/*
  * Simple driver for Texas Instruments LM355x 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/gpio.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-lm355x.h>
  
  enum lm355x_type {
  	CHIP_LM3554 = 0,
  	CHIP_LM3556,
  };
  
  enum lm355x_regs {
  	REG_FLAG = 0,
  	REG_TORCH_CFG,
  	REG_TORCH_CTRL,
  	REG_STROBE_CFG,
  	REG_FLASH_CTRL,
  	REG_INDI_CFG,
  	REG_INDI_CTRL,
  	REG_OPMODE,
  	REG_MAX,
  };
  
  /* operation mode */
  enum lm355x_mode {
  	MODE_SHDN = 0,
  	MODE_INDIC,
  	MODE_TORCH,
  	MODE_FLASH
  };
  
  /* register map info. */
  struct lm355x_reg_data {
  	u8 regno;
  	u8 mask;
  	u8 shift;
  };
  
  struct lm355x_chip_data {
  	struct device *dev;
  	enum lm355x_type type;
  
  	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;
  
  	struct lm355x_platform_data *pdata;
  	struct regmap *regmap;
  	struct mutex lock;
  
  	unsigned int last_flag;
  	struct lm355x_reg_data *regs;
  };
  
  /* specific indicator function for lm3556 */
  enum lm3556_indic_pulse_time {
  	PULSE_TIME_0_MS = 0,
  	PULSE_TIME_32_MS,
  	PULSE_TIME_64_MS,
  	PULSE_TIME_92_MS,
  	PULSE_TIME_128_MS,
  	PULSE_TIME_160_MS,
  	PULSE_TIME_196_MS,
  	PULSE_TIME_224_MS,
  	PULSE_TIME_256_MS,
  	PULSE_TIME_288_MS,
  	PULSE_TIME_320_MS,
  	PULSE_TIME_352_MS,
  	PULSE_TIME_384_MS,
  	PULSE_TIME_416_MS,
  	PULSE_TIME_448_MS,
  	PULSE_TIME_480_MS,
  };
  
  enum lm3556_indic_n_blank {
  	INDIC_N_BLANK_0 = 0,
  	INDIC_N_BLANK_1,
  	INDIC_N_BLANK_2,
  	INDIC_N_BLANK_3,
  	INDIC_N_BLANK_4,
  	INDIC_N_BLANK_5,
  	INDIC_N_BLANK_6,
  	INDIC_N_BLANK_7,
  	INDIC_N_BLANK_8,
  	INDIC_N_BLANK_9,
  	INDIC_N_BLANK_10,
  	INDIC_N_BLANK_11,
  	INDIC_N_BLANK_12,
  	INDIC_N_BLANK_13,
  	INDIC_N_BLANK_14,
  	INDIC_N_BLANK_15,
  };
  
  enum lm3556_indic_period {
  	INDIC_PERIOD_0 = 0,
  	INDIC_PERIOD_1,
  	INDIC_PERIOD_2,
  	INDIC_PERIOD_3,
  	INDIC_PERIOD_4,
  	INDIC_PERIOD_5,
  	INDIC_PERIOD_6,
  	INDIC_PERIOD_7,
  };
  
  #define INDIC_PATTERN_SIZE 4
  
  struct indicator {
  	u8 blinking;
  	u8 period_cnt;
  };
  
  /* indicator pattern data only for lm3556 */
  static struct indicator indicator_pattern[INDIC_PATTERN_SIZE] = {
  	[0] = {(INDIC_N_BLANK_1 << 4) | PULSE_TIME_32_MS, INDIC_PERIOD_1},
  	[1] = {(INDIC_N_BLANK_15 << 4) | PULSE_TIME_32_MS, INDIC_PERIOD_2},
  	[2] = {(INDIC_N_BLANK_10 << 4) | PULSE_TIME_32_MS, INDIC_PERIOD_4},
  	[3] = {(INDIC_N_BLANK_5 << 4) | PULSE_TIME_32_MS, INDIC_PERIOD_7},
  };
  
