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
38struct sharpsl_param_info sharpsl_param;
39EXPORT_SYMBOL(sharpsl_param);
40
41void 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

source code of linux/arch/arm/common/sharpsl_param.c