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
  24 struct menf21bmc_led {
  25         struct led_classdev cdev;
  26         u8 led_bit;
  27         const char *name;
  28         struct i2c_client *i2c_client;
  29 };
  30
  31 static 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
  50 static DEFINE_MUTEX(led_lock);
  51
  52 static void
  53 menf21bmc_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);
  72 err_out:
  73         mutex_unlock(&led_lock);
  74 }
  75
  76 static 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
  98 static struct platform_driver menf21bmc_led = {
  99         .probe          = menf21bmc_led_probe,
 100         .driver         = {
 101                 .name           = "menf21bmc_led",
 102         },
 103 };
 104
 105 module_platform_driver(menf21bmc_led);
 106
 107 MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>");
 108 MODULE_DESCRIPTION("MEN 14F021P00 BMC led driver");
 109 MODULE_LICENSE("GPL v2");
 110 MODULE_ALIAS("platform:menf21bmc_led");