);
  78                         memcpy(buf, ptr, llen);
  79
  80                         ptr += llen;
  81
  82                         if (usb_control_msg
  83                             (dev, usb_sndctrlpipe(dev, 0), 0xa0, 0x40, req, 0,
  84                              buf, llen, 300) != llen) {
  85                                 printk(KERN_ERR
  86                                        "Failed to load isight firmware\n");
  87                                 kfree(buf);
  88                                 ret = -ENODEV;
  89                                 goto out;
  90                         }
  91
  92                         kfree(buf);
  93                 }
  94         }
  95         if (usb_control_msg
  96             (dev, usb_sndctrlpipe(dev, 0), 0xa0, 0x40, 0xe600, 0, "\0", 1,
  97              300) != 1) {
  98                 printk(KERN_ERR "isight firmware loading completion failed\n");
  99                 ret = -ENODEV;
 100         }
 101 out:
 102         release_firmware(firmware);
 103         return ret;
 104 }
 105
 106 static void isight_firmware_disconnect(struct usb_interface *intf)
 107 {
 108 }
 109
 110 static struct usb_driver isight_firmware_driver = {
 111         .name = "isight_firmware",
 112         .probe = isight_firmware_load,
 113         .disconnect = isight_firmware_disconnect,
 114         .id_table = id_table,
 115 };
 116
 117 static int __init isight_firmware_init(void)
 118 {
 119         return usb_register(&isight_firmware_driver);
 120 }
 121
 122 static void __exit isight_firmware_exit(void)
 123 {
 124         usb_deregister(&isight_firmware_driver);
 125 }
 126
 127 module_init(isight_firmware_init);
 128 module_exit(isight_firmware_exit);
 129
 130 MODULE_LICENSE("GPL");
 131 MODULE_AUTHOR("Matthew Garrett <mjg@redhat.com>");