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 
30 static const struct usb_device_id id_table[] = {
31 	{USB_DEVICE(0x05ac, 0x8300)},
32 	{},
33 };
34 
35 MODULE_DEVICE_TABLE(usb, id_table);
36 
37 static 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 
112 out:
113 	kfree(buf);
114 	release_firmware(firmware);
115 	return ret;
116 }
117 
118 MODULE_FIRMWARE("isight.fw");
119 
120 static void isight_firmware_disconnect(struct usb_interface *intf)
121 {
122 }
123 
124 static 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 
131 module_usb_driver(isight_firmware_driver);
132 
133 MODULE_LICENSE("GPL");
134 MODULE_AUTHOR("Matthew Garrett <mjg@redhat.com>");
135