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 
29 static struct usb_device_id id_table[] = {
30 	{USB_DEVICE(0x05ac, 0x8300)},
31 	{},
32 };
33 
34 MODULE_DEVICE_TABLE(usb, id_table);
35 
36 static int isight_firmware_load(struct usb_interface *intf,
37 				const struct usb_device_id *id)
38 {
39 	struct usb_device *dev = interface_to_usbdev(intf);
40 	int llen, len, req, ret = 0;
41 	const struct firmware *firmware;
42 	unsigned char *buf = kmalloc(50, GFP_KERNEL);
43 	unsigned char data[4];
44 	const u8 *ptr;
45 
46 	if (!buf)
47 		return -ENOMEM;
48 
49 	if (request_firmware(&firmware, "isight.fw", &dev->dev) != 0) {
50 		printk(KERN_ERR "Unable to load isight firmware\n");
51 		ret = -ENODEV;
52 		goto out;
53 	}
54 
55 	ptr = firmware->data;
56 
57 	if (usb_control_msg
58 	    (dev, usb_sndctrlpipe(dev, 0), 0xa0, 0x40, 0xe600, 0, "\1", 1,
59 	     300) != 1) {
60 		printk(KERN_ERR
61 		       "Failed to initialise isight firmware loader\n");
62 		ret = -ENODEV;
63 		goto out;
64 	}
65 
66 	while (ptr+4 <= firmware->data+firmware->size) {
67 		memcpy(data, ptr, 4);
68 		len = (data[0] << 8 | data[1]);
69 		req = (data[2] << 8 | data[3]);
70 		ptr += 4;
71 
72 		if (len == 0x8001)
73 			break;	/* success */
74 		else if (len == 0)
75 			continue;
76 
77 		for (; len > 0; req += 50) {
78 			llen = min(len, 50);
79 			len -= llen;
80 			if (ptr+llen > firmware->data+firmware->size) {
81 				printk(KERN_ERR
82 				       "Malformed isight firmware");
83 				ret = -ENODEV;
84 				goto out;
85 			}
86 			memcpy(buf, ptr, llen);
87 
88 			ptr += llen;
89 
90 			if (usb_control_msg
91 			    (dev, usb_sndctrlpipe(dev, 0), 0xa0, 0x40, req, 0,
92 			     buf, llen, 300) != llen) {
93 				printk(KERN_ERR
94 				       "Failed to load isight firmware\n");
95 				ret = -ENODEV;
96 				goto out;
97 			}
98 
99 		}
100 	}
101 
102 	if (usb_control_msg
103 	    (dev, usb_sndctrlpipe(dev, 0), 0xa0, 0x40, 0xe600, 0, "\0", 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 static void isight_firmware_disconnect(struct usb_interface *intf)
116 {
117 }
118 
119 static struct usb_driver isight_firmware_driver = {
120 	.name = "isight_firmware",
121 	.probe = isight_firmware_load,
122 	.disconnect = isight_firmware_disconnect,
123 	.id_table = id_table,
124 };
125 
126 static int __init isight_firmware_init(void)
127 {
128 	return usb_register(&isight_firmware_driver);
129 }
130 
131 static void __exit isight_firmware_exit(void)
132 {
133 	usb_deregister(&isight_firmware_driver);
134 }
135 
136 module_init(isight_firmware_init);
137 module_exit(isight_firmware_exit);
138 
139 MODULE_LICENSE("GPL");
140 MODULE_AUTHOR("Matthew Garrett <mjg@redhat.com>");
141