/*
   * max14577.c - Regulator driver for the Maxim 14577/77836
   *
   * Copyright (C) 2013,2014 Samsung Electronics
   * Krzysztof Kozlowski <k.kozlowski@samsung.com>
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation; either version 2 of the License, or
   * (at your option) any later version.
   *
   * This program 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 General Public License for more details.
   */
  
  #include <linux/module.h>
  #include <linux/platform_device.h>
  #include <linux/regulator/driver.h>
  #include <linux/mfd/max14577.h>
  #include <linux/mfd/max14577-private.h>
  #include <linux/regulator/of_regulator.h>
  
  static int max14577_reg_is_enabled(struct regulator_dev *rdev)
  {
  	int rid = rdev_get_id(rdev);
  	struct regmap *rmap = rdev->regmap;
  	u8 reg_data;
  
  	switch (rid) {
  	case MAX14577_CHARGER:
  		max14577_read_reg(rmap, MAX14577_CHG_REG_CHG_CTRL2, &reg_data);
  		if ((reg_data & CHGCTRL2_MBCHOSTEN_MASK) == 0)
  			return 0;
  		max14577_read_reg(rmap, MAX14577_CHG_REG_STATUS3, &reg_data);
  		if ((reg_data & STATUS3_CGMBC_MASK) == 0)
  			return 0;
  		/* MBCHOSTEN and CGMBC are on */
  		return 1;
  	default:
  		return -EINVAL;
  	}
  }
  
  static int max14577_reg_get_current_limit(struct regulator_dev *rdev)
  {
  	u8 reg_data;
  	struct regmap *rmap = rdev->regmap;
  	struct max14577 *max14577 = rdev_get_drvdata(rdev);
  	const struct maxim_charger_current *limits =
  		&maxim_charger_currents[max14577->dev_type];
  
  	if (rdev_get_id(rdev) != MAX14577_CHARGER)
  		return -EINVAL;
  
  	max14577_read_reg(rmap, MAX14577_CHG_REG_CHG_CTRL4, &reg_data);
  
  	if ((reg_data & CHGCTRL4_MBCICHWRCL_MASK) == 0)
  		return limits->min;
  
  	reg_data = ((reg_data & CHGCTRL4_MBCICHWRCH_MASK) >>
  			CHGCTRL4_MBCICHWRCH_SHIFT);
  	return limits->high_start + reg_data * limits->high_step;
  }
  
  static int max14577_reg_set_current_limit(struct regulator_dev *rdev,
  		int min_uA, int max_uA)
  {
  	u8 reg_data;
  	int ret;
  	struct max14577 *max14577 = rdev_get_drvdata(rdev);
  	const struct maxim_charger_current *limits =
  		&maxim_charger_currents[max14577->dev_type];
  
  	if (rdev_get_id(rdev) != MAX14577_CHARGER)
  		return -EINVAL;
  
  	ret = maxim_charger_calc_reg_current(limits, min_uA, max_uA, &reg_data);
  	if (ret)
  		return ret;
  
  	return max14577_update_reg(rdev->regmap, MAX14577_CHG_REG_CHG_CTRL4,
  			CHGCTRL4_MBCICHWRCL_MASK | CHGCTRL4_MBCICHWRCH_MASK,
  			reg_data);
  }
  
  static struct regulator_ops max14577_safeout_ops = {
  	.is_enabled		= regulator_is_enabled_regmap,
  	.enable			= regulator_enable_regmap,
  	.disable		= regulator_disable_regmap,
  	.list_voltage		= regulator_list_voltage_linear,
  };
  
  static struct regulator_ops max14577_charger_ops = {
  	.is_enabled		= max14577_reg_is_enabled,
  	.enable			= regulator_enable_regmap,
  	.disable		= regulator_disable_regmap,
  	.get_current_limit	= max14577_reg_get_current_limit,
  	.set_current_limit	= max14577_reg_set_current_limit,
  };
  
  #define MAX14577_SAFEOUT_REG	{ \
  	.name		= "SAFEOUT", \
  	.of_match	= of_match_ptr("SAFEOUT"), \
  	.regulators_node = of_match_ptr("regulators"), \
  	.id		= MAX14577_SAFEOUT, \
  	.ops		= &max14577_safeout_ops, \
  	.type		= REGULATOR_VOLTAGE, \
  	.owner		= THIS_MODULE, \
  	.n_voltages	= 1, \
  	.min_uV		= MAX14577_REGULATOR_SAFEOUT_VOLTAGE, \
  	.enable_reg	= MAX14577_REG_CONTROL2, \
  	.enable_mask	= CTRL2_SFOUTORD_MASK, \
  }
  #define MAX14577_CHARGER_REG	{ \
  	.name		= "CHARGER", \
  	.of_match	= of_match_ptr("CHARGER"), \
  	.regulators_node = of_match_ptr("regulators"), \
  	.id		= MAX14577_CHARGER, \
  	.ops		= &max14577_charger_ops, \
  	.type		= REGULATOR_CURRENT, \
  	.owner		= THIS_MODULE, \
  	.enable_reg	= MAX14577_CHG_REG_CHG_CTRL2, \
  	.enable_mask	= CHGCTRL2_MBCHOSTEN_MASK, \
  }
  