  static struct lm355x_reg_data lm3554_regs[REG_MAX] = {
  	[REG_FLAG] = {0xD0, 0xBF, 0},
  	[REG_TORCH_CFG] = {0xE0, 0x80, 7},
  	[REG_TORCH_CTRL] = {0xA0, 0x38, 3},
  	[REG_STROBE_CFG] = {0xE0, 0x04, 2},
  	[REG_FLASH_CTRL] = {0xB0, 0x78, 3},
  	[REG_INDI_CFG] = {0xE0, 0x08, 3},
  	[REG_INDI_CTRL] = {0xA0, 0xC0, 6},
  	[REG_OPMODE] = {0xA0, 0x03, 0},
  };
  
  static struct lm355x_reg_data lm3556_regs[REG_MAX] = {
  	[REG_FLAG] = {0x0B, 0xFF, 0},
  	[REG_TORCH_CFG] = {0x0A, 0x10, 4},
  	[REG_TORCH_CTRL] = {0x09, 0x70, 4},
  	[REG_STROBE_CFG] = {0x0A, 0x20, 5},
  	[REG_FLASH_CTRL] = {0x09, 0x0F, 0},
  	[REG_INDI_CFG] = {0xFF, 0xFF, 0},
  	[REG_INDI_CTRL] = {0x09, 0x70, 4},
  	[REG_OPMODE] = {0x0A, 0x03, 0},
  };
  
  static char lm355x_name[][I2C_NAME_SIZE] = {
  	[CHIP_LM3554] = LM3554_NAME,
  	[CHIP_LM3556] = LM3556_NAME,
  };
  
  /* chip initialize */
  static int lm355x_chip_init(struct lm355x_chip_data *chip)
  {
  	int ret;
  	unsigned int reg_val;
  	struct lm355x_platform_data *pdata = chip->pdata;
  
  	/* input and output pins configuration */
  	switch (chip->type) {
  	case CHIP_LM3554:
  		reg_val = pdata->pin_tx2 | pdata->ntc_pin;
  		ret = regmap_update_bits(chip->regmap, 0xE0, 0x28, reg_val);
  		if (ret < 0)
  			goto out;
  		reg_val = pdata->pass_mode;
  		ret = regmap_update_bits(chip->regmap, 0xA0, 0x04, reg_val);
  		if (ret < 0)
  			goto out;
  		break;
  
  	case CHIP_LM3556:
  		reg_val = pdata->pin_tx2 | pdata->ntc_pin | pdata->pass_mode;
  		ret = regmap_update_bits(chip->regmap, 0x0A, 0xC4, reg_val);
  		if (ret < 0)
  			goto out;
  		break;
  	default:
  		return -ENODATA;
  	}
  
  	return ret;
  out:
  	dev_err(chip->dev, "%s:i2c access fail to register
  ", __func__);
  	return ret;
  }
  
  /* chip control */
  static void lm355x_control(struct lm355x_chip_data *chip,
  			   u8 brightness, enum lm355x_mode opmode)
  {
  	int ret;
  	unsigned int reg_val;
  	struct lm355x_platform_data *pdata = chip->pdata;
  	struct lm355x_reg_data *preg = chip->regs;
  
  	ret = regmap_read(chip->regmap, preg[REG_FLAG].regno, &chip->last_flag);
  	if (ret < 0)
  		goto out;
  	if (chip->last_flag & preg[REG_FLAG].mask)
  		dev_info(chip->dev, "%s Last FLAG is 0x%x
  ",
  			 lm355x_name[chip->type],
  			 chip->last_flag & preg[REG_FLAG].mask);
  	/* brightness 0 means shutdown */
  	if (!brightness)
  		opmode = MODE_SHDN;
  
  	switch (opmode) {
  	case MODE_TORCH:
  		ret =
  		    regmap_update_bits(chip->regmap, preg[REG_TORCH_CTRL].regno,
  				       preg[REG_TORCH_CTRL].mask,
  				       (brightness - 1)
  				       << preg[REG_TORCH_CTRL].shift);
  		if (ret < 0)
  			goto out;
  
