/*
   * Copyright (C) 2011 ST-Ericsson SA.
   * Copyright (C) 2009 Motorola, Inc.
   *
   * License Terms: GNU General Public License v2
   *
   * Simple driver for National Semiconductor LM3530 Backlight driver chip
   *
   * Author: Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>
   * based on leds-lm3530.c by Dan Murphy <D.Murphy@motorola.com>
   */
  
  #include <linux/i2c.h>
  #include <linux/leds.h>
  #include <linux/slab.h>
  #include <linux/platform_device.h>
  #include <linux/input.h>
  #include <linux/led-lm3530.h>
  #include <linux/types.h>

  #include <linux/regulator/consumer.h>

  #include <linux/module.h>

  
  #define LM3530_LED_DEV "lcd-backlight"
  #define LM3530_NAME "lm3530-led"
  
  #define LM3530_GEN_CONFIG		0x10
  #define LM3530_ALS_CONFIG		0x20
  #define LM3530_BRT_RAMP_RATE		0x30
  #define LM3530_ALS_ZONE_REG		0x40
  #define LM3530_ALS_IMP_SELECT		0x41
  #define LM3530_BRT_CTRL_REG		0xA0
  #define LM3530_ALS_ZB0_REG		0x60
  #define LM3530_ALS_ZB1_REG		0x61
  #define LM3530_ALS_ZB2_REG		0x62
  #define LM3530_ALS_ZB3_REG		0x63
  #define LM3530_ALS_Z0T_REG		0x70
  #define LM3530_ALS_Z1T_REG		0x71
  #define LM3530_ALS_Z2T_REG		0x72
  #define LM3530_ALS_Z3T_REG		0x73
  #define LM3530_ALS_Z4T_REG		0x74
  #define LM3530_REG_MAX			15
  
  /* General Control Register */
  #define LM3530_EN_I2C_SHIFT		(0)
  #define LM3530_RAMP_LAW_SHIFT		(1)
  #define LM3530_MAX_CURR_SHIFT		(2)
  #define LM3530_EN_PWM_SHIFT		(5)
  #define LM3530_PWM_POL_SHIFT		(6)
  #define LM3530_EN_PWM_SIMPLE_SHIFT	(7)
  
  #define LM3530_ENABLE_I2C		(1 << LM3530_EN_I2C_SHIFT)
  #define LM3530_ENABLE_PWM		(1 << LM3530_EN_PWM_SHIFT)
  #define LM3530_POL_LOW			(1 << LM3530_PWM_POL_SHIFT)
  #define LM3530_ENABLE_PWM_SIMPLE	(1 << LM3530_EN_PWM_SIMPLE_SHIFT)
  
  /* ALS Config Register Options */
  #define LM3530_ALS_AVG_TIME_SHIFT	(0)
  #define LM3530_EN_ALS_SHIFT		(3)
  #define LM3530_ALS_SEL_SHIFT		(5)
  
  #define LM3530_ENABLE_ALS		(3 << LM3530_EN_ALS_SHIFT)
  
  /* Brightness Ramp Rate Register */
  #define LM3530_BRT_RAMP_FALL_SHIFT	(0)
  #define LM3530_BRT_RAMP_RISE_SHIFT	(3)
  
  /* ALS Resistor Select */
  #define LM3530_ALS1_IMP_SHIFT		(0)
  #define LM3530_ALS2_IMP_SHIFT		(4)
  
  /* Zone Boundary Register defaults */

  #define LM3530_ALS_ZB_MAX		(4)
  #define LM3530_ALS_WINDOW_mV		(1000)
  #define LM3530_ALS_OFFSET_mV		(4)

  
  /* Zone Target Register defaults */

  #define LM3530_DEF_ZT_0			(0x7F)
  #define LM3530_DEF_ZT_1			(0x66)

  #define LM3530_DEF_ZT_2			(0x4C)

  #define LM3530_DEF_ZT_3			(0x33)
  #define LM3530_DEF_ZT_4			(0x19)

  
  struct lm3530_mode_map {
  	const char *mode;
  	enum lm3530_mode mode_val;
  };
  
  static struct lm3530_mode_map mode_map[] = {
  	{ "man", LM3530_BL_MODE_MANUAL },
  	{ "als", LM3530_BL_MODE_ALS },
  	{ "pwm", LM3530_BL_MODE_PWM },
  };
  
  /**
   * struct lm3530_data
   * @led_dev: led class device
   * @client: i2c client
   * @pdata: LM3530 platform data
   * @mode: mode of operation - manual, ALS, PWM

   * @regulator: regulator
   * @brighness: previous brightness value
   * @enable: regulator is enabled

