lm3639_bl.c

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/*
* Simple driver for Texas Instruments LM3639 Backlight + Flash LED 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/slab.h>
#include <linux/i2c.h>
#include <linux/leds.h>
#include <linux/backlight.h>
#include <linux/err.h>
#include <linux/delay.h>
#include <linux/uaccess.h>
#include <linux/interrupt.h>
#include <linux/regmap.h>
#include <linux/platform_data/lm3639_bl.h>

#define REG_DEV_ID  0x00
#define REG_CHECKSUM    0x01
#define REG_BL_CONF_1   0x02
#define REG_BL_CONF_2   0x03
#define REG_BL_CONF_3   0x04
#define REG_BL_CONF_4   0x05
#define REG_FL_CONF_1   0x06
#define REG_FL_CONF_2   0x07
#define REG_FL_CONF_3   0x08
#define REG_IO_CTRL 0x09
#define REG_ENABLE  0x0A
#define REG_FLAG    0x0B
#define REG_MAX     REG_FLAG

struct lm3639_chip_data {
    struct device *dev;
    struct lm3639_platform_data *pdata;

    struct backlight_device *bled;
    struct led_classdev cdev_flash;
    struct led_classdev cdev_torch;
    struct regmap *regmap;

    unsigned int bled_mode;
    unsigned int bled_map;
    unsigned int last_flag;
};

/* initialize chip */
static int __devinit lm3639_chip_init(struct lm3639_chip_data *pchip)
{
    int ret;
    unsigned int reg_val;
    struct lm3639_platform_data *pdata = pchip->pdata;

    /* input pins config. */
    ret =
        regmap_update_bits(pchip->regmap, REG_BL_CONF_1, 0x08,
                   pdata->pin_pwm);
    if (ret < 0)
        goto out;

    reg_val = (pdata->pin_pwm & 0x40) | pdata->pin_strobe | pdata->pin_tx;
    ret = regmap_update_bits(pchip->regmap, REG_IO_CTRL, 0x7C, reg_val);
    if (ret < 0)
        goto out;

    /* init brightness */
    ret = regmap_write(pchip->regmap, REG_BL_CONF_4, pdata->init_brt_led);
    if (ret < 0)
        goto out;

    ret = regmap_write(pchip->regmap, REG_BL_CONF_3, pdata->init_brt_led);
    if (ret < 0)
        goto out;

    /* output pins config. */
    if (!pdata->init_brt_led)
        reg_val = pdata->fled_pins | pdata->bled_pins;
    else
        reg_val = pdata->fled_pins | pdata->bled_pins | 0x01;

    ret = regmap_update_bits(pchip->regmap, REG_ENABLE, 0x79, reg_val);
    if (ret < 0)
        goto out;

    return ret;
out:
    dev_err(pchip->dev, "i2c failed to access register\n");
    return ret;
}

/* update and get brightness */
static int lm3639_bled_update_status(struct backlight_device *bl)
{
    int ret;
    unsigned int reg_val;
    struct lm3639_chip_data *pchip = bl_get_data(bl);
    struct lm3639_platform_data *pdata = pchip->pdata;

    ret = regmap_read(pchip->regmap, REG_FLAG, &reg_val);
    if (ret < 0)
        goto out;

    if (reg_val != 0)
        dev_info(pchip->dev, "last flag is 0x%x\n", reg_val);

    /* pwm control */
    if (pdata->pin_pwm) {
        if (pdata->pwm_set_intensity)
            pdata->pwm_set_intensity(bl->props.brightness,
                         pdata->max_brt_led);
        else
            dev_err(pchip->dev,
                "No pwm control func. in plat-data\n");
        return bl->props.brightness;
    }

    /* i2c control and set brigtness */
    ret = regmap_write(pchip->regmap, REG_BL_CONF_4, bl->props.brightness);
    if (ret < 0)
        goto out;
    ret = regmap_write(pchip->regmap, REG_BL_CONF_3, bl->props.brightness);
    if (ret < 0)
        goto out;

    if (!bl->props.brightness)
        ret = regmap_update_bits(pchip->regmap, REG_ENABLE, 0x01, 0x00);
    else
        ret = regmap_update_bits(pchip->regmap, REG_ENABLE, 0x01, 0x01);
    if (ret < 0)
        goto out;

    return bl->props.brightness;
out:
    dev_err(pchip->dev, "i2c failed to access registers\n");
    return bl->props.brightness;
}

