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

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 *  MEN 14F021P00 Board Management Controller (BMC) LEDs Driver.
   4 *
   5 *  This is the core LED driver of the MEN 14F021P00 BMC.
   6 *  There are four LEDs available which can be switched on and off.
   7 *  STATUS LED, HOT SWAP LED, USER LED 1, USER LED 2
   8 *
   9 *  Copyright (C) 2014 MEN Mikro Elektronik Nuernberg GmbH
  10 */
  11
  12#include <linux/module.h>
  13#include <linux/kernel.h>
  14#include <linux/platform_device.h>
  15#include <linux/leds.h>
  16#include <linux/i2c.h>
  17
  18#define BMC_CMD_LED_GET_SET     0xA0
  19#define BMC_BIT_LED_STATUS      BIT(0)
  20#define BMC_BIT_LED_HOTSWAP     BIT(1)
  21#define BMC_BIT_LED_USER1       BIT(2)
  22#define BMC_BIT_LED_USER2       BIT(3)
  23
  24struct menf21bmc_led {
  25        struct led_classdev cdev;
  26        u8 led_bit;
  27        const char *name;
  28        struct i2c_client *i2c_client;
  29};
  30
  31static struct menf21bmc_led leds[] = {
  32        {
  33                .name = "menf21bmc:led_status",
  34                .led_bit = BMC_BIT_LED_STATUS,
  35        },
  36        {
  37                .name = "menf21bmc:led_hotswap",
  38                .led_bit = BMC_BIT_LED_HOTSWAP,
  39        },
  40        {
  41                .name = "menf21bmc:led_user1",
  42                .led_bit = BMC_BIT_LED_USER1,
  43        },
  44        {
  45                .name = "menf21bmc:led_user2",
  46                .led_bit = BMC_BIT_LED_USER2,
  47        }
  48};
  49
  50static DEFINE_MUTEX(led_lock);
  51
  52static void
  53menf21bmc_led_set(struct led_classdev *led_cdev, enum led_brightness value)
  54{
  55        int led_val;
  56        struct menf21bmc_led *led = container_of(led_cdev,
  57                                        struct menf21bmc_led, cdev);
  58
  59        mutex_lock(&led_lock);
  60        led_val = i2c_smbus_read_byte_data(led->i2c_client,
  61                                           BMC_CMD_LED_GET_SET);
  62        if (led_val < 0)
  63                goto err_out;
  64
  65        if (value == LED_OFF)
  66                led_val &= ~led->led_bit;
  67        else
  68                led_val |= led->led_bit;
  69
  70        i2c_smbus_write_byte_data(led->i2c_client,
  71                                  BMC_CMD_LED_GET_SET, led_val);
  72err_out:
  73        mutex_unlock(&led_lock);
  74}
  75
  76static int menf21bmc_led_probe(struct platform_device *pdev)
  77{
  78        int i;
  79        int ret;
  80        struct i2c_client *i2c_client = to_i2c_client(pdev->dev.parent);
  81
  82        for (i = 0; i < ARRAY_SIZE(leds); i++) {
  83                leds[i].cdev.name = leds[i].name;
  84                leds[i].cdev.brightness_set = menf21bmc_led_set;
  85                leds[i].i2c_client = i2c_client;
  86                ret = devm_led_classdev_register(&pdev->dev, &leds[i].cdev);
  87                if (ret < 0) {
  88                        dev_err(&pdev->dev, "failed to register LED device\n");
  89                        return ret;
  90                }
  91        }
  92        dev_info(&pdev->dev, "MEN 140F21P00 BMC LED device enabled\n");
  93
  94        return 0;
  95
  96}
  97
  98static struct platform_driver menf21bmc_led = {
  99        .probe          = menf21bmc_led_probe,
 100        .driver         = {
 101                .name           = "menf21bmc_led",
 102        },
 103};
 104
 105module_platform_driver(menf21bmc_led);
 106
 107MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>");
 108MODULE_DESCRIPTION("MEN 14F021P00 BMC led driver");
 109MODULE_LICENSE("GPL v2");
 110MODULE_ALIAS("platform:menf21bmc_led");
 111