LXR linux/drivers/leds/leds-menf21bmc.c

   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