leds-lm3642.c

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/*
* Simple driver for Texas Instruments LM3642 LED Flash driver chip
* Copyright (C) 2012 Texas Instruments
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
*/
#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/workqueue.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;

    struct work_struct work_flash;
    struct work_struct work_torch;
    struct work_struct work_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 __devinit 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");
        goto out;
    }

    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 ret;
    }
    if (ret < 0) {
        dev_err(chip->dev, "Failed to write REG_I_CTRL Register\n");
        goto out;
    }

    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);
out:
    return ret;
}

/* torch */

/* torch pin config for lm3642*/
static ssize_t lm3642_torch_pin_store(struct device *dev,
                      struct device_attribute *devAttr,
                      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)
        goto out_strtoint;
    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)
        goto out;

    return size;
out:
    dev_err(chip->dev, "%s:i2c access fail to register\n", __func__);
    return size;
out_strtoint:
    dev_err(chip->dev, "%s: fail to change str to int\n", __func__);
    return size;
}

static DEVICE_ATTR(torch_pin, 0666, NULL, lm3642_torch_pin_store);

static void lm3642_deferred_torch_brightness_set(struct work_struct *work)
{
    struct lm3642_chip_data *chip =
        container_of(work, struct lm3642_chip_data, work_torch);

    mutex_lock(&chip->lock);
    lm3642_control(chip, chip->br_torch, MODES_TORCH);
    mutex_unlock(&chip->lock);
}

static void 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);

    chip->br_torch = brightness;
    schedule_work(&chip->work_torch);
}

/* flash */

/* strobe pin config for lm3642*/
static ssize_t lm3642_strobe_pin_store(struct device *dev,
                       struct device_attribute *devAttr,
                       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)
        goto out_strtoint;
    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)
        goto out;

    return size;
out:
    dev_err(chip->dev, "%s:i2c access fail to register\n", __func__);
    return size;
out_strtoint:
    dev_err(chip->dev, "%s: fail to change str to int\n", __func__);
    return size;
}

static DEVICE_ATTR(strobe_pin, 0666, NULL, lm3642_strobe_pin_store);

static void lm3642_deferred_strobe_brightness_set(struct work_struct *work)
{
    struct lm3642_chip_data *chip =
        container_of(work, struct lm3642_chip_data, work_flash);

    mutex_lock(&chip->lock);
    lm3642_control(chip, chip->br_flash, MODES_FLASH);
    mutex_unlock(&chip->lock);
}

static void 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);

    chip->br_flash = brightness;
    schedule_work(&chip->work_flash);
}

/* indicator */
static void lm3642_deferred_indicator_brightness_set(struct work_struct *work)
{
    struct lm3642_chip_data *chip =
        container_of(work, struct lm3642_chip_data, work_indicator);

    mutex_lock(&chip->lock);
    lm3642_control(chip, chip->br_indicator, MODES_INDIC);
    mutex_unlock(&chip->lock);
}

static void 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);

    chip->br_indicator = brightness;
    schedule_work(&chip->work_indicator);
}

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

static int __devinit lm3642_probe(struct i2c_client *client,
                  const struct i2c_device_id *id)
{
    struct lm3642_platform_data *pdata = client->dev.platform_data;
    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 */
    INIT_WORK(&chip->work_flash, lm3642_deferred_strobe_brightness_set);
    chip->cdev_flash.name = "flash";
    chip->cdev_flash.max_brightness = 16;
    chip->cdev_flash.brightness_set = lm3642_strobe_brightness_set;
    err = led_classdev_register((struct device *)
                    &client->dev, &chip->cdev_flash);
    if (err < 0) {
        dev_err(chip->dev, "failed to register flash\n");
        goto err_out;
    }
    err = device_create_file(chip->cdev_flash.dev, &dev_attr_strobe_pin);
    if (err < 0) {
        dev_err(chip->dev, "failed to create strobe-pin file\n");
        goto err_create_flash_pin_file;
    }

    /* torch */
    INIT_WORK(&chip->work_torch, lm3642_deferred_torch_brightness_set);
    chip->cdev_torch.name = "torch";
    chip->cdev_torch.max_brightness = 8;
    chip->cdev_torch.brightness_set = lm3642_torch_brightness_set;
    err = led_classdev_register((struct device *)
                    &client->dev, &chip->cdev_torch);
    if (err < 0) {
        dev_err(chip->dev, "failed to register torch\n");
        goto err_create_torch_file;
    }
    err = device_create_file(chip->cdev_torch.dev, &dev_attr_torch_pin);
    if (err < 0) {
        dev_err(chip->dev, "failed to create torch-pin file\n");
        goto err_create_torch_pin_file;
    }

    /* indicator */
    INIT_WORK(&chip->work_indicator,
          lm3642_deferred_indicator_brightness_set);
    chip->cdev_indicator.name = "indicator";
    chip->cdev_indicator.max_brightness = 8;
    chip->cdev_indicator.brightness_set = lm3642_indicator_brightness_set;
    err = led_classdev_register((struct device *)
                    &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:
    device_remove_file(chip->cdev_torch.dev, &dev_attr_torch_pin);
err_create_torch_pin_file:
    led_classdev_unregister(&chip->cdev_torch);
err_create_torch_file:
    device_remove_file(chip->cdev_flash.dev, &dev_attr_strobe_pin);
err_create_flash_pin_file:
    led_classdev_unregister(&chip->cdev_flash);
err_out:
    return err;
}

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

    led_classdev_unregister(&chip->cdev_indicator);
    flush_work(&chip->work_indicator);
    device_remove_file(chip->cdev_torch.dev, &dev_attr_torch_pin);
    led_classdev_unregister(&chip->cdev_torch);
    flush_work(&chip->work_torch);
    device_remove_file(chip->cdev_flash.dev, &dev_attr_strobe_pin);
    led_classdev_unregister(&chip->cdev_flash);
    flush_work(&chip->work_flash);
    regmap_write(chip->regmap, REG_ENABLE, 0);
    return 0;
}

static const struct i2c_device_id lm3642_id[] = {
    {LM3642_NAME, 0},
    {}
};

MODULE_DEVICE_TABLE(i2c, lm3642_id);

static struct i2c_driver lm3642_i2c_driver = {
    .driver = {
           .name = LM3642_NAME,
           .owner = THIS_MODULE,
           .pm = NULL,
           },
    .probe = lm3642_probe,
    .remove = __devexit_p(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 <[email protected]>");
MODULE_AUTHOR("G.Shark Jeong <[email protected]>");
MODULE_LICENSE("GPL v2");