aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/leds/leds-alix2.c
blob: 731d4eef342590dca6566f229d60d7f8add6b872 (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
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
/*
 * LEDs driver for PCEngines ALIX.2 and ALIX.3
 *
 * Copyright (C) 2008 Constantin Baranov <const@mimas.ru>
 */

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

static int force = 0;
module_param(force, bool, 0444);
MODULE_PARM_DESC(force, "Assume system has ALIX.2/ALIX.3 style LEDs");

struct alix_led {
	struct led_classdev cdev;
	unsigned short port;
	unsigned int on_value;
	unsigned int off_value;
};

static void alix_led_set(struct led_classdev *led_cdev,
			 enum led_brightness brightness)
{
	struct alix_led *led_dev =
		container_of(led_cdev, struct alix_led, cdev);

	if (brightness)
		outl(led_dev->on_value, led_dev->port);
	else
		outl(led_dev->off_value, led_dev->port);
}

static struct alix_led alix_leds[] = {
	{
		.cdev = {
			.name = "alix:1",
			.brightness_set = alix_led_set,
		},
		.port = 0x6100,
		.on_value = 1 << 22,
		.off_value = 1 << 6,
	},
	{
		.cdev = {
			.name = "alix:2",
			.brightness_set = alix_led_set,
		},
		.port = 0x6180,
		.on_value = 1 << 25,
		.off_value = 1 << 9,
	},
	{
		.cdev = {
			.name = "alix:3",
			.brightness_set = alix_led_set,
		},
		.port = 0x6180,
		.on_value = 1 << 27,
		.off_value = 1 << 11,
	},
};

static int __init alix_led_probe(struct platform_device *pdev)
{
	int i;
	int ret;

	for (i = 0; i < ARRAY_SIZE(alix_leds); i++) {
		alix_leds[i].cdev.flags |= LED_CORE_SUSPENDRESUME;
		ret = led_classdev_register(&pdev->dev, &alix_leds[i].cdev);
		if (ret < 0)
			goto fail;
	}
	return 0;

fail:
	while (--i >= 0)
		led_classdev_unregister(&alix_leds[i].cdev);
	return ret;
}

static int alix_led_remove(struct platform_device *pdev)
{
	int i;

	for (i = 0; i < ARRAY_SIZE(alix_leds); i++)
		led_classdev_unregister(&alix_leds[i].cdev);
	return 0;
}

static struct platform_driver alix_led_driver = {
	.remove = alix_led_remove,
	.driver = {
		.name = KBUILD_MODNAME,
		.owner = THIS_MODULE,
	},
};

static int __init alix_present(void)
{
	const unsigned long bios_phys = 0x000f0000;
	const size_t bios_len = 0x00010000;
	const char alix_sig[] = "PC Engines ALIX.";
	const size_t alix_sig_len = sizeof(alix_sig) - 1;

	const char *bios_virt;
	const char *scan_end;
	const char *p;
	int ret = 0;

	if (force) {
		printk(KERN_NOTICE "%s: forced to skip BIOS test, "
		       "assume system has ALIX.2 style LEDs\n",
		       KBUILD_MODNAME);
		ret = 1;
		goto out;
	}

	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;

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

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

out:
	return ret;
}

static struct platform_device *pdev;

static int __init alix_led_init(void)
{
	int ret;

	if (!alix_present()) {
		ret = -ENODEV;
		goto out;
	}

	/* enable output on GPIO for LED 1,2,3 */
	outl(1 << 6, 0x6104);
	outl(1 << 9, 0x6184);
	outl(1 << 11, 0x6184);

	pdev = platform_device_register_simple(KBUILD_MODNAME, -1, NULL, 0);
	if (!IS_ERR(pdev)) {
		ret = platform_driver_probe(&alix_led_driver, alix_led_probe);
		if (ret)
			platform_device_unregister(pdev);
	} else
		ret = PTR_ERR(pdev);

out:
	return ret;
}

static void __exit alix_led_exit(void)
{
	platform_device_unregister(pdev);
	platform_driver_unregister(&alix_led_driver);
}

module_init(alix_led_init);
module_exit(alix_led_exit);

MODULE_AUTHOR("Constantin Baranov <const@mimas.ru>");
MODULE_DESCRIPTION("PCEngines ALIX.2 and ALIX.3 LED driver");
MODULE_LICENSE("GPL");