LXR linux/drivers/usb/misc/isight

   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
  27static const struct usb_device_id id_table[] = {
  28        {USB_DEVICE(0x05ac, 0x8300)},
  29        {},
  30};
  31
  32MODULE_DEVICE_TABLE(usb, id_table);
  33
  34static 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
 109out:
 110        kfree(buf);
 111        release_firmware(firmware);
 112        return ret;
 113}
 114
 115MODULE_FIRMWARE("isight.fw");
 116
 117static void isight_firmware_disconnect(struct usb_interface *intf)
 118{
 119}
 120
 121static 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
 128module_usb_driver(isight_firmware_driver);
 129
 130MODULE_LICENSE("GPL");
 131MODULE_AUTHOR("Matthew Garrett <mjg@redhat.com>");
 132