/*

   * da9211-regulator.c - Regulator device driver for DA9211/DA9212

   * /DA9213/DA9223/DA9214/DA9224/DA9215/DA9225

   * Copyright (C) 2015  Dialog Semiconductor Ltd.

   *
   * This library is free software; you can redistribute it and/or
   * modify it under the terms of the GNU Library General Public
   * License as published by the Free Software Foundation; either
   * version 2 of the License, or (at your option) any later version.
   *
   * This library is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   * Library General Public License for more details.
   */
  
  #include <linux/err.h>

  #include <linux/i2c.h>
  #include <linux/module.h>
  #include <linux/init.h>
  #include <linux/slab.h>
  #include <linux/regulator/driver.h>
  #include <linux/regulator/machine.h>
  #include <linux/regmap.h>
  #include <linux/irq.h>
  #include <linux/interrupt.h>

  #include <linux/gpio/consumer.h>

  #include <linux/regulator/of_regulator.h>

  #include <linux/regulator/da9211.h>
  #include "da9211-regulator.h"

  /* DEVICE IDs */
  #define DA9211_DEVICE_ID	0x22
  #define DA9213_DEVICE_ID	0x23

  #define DA9215_DEVICE_ID	0x24

  #define DA9211_BUCK_MODE_SLEEP	1
  #define DA9211_BUCK_MODE_SYNC	2
  #define DA9211_BUCK_MODE_AUTO	3
  
  /* DA9211 REGULATOR IDs */
  #define DA9211_ID_BUCKA	0
  #define DA9211_ID_BUCKB	1
  
  struct da9211 {
  	struct device *dev;
  	struct regmap *regmap;
  	struct da9211_pdata *pdata;
  	struct regulator_dev *rdev[DA9211_MAX_REGULATORS];
  	int num_regulator;
  	int chip_irq;

  	int chip_id;

  };
  
  static const struct regmap_range_cfg da9211_regmap_range[] = {
  	{
  		.selector_reg = DA9211_REG_PAGE_CON,
  		.selector_mask  = DA9211_REG_PAGE_MASK,
  		.selector_shift = DA9211_REG_PAGE_SHIFT,
  		.window_start = 0,
  		.window_len = 256,
  		.range_min = 0,

  		.range_max = 5*128,

  	},
  };
  
  static const struct regmap_config da9211_regmap_config = {
  	.reg_bits = 8,
  	.val_bits = 8,

  	.max_register = 5 * 128,

  	.ranges = da9211_regmap_range,
  	.num_ranges = ARRAY_SIZE(da9211_regmap_range),
  };
  
  /* Default limits measured in millivolts and milliamps */
  #define DA9211_MIN_MV		300
  #define DA9211_MAX_MV		1570
  #define DA9211_STEP_MV		10

  /* Current limits for DA9211 buck (uA) indices
   * corresponds with register values
   */

  static const int da9211_current_limits[] = {
  	2000000, 2200000, 2400000, 2600000, 2800000, 3000000, 3200000, 3400000,
  	3600000, 3800000, 4000000, 4200000, 4400000, 4600000, 4800000, 5000000
  };

  /* Current limits for DA9213 buck (uA) indices
   * corresponds with register values
   */
  static const int da9213_current_limits[] = {
  	3000000, 3200000, 3400000, 3600000, 3800000, 4000000, 4200000, 4400000,
  	4600000, 4800000, 5000000, 5200000, 5400000, 5600000, 5800000, 6000000
  };

