rt2x00firmware.c revision 811aa9cad1bd927999888ab56ed9592519d2fef6 
1/*
2	Copyright (C) 2004 - 2008 rt2x00 SourceForge Project
3	<http://rt2x00.serialmonkey.com>
4
5	This program is free software; you can redistribute it and/or modify
6	it under the terms of the GNU General Public License as published by
7	the Free Software Foundation; either version 2 of the License, or
8	(at your option) any later version.
9
10	This program is distributed in the hope that it will be useful,
11	but WITHOUT ANY WARRANTY; without even the implied warranty of
12	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13	GNU General Public License for more details.
14
15	You should have received a copy of the GNU General Public License
16	along with this program; if not, write to the
17	Free Software Foundation, Inc.,
18	59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
19 */
20
21/*
22	Module: rt2x00lib
23	Abstract: rt2x00 firmware loading routines.
24 */
25
26#include <linux/crc-itu-t.h>
27#include <linux/kernel.h>
28#include <linux/module.h>
29
30#include "rt2x00.h"
31#include "rt2x00lib.h"
32
33static int rt2x00lib_request_firmware(struct rt2x00_dev *rt2x00dev)
34{
35	struct device *device = wiphy_dev(rt2x00dev->hw->wiphy);
36	const struct firmware *fw;
37	char *fw_name;
38	int retval;
39	u16 crc;
40	u16 tmp;
41
42	/*
43	 * Read correct firmware from harddisk.
44	 */
45	fw_name = rt2x00dev->ops->lib->get_firmware_name(rt2x00dev);
46	if (!fw_name) {
47		ERROR(rt2x00dev,
48		      "Invalid firmware filename.\n"
49		      "Please file bug report to %s.\n", DRV_PROJECT);
50		return -EINVAL;
51	}
52
53	INFO(rt2x00dev, "Loading firmware file '%s'.\n", fw_name);
54
55	retval = request_firmware(&fw, fw_name, device);
56	if (retval) {
57		ERROR(rt2x00dev, "Failed to request Firmware.\n");
58		return retval;
59	}
60
61	if (!fw || !fw->size || !fw->data) {
62		ERROR(rt2x00dev, "Failed to read Firmware.\n");
63		return -ENOENT;
64	}
65
66	/*
67	 * Validate the firmware using 16 bit CRC.
68	 * The last 2 bytes of the firmware are the CRC
69	 * so substract those 2 bytes from the CRC checksum,
70	 * and set those 2 bytes to 0 when calculating CRC.
71	 */
72	tmp = 0;
73	crc = crc_itu_t(0, fw->data, fw->size - 2);
74	crc = crc_itu_t(crc, (u8 *)&tmp, 2);
75
76	if (crc != (fw->data[fw->size - 2] << 8 | fw->data[fw->size - 1])) {
77		ERROR(rt2x00dev, "Firmware CRC error.\n");
78		retval = -ENOENT;
79		goto exit;
80	}
81
82	INFO(rt2x00dev, "Firmware detected - version: %d.%d.\n",
83	     fw->data[fw->size - 4], fw->data[fw->size - 3]);
84
85	rt2x00dev->fw = fw;
86
87	return 0;
88
89exit:
90	release_firmware(fw);
91
92	return retval;
93}
94
95int rt2x00lib_load_firmware(struct rt2x00_dev *rt2x00dev)
96{
97	int retval;
98
99	if (!rt2x00dev->fw) {
100		retval = rt2x00lib_request_firmware(rt2x00dev);
101		if (retval)
102			return retval;
103	}
104
105	/*
106	 * Send firmware to the device.
107	 */
108	retval = rt2x00dev->ops->lib->load_firmware(rt2x00dev,
109						    rt2x00dev->fw->data,
110						    rt2x00dev->fw->size);
111	return retval;
112}
113
114void rt2x00lib_free_firmware(struct rt2x00_dev *rt2x00dev)
115{
116	release_firmware(rt2x00dev->fw);
117	rt2x00dev->fw = NULL;
118}
119
120