  		if (pdata->pin_tx1 != LM355x_PIN_TORCH_DISABLE) {
  			ret =
  			    regmap_update_bits(chip->regmap,
  					       preg[REG_TORCH_CFG].regno,
  					       preg[REG_TORCH_CFG].mask,
  					       0x01 <<
  					       preg[REG_TORCH_CFG].shift);
  			if (ret < 0)
  				goto out;
  			opmode = MODE_SHDN;
  			dev_info(chip->dev,
  				 "torch brt is set - ext. torch pin mode
  ");
  		}
  		break;
  
  	case MODE_FLASH:
  
  		ret =
  		    regmap_update_bits(chip->regmap, preg[REG_FLASH_CTRL].regno,
  				       preg[REG_FLASH_CTRL].mask,
  				       (brightness - 1)
  				       << preg[REG_FLASH_CTRL].shift);
  		if (ret < 0)
  			goto out;
  
  		if (pdata->pin_strobe != LM355x_PIN_STROBE_DISABLE) {
  			if (chip->type == CHIP_LM3554)
  				reg_val = 0x00;
  			else
  				reg_val = 0x01;
  			ret =
  			    regmap_update_bits(chip->regmap,
  					       preg[REG_STROBE_CFG].regno,
  					       preg[REG_STROBE_CFG].mask,
  					       reg_val <<
  					       preg[REG_STROBE_CFG].shift);
  			if (ret < 0)
  				goto out;
  			opmode = MODE_SHDN;
  			dev_info(chip->dev,
  				 "flash brt is set - ext. strobe pin mode
  ");
  		}
  		break;
  
  	case MODE_INDIC:
  		ret =
  		    regmap_update_bits(chip->regmap, preg[REG_INDI_CTRL].regno,
  				       preg[REG_INDI_CTRL].mask,
  				       (brightness - 1)
  				       << preg[REG_INDI_CTRL].shift);
  		if (ret < 0)
  			goto out;
  
  		if (pdata->pin_tx2 != LM355x_PIN_TX_DISABLE) {
  			ret =
  			    regmap_update_bits(chip->regmap,
  					       preg[REG_INDI_CFG].regno,
  					       preg[REG_INDI_CFG].mask,
  					       0x01 <<
  					       preg[REG_INDI_CFG].shift);
  			if (ret < 0)
  				goto out;
  			opmode = MODE_SHDN;
  		}
  		break;
  	case MODE_SHDN:
  		break;
  	default:
  		return;
  	}
  	/* operation mode control */
  	ret = regmap_update_bits(chip->regmap, preg[REG_OPMODE].regno,
  				 preg[REG_OPMODE].mask,
  				 opmode << preg[REG_OPMODE].shift);
  	if (ret < 0)
  		goto out;
  	return;
  out:
  	dev_err(chip->dev, "%s:i2c access fail to register
  ", __func__);
  	return;
  }
  
  /* torch */
  static void lm355x_deferred_torch_brightness_set(struct work_struct *work)
  {
  	struct lm355x_chip_data *chip =
  	    container_of(work, struct lm355x_chip_data, work_torch);
  
  	mutex_lock(&chip->lock);
  	lm355x_control(chip, chip->br_torch, MODE_TORCH);
  	mutex_unlock(&chip->lock);
  }
  
  static void lm355x_torch_brightness_set(struct led_classdev *cdev,
  					enum led_brightness brightness)
  {
  	struct lm355x_chip_data *chip =
  	    container_of(cdev, struct lm355x_chip_data, cdev_torch);
  
  	chip->br_torch = brightness;
  	schedule_work(&chip->work_torch);
  }
  
  /* flash */
  static void lm355x_deferred_strobe_brightness_set(struct work_struct *work)
  {
  	struct lm355x_chip_data *chip =
  	    container_of(work, struct lm355x_chip_data, work_flash);
  
