aboutsummaryrefslogtreecommitdiff
path: root/drivers/leds/leds-menf21bmc.c
blob: 89dd57769e3b027b498cad3a0bc353d7e782ebf0 (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
/*
 *  MEN 14F021P00 Board Management Controller (BMC) LEDs Driver.
 *
 *  This is the core LED driver of the MEN 14F021P00 BMC.
 *  There are four LEDs available which can be switched on and off.
 *  STATUS LED, HOT SWAP LED, USER LED 1, USER LED 2
 *
 *  Copyright (C) 2014 MEN Mikro Elektronik Nuernberg GmbH
 *
 *  This program is free software; you can redistribute  it and/or modify it
 *  under  the terms of  the GNU General  Public License as published by the
 *  Free Software Foundation;  either version 2 of the  License, or (at your
 *  option) any later version.
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/leds.h>
#include <linux/i2c.h>

#define BMC_CMD_LED_GET_SET	0xA0
#define BMC_BIT_LED_STATUS	BIT(0)
#define BMC_BIT_LED_HOTSWAP	BIT(1)
#define BMC_BIT_LED_USER1	BIT(2)
#define BMC_BIT_LED_USER2	BIT(3)

struct menf21bmc_led {
	struct led_classdev cdev;
	u8 led_bit;
	const char *name;
	struct i2c_client *i2c_client;
};

static struct menf21bmc_led leds[] = {
	{
		.name = "menf21bmc:led_status",
		.led_bit = BMC_BIT_LED_STATUS,
	},
	{
		.name = "menf21bmc:led_hotswap",
		.led_bit = BMC_BIT_LED_HOTSWAP,
	},
	{
		.name = "menf21bmc:led_user1",
		.led_bit = BMC_BIT_LED_USER1,
	},
	{
		.name = "menf21bmc:led_user2",
		.led_bit = BMC_BIT_LED_USER2,
	}
};

static DEFINE_MUTEX(led_lock);

static void
menf21bmc_led_set(struct led_classdev *led_cdev, enum led_brightness value)
{
	int led_val;
	struct menf21bmc_led *led = container_of(led_cdev,
					struct menf21bmc_led, cdev);

	mutex_lock(&led_lock);
	led_val = i2c_smbus_read_byte_data(led->i2c_client,
					   BMC_CMD_LED_GET_SET);
	if (led_val < 0)
		goto err_out;

	if (value == LED_OFF)
		led_val &= ~led->led_bit;
	else
		led_val |= led->led_bit;

	i2c_smbus_write_byte_data(led->i2c_client,
				  BMC_CMD_LED_GET_SET, led_val);
err_out:
	mutex_unlock(&led_lock);
}

static int menf21bmc_led_probe(struct platform_device *pdev)
{
	int i;
	int ret;
	struct i2c_client *i2c_client = to_i2c_client(pdev->dev.parent);

	for (i = 0; i < ARRAY_SIZE(leds); i++) {
		leds[i].cdev.name = leds[i].name;
		leds[i].cdev.brightness_set = menf21bmc_led_set;
		leds[i].i2c_client = i2c_client;
		ret = led_classdev_register(&pdev->dev, &leds[i].cdev);
		if (ret < 0)
			goto err_free_leds;
	}
	dev_info(&pdev->dev, "MEN 140F21P00 BMC LED device enabled\n");

	return 0;

err_free_leds:
	dev_err(&pdev->dev, "failed to register LED device\n");

	for (i = i - 1; i >= 0; i--)
		led_classdev_unregister(&leds[i].cdev);

	return ret;
}

static int menf21bmc_led_remove(struct platform_device *pdev)
{
	int i;

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

	return 0;
}

static struct platform_driver menf21bmc_led = {
	.probe		= menf21bmc_led_probe,
	.remove		= menf21bmc_led_remove,
	.driver		= {
		.name		= "menf21bmc_led",
		.owner		= THIS_MODULE,
	},
};

module_platform_driver(menf21bmc_led);

MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>");
MODULE_DESCRIPTION("MEN 14F021P00 BMC led driver");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:menf21bmc_led");