/*
   * Copyright (c) 2015 MediaTek Inc.
   * Author: Henry Chen <henryc.chen@mediatek.com>
   *
   * 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.
   *
   * 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/err.h>
  #include <linux/gpio.h>
  #include <linux/i2c.h>
  #include <linux/init.h>
  #include <linux/interrupt.h>
  #include <linux/module.h>
  #include <linux/regmap.h>
  #include <linux/regulator/driver.h>
  #include <linux/regulator/machine.h>
  #include <linux/regulator/of_regulator.h>
  #include <linux/regulator/mt6311.h>
  #include <linux/slab.h>
  #include "mt6311-regulator.h"
  
  static const struct regmap_config mt6311_regmap_config = {
  	.reg_bits = 8,
  	.val_bits = 8,
  	.max_register = MT6311_FQMTR_CON4,

  	.cache_type = REGCACHE_RBTREE,

  };
  
  /* Default limits measured in millivolts and milliamps */
  #define MT6311_MIN_UV		600000

  #define MT6311_MAX_UV		1393750

  #define MT6311_STEP_UV		6250
  
  static const struct regulator_linear_range buck_volt_range[] = {
  	REGULATOR_LINEAR_RANGE(MT6311_MIN_UV, 0, 0x7f, MT6311_STEP_UV),
  };

  static const struct regulator_ops mt6311_buck_ops = {

  	.list_voltage = regulator_list_voltage_linear_range,
  	.map_voltage = regulator_map_voltage_linear_range,
  	.set_voltage_sel = regulator_set_voltage_sel_regmap,
  	.get_voltage_sel = regulator_get_voltage_sel_regmap,
  	.set_voltage_time_sel = regulator_set_voltage_time_sel,
  	.enable = regulator_enable_regmap,
  	.disable = regulator_disable_regmap,
  	.is_enabled = regulator_is_enabled_regmap,
  };

  static const struct regulator_ops mt6311_ldo_ops = {

  	.enable = regulator_enable_regmap,
  	.disable = regulator_disable_regmap,
  	.is_enabled = regulator_is_enabled_regmap,
  };
  
  #define MT6311_BUCK(_id) \
  {\
  	.name = #_id,\
  	.ops = &mt6311_buck_ops,\
  	.of_match = of_match_ptr(#_id),\
  	.regulators_node = of_match_ptr("regulators"),\
  	.type = REGULATOR_VOLTAGE,\
  	.id = MT6311_ID_##_id,\
  	.n_voltages = (MT6311_MAX_UV - MT6311_MIN_UV) / MT6311_STEP_UV + 1,\
  	.min_uV = MT6311_MIN_UV,\
  	.uV_step = MT6311_STEP_UV,\
  	.owner = THIS_MODULE,\
  	.linear_ranges = buck_volt_range, \
  	.n_linear_ranges = ARRAY_SIZE(buck_volt_range), \
  	.enable_reg = MT6311_VDVFS11_CON9,\
  	.enable_mask = MT6311_PMIC_VDVFS11_EN_MASK,\
  	.vsel_reg = MT6311_VDVFS11_CON12,\
  	.vsel_mask = MT6311_PMIC_VDVFS11_VOSEL_MASK,\
  }
  
  #define MT6311_LDO(_id) \
  {\
  	.name = #_id,\
  	.ops = &mt6311_ldo_ops,\
  	.of_match = of_match_ptr(#_id),\
  	.regulators_node = of_match_ptr("regulators"),\
  	.type = REGULATOR_VOLTAGE,\
  	.id = MT6311_ID_##_id,\
  	.owner = THIS_MODULE,\
  	.enable_reg = MT6311_LDO_CON3,\
  	.enable_mask = MT6311_PMIC_RG_VBIASN_EN_MASK,\
  }

  static const struct regulator_desc mt6311_regulators[] = {

  	MT6311_BUCK(VDVFS),
  	MT6311_LDO(VBIASN),
  };
  
  /*
   * I2C driver interface functions
   */
  static int mt6311_i2c_probe(struct i2c_client *i2c,
  		const struct i2c_device_id *id)
  {
  	struct regulator_config config = { };
  	struct regulator_dev *rdev;
  	struct regmap *regmap;

  	int i, ret;

  	unsigned int data;
  
  	regmap = devm_regmap_init_i2c(i2c, &mt6311_regmap_config);
  	if (IS_ERR(regmap)) {

  		ret = PTR_ERR(regmap);

  		dev_err(&i2c->dev, "Failed to allocate register map: %d
  ",

  			ret);
  		return ret;

  	}
  
  	ret = regmap_read(regmap, MT6311_SWCID, &data);
  	if (ret < 0) {
  		dev_err(&i2c->dev, "Failed to read DEVICE_ID reg: %d
  ", ret);
  		return ret;
  	}
  
  	switch (data) {
  	case MT6311_E1_CID_CODE:
  	case MT6311_E2_CID_CODE:
  	case MT6311_E3_CID_CODE:
  		break;
  	default:
  		dev_err(&i2c->dev, "Unsupported device id = 0x%x.
  ", data);
  		return -ENODEV;
  	}
  
  	for (i = 0; i < MT6311_MAX_REGULATORS; i++) {
  		config.dev = &i2c->dev;
  		config.regmap = regmap;
  
  		rdev = devm_regulator_register(&i2c->dev,
  			&mt6311_regulators[i], &config);
  		if (IS_ERR(rdev)) {
  			dev_err(&i2c->dev,
  				"Failed to register MT6311 regulator
  ");
  			return PTR_ERR(rdev);
  		}
  	}
  
  	return 0;
  }
  
  static const struct i2c_device_id mt6311_i2c_id[] = {
  	{"mt6311", 0},
  	{},
  };
  MODULE_DEVICE_TABLE(i2c, mt6311_i2c_id);
  
  #ifdef CONFIG_OF
  static const struct of_device_id mt6311_dt_ids[] = {
  	{ .compatible = "mediatek,mt6311-regulator",
  	  .data = &mt6311_i2c_id[0] },
  	{},
  };
  MODULE_DEVICE_TABLE(of, mt6311_dt_ids);
  #endif
  
  static struct i2c_driver mt6311_regulator_driver = {
  	.driver = {
  		.name = "mt6311",

  		.of_match_table = of_match_ptr(mt6311_dt_ids),
  	},
  	.probe = mt6311_i2c_probe,
  	.id_table = mt6311_i2c_id,
  };
  
  module_i2c_driver(mt6311_regulator_driver);
  
  MODULE_AUTHOR("Henry Chen <henryc.chen@mediatek.com>");
  MODULE_DESCRIPTION("Regulator device driver for Mediatek MT6311");
  MODULE_LICENSE("GPL v2");