static int lm3639_bled_get_brightness(struct backlight_device *bl)
{
    int ret;
    unsigned int reg_val;
    struct lm3639_chip_data *pchip = bl_get_data(bl);
    struct lm3639_platform_data *pdata = pchip->pdata;

    if (pdata->pin_pwm) {
        if (pdata->pwm_get_intensity)
            bl->props.brightness = pdata->pwm_get_intensity();
        else
            dev_err(pchip->dev,
                "No pwm control func. in plat-data\n");
        return bl->props.brightness;
    }

    ret = regmap_read(pchip->regmap, REG_BL_CONF_1, &reg_val);
    if (ret < 0)
        goto out;
    if (reg_val & 0x10)
        ret = regmap_read(pchip->regmap, REG_BL_CONF_4, &reg_val);
    else
        ret = regmap_read(pchip->regmap, REG_BL_CONF_3, &reg_val);
    if (ret < 0)
        goto out;
    bl->props.brightness = reg_val;

    return bl->props.brightness;
out:
    dev_err(pchip->dev, "i2c failed to access register\n");
    return bl->props.brightness;
}

static const struct backlight_ops lm3639_bled_ops = {
    .options = BL_CORE_SUSPENDRESUME,
    .update_status = lm3639_bled_update_status,
    .get_brightness = lm3639_bled_get_brightness,
};

/* backlight mapping mode */
static ssize_t lm3639_bled_mode_store(struct device *dev,
                      struct device_attribute *devAttr,
                      const char *buf, size_t size)
{
    ssize_t ret;
    struct lm3639_chip_data *pchip = dev_get_drvdata(dev);
    unsigned int state;

    ret = kstrtouint(buf, 10, &state);
    if (ret)
        goto out_input;

    if (!state)
        ret =
            regmap_update_bits(pchip->regmap, REG_BL_CONF_1, 0x10,
                       0x00);
    else
        ret =
            regmap_update_bits(pchip->regmap, REG_BL_CONF_1, 0x10,
                       0x10);

    if (ret < 0)
        goto out;

    return size;

out:
    dev_err(pchip->dev, "%s:i2c access fail to register\n", __func__);
    return ret;

out_input:
    dev_err(pchip->dev, "%s:input conversion fail\n", __func__);
    return ret;

}

static DEVICE_ATTR(bled_mode, 0666, NULL, lm3639_bled_mode_store);

/* torch */
static void lm3639_torch_brightness_set(struct led_classdev *cdev,
                    enum led_brightness brightness)
{
    int ret;
    unsigned int reg_val;
    struct lm3639_chip_data *pchip;

    pchip = container_of(cdev, struct lm3639_chip_data, cdev_torch);

    ret = regmap_read(pchip->regmap, REG_FLAG, &reg_val);
    if (ret < 0)
        goto out;
    if (reg_val != 0)
        dev_info(pchip->dev, "last flag is 0x%x\n", reg_val);

    /* brightness 0 means off state */
    if (!brightness) {
        ret = regmap_update_bits(pchip->regmap, REG_ENABLE, 0x06, 0x00);
        if (ret < 0)
            goto out;
        return;
    }

    ret = regmap_update_bits(pchip->regmap,
                 REG_FL_CONF_1, 0x70, (brightness - 1) << 4);
    if (ret < 0)
        goto out;
    ret = regmap_update_bits(pchip->regmap, REG_ENABLE, 0x06, 0x02);
    if (ret < 0)
        goto out;

    return;
out:
    dev_err(pchip->dev, "i2c failed to access register\n");
    return;
}

/* flash */
static void lm3639_flash_brightness_set(struct led_classdev *cdev,
                    enum led_brightness brightness)
{
    int ret;
    unsigned int reg_val;
    struct lm3639_chip_data *pchip;

    pchip = container_of(cdev, struct lm3639_chip_data, cdev_flash);

    ret = regmap_read(pchip->regmap, REG_FLAG, &reg_val);
    if (ret < 0)
        goto out;
    if (reg_val != 0)
        dev_info(pchip->dev, "last flag is 0x%x\n", reg_val);

    /* torch off before flash control */
    ret = regmap_update_bits(pchip->regmap, REG_ENABLE, 0x06, 0x00);
    if (ret < 0)
        goto out;

