arch/arm/common/sharpsl_param.c

   1 /*
   2  * Hardware parameter area specific to Sharp SL series devices
   3  *
   4  * Copyright (c) 2005 Richard Purdie
   5  *
   6  * Based on Sharp's 2.4 kernel patches
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  *
  12  */
  13
  14 #include <linux/kernel.h>
  15 #include <linux/module.h>
  16 #include <linux/string.h>
  17 #include <asm/mach/sharpsl_param.h>
  18 #include <asm/memory.h>
  19
  20 /*
  21  * Certain hardware parameters determined at the time of device manufacture,
  22  * typically including LCD parameters are loaded by the bootloader at the
  23  * address PARAM_BASE. As the kernel will overwrite them, we need to store
  24  * them early in the boot process, then pass them to the appropriate drivers.
  25  * Not all devices use all parameters but the format is common to all.
  26  */
  27 #ifdef CONFIG_ARCH_SA1100
  28 #define PARAM_BASE      0xe8ffc000
  29 #define param_start(x)  (void *)(x)
  30 #else
  31 #define PARAM_BASE      0xa0000a00
  32 #define param_start(x)  __va(x)
  33 #endif
  34 #define MAGIC_CHG(a,b,c,d) ( ( d << 24 ) | ( c << 16 )  | ( b << 8 ) | a )
  35
  36 #define COMADJ_MAGIC    MAGIC_CHG('C','M','A','D')
  37 #define UUID_MAGIC      MAGIC_CHG('U','U','I','D')
  38 #define TOUCH_MAGIC     MAGIC_CHG('T','U','C','H')
  39 #define AD_MAGIC        MAGIC_CHG('B','V','A','D')
  40 #define PHAD_MAGIC      MAGIC_CHG('P','H','A','D')
  41
  42 struct sharpsl_param_info sharpsl_param;
  43 EXPORT_SYMBOL(sharpsl_param);
  44
  45 void sharpsl_save_param(void)
  46 {
  47         memcpy(&sharpsl_param, param_start(PARAM_BASE), sizeof(struct sharpsl_param_info));
  48
  49         if (sharpsl_param.comadj_keyword != COMADJ_MAGIC)
  50                 sharpsl_param.comadj=-1;
  51
  52         if (sharpsl_param.phad_keyword != PHAD_MAGIC)
  53                 sharpsl_param.phadadj=-1;
  54
  55         if (sharpsl_param.uuid_keyword != UUID_MAGIC)
  56                 sharpsl_param.uuid[0]=-1;
  57
  58         if (sharpsl_param.touch_keyword != TOUCH_MAGIC)
  59                 sharpsl_param.touch_xp=-1;
  60
  61         if (sharpsl_param.adadj_keyword != AD_MAGIC)
  62                 sharpsl_param.adadj=-1;
  63 }
  64
  65