drivers/net/wireless/rt2x00/rt2x00firmware.c

   1 /*
   2         Copyright (C) 2004 - 2007 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
  33 static 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
  89 exit:
  90         release_firmware(fw);
  91
  92         return retval;
  93 }
  94
  95 int 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
 114 void rt2x00lib_free_firmware(struct rt2x00_dev *rt2x00dev)
 115 {
 116         release_firmware(rt2x00dev->fw);
 117         rt2x00dev->fw = NULL;
 118 }
 119