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 = devm_led_classdev_register(&pdev->dev, &leds[i].cdev);
 91		if (ret < 0) {
 92			dev_err(&pdev->dev, "failed to register LED device\n");
 93			return ret;
 94		}
 95	}
 96	dev_info(&pdev->dev, "MEN 140F21P00 BMC LED device enabled\n");
 97
 98	return 0;
 99
100}
101
102static struct platform_driver menf21bmc_led = {
103	.probe		= menf21bmc_led_probe,
104	.driver		= {
105		.name		= "menf21bmc_led",
106	},
107};
108
109module_platform_driver(menf21bmc_led);
110
111MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>");
112MODULE_DESCRIPTION("MEN 14F021P00 BMC led driver");
113MODULE_LICENSE("GPL v2");
114MODULE_ALIAS("platform:menf21bmc_led");