   */
  struct lm3530_data {
  	struct led_classdev led_dev;
  	struct i2c_client *client;
  	struct lm3530_platform_data *pdata;
  	enum lm3530_mode mode;

  	struct regulator *regulator;
  	enum led_brightness brightness;
  	bool enable;

  };
  
  static const u8 lm3530_reg[LM3530_REG_MAX] = {
  	LM3530_GEN_CONFIG,
  	LM3530_ALS_CONFIG,
  	LM3530_BRT_RAMP_RATE,
  	LM3530_ALS_ZONE_REG,
  	LM3530_ALS_IMP_SELECT,
  	LM3530_BRT_CTRL_REG,
  	LM3530_ALS_ZB0_REG,
  	LM3530_ALS_ZB1_REG,
  	LM3530_ALS_ZB2_REG,
  	LM3530_ALS_ZB3_REG,
  	LM3530_ALS_Z0T_REG,
  	LM3530_ALS_Z1T_REG,
  	LM3530_ALS_Z2T_REG,
  	LM3530_ALS_Z3T_REG,
  	LM3530_ALS_Z4T_REG,
  };
  
  static int lm3530_get_mode_from_str(const char *str)
  {
  	int i;
  
  	for (i = 0; i < ARRAY_SIZE(mode_map); i++)
  		if (sysfs_streq(str, mode_map[i].mode))
  			return mode_map[i].mode_val;
  
  	return -1;
  }
  
  static int lm3530_init_registers(struct lm3530_data *drvdata)
  {
  	int ret = 0;
  	int i;
  	u8 gen_config;
  	u8 als_config = 0;
  	u8 brt_ramp;
  	u8 als_imp_sel = 0;
  	u8 brightness;
  	u8 reg_val[LM3530_REG_MAX];

  	u8 zones[LM3530_ALS_ZB_MAX];
  	u32 als_vmin, als_vmax, als_vstep;

  	struct lm3530_platform_data *pltfm = drvdata->pdata;
  	struct i2c_client *client = drvdata->client;
  
  	gen_config = (pltfm->brt_ramp_law << LM3530_RAMP_LAW_SHIFT) |
  			((pltfm->max_current & 7) << LM3530_MAX_CURR_SHIFT);
  
  	if (drvdata->mode == LM3530_BL_MODE_MANUAL ||
  	    drvdata->mode == LM3530_BL_MODE_ALS)
  		gen_config |= (LM3530_ENABLE_I2C);
  
  	if (drvdata->mode == LM3530_BL_MODE_ALS) {

  		if (pltfm->als_vmax == 0) {
  			pltfm->als_vmin = als_vmin = 0;
  			pltfm->als_vmin = als_vmax = LM3530_ALS_WINDOW_mV;
  		}
  
  		als_vmin = pltfm->als_vmin;
  		als_vmax = pltfm->als_vmax;
  
  		if ((als_vmax - als_vmin) > LM3530_ALS_WINDOW_mV)
  			pltfm->als_vmax = als_vmax =
  				als_vmin + LM3530_ALS_WINDOW_mV;
  
  		/* n zone boundary makes n+1 zones */
  		als_vstep = (als_vmax - als_vmin) / (LM3530_ALS_ZB_MAX + 1);
  
  		for (i = 0; i < LM3530_ALS_ZB_MAX; i++)
  			zones[i] = (((als_vmin + LM3530_ALS_OFFSET_mV) +
  					als_vstep + (i * als_vstep)) * LED_FULL)
  					/ 1000;

  		als_config =
  			(pltfm->als_avrg_time << LM3530_ALS_AVG_TIME_SHIFT) |
  			(LM3530_ENABLE_ALS) |
  			(pltfm->als_input_mode << LM3530_ALS_SEL_SHIFT);
  
  		als_imp_sel =
  			(pltfm->als1_resistor_sel << LM3530_ALS1_IMP_SHIFT) |
  			(pltfm->als2_resistor_sel << LM3530_ALS2_IMP_SHIFT);

  	}
  
  	if (drvdata->mode == LM3530_BL_MODE_PWM)
  		gen_config |= (LM3530_ENABLE_PWM) |
  				(pltfm->pwm_pol_hi << LM3530_PWM_POL_SHIFT) |
  				(LM3530_ENABLE_PWM_SIMPLE);
  
  	brt_ramp = (pltfm->brt_ramp_fall << LM3530_BRT_RAMP_FALL_SHIFT) |
  			(pltfm->brt_ramp_rise << LM3530_BRT_RAMP_RISE_SHIFT);

  	if (drvdata->brightness)
  		brightness = drvdata->brightness;
  	else
  		brightness = drvdata->brightness = pltfm->brt_val;