  	mutex_lock(&chip->lock);
  	lm355x_control(chip, chip->br_flash, MODE_FLASH);
  	mutex_unlock(&chip->lock);
  }
  
  static void lm355x_strobe_brightness_set(struct led_classdev *cdev,
  					 enum led_brightness brightness)
  {
  	struct lm355x_chip_data *chip =
  	    container_of(cdev, struct lm355x_chip_data, cdev_flash);
  
  	chip->br_flash = brightness;
  	schedule_work(&chip->work_flash);
  }
  
  /* indicator */
  static void lm355x_deferred_indicator_brightness_set(struct work_struct *work)
  {
  	struct lm355x_chip_data *chip =
  	    container_of(work, struct lm355x_chip_data, work_indicator);
  
  	mutex_lock(&chip->lock);
  	lm355x_control(chip, chip->br_indicator, MODE_INDIC);
  	mutex_unlock(&chip->lock);
  }
  
  static void lm355x_indicator_brightness_set(struct led_classdev *cdev,
  					    enum led_brightness brightness)
  {
  	struct lm355x_chip_data *chip =
  	    container_of(cdev, struct lm355x_chip_data, cdev_indicator);
  
  	chip->br_indicator = brightness;
  	schedule_work(&chip->work_indicator);
  }
  
  /* indicator pattern only for lm3556*/
  static ssize_t lm3556_indicator_pattern_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 lm355x_chip_data *chip =
  	    container_of(led_cdev, struct lm355x_chip_data, cdev_indicator);
  	unsigned int state;
  
  	ret = kstrtouint(buf, 10, &state);
  	if (ret)
  		goto out;
  	if (state > INDIC_PATTERN_SIZE - 1)
  		state = INDIC_PATTERN_SIZE - 1;
  
  	ret = regmap_write(chip->regmap, 0x04,
  			   indicator_pattern[state].blinking);
  	if (ret < 0)
  		goto out;
  
  	ret = regmap_write(chip->regmap, 0x05,
  			   indicator_pattern[state].period_cnt);
  	if (ret < 0)
  		goto out;
  
  	return size;
  out:
  	dev_err(chip->dev, "%s:i2c access fail to register
  ", __func__);
  	return ret;
  }
  
  static DEVICE_ATTR(pattern, S_IWUSR, NULL, lm3556_indicator_pattern_store);
  
  static struct attribute *lm355x_indicator_attrs[] = {
  	&dev_attr_pattern.attr,
  	NULL
  };
  ATTRIBUTE_GROUPS(lm355x_indicator);
  
  static const struct regmap_config lm355x_regmap = {
  	.reg_bits = 8,
  	.val_bits = 8,
  	.max_register = 0xFF,
  };
  
  /* module initialize */
  static int lm355x_probe(struct i2c_client *client,
  				  const struct i2c_device_id *id)
  {
  	struct lm355x_platform_data *pdata = dev_get_platdata(&client->dev);
  	struct lm355x_chip_data *chip;
  
  	int err;
  
  	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
  		dev_err(&client->dev, "i2c functionality check fail.
  ");
  		return -EOPNOTSUPP;
  	}
  
  	if (pdata == NULL) {
  		dev_err(&client->dev, "needs Platform Data.
  ");
  		return -ENODATA;
  	}
  
  	chip = devm_kzalloc(&client->dev,
  			    sizeof(struct lm355x_chip_data), GFP_KERNEL);
  	if (!chip)
  		return -ENOMEM;
  
  	chip->dev = &client->dev;
  	chip->type = id->driver_data;
  	switch (id->driver_data) {
  	case CHIP_LM3554:
  		chip->regs = lm3554_regs;
  		break;
  	case CHIP_LM3556:
  		chip->regs = lm3556_regs;
  		break;
  	default:
  		return -ENOSYS;
  	}
  	chip->pdata = pdata;
  
  	chip->regmap = devm_regmap_init_i2c(client, &lm355x_regmap);
  	if (IS_ERR(chip->regmap)) {
  		err = PTR_ERR(chip->regmap);
  		dev_err(&client->dev,
  			"Failed to allocate register map: %d
  ", err);
  		return err;
  	}
  
  	mutex_init(&chip->lock);
  	i2c_set_clientdata(client, chip);
  
  	err = lm355x_chip_init(chip);
  	if (err < 0)
  		goto err_out;
  
