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;
43 	unsigned char data[4];
44 	char *ptr;
45 
46 	if (request_firmware(&firmware, "isight.fw", &dev->dev) != 0) {
47 		printk(KERN_ERR "Unable to load isight firmware\n");
48 		return -ENODEV;
49 	}
50 
51 	ptr = firmware->data;
52 
53 	if (usb_control_msg
54 	    (dev, usb_sndctrlpipe(dev, 0), 0xa0, 0x40, 0xe600, 0, "\1", 1,
55 	     300) != 1) {
56 		printk(KERN_ERR
57 		       "Failed to initialise isight firmware loader\n");
58 		ret = -ENODEV;
59 		goto out;
60 	}
61 
62 	while (1) {
63 		memcpy(data, ptr, 4);
64 		len = (data[0] << 8 | data[1]);
65 		req = (data[2] << 8 | data[3]);
66 		ptr += 4;
67 
68 		if (len == 0x8001)
69 			break;	/* success */
70 		else if (len == 0)
71 			continue;
72 
73 		for (; len > 0; req += 50) {
74 			llen = len > 50 ? 50 : len;
75 			len -= llen;
76 
77 			buf = kmalloc(llen, GFP_KERNEL);
78 			memcpy(buf, ptr, llen);
79 
80 			ptr += llen;
81 
82 			if (usb_control_msg
83 			    (dev, usb_sndctrlpipe(dev, 0), 0xa0, 0x40, req, 0,
84 			     buf, llen, 300) != llen) {
85 				printk(KERN_ERR
86 				       "Failed to load isight firmware\n");
87 				kfree(buf);
88 				ret = -ENODEV;
89 				goto out;
90 			}
91 
92 			kfree(buf);
93 		}
94 	}
95 	if (usb_control_msg
96 	    (dev, usb_sndctrlpipe(dev, 0), 0xa0, 0x40, 0xe600, 0, "\0", 1,
97 	     300) != 1) {
98 		printk(KERN_ERR "isight firmware loading completion failed\n");
99 		ret = -ENODEV;
100 	}
101 out:
102 	release_firmware(firmware);
103 	return ret;
104 }
105 
106 static void isight_firmware_disconnect(struct usb_interface *intf)
107 {
108 }
109 
110 static struct usb_driver isight_firmware_driver = {
111 	.name = "isight_firmware",
112 	.probe = isight_firmware_load,
113 	.disconnect = isight_firmware_disconnect,
114 	.id_table = id_table,
115 };
116 
117 static int __init isight_firmware_init(void)
118 {
119 	return usb_register(&isight_firmware_driver);
120 }
121 
122 static void __exit isight_firmware_exit(void)
123 {
124 	usb_deregister(&isight_firmware_driver);
125 }
126 
127 module_init(isight_firmware_init);
128 module_exit(isight_firmware_exit);
129 
130 MODULE_LICENSE("GPL");
131 MODULE_AUTHOR("Matthew Garrett <mjg@redhat.com>");
132