  
  	reg_val[0] = gen_config;	/* LM3530_GEN_CONFIG */
  	reg_val[1] = als_config;	/* LM3530_ALS_CONFIG */
  	reg_val[2] = brt_ramp;		/* LM3530_BRT_RAMP_RATE */
  	reg_val[3] = 0x00;		/* LM3530_ALS_ZONE_REG */
  	reg_val[4] = als_imp_sel;	/* LM3530_ALS_IMP_SELECT */
  	reg_val[5] = brightness;	/* LM3530_BRT_CTRL_REG */

  	reg_val[6] = zones[0];		/* LM3530_ALS_ZB0_REG */
  	reg_val[7] = zones[1];		/* LM3530_ALS_ZB1_REG */
  	reg_val[8] = zones[2];		/* LM3530_ALS_ZB2_REG */
  	reg_val[9] = zones[3];		/* LM3530_ALS_ZB3_REG */

  	reg_val[10] = LM3530_DEF_ZT_0;	/* LM3530_ALS_Z0T_REG */
  	reg_val[11] = LM3530_DEF_ZT_1;	/* LM3530_ALS_Z1T_REG */
  	reg_val[12] = LM3530_DEF_ZT_2;	/* LM3530_ALS_Z2T_REG */
  	reg_val[13] = LM3530_DEF_ZT_3;	/* LM3530_ALS_Z3T_REG */
  	reg_val[14] = LM3530_DEF_ZT_4;	/* LM3530_ALS_Z4T_REG */

  	if (!drvdata->enable) {
  		ret = regulator_enable(drvdata->regulator);
  		if (ret) {
  			dev_err(&drvdata->client->dev,
  					"Enable regulator failed
  ");
  			return ret;
  		}
  		drvdata->enable = true;
  	}

  	for (i = 0; i < LM3530_REG_MAX; i++) {
  		ret = i2c_smbus_write_byte_data(client,
  				lm3530_reg[i], reg_val[i]);
  		if (ret)
  			break;
  	}
  
  	return ret;
  }
  
  static void lm3530_brightness_set(struct led_classdev *led_cdev,
  				     enum led_brightness brt_val)
  {
  	int err;
  	struct lm3530_data *drvdata =
  	    container_of(led_cdev, struct lm3530_data, led_dev);
  
  	switch (drvdata->mode) {
  	case LM3530_BL_MODE_MANUAL:

  		if (!drvdata->enable) {
  			err = lm3530_init_registers(drvdata);
  			if (err) {
  				dev_err(&drvdata->client->dev,
  					"Register Init failed: %d
  ", err);
  				break;
  			}
  		}

  		/* set the brightness in brightness control register*/
  		err = i2c_smbus_write_byte_data(drvdata->client,
  				LM3530_BRT_CTRL_REG, brt_val / 2);
  		if (err)
  			dev_err(&drvdata->client->dev,
  				"Unable to set brightness: %d
  ", err);

  		else
  			drvdata->brightness = brt_val / 2;
  
  		if (brt_val == 0) {
  			err = regulator_disable(drvdata->regulator);
  			if (err)
  				dev_err(&drvdata->client->dev,
  					"Disable regulator failed
  ");
  			drvdata->enable = false;
  		}

  		break;
  	case LM3530_BL_MODE_ALS:
  		break;
  	case LM3530_BL_MODE_PWM:
  		break;
  	default:
  		break;
  	}
  }

  static ssize_t lm3530_mode_get(struct device *dev,
  		struct device_attribute *attr, char *buf)
  {
  	struct i2c_client *client = container_of(
  					dev->parent, struct i2c_client, dev);
  	struct lm3530_data *drvdata = i2c_get_clientdata(client);
  	int i, len = 0;
  
  	for (i = 0; i < ARRAY_SIZE(mode_map); i++)
  		if (drvdata->mode == mode_map[i].mode_val)
  			len += sprintf(buf + len, "[%s] ", mode_map[i].mode);
  		else
  			len += sprintf(buf + len, "%s ", mode_map[i].mode);
  
  	len += sprintf(buf + len, "
  ");
  
  	return len;
  }

  
  static ssize_t lm3530_mode_set(struct device *dev, struct device_attribute
  				   *attr, const char *buf, size_t size)
  {
  	int err;
  	struct i2c_client *client = container_of(
  					dev->parent, struct i2c_client, dev);
  	struct lm3530_data *drvdata = i2c_get_clientdata(client);
  	int mode;
  
  	mode = lm3530_get_mode_from_str(buf);
  	if (mode < 0) {
  		dev_err(dev, "Invalid mode
  ");
  		return -EINVAL;
  	}
  
