linux-sg2042/drivers/leds/leds-menf21bmc.c

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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\n");
return ret;
}
}
dev_info(&pdev->dev, "MEN 140F21P00 BMC LED device enabled\n");
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");