xref: /openbmc/linux/arch/arm/common/sharpsl_param.c (revision 9cfc5c90)
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 
66