  	if (mode == LM3530_BL_MODE_MANUAL)
  		drvdata->mode = LM3530_BL_MODE_MANUAL;
  	else if (mode == LM3530_BL_MODE_ALS)
  		drvdata->mode = LM3530_BL_MODE_ALS;
  	else if (mode == LM3530_BL_MODE_PWM) {
  		dev_err(dev, "PWM mode not supported
  ");
  		return -EINVAL;
  	}
  
  	err = lm3530_init_registers(drvdata);
  	if (err) {
  		dev_err(dev, "Setting %s Mode failed :%d
  ", buf, err);
  		return err;
  	}
  
  	return sizeof(drvdata->mode);
  }

  static DEVICE_ATTR(mode, 0644, lm3530_mode_get, lm3530_mode_set);

  
  static int __devinit lm3530_probe(struct i2c_client *client,
  			   const struct i2c_device_id *id)
  {
  	struct lm3530_platform_data *pdata = client->dev.platform_data;
  	struct lm3530_data *drvdata;
  	int err = 0;
  
  	if (pdata == NULL) {
  		dev_err(&client->dev, "platform data required
  ");
  		err = -ENODEV;
  		goto err_out;
  	}
  
  	/* BL mode */
  	if (pdata->mode > LM3530_BL_MODE_PWM) {
  		dev_err(&client->dev, "Illegal Mode request
  ");
  		err = -EINVAL;
  		goto err_out;
  	}
  
  	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
  		dev_err(&client->dev, "I2C_FUNC_I2C not supported
  ");
  		err = -EIO;
  		goto err_out;
  	}
  
  	drvdata = kzalloc(sizeof(struct lm3530_data), GFP_KERNEL);
  	if (drvdata == NULL) {
  		err = -ENOMEM;
  		goto err_out;
  	}
  
  	drvdata->mode = pdata->mode;
  	drvdata->client = client;
  	drvdata->pdata = pdata;

  	drvdata->brightness = LED_OFF;
  	drvdata->enable = false;

  	drvdata->led_dev.name = LM3530_LED_DEV;
  	drvdata->led_dev.brightness_set = lm3530_brightness_set;
  
  	i2c_set_clientdata(client, drvdata);

  	drvdata->regulator = regulator_get(&client->dev, "vin");
  	if (IS_ERR(drvdata->regulator)) {
  		dev_err(&client->dev, "regulator get failed
  ");
  		err = PTR_ERR(drvdata->regulator);
  		drvdata->regulator = NULL;
  		goto err_regulator_get;

  	}

  	if (drvdata->pdata->brt_val) {
  		err = lm3530_init_registers(drvdata);
  		if (err < 0) {
  			dev_err(&client->dev,
  				"Register Init failed: %d
  ", err);
  			err = -ENODEV;
  			goto err_reg_init;
  		}
  	}
  	err = led_classdev_register(&client->dev, &drvdata->led_dev);

  	if (err < 0) {
  		dev_err(&client->dev, "Register led class failed: %d
  ", err);
  		err = -ENODEV;
  		goto err_class_register;
  	}
  
  	err = device_create_file(drvdata->led_dev.dev, &dev_attr_mode);
  	if (err < 0) {
  		dev_err(&client->dev, "File device creation failed: %d
  ", err);
  		err = -ENODEV;
  		goto err_create_file;
  	}
  
  	return 0;
  
  err_create_file:
  	led_classdev_unregister(&drvdata->led_dev);
  err_class_register:
  err_reg_init:

  	regulator_put(drvdata->regulator);
  err_regulator_get:

  	kfree(drvdata);
  err_out:
  	return err;
  }
  
  static int __devexit lm3530_remove(struct i2c_client *client)
  {
  	struct lm3530_data *drvdata = i2c_get_clientdata(client);
  
  	device_remove_file(drvdata->led_dev.dev, &dev_attr_mode);

  
  	if (drvdata->enable)
  		regulator_disable(drvdata->regulator);
  	regulator_put(drvdata->regulator);

  	led_classdev_unregister(&drvdata->led_dev);
  	kfree(drvdata);
  	return 0;
  }
  
  static const struct i2c_device_id lm3530_id[] = {
  	{LM3530_NAME, 0},
  	{}
  };

  MODULE_DEVICE_TABLE(i2c, lm3530_id);

  
  static struct i2c_driver lm3530_i2c_driver = {
  	.probe = lm3530_probe,

  	.remove = __devexit_p(lm3530_remove),

  	.id_table = lm3530_id,
  	.driver = {
  		.name = LM3530_NAME,
  		.owner = THIS_MODULE,
  	},
  };

  module_i2c_driver(lm3530_i2c_driver);

  
  MODULE_DESCRIPTION("Back Light driver for LM3530");
  MODULE_LICENSE("GPL v2");
  MODULE_AUTHOR("Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>");