root/drivers/leds/leds-lm3642.c
// SPDX-License-Identifier: GPL-2.0-only
/*
* Simple driver for Texas Instruments LM3642 LED Flash driver chip
* Copyright (C) 2012 Texas Instruments
*/
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/leds.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/fs.h>
#include <linux/regmap.h>
#include <linux/platform_data/leds-lm3642.h>

#define REG_FILT_TIME                   (0x0)
#define REG_IVFM_MODE                   (0x1)
#define REG_TORCH_TIME                  (0x6)
#define REG_FLASH                       (0x8)
#define REG_I_CTRL                      (0x9)
#define REG_ENABLE                      (0xA)
#define REG_FLAG                        (0xB)
#define REG_MAX                         (0xB)

#define UVLO_EN_SHIFT                   (7)
#define IVM_D_TH_SHIFT                  (2)
#define TORCH_RAMP_UP_TIME_SHIFT        (3)
#define TORCH_RAMP_DN_TIME_SHIFT        (0)
#define INDUCTOR_I_LIMIT_SHIFT          (6)
#define FLASH_RAMP_TIME_SHIFT           (3)
#define FLASH_TOUT_TIME_SHIFT           (0)
#define TORCH_I_SHIFT                   (4)
#define FLASH_I_SHIFT                   (0)
#define IVFM_SHIFT                      (7)
#define TX_PIN_EN_SHIFT                 (6)
#define STROBE_PIN_EN_SHIFT             (5)
#define TORCH_PIN_EN_SHIFT              (4)
#define MODE_BITS_SHIFT                 (0)

#define UVLO_EN_MASK                    (0x1)
#define IVM_D_TH_MASK                   (0x7)
#define TORCH_RAMP_UP_TIME_MASK         (0x7)
#define TORCH_RAMP_DN_TIME_MASK         (0x7)
#define INDUCTOR_I_LIMIT_MASK           (0x1)
#define FLASH_RAMP_TIME_MASK            (0x7)
#define FLASH_TOUT_TIME_MASK            (0x7)
#define TORCH_I_MASK                    (0x7)
#define FLASH_I_MASK                    (0xF)
#define IVFM_MASK                       (0x1)
#define TX_PIN_EN_MASK                  (0x1)
#define STROBE_PIN_EN_MASK              (0x1)
#define TORCH_PIN_EN_MASK               (0x1)
#define MODE_BITS_MASK                  (0x73)
#define EX_PIN_CONTROL_MASK             (0x71)
#define EX_PIN_ENABLE_MASK              (0x70)

enum lm3642_mode {
        MODES_STASNDBY = 0,
        MODES_INDIC,
        MODES_TORCH,
        MODES_FLASH
};

struct lm3642_chip_data {
        struct device *dev;

        struct led_classdev cdev_flash;
        struct led_classdev cdev_torch;
        struct led_classdev cdev_indicator;

        u8 br_flash;
        u8 br_torch;
        u8 br_indicator;

        enum lm3642_torch_pin_enable torch_pin;
        enum lm3642_strobe_pin_enable strobe_pin;
        enum lm3642_tx_pin_enable tx_pin;

        struct lm3642_platform_data *pdata;
        struct regmap *regmap;
        struct mutex lock;

        unsigned int last_flag;
};

/* chip initialize */
static int lm3642_chip_init(struct lm3642_chip_data *chip)
{
        int ret;
        struct lm3642_platform_data *pdata = chip->pdata;

        /* set enable register */
        ret = regmap_update_bits(chip->regmap, REG_ENABLE, EX_PIN_ENABLE_MASK,
                                 pdata->tx_pin);
        if (ret < 0)
                dev_err(chip->dev, "Failed to update REG_ENABLE Register\n");
        return ret;
}

/* chip control */
static int lm3642_control(struct lm3642_chip_data *chip,
                          u8 brightness, enum lm3642_mode opmode)
{
        int ret;

        ret = regmap_read(chip->regmap, REG_FLAG, &chip->last_flag);
        if (ret < 0) {
                dev_err(chip->dev, "Failed to read REG_FLAG Register\n");
                return ret;
        }

        if (chip->last_flag)
                dev_info(chip->dev, "Last FLAG is 0x%x\n", chip->last_flag);