  /* Current limits for DA9215 buck (uA) indices
   * corresponds with register values
   */
  static const int da9215_current_limits[] = {
  	4000000, 4200000, 4400000, 4600000, 4800000, 5000000, 5200000, 5400000,
  	5600000, 5800000, 6000000, 6200000, 6400000, 6600000, 6800000, 7000000
  };

  
  static unsigned int da9211_buck_get_mode(struct regulator_dev *rdev)
  {
  	int id = rdev_get_id(rdev);
  	struct da9211 *chip = rdev_get_drvdata(rdev);
  	unsigned int data;
  	int ret, mode = 0;
  
  	ret = regmap_read(chip->regmap, DA9211_REG_BUCKA_CONF+id, &data);
  	if (ret < 0)
  		return ret;
  
  	switch (data & 0x03) {
  	case DA9211_BUCK_MODE_SYNC:
  		mode = REGULATOR_MODE_FAST;
  		break;
  	case DA9211_BUCK_MODE_AUTO:
  		mode = REGULATOR_MODE_NORMAL;
  		break;
  	case DA9211_BUCK_MODE_SLEEP:
  		mode = REGULATOR_MODE_STANDBY;
  		break;
  	}
  
  	return mode;
  }
  
  static int da9211_buck_set_mode(struct regulator_dev *rdev,
  					unsigned int mode)
  {
  	int id = rdev_get_id(rdev);
  	struct da9211 *chip = rdev_get_drvdata(rdev);
  	int val = 0;
  
  	switch (mode) {
  	case REGULATOR_MODE_FAST:
  		val = DA9211_BUCK_MODE_SYNC;
  		break;
  	case REGULATOR_MODE_NORMAL:
  		val = DA9211_BUCK_MODE_AUTO;
  		break;
  	case REGULATOR_MODE_STANDBY:
  		val = DA9211_BUCK_MODE_SLEEP;
  		break;
  	}
  
  	return regmap_update_bits(chip->regmap, DA9211_REG_BUCKA_CONF+id,
  					0x03, val);
  }
  
  static int da9211_set_current_limit(struct regulator_dev *rdev, int min,
  				    int max)
  {
  	int id = rdev_get_id(rdev);
  	struct da9211 *chip = rdev_get_drvdata(rdev);

  	int i, max_size;
  	const int *current_limits;
  
  	switch (chip->chip_id) {
  	case DA9211:
  		current_limits = da9211_current_limits;
  		max_size = ARRAY_SIZE(da9211_current_limits)-1;
  		break;
  	case DA9213:
  		current_limits = da9213_current_limits;
  		max_size = ARRAY_SIZE(da9213_current_limits)-1;
  		break;

  	case DA9215:
  		current_limits = da9215_current_limits;
  		max_size = ARRAY_SIZE(da9215_current_limits)-1;
  		break;

  	default:
  		return -EINVAL;
  	}

  
  	/* search for closest to maximum */

  	for (i = max_size; i >= 0; i--) {
  		if (min <= current_limits[i] &&
  		    max >= current_limits[i]) {

  				return regmap_update_bits(chip->regmap,
  					DA9211_REG_BUCK_ILIM,
  					(0x0F << id*4), (i << id*4));
  		}
  	}
  
  	return -EINVAL;
  }
  
  static int da9211_get_current_limit(struct regulator_dev *rdev)
  {
  	int id = rdev_get_id(rdev);
  	struct da9211 *chip = rdev_get_drvdata(rdev);
  	unsigned int data;
  	int ret;

  	const int *current_limits;
  
  	switch (chip->chip_id) {
  	case DA9211:
  		current_limits = da9211_current_limits;
  		break;
  	case DA9213:
  		current_limits = da9213_current_limits;
  		break;

  	case DA9215:
  		current_limits = da9215_current_limits;
  		break;

  	default:
  		return -EINVAL;
  	}

  
  	ret = regmap_read(chip->regmap, DA9211_REG_BUCK_ILIM, &data);
  	if (ret < 0)
  		return ret;

  	/* select one of 16 values: 0000 (2000mA or 3000mA)
  	 * to 1111 (5000mA or 6000mA).
  	 */

  	data = (data >> id*4) & 0x0F;

  	return current_limits[data];

