xref: /openbmc/linux/arch/arm/common/sharpsl_param.c (revision a9ff6961)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Hardware parameter area specific to Sharp SL series devices
4  *
5  * Copyright (c) 2005 Richard Purdie
6  *
7  * Based on Sharp's 2.4 kernel patches
8  */
9 
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/string.h>
13 #include <asm/mach/sharpsl_param.h>
14 #include <asm/page.h>
15 
16 /*
17  * Certain hardware parameters determined at the time of device manufacture,
18  * typically including LCD parameters are loaded by the bootloader at the
19  * address PARAM_BASE. As the kernel will overwrite them, we need to store
20  * them early in the boot process, then pass them to the appropriate drivers.
21  * Not all devices use all parameters but the format is common to all.
22  */
23 #ifdef CONFIG_ARCH_SA1100
24 #define PARAM_BASE	0xe8ffc000
25 #define param_start(x)	(void *)(x)
26 #else
27 #define PARAM_BASE	0xa0000a00
28 #define param_start(x)	__va(x)
29 #endif
30 #define MAGIC_CHG(a,b,c,d) ( ( d << 24 ) | ( c << 16 )  | ( b << 8 ) | a )
31 
32 #define COMADJ_MAGIC	MAGIC_CHG('C','M','A','D')
33 #define UUID_MAGIC	MAGIC_CHG('U','U','I','D')
34 #define TOUCH_MAGIC	MAGIC_CHG('T','U','C','H')
35 #define AD_MAGIC	MAGIC_CHG('B','V','A','D')
36 #define PHAD_MAGIC	MAGIC_CHG('P','H','A','D')
37 
38 struct sharpsl_param_info sharpsl_param;
39 EXPORT_SYMBOL(sharpsl_param);
40 
sharpsl_save_param(void)41 void sharpsl_save_param(void)
42 {
43 	struct sharpsl_param_info *params = param_start(PARAM_BASE);
44 
45 	memcpy(&sharpsl_param, params, sizeof(*params));
46 
47 	if (sharpsl_param.comadj_keyword != COMADJ_MAGIC)
48 		sharpsl_param.comadj=-1;
49 
50 	if (sharpsl_param.phad_keyword != PHAD_MAGIC)
51 		sharpsl_param.phadadj=-1;
52 
53 	if (sharpsl_param.uuid_keyword != UUID_MAGIC)
54 		sharpsl_param.uuid[0]=-1;
55 
56 	if (sharpsl_param.touch_keyword != TOUCH_MAGIC)
57 		sharpsl_param.touch_xp=-1;
58 
59 	if (sharpsl_param.adadj_keyword != AD_MAGIC)
60 		sharpsl_param.adadj=-1;
61 }
62 
63 
64