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
30static const struct usb_device_id id_table[] = {
31	{USB_DEVICE(0x05ac, 0x8300)},
32	{},
33};
34
35MODULE_DEVICE_TABLE(usb, id_table);
36
37static 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	buf[0] = 0x01;
59	if (usb_control_msg
60	    (dev, usb_sndctrlpipe(dev, 0), 0xa0, 0x40, 0xe600, 0, buf, 1,
61	     300) != 1) {
62		printk(KERN_ERR
63		       "Failed to initialise isight firmware loader\n");
64		ret = -ENODEV;
65		goto out;
66	}
67
68	while (ptr+4 <= firmware->data+firmware->size) {
69		memcpy(data, ptr, 4);
70		len = (data[0] << 8 | data[1]);
71		req = (data[2] << 8 | data[3]);
72		ptr += 4;
73
74		if (len == 0x8001)
75			break;	/* success */
76		else if (len == 0)
77			continue;
78
79		for (; len > 0; req += 50) {
80			llen = min(len, 50);
81			len -= llen;
82			if (ptr+llen > firmware->data+firmware->size) {
83				printk(KERN_ERR
84				       "Malformed isight firmware");
85				ret = -ENODEV;
86				goto out;
87			}
88			memcpy(buf, ptr, llen);
89
90			ptr += llen;
91
92			if (usb_control_msg
93			    (dev, usb_sndctrlpipe(dev, 0), 0xa0, 0x40, req, 0,
94			     buf, llen, 300) != llen) {
95				printk(KERN_ERR
96				       "Failed to load isight firmware\n");
97				ret = -ENODEV;
98				goto out;
99			}
100
101		}
102	}
103
104	buf[0] = 0x00;
105	if (usb_control_msg
106	    (dev, usb_sndctrlpipe(dev, 0), 0xa0, 0x40, 0xe600, 0, buf, 1,
107	     300) != 1) {
108		printk(KERN_ERR "isight firmware loading completion failed\n");
109		ret = -ENODEV;
110	}
111
112out:
113	kfree(buf);
114	release_firmware(firmware);
115	return ret;
116}
117
118MODULE_FIRMWARE("isight.fw");
119
120static void isight_firmware_disconnect(struct usb_interface *intf)
121{
122}
123
124static struct usb_driver isight_firmware_driver = {
125	.name = "isight_firmware",
126	.probe = isight_firmware_load,
127	.disconnect = isight_firmware_disconnect,
128	.id_table = id_table,
129};
130
131module_usb_driver(isight_firmware_driver);
132
133MODULE_LICENSE("GPL");
134MODULE_AUTHOR("Matthew Garrett <mjg@redhat.com>");
135