  }

  static const struct regulator_ops da9211_buck_ops = {

  	.get_mode = da9211_buck_get_mode,
  	.set_mode = da9211_buck_set_mode,
  	.enable = regulator_enable_regmap,
  	.disable = regulator_disable_regmap,
  	.is_enabled = regulator_is_enabled_regmap,
  	.set_voltage_sel = regulator_set_voltage_sel_regmap,
  	.get_voltage_sel = regulator_get_voltage_sel_regmap,
  	.list_voltage = regulator_list_voltage_linear,
  	.set_current_limit = da9211_set_current_limit,
  	.get_current_limit = da9211_get_current_limit,
  };
  
  #define DA9211_BUCK(_id) \
  {\
  	.name = #_id,\
  	.ops = &da9211_buck_ops,\
  	.type = REGULATOR_VOLTAGE,\
  	.id = DA9211_ID_##_id,\
  	.n_voltages = (DA9211_MAX_MV - DA9211_MIN_MV) / DA9211_STEP_MV + 1,\
  	.min_uV = (DA9211_MIN_MV * 1000),\
  	.uV_step = (DA9211_STEP_MV * 1000),\
  	.enable_reg = DA9211_REG_BUCKA_CONT + DA9211_ID_##_id,\
  	.enable_mask = DA9211_BUCKA_EN,\
  	.vsel_reg = DA9211_REG_VBUCKA_A + DA9211_ID_##_id * 2,\
  	.vsel_mask = DA9211_VBUCK_MASK,\
  	.owner = THIS_MODULE,\
  }
  
  static struct regulator_desc da9211_regulators[] = {
  	DA9211_BUCK(BUCKA),
  	DA9211_BUCK(BUCKB),
  };

  #ifdef CONFIG_OF
  static struct of_regulator_match da9211_matches[] = {
  	[DA9211_ID_BUCKA] = { .name = "BUCKA" },
  	[DA9211_ID_BUCKB] = { .name = "BUCKB" },
  	};
  
  static struct da9211_pdata *da9211_parse_regulators_dt(
  		struct device *dev)
  {
  	struct da9211_pdata *pdata;
  	struct device_node *node;
  	int i, num, n;
  
  	node = of_get_child_by_name(dev->of_node, "regulators");
  	if (!node) {
  		dev_err(dev, "regulators node not found
  ");
  		return ERR_PTR(-ENODEV);
  	}
  
  	num = of_regulator_match(dev, node, da9211_matches,
  				 ARRAY_SIZE(da9211_matches));
  	of_node_put(node);
  	if (num < 0) {
  		dev_err(dev, "Failed to match regulators
  ");
  		return ERR_PTR(-EINVAL);
  	}
  
  	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
  	if (!pdata)
  		return ERR_PTR(-ENOMEM);
  
  	pdata->num_buck = num;
  
  	n = 0;
  	for (i = 0; i < ARRAY_SIZE(da9211_matches); i++) {
  		if (!da9211_matches[i].init_data)
  			continue;
  
  		pdata->init_data[n] = da9211_matches[i].init_data;

  		pdata->reg_node[n] = da9211_matches[i].of_node;

  		pdata->gpiod_ren[n] = devm_gpiod_get_from_of_node(dev,

  				  da9211_matches[i].of_node,
  				  "enable",
  				  0,
  				  GPIOD_OUT_HIGH | GPIOD_FLAGS_BIT_NONEXCLUSIVE,
  				  "da9211-enable");

  		n++;

  	}

  
  	return pdata;
  }
  #else
  static struct da9211_pdata *da9211_parse_regulators_dt(
  		struct device *dev)
  {
  	return ERR_PTR(-ENODEV);
  }
  #endif

  static irqreturn_t da9211_irq_handler(int irq, void *data)
  {
  	struct da9211 *chip = data;
  	int reg_val, err, ret = IRQ_NONE;
  
  	err = regmap_read(chip->regmap, DA9211_REG_EVENT_B, &reg_val);
  	if (err < 0)
  		goto error_i2c;
  
  	if (reg_val & DA9211_E_OV_CURR_A) {
  		regulator_notifier_call_chain(chip->rdev[0],