  	/* flash */
  	INIT_WORK(&chip->work_flash, lm355x_deferred_strobe_brightness_set);
  	chip->cdev_flash.name = "flash";
  	chip->cdev_flash.max_brightness = 16;
  	chip->cdev_flash.brightness_set = lm355x_strobe_brightness_set;
  	chip->cdev_flash.default_trigger = "flash";
  	err = led_classdev_register((struct device *)
  				    &client->dev, &chip->cdev_flash);
  	if (err < 0)
  		goto err_out;
  	/* torch */
  	INIT_WORK(&chip->work_torch, lm355x_deferred_torch_brightness_set);
  	chip->cdev_torch.name = "torch";
  	chip->cdev_torch.max_brightness = 8;
  	chip->cdev_torch.brightness_set = lm355x_torch_brightness_set;
  	chip->cdev_torch.default_trigger = "torch";
  	err = led_classdev_register((struct device *)
  				    &client->dev, &chip->cdev_torch);
  	if (err < 0)
  		goto err_create_torch_file;
  	/* indicator */
  	INIT_WORK(&chip->work_indicator,
  		  lm355x_deferred_indicator_brightness_set);
  	chip->cdev_indicator.name = "indicator";
  	if (id->driver_data == CHIP_LM3554)
  		chip->cdev_indicator.max_brightness = 4;
  	else
  		chip->cdev_indicator.max_brightness = 8;
  	chip->cdev_indicator.brightness_set = lm355x_indicator_brightness_set;
  	/* indicator pattern control only for LM3556 */
  	if (id->driver_data == CHIP_LM3556)
  		chip->cdev_indicator.groups = lm355x_indicator_groups;
  	err = led_classdev_register((struct device *)
  				    &client->dev, &chip->cdev_indicator);
  	if (err < 0)
  		goto err_create_indicator_file;
  
  	dev_info(&client->dev, "%s is initialized
  ",
  		 lm355x_name[id->driver_data]);
  	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 int lm355x_remove(struct i2c_client *client)
  {
  	struct lm355x_chip_data *chip = i2c_get_clientdata(client);
  	struct lm355x_reg_data *preg = chip->regs;
  
  	regmap_write(chip->regmap, preg[REG_OPMODE].regno, 0);
  	led_classdev_unregister(&chip->cdev_indicator);
  	flush_work(&chip->work_indicator);
  	led_classdev_unregister(&chip->cdev_torch);
  	flush_work(&chip->work_torch);
  	led_classdev_unregister(&chip->cdev_flash);
  	flush_work(&chip->work_flash);
  	dev_info(&client->dev, "%s is removed
  ", lm355x_name[chip->type]);
  
  	return 0;
  }
  
  static const struct i2c_device_id lm355x_id[] = {
  	{LM3554_NAME, CHIP_LM3554},
  	{LM3556_NAME, CHIP_LM3556},
  	{}
  };
  
  MODULE_DEVICE_TABLE(i2c, lm355x_id);
  
  static struct i2c_driver lm355x_i2c_driver = {
  	.driver = {
  		   .name = LM355x_NAME,
  		   .pm = NULL,
  		   },
  	.probe = lm355x_probe,
  	.remove = lm355x_remove,
  	.id_table = lm355x_id,
  };
  
  module_i2c_driver(lm355x_i2c_driver);
  
  MODULE_DESCRIPTION("Texas Instruments Flash Lighting driver for LM355x");
  MODULE_AUTHOR("Daniel Jeong <daniel.jeong@ti.com>");
  MODULE_AUTHOR("G.Shark Jeong <gshark.jeong@gmail.com>");
  MODULE_LICENSE("GPL v2");