// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  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
 */

#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");