    /* brightness 0 means off state */
    if (!brightness)
        return;

    ret = regmap_update_bits(pchip->regmap,
                 REG_FL_CONF_1, 0x0F, brightness - 1);
    if (ret < 0)
        goto out;
    ret = regmap_update_bits(pchip->regmap, REG_ENABLE, 0x06, 0x06);
    if (ret < 0)
        goto out;

    return;
out:
    dev_err(pchip->dev, "i2c failed to access register\n");
    return;
}

static const struct regmap_config lm3639_regmap = {
    .reg_bits = 8,
    .val_bits = 8,
    .max_register = REG_MAX,
};

static int __devinit lm3639_probe(struct i2c_client *client,
                  const struct i2c_device_id *id)
{
    int ret;
    struct lm3639_chip_data *pchip;
    struct lm3639_platform_data *pdata = client->dev.platform_data;
    struct backlight_properties props;

    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;
    }

    pchip = devm_kzalloc(&client->dev,
                 sizeof(struct lm3639_chip_data), GFP_KERNEL);
    if (!pchip)
        return -ENOMEM;

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

    pchip->regmap = devm_regmap_init_i2c(client, &lm3639_regmap);
    if (IS_ERR(pchip->regmap)) {
        ret = PTR_ERR(pchip->regmap);
        dev_err(&client->dev, "fail : allocate register map: %d\n",
            ret);
        return ret;
    }
    i2c_set_clientdata(client, pchip);

    /* chip initialize */
    ret = lm3639_chip_init(pchip);
    if (ret < 0) {
        dev_err(&client->dev, "fail : chip init\n");
        goto err_out;
    }

    /* backlight */
    props.type = BACKLIGHT_RAW;
    props.brightness = pdata->init_brt_led;
    props.max_brightness = pdata->max_brt_led;
    pchip->bled =
        backlight_device_register("lm3639_bled", pchip->dev, pchip,
                      &lm3639_bled_ops, &props);
    if (IS_ERR(pchip->bled)) {
        dev_err(&client->dev, "fail : backlight register\n");
        ret = -EIO;
        goto err_out;
    }

    ret = device_create_file(&(pchip->bled->dev), &dev_attr_bled_mode);
    if (ret < 0) {
        dev_err(&client->dev, "failed : add sysfs entries\n");
        ret = -EIO;
        goto err_bled_mode;
    }

    /* flash */
    pchip->cdev_flash.name = "lm3639_flash";
    pchip->cdev_flash.max_brightness = 16;
    pchip->cdev_flash.brightness_set = lm3639_flash_brightness_set;
    ret = led_classdev_register((struct device *)
                    &client->dev, &pchip->cdev_flash);
    if (ret < 0) {
        dev_err(&client->dev, "fail : flash register\n");
        ret = -EIO;
        goto err_flash;
    }

    /* torch */
    pchip->cdev_torch.name = "lm3639_torch";
    pchip->cdev_torch.max_brightness = 8;
    pchip->cdev_torch.brightness_set = lm3639_torch_brightness_set;
    ret = led_classdev_register((struct device *)
                    &client->dev, &pchip->cdev_torch);
    if (ret < 0) {
        dev_err(&client->dev, "fail : torch register\n");
        ret = -EIO;
        goto err_torch;
    }

    return 0;

err_torch:
    led_classdev_unregister(&pchip->cdev_flash);
err_flash:
    device_remove_file(&(pchip->bled->dev), &dev_attr_bled_mode);
err_bled_mode:
    backlight_device_unregister(pchip->bled);
err_out:
    return ret;
}

static int __devexit lm3639_remove(struct i2c_client *client)
{
    struct lm3639_chip_data *pchip = i2c_get_clientdata(client);

    regmap_write(pchip->regmap, REG_ENABLE, 0x00);

    if (&pchip->cdev_torch)
        led_classdev_unregister(&pchip->cdev_torch);
    if (&pchip->cdev_flash)
        led_classdev_unregister(&pchip->cdev_flash);
    if (pchip->bled) {
        device_remove_file(&(pchip->bled->dev), &dev_attr_bled_mode);
        backlight_device_unregister(pchip->bled);
    }
    return 0;
}

static const struct i2c_device_id lm3639_id[] = {
    {LM3639_NAME, 0},
    {}
};

MODULE_DEVICE_TABLE(i2c, lm3639_id);
static struct i2c_driver lm3639_i2c_driver = {
    .driver = {
           .name = LM3639_NAME,
           },
    .probe = lm3639_probe,
    .remove = __devexit_p(lm3639_remove),
    .id_table = lm3639_id,
};

module_i2c_driver(lm3639_i2c_driver);

MODULE_DESCRIPTION("Texas Instruments Backlight+Flash LED driver for LM3639");
MODULE_AUTHOR("Daniel Jeong <[email protected]>");
MODULE_AUTHOR("G.Shark Jeong <[email protected]>");
MODULE_LICENSE("GPL v2");