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 
27 static const struct usb_device_id id_table[] = {
28 	{USB_DEVICE(0x05ac, 0x8300)},
29 	{},
30 };
31 
32 MODULE_DEVICE_TABLE(usb, id_table);
33 
34 static 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 
109 out:
110 	kfree(buf);
111 	release_firmware(firmware);
112 	return ret;
113 }
114 
115 MODULE_FIRMWARE("isight.fw");
116 
117 static void isight_firmware_disconnect(struct usb_interface *intf)
118 {
119 }
120 
121 static 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 
128 module_usb_driver(isight_firmware_driver);
129 
130 MODULE_LICENSE("GPL");
131 MODULE_AUTHOR("Matthew Garrett <mjg@redhat.com>");
132