        /* brightness 0 means off-state */
        if (!brightness)
                opmode = MODES_STASNDBY;

        switch (opmode) {
        case MODES_TORCH:
                ret = regmap_update_bits(chip->regmap, REG_I_CTRL,
                                         TORCH_I_MASK << TORCH_I_SHIFT,
                                         (brightness - 1) << TORCH_I_SHIFT);

                if (chip->torch_pin)
                        opmode |= (TORCH_PIN_EN_MASK << TORCH_PIN_EN_SHIFT);
                break;

        case MODES_FLASH:
                ret = regmap_update_bits(chip->regmap, REG_I_CTRL,
                                         FLASH_I_MASK << FLASH_I_SHIFT,
                                         (brightness - 1) << FLASH_I_SHIFT);

                if (chip->strobe_pin)
                        opmode |= (STROBE_PIN_EN_MASK << STROBE_PIN_EN_SHIFT);
                break;

        case MODES_INDIC:
                ret = regmap_update_bits(chip->regmap, REG_I_CTRL,
                                         TORCH_I_MASK << TORCH_I_SHIFT,
                                         (brightness - 1) << TORCH_I_SHIFT);
                break;

        case MODES_STASNDBY:

                break;

        default:
                return -EINVAL;
        }
        if (ret < 0) {
                dev_err(chip->dev, "Failed to write REG_I_CTRL Register\n");
                return ret;
        }

        if (chip->tx_pin)
                opmode |= (TX_PIN_EN_MASK << TX_PIN_EN_SHIFT);

        ret = regmap_update_bits(chip->regmap, REG_ENABLE,
                                 MODE_BITS_MASK << MODE_BITS_SHIFT,
                                 opmode << MODE_BITS_SHIFT);
        return ret;
}

/* torch */

/* torch pin config for lm3642 */
static ssize_t torch_pin_store(struct device *dev,
                               struct device_attribute *attr,
                               const char *buf, size_t size)
{
        ssize_t ret;
        struct led_classdev *led_cdev = dev_get_drvdata(dev);
        struct lm3642_chip_data *chip =
            container_of(led_cdev, struct lm3642_chip_data, cdev_indicator);
        unsigned int state;

        ret = kstrtouint(buf, 10, &state);
        if (ret)
                return ret;
        if (state != 0)
                state = 0x01 << TORCH_PIN_EN_SHIFT;

        chip->torch_pin = state;
        ret = regmap_update_bits(chip->regmap, REG_ENABLE,
                                 TORCH_PIN_EN_MASK << TORCH_PIN_EN_SHIFT,
                                 state);
        if (ret < 0) {
                dev_err(chip->dev, "%s:i2c access fail to register\n", __func__);
                return ret;
        }

        return size;
}

static DEVICE_ATTR_WO(torch_pin);

static int lm3642_torch_brightness_set(struct led_classdev *cdev,
                                        enum led_brightness brightness)
{
        struct lm3642_chip_data *chip =
            container_of(cdev, struct lm3642_chip_data, cdev_torch);
        int ret;

        mutex_lock(&chip->lock);
        chip->br_torch = brightness;
        ret = lm3642_control(chip, chip->br_torch, MODES_TORCH);
        mutex_unlock(&chip->lock);
        return ret;
}

/* flash */

/* strobe pin config for lm3642*/
static ssize_t strobe_pin_store(struct device *dev,
                                struct device_attribute *attr,
                                const char *buf, size_t size)
{
        ssize_t ret;
        struct led_classdev *led_cdev = dev_get_drvdata(dev);
        struct lm3642_chip_data *chip =
            container_of(led_cdev, struct lm3642_chip_data, cdev_indicator);
        unsigned int state;

        ret = kstrtouint(buf, 10, &state);
        if (ret)
                return ret;
        if (state != 0)
                state = 0x01 << STROBE_PIN_EN_SHIFT;

        chip->strobe_pin = state;
        ret = regmap_update_bits(chip->regmap, REG_ENABLE,
                                 STROBE_PIN_EN_MASK << STROBE_PIN_EN_SHIFT,
                                 state);
        if (ret < 0) {
                dev_err(chip->dev, "%s:i2c access fail to register\n", __func__);
                return ret;
        }

        return size;
}

static DEVICE_ATTR_WO(strobe_pin);

static int lm3642_strobe_brightness_set(struct led_classdev *cdev,
                                         enum led_brightness brightness)
{
        struct lm3642_chip_data *chip =
            container_of(cdev, struct lm3642_chip_data, cdev_flash);
        int ret;

        mutex_lock(&chip->lock);
        chip->br_flash = brightness;
        ret = lm3642_control(chip, chip->br_flash, MODES_FLASH);
        mutex_unlock(&chip->lock);
        return ret;
}