  static const struct regulator_desc max14577_supported_regulators[] = {
  	[MAX14577_SAFEOUT] = MAX14577_SAFEOUT_REG,
  	[MAX14577_CHARGER] = MAX14577_CHARGER_REG,
  };
  
  static struct regulator_ops max77836_ldo_ops = {
  	.is_enabled		= regulator_is_enabled_regmap,
  	.enable			= regulator_enable_regmap,
  	.disable		= regulator_disable_regmap,
  	.list_voltage		= regulator_list_voltage_linear,
  	.map_voltage		= regulator_map_voltage_linear,
  	.get_voltage_sel	= regulator_get_voltage_sel_regmap,
  	.set_voltage_sel	= regulator_set_voltage_sel_regmap,
  	/* TODO: add .set_suspend_mode */
  };
  
  #define MAX77836_LDO_REG(num)	{ \
  	.name		= "LDO" # num, \
  	.of_match	= of_match_ptr("LDO" # num), \
  	.regulators_node = of_match_ptr("regulators"), \
  	.id		= MAX77836_LDO ## num, \
  	.ops		= &max77836_ldo_ops, \
  	.type		= REGULATOR_VOLTAGE, \
  	.owner		= THIS_MODULE, \
  	.n_voltages	= MAX77836_REGULATOR_LDO_VOLTAGE_STEPS_NUM, \
  	.min_uV		= MAX77836_REGULATOR_LDO_VOLTAGE_MIN, \
  	.uV_step	= MAX77836_REGULATOR_LDO_VOLTAGE_STEP, \
  	.enable_reg	= MAX77836_LDO_REG_CNFG1_LDO ## num, \
  	.enable_mask	= MAX77836_CNFG1_LDO_PWRMD_MASK, \
  	.vsel_reg	= MAX77836_LDO_REG_CNFG1_LDO ## num, \
  	.vsel_mask	= MAX77836_CNFG1_LDO_TV_MASK, \
  }
  
  static const struct regulator_desc max77836_supported_regulators[] = {
  	[MAX14577_SAFEOUT] = MAX14577_SAFEOUT_REG,
  	[MAX14577_CHARGER] = MAX14577_CHARGER_REG,
  	[MAX77836_LDO1] = MAX77836_LDO_REG(1),
  	[MAX77836_LDO2] = MAX77836_LDO_REG(2),
  };
  
  #ifdef CONFIG_OF
  static struct of_regulator_match max14577_regulator_matches[] = {
  	{ .name	= "SAFEOUT", },
  	{ .name = "CHARGER", },
  };
  
  static struct of_regulator_match max77836_regulator_matches[] = {
  	{ .name	= "SAFEOUT", },
  	{ .name = "CHARGER", },
  	{ .name = "LDO1", },
  	{ .name = "LDO2", },
  };
  
  static inline struct regulator_init_data *match_init_data(int index,
  		enum maxim_device_type dev_type)
  {
  	switch (dev_type) {
  	case MAXIM_DEVICE_TYPE_MAX77836:
  		return max77836_regulator_matches[index].init_data;
  
  	case MAXIM_DEVICE_TYPE_MAX14577:
  	default:
  		return max14577_regulator_matches[index].init_data;
  	}
  }
  
  static inline struct device_node *match_of_node(int index,
  		enum maxim_device_type dev_type)
  {
  	switch (dev_type) {
  	case MAXIM_DEVICE_TYPE_MAX77836:
  		return max77836_regulator_matches[index].of_node;
  
  	case MAXIM_DEVICE_TYPE_MAX14577:
  	default:
  		return max14577_regulator_matches[index].of_node;
  	}
  }
  #else /* CONFIG_OF */
  static inline struct regulator_init_data *match_init_data(int index,
  		enum maxim_device_type dev_type)
  {
  	return NULL;
  }
  
  static inline struct device_node *match_of_node(int index,
  		enum maxim_device_type dev_type)
  {
  	return NULL;
  }
  #endif /* CONFIG_OF */
  