  			REGULATOR_EVENT_OVER_CURRENT, NULL);

  
  		err = regmap_write(chip->regmap, DA9211_REG_EVENT_B,
  			DA9211_E_OV_CURR_A);
  		if (err < 0)
  			goto error_i2c;
  
  		ret = IRQ_HANDLED;
  	}
  
  	if (reg_val & DA9211_E_OV_CURR_B) {
  		regulator_notifier_call_chain(chip->rdev[1],

  			REGULATOR_EVENT_OVER_CURRENT, NULL);

  
  		err = regmap_write(chip->regmap, DA9211_REG_EVENT_B,
  			DA9211_E_OV_CURR_B);
  		if (err < 0)
  			goto error_i2c;
  
  		ret = IRQ_HANDLED;
  	}
  
  	return ret;
  
  error_i2c:
  	dev_err(chip->dev, "I2C error : %d
  ", err);
  	return IRQ_NONE;
  }
  
  static int da9211_regulator_init(struct da9211 *chip)
  {
  	struct regulator_config config = { };
  	int i, ret;
  	unsigned int data;
  
  	ret = regmap_read(chip->regmap, DA9211_REG_CONFIG_E, &data);
  	if (ret < 0) {

  		dev_err(chip->dev, "Failed to read CONFIG_E reg: %d
  ", ret);

  		return ret;

  	}
  
  	data &= DA9211_SLAVE_SEL;
  	/* If configuration for 1/2 bucks is different between platform data
  	 * and the register, driver should exit.
  	 */

  	if (chip->pdata->num_buck == 1 && data == 0x00)
  		chip->num_regulator = 1;
  	else if (chip->pdata->num_buck == 2 && data != 0x00)
  		chip->num_regulator = 2;
  	else {

  		dev_err(chip->dev, "Configuration is mismatched
  ");

  		return -EINVAL;

  	}
  
  	for (i = 0; i < chip->num_regulator; i++) {

  		config.init_data = chip->pdata->init_data[i];

  		config.dev = chip->dev;
  		config.driver_data = chip;
  		config.regmap = chip->regmap;

  		config.of_node = chip->pdata->reg_node[i];

  		if (chip->pdata->gpiod_ren[i])
  			config.ena_gpiod = chip->pdata->gpiod_ren[i];
  		else
  			config.ena_gpiod = NULL;

  		/*
  		 * Hand the GPIO descriptor management over to the regulator
  		 * core, remove it from GPIO devres management.
  		 */
  		if (config.ena_gpiod)
  			devm_gpiod_unhinge(chip->dev, config.ena_gpiod);

  		chip->rdev[i] = devm_regulator_register(chip->dev,
  			&da9211_regulators[i], &config);
  		if (IS_ERR(chip->rdev[i])) {
  			dev_err(chip->dev,
  				"Failed to register DA9211 regulator
  ");

  			return PTR_ERR(chip->rdev[i]);

  		}
  
  		if (chip->chip_irq != 0) {
  			ret = regmap_update_bits(chip->regmap,

  				DA9211_REG_MASK_B, DA9211_M_OV_CURR_A << i, 0);

  			if (ret < 0) {
  				dev_err(chip->dev,
  					"Failed to update mask reg: %d
  ", ret);

  				return ret;

  			}
  		}
  	}
  
  	return 0;

  }

  /*
   * I2C driver interface functions
   */
  static int da9211_i2c_probe(struct i2c_client *i2c,
  		const struct i2c_device_id *id)
  {
  	struct da9211 *chip;
  	int error, ret;

  	unsigned int data;

  
  	chip = devm_kzalloc(&i2c->dev, sizeof(struct da9211), GFP_KERNEL);

  	if (!chip)
  		return -ENOMEM;

  
  	chip->dev = &i2c->dev;
  	chip->regmap = devm_regmap_init_i2c(i2c, &da9211_regmap_config);
  	if (IS_ERR(chip->regmap)) {
  		error = PTR_ERR(chip->regmap);

  		dev_err(chip->dev, "Failed to allocate register map: %d
  ",

  			error);
  		return error;
  	}
  
  	i2c_set_clientdata(i2c, chip);
  
