summaryrefslogtreecommitdiffstats
path: root/arch/x86/platform/geode/alix.c
blob: ca1973699d3d7002871d8de2a7c3db5a0315c136 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
/*
 * System Specific setup for PCEngines ALIX.
 * At the moment this means setup of GPIO control of LEDs
 * on Alix.2/3/6 boards.
 *
 *
 * Copyright (C) 2008 Constantin Baranov <const@mimas.ru>
 * Copyright (C) 2011 Ed Wildgoose <kernel@wildgooses.com>
 *
 * TODO: There are large similarities with leds-net5501.c
 * by Alessandro Zummo <a.zummo@towertech.it>
 * In the future leds-net5501.c should be migrated over to platform
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2
 * as published by the Free Software Foundation.
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/string.h>
#include <linux/module.h>
#include <linux/leds.h>
#include <linux/platform_device.h>
#include <linux/gpio.h>

#include <asm/geode.h>

static int force = 0;
module_param(force, bool, 0444);
/* FIXME: Award bios is not automatically detected as Alix platform */
MODULE_PARM_DESC(force, "Force detection as ALIX.2/ALIX.3 platform");

static struct gpio_led alix_leds[] = {
	{
		.name = "alix:1",
		.gpio = 6,
		.default_trigger = "default-on",
		.active_low = 1,
	},
	{
		.name = "alix:2",
		.gpio = 25,
		.default_trigger = "default-off",
		.active_low = 1,
	},
	{
		.name = "alix:3",
		.gpio = 27,
		.default_trigger = "default-off",
		.active_low = 1,
	},
};

static struct gpio_led_platform_data alix_leds_data = {
	.num_leds = ARRAY_SIZE(alix_leds),
	.leds = alix_leds,
};

static struct platform_device alix_leds_dev = {
	.name = "leds-gpio",
	.id = -1,
	.dev.platform_data = &alix_leds_data,
};

static void __init register_alix(void)
{
	/* Setup LED control through leds-gpio driver */
	platform_device_register(&alix_leds_dev);
}

static int __init alix_present(unsigned long bios_phys,
				const char *alix_sig,
				size_t alix_sig_len)
{
	const size_t bios_len = 0x00010000;
	const char *bios_virt;
	const char *scan_end;
	const char *p;
	char name[64];

	if (force) {
		printk(KERN_NOTICE "%s: forced to skip BIOS test, "
		       "assume system is ALIX.2/ALIX.3\n",
		       KBUILD_MODNAME);
		return 1;
	}

	bios_virt = phys_to_virt(bios_phys);
	scan_end = bios_virt + bios_len - (alix_sig_len + 2);
	for (p = bios_virt; p < scan_end; p++) {
		const char *tail;
		char *a;

		if (memcmp(p, alix_sig, alix_sig_len) != 0)
			continue;

		memcpy(name, p, sizeof(name));

		/* remove the first \0 character from string */
		a = strchr(name, '\0');
		if (a)
			*a = ' ';

		/* cut the string at a newline */
		a = strchr(name, '\r');
		if (a)
			*a = '\0';

		tail = p + alix_sig_len;
		if ((tail[0] == '2' || tail[0] == '3')) {
			printk(KERN_INFO
			       "%s: system is recognized as \"%s\"\n",
			       KBUILD_MODNAME, name);
			return 1;
		}
	}

	return 0;
}

static int __init alix_init(void)
{
	const char tinybios_sig[] = "PC Engines ALIX.";
	const char coreboot_sig[] = "PC Engines\0ALIX.";

	if (!is_geode())
		return 0;

	if (alix_present(0xf0000, tinybios_sig, sizeof(tinybios_sig) - 1) ||
	    alix_present(0x500, coreboot_sig, sizeof(coreboot_sig) - 1))
		register_alix();

	return 0;
}

module_init(alix_init);

MODULE_AUTHOR("Ed Wildgoose <kernel@wildgooses.com>");
MODULE_DESCRIPTION("PCEngines ALIX System Setup");
MODULE_LICENSE("GPL");