root/drivers/leds/leds-max8997.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * leds-max8997.c - LED class driver for MAX8997 LEDs.
 *
 * Copyright (C) 2011 Samsung Electronics
 * Donggeun Kim <dg77.kim@samsung.com>
 */

#include <linux/module.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/leds.h>
#include <linux/mfd/max8997.h>
#include <linux/mfd/max8997-private.h>
#include <linux/platform_device.h>

#define MAX8997_LED_FLASH_SHIFT                 3
#define MAX8997_LED_FLASH_CUR_MASK              0xf8
#define MAX8997_LED_MOVIE_SHIFT                 4
#define MAX8997_LED_MOVIE_CUR_MASK              0xf0

#define MAX8997_LED_FLASH_MAX_BRIGHTNESS        0x1f
#define MAX8997_LED_MOVIE_MAX_BRIGHTNESS        0xf
#define MAX8997_LED_NONE_MAX_BRIGHTNESS         0

#define MAX8997_LED0_FLASH_MASK                 0x1
#define MAX8997_LED0_FLASH_PIN_MASK             0x5
#define MAX8997_LED0_MOVIE_MASK                 0x8
#define MAX8997_LED0_MOVIE_PIN_MASK             0x28

#define MAX8997_LED1_FLASH_MASK                 0x2
#define MAX8997_LED1_FLASH_PIN_MASK             0x6
#define MAX8997_LED1_MOVIE_MASK                 0x10
#define MAX8997_LED1_MOVIE_PIN_MASK             0x30

#define MAX8997_LED_BOOST_ENABLE_MASK           (1 << 6)

struct max8997_led {
        struct max8997_dev *iodev;
        struct led_classdev cdev;
        bool enabled;
        int id;
        enum max8997_led_mode led_mode;
        struct mutex mutex;
};

static void max8997_led_set_mode(struct max8997_led *led,
                        enum max8997_led_mode mode)
{
        int ret;
        struct i2c_client *client = led->iodev->i2c;
        u8 mask = 0, val;

        switch (mode) {
        case MAX8997_FLASH_MODE:
                mask = MAX8997_LED1_FLASH_MASK | MAX8997_LED0_FLASH_MASK;
                val = led->id ?
                      MAX8997_LED1_FLASH_MASK : MAX8997_LED0_FLASH_MASK;
                led->cdev.max_brightness = MAX8997_LED_FLASH_MAX_BRIGHTNESS;
                break;
        case MAX8997_MOVIE_MODE:
                mask = MAX8997_LED1_MOVIE_MASK | MAX8997_LED0_MOVIE_MASK;
                val = led->id ?
                      MAX8997_LED1_MOVIE_MASK : MAX8997_LED0_MOVIE_MASK;
                led->cdev.max_brightness = MAX8997_LED_MOVIE_MAX_BRIGHTNESS;
                break;
        case MAX8997_FLASH_PIN_CONTROL_MODE:
                mask = MAX8997_LED1_FLASH_PIN_MASK |
                       MAX8997_LED0_FLASH_PIN_MASK;
                val = led->id ?
                      MAX8997_LED1_FLASH_PIN_MASK : MAX8997_LED0_FLASH_PIN_MASK;
                led->cdev.max_brightness = MAX8997_LED_FLASH_MAX_BRIGHTNESS;
                break;
        case MAX8997_MOVIE_PIN_CONTROL_MODE:
                mask = MAX8997_LED1_MOVIE_PIN_MASK |
                       MAX8997_LED0_MOVIE_PIN_MASK;
                val = led->id ?
                      MAX8997_LED1_MOVIE_PIN_MASK : MAX8997_LED0_MOVIE_PIN_MASK;
                led->cdev.max_brightness = MAX8997_LED_MOVIE_MAX_BRIGHTNESS;
                break;
        default:
                led->cdev.max_brightness = MAX8997_LED_NONE_MAX_BRIGHTNESS;
                break;
        }

        if (mask) {
                ret = max8997_update_reg(client, MAX8997_REG_LEN_CNTL, val,
                                         mask);
                if (ret)
                        dev_err(led->iodev->dev,
                                "failed to update register(%d)\n", ret);
        }

        led->led_mode = mode;
}

static void max8997_led_enable(struct max8997_led *led, bool enable)
{
        int ret;
        struct i2c_client *client = led->iodev->i2c;
        u8 val = 0, mask = MAX8997_LED_BOOST_ENABLE_MASK;

        if (led->enabled == enable)
                return;

        val = enable ? MAX8997_LED_BOOST_ENABLE_MASK : 0;

        ret = max8997_update_reg(client, MAX8997_REG_BOOST_CNTL, val, mask);
        if (ret)
                dev_err(led->iodev->dev,
                        "failed to update register(%d)\n", ret);

        led->enabled = enable;
}

static void max8997_led_set_current(struct max8997_led *led,
                                enum led_brightness value)
{
        int ret;
        struct i2c_client *client = led->iodev->i2c;
        u8 val = 0, mask = 0, reg = 0;

