isight_firmware.c

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/*
 * Driver for loading USB isight firmware
 *
 * Copyright (C) 2008 Matthew Garrett <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation, version 2.
 *
 * The USB isight cameras in recent Apples are roughly compatible with the USB
 * video class specification, and can be driven by uvcvideo. However, they
 * need firmware to be loaded beforehand. After firmware loading, the device
 * detaches from the USB bus and reattaches with a new device ID. It can then
 * be claimed by the uvc driver.
 *
 * The firmware is non-free and must be extracted by the user. Tools to do this
 * are available at http://bersace03.free.fr/ift/
 *
 * The isight firmware loading was reverse engineered by Johannes Berg
 * <[email protected]>, and this driver is based on code by Ronald
 * Bultje <[email protected]>
 */

#include <linux/usb.h>
#include <linux/firmware.h>
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/slab.h>

static const struct usb_device_id id_table[] = {
    {USB_DEVICE(0x05ac, 0x8300)},
    {},
};

MODULE_DEVICE_TABLE(usb, id_table);

static int isight_firmware_load(struct usb_interface *intf,
                const struct usb_device_id *id)
{
    struct usb_device *dev = interface_to_usbdev(intf);
    int llen, len, req, ret = 0;
    const struct firmware *firmware;
    unsigned char *buf = kmalloc(50, GFP_KERNEL);
    unsigned char data[4];
    const u8 *ptr;

    if (!buf)
        return -ENOMEM;

    if (request_firmware(&firmware, "isight.fw", &dev->dev) != 0) {
        printk(KERN_ERR "Unable to load isight firmware\n");
        ret = -ENODEV;
        goto out;
    }

    ptr = firmware->data;

    buf[0] = 0x01;
    if (usb_control_msg
        (dev, usb_sndctrlpipe(dev, 0), 0xa0, 0x40, 0xe600, 0, buf, 1,
         300) != 1) {
        printk(KERN_ERR
               "Failed to initialise isight firmware loader\n");
        ret = -ENODEV;
        goto out;
    }

    while (ptr+4 <= firmware->data+firmware->size) {
        memcpy(data, ptr, 4);
        len = (data[0] << 8 | data[1]);
        req = (data[2] << 8 | data[3]);
        ptr += 4;

        if (len == 0x8001)
            break;  /* success */
        else if (len == 0)
            continue;

        for (; len > 0; req += 50) {
            llen = min(len, 50);
            len -= llen;
            if (ptr+llen > firmware->data+firmware->size) {
                printk(KERN_ERR
                       "Malformed isight firmware");
                ret = -ENODEV;
                goto out;
            }
            memcpy(buf, ptr, llen);

            ptr += llen;

            if (usb_control_msg
                (dev, usb_sndctrlpipe(dev, 0), 0xa0, 0x40, req, 0,
                 buf, llen, 300) != llen) {
                printk(KERN_ERR
                       "Failed to load isight firmware\n");
                ret = -ENODEV;
                goto out;
            }

        }
    }

    buf[0] = 0x00;
    if (usb_control_msg
        (dev, usb_sndctrlpipe(dev, 0), 0xa0, 0x40, 0xe600, 0, buf, 1,
         300) != 1) {
        printk(KERN_ERR "isight firmware loading completion failed\n");
        ret = -ENODEV;
    }

out:
    kfree(buf);
    release_firmware(firmware);
    return ret;
}

MODULE_FIRMWARE("isight.fw");

static void isight_firmware_disconnect(struct usb_interface *intf)
{
}

static struct usb_driver isight_firmware_driver = {
    .name = "isight_firmware",
    .probe = isight_firmware_load,
    .disconnect = isight_firmware_disconnect,
    .id_table = id_table,
};

module_usb_driver(isight_firmware_driver);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Matthew Garrett <[email protected]>");