drivers/usb/misc/isight_firmware.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Driver for loading USB isight firmware
   4  *
   5  * Copyright (C) 2008 Matthew Garrett <mjg@redhat.com>
   6  *
   7  * The USB isight cameras in recent Apples are roughly compatible with the USB
   8  * video class specification, and can be driven by uvcvideo. However, they
   9  * need firmware to be loaded beforehand. After firmware loading, the device
  10  * detaches from the USB bus and reattaches with a new device ID. It can then
  11  * be claimed by the uvc driver.
  12  *
  13  * The firmware is non-free and must be extracted by the user. Tools to do this
  14  * are available at http://bersace03.free.fr/ift/
  15  *
  16  * The isight firmware loading was reverse engineered by Johannes Berg
  17  * <johannes@sipsolutions.de>, and this driver is based on code by Ronald
  18  * Bultje <rbultje@ronald.bitfreak.net>
  19  */
  20
  21 #include <linux/usb.h>
  22 #include <linux/firmware.h>
  23 #include <linux/errno.h>
  24 #include <linux/module.h>
  25 #include <linux/slab.h>
  26
  27 static const struct usb_device_id id_table[] = {
  28         {USB_DEVICE(0x05ac, 0x8300)},
  29         {},
  30 };
  31
  32 MODULE_DEVICE_TABLE(usb, id_table);
  33
  34 static int isight_firmware_load(struct usb_interface *intf,
  35                                 const struct usb_device_id *id)
  36 {
  37         struct usb_device *dev = interface_to_usbdev(intf);
  38         int llen, len, req, ret = 0;
  39         const struct firmware *firmware;
  40         unsigned char *buf = kmalloc(50, GFP_KERNEL);
  41         unsigned char data[4];
  42         const u8 *ptr;
  43
  44         if (!buf)
  45                 return -ENOMEM;
  46
  47         if (request_firmware(&firmware, "isight.fw", &dev->dev) != 0) {
  48                 printk(KERN_ERR "Unable to load isight firmware\n");
  49                 ret = -ENODEV;
  50                 goto out;
  51         }
  52
  53         ptr = firmware->data;
  54
  55         buf[0] = 0x01;
  56         if (usb_control_msg
  57             (dev, usb_sndctrlpipe(dev, 0), 0xa0, 0x40, 0xe600, 0, buf, 1,
  58              300) != 1) {
  59                 printk(KERN_ERR
  60                        "Failed to initialise isight firmware loader\n");
  61                 ret = -ENODEV;
  62                 goto out;
  63         }
  64
  65         while (ptr+4 <= firmware->data+firmware->size) {
  66                 memcpy(data, ptr, 4);
  67                 len = (data[0] << 8 | data[1]);
  68                 req = (data[2] << 8 | data[3]);
  69                 ptr += 4;
  70
  71                 if (len == 0x8001)
  72                         break;  /* success */
  73                 else if (len == 0)
  74                         continue;
  75
  76                 for (; len > 0; req += 50) {
  77                         llen = min(len, 50);
  78                         len -= llen;
  79                         if (ptr+llen > firmware->data+firmware->size) {
  80                                 printk(KERN_ERR
  81                                        "Malformed isight firmware");
  82                                 ret = -ENODEV;
  83                                 goto out;
  84                         }
  85                         memcpy(buf, ptr, llen);
  86
  87                         ptr += llen;
  88
  89                         if (usb_control_msg
  90                             (dev, usb_sndctrlpipe(dev, 0), 0xa0, 0x40, req, 0,
  91                              buf, llen, 300) != llen) {
  92                                 printk(KERN_ERR
  93                                        "Failed to load isight firmware\n");
  94                                 ret = -ENODEV;
  95                                 goto out;
  96                         }
  97
  98                 }
  99         }
 100
 101         buf[0] = 0x00;
 102         if (usb_control_msg
 103             (dev, usb_sndctrlpipe(dev, 0), 0xa0, 0x40, 0xe600, 0, buf, 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 MODULE_FIRMWARE("isight.fw");
 116
 117 static void isight_firmware_disconnect(struct usb_interface *intf)
 118 {
 119 }
 120
 121 static struct usb_driver isight_firmware_driver = {
 122         .name = "isight_firmware",
 123         .probe = isight_firmware_load,
 124         .disconnect = isight_firmware_disconnect,
 125         .id_table = id_table,
 126 };
 127
 128 module_usb_driver(isight_firmware_driver);
 129
 130 MODULE_LICENSE("GPL");
 131 MODULE_AUTHOR("Matthew Garrett <mjg@redhat.com>");