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