1/*
2 *  MEN 14F021P00 Board Management Controller (BMC) LEDs Driver.
3 *
4 *  This is the core LED driver of the MEN 14F021P00 BMC.
5 *  There are four LEDs available which can be switched on and off.
6 *  STATUS LED, HOT SWAP LED, USER LED 1, USER LED 2
7 *
8 *  Copyright (C) 2014 MEN Mikro Elektronik Nuernberg GmbH
9 *
10 *  This program is free software; you can redistribute  it and/or modify it
11 *  under  the terms of  the GNU General  Public License as published by the
12 *  Free Software Foundation;  either version 2 of the  License, or (at your
13 *  option) any later version.
14 */
15
16#include <linux/module.h>
17#include <linux/kernel.h>
18#include <linux/platform_device.h>
19#include <linux/leds.h>
20#include <linux/i2c.h>
21
22#define BMC_CMD_LED_GET_SET	0xA0
23#define BMC_BIT_LED_STATUS	BIT(0)
24#define BMC_BIT_LED_HOTSWAP	BIT(1)
25#define BMC_BIT_LED_USER1	BIT(2)
26#define BMC_BIT_LED_USER2	BIT(3)
27
28struct menf21bmc_led {
29	struct led_classdev cdev;
30	u8 led_bit;
31	const char *name;
32	struct i2c_client *i2c_client;
33};
34
35static struct menf21bmc_led leds[] = {
36	{
37		.name = "menf21bmc:led_status",
38		.led_bit = BMC_BIT_LED_STATUS,
39	},
40	{
41		.name = "menf21bmc:led_hotswap",
42		.led_bit = BMC_BIT_LED_HOTSWAP,
43	},
44	{
45		.name = "menf21bmc:led_user1",
46		.led_bit = BMC_BIT_LED_USER1,
47	},
48	{
49		.name = "menf21bmc:led_user2",
50		.led_bit = BMC_BIT_LED_USER2,
51	}
52};
53
54static DEFINE_MUTEX(led_lock);
55
56static void
57menf21bmc_led_set(struct led_classdev *led_cdev, enum led_brightness value)
58{
59	int led_val;
60	struct menf21bmc_led *led = container_of(led_cdev,
61					struct menf21bmc_led, cdev);
62
63	mutex_lock(&led_lock);
64	led_val = i2c_smbus_read_byte_data(led->i2c_client,
65					   BMC_CMD_LED_GET_SET);
66	if (led_val < 0)
67		goto err_out;
68
69	if (value == LED_OFF)
70		led_val &= ~led->led_bit;
71	else
72		led_val |= led->led_bit;
73
74	i2c_smbus_write_byte_data(led->i2c_client,
75				  BMC_CMD_LED_GET_SET, led_val);
76err_out:
77	mutex_unlock(&led_lock);
78}
79
80static int menf21bmc_led_probe(struct platform_device *pdev)
81{
82	int i;
83	int ret;
84	struct i2c_client *i2c_client = to_i2c_client(pdev->dev.parent);
85
86	for (i = 0; i < ARRAY_SIZE(leds); i++) {
87		leds[i].cdev.name = leds[i].name;
88		leds[i].cdev.brightness_set = menf21bmc_led_set;
89		leds[i].i2c_client = i2c_client;
90		ret = led_classdev_register(&pdev->dev, &leds[i].cdev);
91		if (ret < 0)
92			goto err_free_leds;
93	}
94	dev_info(&pdev->dev, "MEN 140F21P00 BMC LED device enabled\n");
95
96	return 0;
97
98err_free_leds:
99	dev_err(&pdev->dev, "failed to register LED device\n");
100
101	for (i = i - 1; i >= 0; i--)
102		led_classdev_unregister(&leds[i].cdev);
103
104	return ret;
105}
106
107static int menf21bmc_led_remove(struct platform_device *pdev)
108{
109	int i;
110
111	for (i = 0; i < ARRAY_SIZE(leds); i++)
112		led_classdev_unregister(&leds[i].cdev);
113
114	return 0;
115}
116
117static struct platform_driver menf21bmc_led = {
118	.probe		= menf21bmc_led_probe,
119	.remove		= menf21bmc_led_remove,
120	.driver		= {
121		.name		= "menf21bmc_led",
122	},
123};
124
125module_platform_driver(menf21bmc_led);
126
127MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>");
128MODULE_DESCRIPTION("MEN 14F021P00 BMC led driver");
129MODULE_LICENSE("GPL v2");
130MODULE_ALIAS("platform:menf21bmc_led");
131