        switch (led->led_mode) {
        case MAX8997_FLASH_MODE:
        case MAX8997_FLASH_PIN_CONTROL_MODE:
                val = value << MAX8997_LED_FLASH_SHIFT;
                mask = MAX8997_LED_FLASH_CUR_MASK;
                reg = led->id ? MAX8997_REG_FLASH2_CUR : MAX8997_REG_FLASH1_CUR;
                break;
        case MAX8997_MOVIE_MODE:
        case MAX8997_MOVIE_PIN_CONTROL_MODE:
                val = value << MAX8997_LED_MOVIE_SHIFT;
                mask = MAX8997_LED_MOVIE_CUR_MASK;
                reg = MAX8997_REG_MOVIE_CUR;
                break;
        default:
                break;
        }

        if (mask) {
                ret = max8997_update_reg(client, reg, val, mask);
                if (ret)
                        dev_err(led->iodev->dev,
                                "failed to update register(%d)\n", ret);
        }
}

static void max8997_led_brightness_set(struct led_classdev *led_cdev,
                                enum led_brightness value)
{
        struct max8997_led *led =
                        container_of(led_cdev, struct max8997_led, cdev);

        if (value) {
                max8997_led_set_current(led, value);
                max8997_led_enable(led, true);
        } else {
                max8997_led_set_current(led, value);
                max8997_led_enable(led, false);
        }
}

static ssize_t mode_show(struct device *dev,
                         struct device_attribute *attr, char *buf)
{
        struct led_classdev *led_cdev = dev_get_drvdata(dev);
        struct max8997_led *led =
                        container_of(led_cdev, struct max8997_led, cdev);
        ssize_t ret = 0;

        mutex_lock(&led->mutex);

        switch (led->led_mode) {
        case MAX8997_FLASH_MODE:
                ret += sprintf(buf, "FLASH\n");
                break;
        case MAX8997_MOVIE_MODE:
                ret += sprintf(buf, "MOVIE\n");
                break;
        case MAX8997_FLASH_PIN_CONTROL_MODE:
                ret += sprintf(buf, "FLASH_PIN_CONTROL\n");
                break;
        case MAX8997_MOVIE_PIN_CONTROL_MODE:
                ret += sprintf(buf, "MOVIE_PIN_CONTROL\n");
                break;
        default:
                ret += sprintf(buf, "NONE\n");
                break;
        }

        mutex_unlock(&led->mutex);

        return ret;
}

static ssize_t mode_store(struct device *dev,
                          struct device_attribute *attr,
                          const char *buf, size_t size)
{
        struct led_classdev *led_cdev = dev_get_drvdata(dev);
        struct max8997_led *led =
                        container_of(led_cdev, struct max8997_led, cdev);
        enum max8997_led_mode mode;

        mutex_lock(&led->mutex);

        if (!strncmp(buf, "FLASH_PIN_CONTROL", 17))
                mode = MAX8997_FLASH_PIN_CONTROL_MODE;
        else if (!strncmp(buf, "MOVIE_PIN_CONTROL", 17))
                mode = MAX8997_MOVIE_PIN_CONTROL_MODE;
        else if (!strncmp(buf, "FLASH", 5))
                mode = MAX8997_FLASH_MODE;
        else if (!strncmp(buf, "MOVIE", 5))
                mode = MAX8997_MOVIE_MODE;
        else
                mode = MAX8997_NONE;

        max8997_led_set_mode(led, mode);

        mutex_unlock(&led->mutex);

        return size;
}

static DEVICE_ATTR_RW(mode);

static struct attribute *max8997_attrs[] = {
        &dev_attr_mode.attr,
        NULL
};
ATTRIBUTE_GROUPS(max8997);

static int max8997_led_probe(struct platform_device *pdev)
{
        struct max8997_dev *iodev = dev_get_drvdata(pdev->dev.parent);
        struct max8997_platform_data *pdata = dev_get_platdata(iodev->dev);
        struct max8997_led *led;
        char name[20];
        int ret = 0;

        led = devm_kzalloc(&pdev->dev, sizeof(*led), GFP_KERNEL);
        if (led == NULL)
                return -ENOMEM;

        led->id = pdev->id;
        snprintf(name, sizeof(name), "max8997-led%d", pdev->id);

        led->cdev.name = name;
        led->cdev.brightness_set = max8997_led_brightness_set;
        led->cdev.flags |= LED_CORE_SUSPENDRESUME;
        led->cdev.brightness = 0;
        led->cdev.groups = max8997_groups;
        led->iodev = iodev;

        /* initialize mode and brightness according to platform_data */
        if (pdata && pdata->led_pdata) {
                u8 mode = 0, brightness = 0;

                mode = pdata->led_pdata->mode[led->id];
                brightness = pdata->led_pdata->brightness[led->id];

                max8997_led_set_mode(led, mode);

                if (brightness > led->cdev.max_brightness)
                        brightness = led->cdev.max_brightness;
                max8997_led_set_current(led, brightness);
                led->cdev.brightness = brightness;
        } else {
                max8997_led_set_mode(led, MAX8997_NONE);
                max8997_led_set_current(led, 0);
        }

        mutex_init(&led->mutex);

        ret = devm_led_classdev_register(&pdev->dev, &led->cdev);
        if (ret < 0)
                return ret;

        return 0;
}

static struct platform_driver max8997_led_driver = {
        .driver = {
                .name  = "max8997-led",
        },
        .probe  = max8997_led_probe,
};

module_platform_driver(max8997_led_driver);

MODULE_AUTHOR("Donggeun Kim <dg77.kim@samsung.com>");
MODULE_DESCRIPTION("MAX8997 LED driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:max8997-led");