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 #include <linux/slab.h>
  29
  30 static const struct usb_device_id id_table[] = {
  31         {USB_DEVICE(0x05ac, 0x8300)},
  32         {},
  33 };
  34
  35 MODULE_DEVICE_TABLE(usb, id_table);
  36
  37 static int isight_firmware_load(struct usb_interface *intf,
  38                                 const struct usb_device_id *id)
  39 {
  40         struct usb_device *dev = interface_to_usbdev(intf);
  41         int llen, len, req, ret = 0;
  42         const struct firmware *firmware;
  43         unsigned char *buf = kmalloc(50, GFP_KERNEL);
  44         unsigned char data[4];
  45         const u8 *ptr;
  46
  47         if (!buf)
  48                 return -ENOMEM;
  49
  50         if (request_firmware(&firmware, "isight.fw", &dev->dev) != 0) {
  51                 printk(KERN_ERR "Unable to load isight firmware\n");
  52                 ret = -ENODEV;
  53                 goto out;
  54         }
  55
  56         ptr = firmware->data;
  57
  58         if (usb_control_msg
  59             (dev, usb_sndctrlpipe(dev, 0), 0xa0, 0x40, 0xe600, 0, "\1", 1,
  60              300) != 1) {
  61                 printk(KERN_ERR
  62                        "Failed to initialise isight firmware loader\n");
  63                 ret = -ENODEV;
  64                 goto out;
  65         }
  66
  67         while (ptr+4 <= firmware->data+firmware->size) {
  68                 memcpy(data, ptr, 4);
  69                 len = (data[0] << 8 | data[1]);
  70                 req = (data[2] << 8 | data[3]);
  71                 ptr += 4;
  72
  73                 if (len == 0x8001)
  74                         break;  /* success */
  75                 else if (len == 0)
  76                         continue;
  77
  78                 for (; len > 0; req += 50) {
  79                         llen = min(len, 50);
  80                         len -= llen;
  81                         if (ptr+llen > firmware->data+firmware->size) {
  82                                 printk(KERN_ERR
  83                                        "Malformed isight firmware");
  84                                 ret = -ENODEV;
  85                                 goto out;
  86                         }
  87                         memcpy(buf, ptr, llen);
  88
  89                         ptr += llen;
  90
  91                         if (usb_control_msg
  92                             (dev, usb_sndctrlpipe(dev, 0), 0xa0, 0x40, req, 0,
  93                              buf, llen, 300) != llen) {
  94                                 printk(KERN_ERR
  95                                        "Failed to load isight firmware\n");
  96                                 ret = -ENODEV;
  97                                 goto out;
  98                         }
  99
 100                 }
 101         }
 102
 103         if (usb_control_msg
 104             (dev, usb_sndctrlpipe(dev, 0), 0xa0, 0x40, 0xe600, 0, "\0", 1,
 105              300) != 1) {
 106                 printk(KERN_ERR "isight firmware loading completion failed\n");
 107                 ret = -ENODEV;
 108         }
 109
 110 out:
 111         kfree(buf);
 112         release_firmware(firmware);
 113         return ret;
 114 }
 115
 116 MODULE_FIRMWARE("isight.fw");
 117
 118 static void isight_firmware_disconnect(struct usb_interface *intf)
 119 {
 120 }
 121
 122 static struct usb_driver isight_firmware_driver = {
 123         .name = "isight_firmware",
 124         .probe = isight_firmware_load,
 125         .disconnect = isight_firmware_disconnect,
 126         .id_table = id_table,
 127 };
 128
 129 static int __init isight_firmware_init(void)
 130 {
 131         return usb_register(&isight_firmware_driver);
 132 }
 133
 134 static void __exit isight_firmware_exit(void)
 135 {
 136         usb_deregister(&isight_firmware_driver);
 137 }
 138
 139 module_init(isight_firmware_init);
 140 module_exit(isight_firmware_exit);
 141
 142 MODULE_LICENSE("GPL");
 143 MODULE_AUTHOR("Matthew Garrett <mjg@redhat.com>");