  	chip->pdata = i2c->dev.platform_data;

  
  	ret = regmap_read(chip->regmap, DA9211_REG_DEVICE_ID, &data);
  	if (ret < 0) {
  		dev_err(chip->dev, "Failed to read DEVICE_ID reg: %d
  ", ret);
  		return ret;
  	}
  
  	switch (data) {
  	case DA9211_DEVICE_ID:
  		chip->chip_id = DA9211;
  		break;
  	case DA9213_DEVICE_ID:
  		chip->chip_id = DA9213;
  		break;

  	case DA9215_DEVICE_ID:
  		chip->chip_id = DA9215;
  		break;

  	default:
  		dev_err(chip->dev, "Unsupported device id = 0x%x.
  ", data);

  		return -ENODEV;
  	}

  	if (!chip->pdata)
  		chip->pdata = da9211_parse_regulators_dt(chip->dev);
  
  	if (IS_ERR(chip->pdata)) {
  		dev_err(chip->dev, "No regulators defined for the platform
  ");
  		return PTR_ERR(chip->pdata);
  	}

  	chip->chip_irq = i2c->irq;
  
  	if (chip->chip_irq != 0) {
  		ret = devm_request_threaded_irq(chip->dev, chip->chip_irq, NULL,
  					da9211_irq_handler,
  					IRQF_TRIGGER_LOW|IRQF_ONESHOT,
  					"da9211", chip);
  		if (ret != 0) {
  			dev_err(chip->dev, "Failed to request IRQ: %d
  ",
  				chip->chip_irq);
  			return ret;
  		}
  	} else {
  		dev_warn(chip->dev, "No IRQ configured
  ");
  	}
  
  	ret = da9211_regulator_init(chip);
  
  	if (ret < 0)

  		dev_err(chip->dev, "Failed to initialize regulator: %d
  ", ret);

  
  	return ret;
  }

  static const struct i2c_device_id da9211_i2c_id[] = {

  	{"da9211", DA9211},

  	{"da9212", DA9212},

  	{"da9213", DA9213},

  	{"da9223", DA9223},

  	{"da9214", DA9214},

  	{"da9224", DA9224},

  	{"da9215", DA9215},

  	{"da9225", DA9225},

  	{},
  };

  MODULE_DEVICE_TABLE(i2c, da9211_i2c_id);

  #ifdef CONFIG_OF
  static const struct of_device_id da9211_dt_ids[] = {
  	{ .compatible = "dlg,da9211", .data = &da9211_i2c_id[0] },

  	{ .compatible = "dlg,da9212", .data = &da9211_i2c_id[1] },
  	{ .compatible = "dlg,da9213", .data = &da9211_i2c_id[2] },

  	{ .compatible = "dlg,da9223", .data = &da9211_i2c_id[3] },
  	{ .compatible = "dlg,da9214", .data = &da9211_i2c_id[4] },
  	{ .compatible = "dlg,da9224", .data = &da9211_i2c_id[5] },
  	{ .compatible = "dlg,da9215", .data = &da9211_i2c_id[6] },
  	{ .compatible = "dlg,da9225", .data = &da9211_i2c_id[7] },

  	{},
  };
  MODULE_DEVICE_TABLE(of, da9211_dt_ids);
  #endif

  static struct i2c_driver da9211_regulator_driver = {
  	.driver = {
  		.name = "da9211",

  		.of_match_table = of_match_ptr(da9211_dt_ids),

  	},
  	.probe = da9211_i2c_probe,

  	.id_table = da9211_i2c_id,
  };
  
  module_i2c_driver(da9211_regulator_driver);
  
  MODULE_AUTHOR("James Ban <James.Ban.opensource@diasemi.com>");

  MODULE_DESCRIPTION("DA9211/DA9212/DA9213/DA9223/DA9214/DA9224/DA9215/DA9225 regulator driver");

  MODULE_LICENSE("GPL");