/* indicator */
static int lm3642_indicator_brightness_set(struct led_classdev *cdev,
                                            enum led_brightness brightness)
{
        struct lm3642_chip_data *chip =
            container_of(cdev, struct lm3642_chip_data, cdev_indicator);
        int ret;

        mutex_lock(&chip->lock);
        chip->br_indicator = brightness;
        ret = lm3642_control(chip, chip->br_indicator, MODES_INDIC);
        mutex_unlock(&chip->lock);
        return ret;
}

static const struct regmap_config lm3642_regmap = {
        .reg_bits = 8,
        .val_bits = 8,
        .max_register = REG_MAX,
};

static struct attribute *lm3642_flash_attrs[] = {
        &dev_attr_strobe_pin.attr,
        NULL
};
ATTRIBUTE_GROUPS(lm3642_flash);

static struct attribute *lm3642_torch_attrs[] = {
        &dev_attr_torch_pin.attr,
        NULL
};
ATTRIBUTE_GROUPS(lm3642_torch);

static int lm3642_probe(struct i2c_client *client)
{
        struct lm3642_platform_data *pdata = dev_get_platdata(&client->dev);
        struct lm3642_chip_data *chip;

        int err;

        if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
                dev_err(&client->dev, "i2c functionality check fail.\n");
                return -EOPNOTSUPP;
        }

        if (pdata == NULL) {
                dev_err(&client->dev, "needs Platform Data.\n");
                return -ENODATA;
        }

        chip = devm_kzalloc(&client->dev,
                            sizeof(struct lm3642_chip_data), GFP_KERNEL);
        if (!chip)
                return -ENOMEM;

        chip->dev = &client->dev;
        chip->pdata = pdata;

        chip->tx_pin = pdata->tx_pin;
        chip->torch_pin = pdata->torch_pin;
        chip->strobe_pin = pdata->strobe_pin;

        chip->regmap = devm_regmap_init_i2c(client, &lm3642_regmap);
        if (IS_ERR(chip->regmap)) {
                err = PTR_ERR(chip->regmap);
                dev_err(&client->dev, "Failed to allocate register map: %d\n",
                        err);
                return err;
        }

        mutex_init(&chip->lock);
        i2c_set_clientdata(client, chip);

        err = lm3642_chip_init(chip);
        if (err < 0)
                goto err_out;

        /* flash */
        chip->cdev_flash.name = "flash";
        chip->cdev_flash.max_brightness = 16;
        chip->cdev_flash.brightness_set_blocking = lm3642_strobe_brightness_set;
        chip->cdev_flash.default_trigger = "flash";
        chip->cdev_flash.groups = lm3642_flash_groups;
        err = led_classdev_register(&client->dev, &chip->cdev_flash);
        if (err < 0) {
                dev_err(chip->dev, "failed to register flash\n");
                goto err_out;
        }

        /* torch */
        chip->cdev_torch.name = "torch";
        chip->cdev_torch.max_brightness = 8;
        chip->cdev_torch.brightness_set_blocking = lm3642_torch_brightness_set;
        chip->cdev_torch.default_trigger = "torch";
        chip->cdev_torch.groups = lm3642_torch_groups;
        err = led_classdev_register(&client->dev, &chip->cdev_torch);
        if (err < 0) {
                dev_err(chip->dev, "failed to register torch\n");
                goto err_create_torch_file;
        }

        /* indicator */
        chip->cdev_indicator.name = "indicator";
        chip->cdev_indicator.max_brightness = 8;
        chip->cdev_indicator.brightness_set_blocking =
                                                lm3642_indicator_brightness_set;
        err = led_classdev_register(&client->dev, &chip->cdev_indicator);
        if (err < 0) {
                dev_err(chip->dev, "failed to register indicator\n");
                goto err_create_indicator_file;
        }

        dev_info(&client->dev, "LM3642 is initialized\n");
        return 0;

err_create_indicator_file:
        led_classdev_unregister(&chip->cdev_torch);
err_create_torch_file:
        led_classdev_unregister(&chip->cdev_flash);
err_out:
        return err;
}

static void lm3642_remove(struct i2c_client *client)
{
        struct lm3642_chip_data *chip = i2c_get_clientdata(client);

        led_classdev_unregister(&chip->cdev_indicator);
        led_classdev_unregister(&chip->cdev_torch);
        led_classdev_unregister(&chip->cdev_flash);
        regmap_write(chip->regmap, REG_ENABLE, 0);
}

static const struct i2c_device_id lm3642_id[] = {
        { LM3642_NAME },
        {}
};

MODULE_DEVICE_TABLE(i2c, lm3642_id);

static struct i2c_driver lm3642_i2c_driver = {
        .driver = {
                   .name = LM3642_NAME,
                   .pm = NULL,
                   },
        .probe = lm3642_probe,
        .remove = lm3642_remove,
        .id_table = lm3642_id,
};

module_i2c_driver(lm3642_i2c_driver);

MODULE_DESCRIPTION("Texas Instruments Flash Lighting driver for LM3642");
MODULE_AUTHOR("Daniel Jeong <daniel.jeong@ti.com>");
MODULE_AUTHOR("G.Shark Jeong <gshark.jeong@gmail.com>");
MODULE_LICENSE("GPL v2");