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kernel/linux-rt-4.4.41/drivers/leds/leds-menf21bmc.c 2.74 KB
5113f6f70   김현기   kernel add
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  /*
   *  MEN 14F021P00 Board Management Controller (BMC) LEDs Driver.
   *
   *  This is the core LED driver of the MEN 14F021P00 BMC.
   *  There are four LEDs available which can be switched on and off.
   *  STATUS LED, HOT SWAP LED, USER LED 1, USER LED 2
   *
   *  Copyright (C) 2014 MEN Mikro Elektronik Nuernberg GmbH
   *
   *  This program is free software; you can redistribute  it and/or modify it
   *  under  the terms of  the GNU General  Public License as published by the
   *  Free Software Foundation;  either version 2 of the  License, or (at your
   *  option) any later version.
   */
  
  #include <linux/module.h>
  #include <linux/kernel.h>
  #include <linux/platform_device.h>
  #include <linux/leds.h>
  #include <linux/i2c.h>
  
  #define BMC_CMD_LED_GET_SET	0xA0
  #define BMC_BIT_LED_STATUS	BIT(0)
  #define BMC_BIT_LED_HOTSWAP	BIT(1)
  #define BMC_BIT_LED_USER1	BIT(2)
  #define BMC_BIT_LED_USER2	BIT(3)
  
  struct menf21bmc_led {
  	struct led_classdev cdev;
  	u8 led_bit;
  	const char *name;
  	struct i2c_client *i2c_client;
  };
  
  static struct menf21bmc_led leds[] = {
  	{
  		.name = "menf21bmc:led_status",
  		.led_bit = BMC_BIT_LED_STATUS,
  	},
  	{
  		.name = "menf21bmc:led_hotswap",
  		.led_bit = BMC_BIT_LED_HOTSWAP,
  	},
  	{
  		.name = "menf21bmc:led_user1",
  		.led_bit = BMC_BIT_LED_USER1,
  	},
  	{
  		.name = "menf21bmc:led_user2",
  		.led_bit = BMC_BIT_LED_USER2,
  	}
  };
  
  static DEFINE_MUTEX(led_lock);
  
  static void
  menf21bmc_led_set(struct led_classdev *led_cdev, enum led_brightness value)
  {
  	int led_val;
  	struct menf21bmc_led *led = container_of(led_cdev,
  					struct menf21bmc_led, cdev);
  
  	mutex_lock(&led_lock);
  	led_val = i2c_smbus_read_byte_data(led->i2c_client,
  					   BMC_CMD_LED_GET_SET);
  	if (led_val < 0)
  		goto err_out;
  
  	if (value == LED_OFF)
  		led_val &= ~led->led_bit;
  	else
  		led_val |= led->led_bit;
  
  	i2c_smbus_write_byte_data(led->i2c_client,
  				  BMC_CMD_LED_GET_SET, led_val);
  err_out:
  	mutex_unlock(&led_lock);
  }
  
  static int menf21bmc_led_probe(struct platform_device *pdev)
  {
  	int i;
  	int ret;
  	struct i2c_client *i2c_client = to_i2c_client(pdev->dev.parent);
  
  	for (i = 0; i < ARRAY_SIZE(leds); i++) {
  		leds[i].cdev.name = leds[i].name;
  		leds[i].cdev.brightness_set = menf21bmc_led_set;
  		leds[i].i2c_client = i2c_client;
  		ret = devm_led_classdev_register(&pdev->dev, &leds[i].cdev);
  		if (ret < 0) {
  			dev_err(&pdev->dev, "failed to register LED device
  ");
  			return ret;
  		}
  	}
  	dev_info(&pdev->dev, "MEN 140F21P00 BMC LED device enabled
  ");
  
  	return 0;
  
  }
  
  static struct platform_driver menf21bmc_led = {
  	.probe		= menf21bmc_led_probe,
  	.driver		= {
  		.name		= "menf21bmc_led",
  	},
  };
  
  module_platform_driver(menf21bmc_led);
  
  MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>");
  MODULE_DESCRIPTION("MEN 14F021P00 BMC led driver");
  MODULE_LICENSE("GPL v2");
  MODULE_ALIAS("platform:menf21bmc_led");