  /**
   * Registers for regulators of max77836 use different I2C slave addresses so
   * different regmaps must be used for them.
   *
   * Returns proper regmap for accessing regulator passed by id.
   */
  static struct regmap *max14577_get_regmap(struct max14577 *max14577,
  		int reg_id)
  {
  	switch (max14577->dev_type) {
  	case MAXIM_DEVICE_TYPE_MAX77836:
  		switch (reg_id) {
  		case MAX77836_SAFEOUT ... MAX77836_CHARGER:
  			return max14577->regmap;
  		default:
  			/* MAX77836_LDO1 ... MAX77836_LDO2 */
  			return max14577->regmap_pmic;
  		}
  
  	case MAXIM_DEVICE_TYPE_MAX14577:
  	default:
  		return max14577->regmap;
  	}
  }
  
  static int max14577_regulator_probe(struct platform_device *pdev)
  {
  	struct max14577 *max14577 = dev_get_drvdata(pdev->dev.parent);
  	struct max14577_platform_data *pdata = dev_get_platdata(max14577->dev);
  	int i, ret = 0;
  	struct regulator_config config = {};
  	const struct regulator_desc *supported_regulators;
  	unsigned int supported_regulators_size;
  	enum maxim_device_type dev_type = max14577->dev_type;
  
  	switch (dev_type) {
  	case MAXIM_DEVICE_TYPE_MAX77836:
  		supported_regulators = max77836_supported_regulators;
  		supported_regulators_size = ARRAY_SIZE(max77836_supported_regulators);
  		break;
  	case MAXIM_DEVICE_TYPE_MAX14577:
  	default:
  		supported_regulators = max14577_supported_regulators;
  		supported_regulators_size = ARRAY_SIZE(max14577_supported_regulators);
  	}
  
  	config.dev = max14577->dev;
  	config.driver_data = max14577;
  
  	for (i = 0; i < supported_regulators_size; i++) {
  		struct regulator_dev *regulator;
  		/*
  		 * Index of supported_regulators[] is also the id and must
  		 * match index of pdata->regulators[].
  		 */
  		if (pdata && pdata->regulators) {
  			config.init_data = pdata->regulators[i].initdata;
  			config.of_node = pdata->regulators[i].of_node;
  		} else {
  			config.init_data = match_init_data(i, dev_type);
  			config.of_node = match_of_node(i, dev_type);
  		}
  		config.regmap = max14577_get_regmap(max14577,
  				supported_regulators[i].id);
  
  		regulator = devm_regulator_register(&pdev->dev,
  				&supported_regulators[i], &config);
  		if (IS_ERR(regulator)) {
  			ret = PTR_ERR(regulator);
  			dev_err(&pdev->dev,
  					"Regulator init failed for %d/%s with error: %d
  ",
  					i, supported_regulators[i].name, ret);
  			return ret;
  		}
  	}
  
  	return ret;
  }
  
  static const struct platform_device_id max14577_regulator_id[] = {
  	{ "max14577-regulator", MAXIM_DEVICE_TYPE_MAX14577, },
  	{ "max77836-regulator", MAXIM_DEVICE_TYPE_MAX77836, },
  	{ }
  };
  MODULE_DEVICE_TABLE(platform, max14577_regulator_id);
  
  static struct platform_driver max14577_regulator_driver = {
  	.driver = {
  		   .name = "max14577-regulator",
  		   },
  	.probe		= max14577_regulator_probe,
  	.id_table	= max14577_regulator_id,
  };
  
  static int __init max14577_regulator_init(void)
  {
  	BUILD_BUG_ON(ARRAY_SIZE(max14577_supported_regulators) != MAX14577_REGULATOR_NUM);
  	BUILD_BUG_ON(ARRAY_SIZE(max77836_supported_regulators) != MAX77836_REGULATOR_NUM);
  
  	BUILD_BUG_ON(MAX77836_REGULATOR_LDO_VOLTAGE_MIN +
  			(MAX77836_REGULATOR_LDO_VOLTAGE_STEP *
  			  (MAX77836_REGULATOR_LDO_VOLTAGE_STEPS_NUM - 1)) !=
  			MAX77836_REGULATOR_LDO_VOLTAGE_MAX);
  
  	return platform_driver_register(&max14577_regulator_driver);
  }
  subsys_initcall(max14577_regulator_init);
  
  static void __exit max14577_regulator_exit(void)
  {
  	platform_driver_unregister(&max14577_regulator_driver);
  }
  module_exit(max14577_regulator_exit);
  
  MODULE_AUTHOR("Krzysztof Kozlowski <k.kozlowski@samsung.com>");
  MODULE_DESCRIPTION("Maxim 14577/77836 regulator driver");
  MODULE_LICENSE("GPL");
  MODULE_ALIAS("platform:max14577-regulator");