/*
  * da9052-regulator.c: Regulator driver for DA9052
  *
  * Copyright(c) 2011 Dialog Semiconductor Ltd.
  *
  * Author: David Dajun Chen <dchen@diasemi.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.
  *
  */
  
  #include <linux/module.h>
  #include <linux/moduleparam.h>
  #include <linux/init.h>
  #include <linux/err.h>
  #include <linux/platform_device.h>
  #include <linux/regulator/driver.h>
  #include <linux/regulator/machine.h>
  #ifdef CONFIG_OF
  #include <linux/of.h>
  #include <linux/regulator/of_regulator.h>
  #endif
  
  #include <linux/mfd/da9052/da9052.h>
  #include <linux/mfd/da9052/reg.h>
  #include <linux/mfd/da9052/pdata.h>
  
  /* Buck step size */
  #define DA9052_BUCK_PERI_3uV_STEP		100000
  #define DA9052_BUCK_PERI_REG_MAP_UPTO_3uV	24
  #define DA9052_CONST_3uV			3000000
  
  #define DA9052_MIN_UA		0
  #define DA9052_MAX_UA		3
  #define DA9052_CURRENT_RANGE	4
  
  /* Bit masks */
  #define DA9052_BUCK_ILIM_MASK_EVEN	0x0c
  #define DA9052_BUCK_ILIM_MASK_ODD	0xc0
  
  /* DA9052 REGULATOR IDs */
  #define DA9052_ID_BUCK1		0
  #define DA9052_ID_BUCK2		1
  #define DA9052_ID_BUCK3		2
  #define DA9052_ID_BUCK4		3
  #define DA9052_ID_LDO1		4
  #define DA9052_ID_LDO2		5
  #define DA9052_ID_LDO3		6
  #define DA9052_ID_LDO4		7
  #define DA9052_ID_LDO5		8
  #define DA9052_ID_LDO6		9
  #define DA9052_ID_LDO7		10
  #define DA9052_ID_LDO8		11
  #define DA9052_ID_LDO9		12
  #define DA9052_ID_LDO10		13
  
  static const u32 da9052_current_limits[3][4] = {
  	{700000, 800000, 1000000, 1200000},	/* DA9052-BC BUCKs */
  	{1600000, 2000000, 2400000, 3000000},	/* DA9053-AA/Bx BUCK-CORE */
  	{800000, 1000000, 1200000, 1500000},	/* DA9053-AA/Bx BUCK-PRO,
  						 * BUCK-MEM and BUCK-PERI
  						*/
  };
  
  struct da9052_regulator_info {
  	struct regulator_desc reg_desc;
  	int step_uV;
  	int min_uV;
  	int max_uV;
  	unsigned char activate_bit;
  };
  
  struct da9052_regulator {
  	struct da9052 *da9052;
  	struct da9052_regulator_info *info;
  	struct regulator_dev *rdev;
  };
  
  static int verify_range(struct da9052_regulator_info *info,
  			 int min_uV, int max_uV)
  {
  	if (min_uV > info->max_uV || max_uV < info->min_uV)
  		return -EINVAL;
  
  	return 0;
  }
  
  static int da9052_dcdc_get_current_limit(struct regulator_dev *rdev)
  {
  	struct da9052_regulator *regulator = rdev_get_drvdata(rdev);
  	int offset = rdev_get_id(rdev);
  	int ret, row = 2;
  
  	ret = da9052_reg_read(regulator->da9052, DA9052_BUCKA_REG + offset/2);
  	if (ret < 0)
  		return ret;
  
  	/* Determine the even or odd position of the buck current limit
  	 * register field
  	*/
  	if (offset % 2 == 0)
  		ret = (ret & DA9052_BUCK_ILIM_MASK_EVEN) >> 2;
  	else
  		ret = (ret & DA9052_BUCK_ILIM_MASK_ODD) >> 6;
  
  	/* Select the appropriate current limit range */
  	if (regulator->da9052->chip_id == DA9052)
  		row = 0;
  	else if (offset == 0)
  		row = 1;
  
  	return da9052_current_limits[row][ret];
  }
  
  static int da9052_dcdc_set_current_limit(struct regulator_dev *rdev, int min_uA,
  					  int max_uA)
  {
  	struct da9052_regulator *regulator = rdev_get_drvdata(rdev);
  	int offset = rdev_get_id(rdev);
  	int reg_val = 0;
  	int i, row = 2;
  
  	/* Select the appropriate current limit range */
  	if (regulator->da9052->chip_id == DA9052)
  		row = 0;
  	else if (offset == 0)
  		row = 1;
  
  	for (i = DA9052_CURRENT_RANGE - 1; i >= 0; i--) {
  		if ((min_uA <= da9052_current_limits[row][i]) &&
  		    (da9052_current_limits[row][i] <= max_uA)) {
  			reg_val = i;
  			break;
  		}
  	}
  
  	if (i < 0)
  		return -EINVAL;
  
  	/* Determine the even or odd position of the buck current limit
  	 * register field
  	*/
  	if (offset % 2 == 0)
  		return da9052_reg_update(regulator->da9052,
  					 DA9052_BUCKA_REG + offset/2,
  					 DA9052_BUCK_ILIM_MASK_EVEN,
  					 reg_val << 2);
  	else
  		return da9052_reg_update(regulator->da9052,
  					 DA9052_BUCKA_REG + offset/2,
  					 DA9052_BUCK_ILIM_MASK_ODD,
  					 reg_val << 6);
  }
  
  static int da9052_list_voltage(struct regulator_dev *rdev,
  				unsigned int selector)
  {
  	struct da9052_regulator *regulator = rdev_get_drvdata(rdev);
  	struct da9052_regulator_info *info = regulator->info;
  	int id = rdev_get_id(rdev);
  	int volt_uV;
  
  	if ((id == DA9052_ID_BUCK4) && (regulator->da9052->chip_id == DA9052)
  		&& (selector >= DA9052_BUCK_PERI_REG_MAP_UPTO_3uV)) {
  		volt_uV = ((DA9052_BUCK_PERI_REG_MAP_UPTO_3uV * info->step_uV)
  			  + info->min_uV);
  		volt_uV += (selector - DA9052_BUCK_PERI_REG_MAP_UPTO_3uV)
  				    * (DA9052_BUCK_PERI_3uV_STEP);
  	} else {
  		volt_uV = (selector * info->step_uV) + info->min_uV;
  	}
  
  	if (volt_uV > info->max_uV)
  		return -EINVAL;
  
  	return volt_uV;
  }
  
  static int da9052_map_voltage(struct regulator_dev *rdev,
  			      int min_uV, int max_uV)
  {
  	struct da9052_regulator *regulator = rdev_get_drvdata(rdev);
  	struct da9052_regulator_info *info = regulator->info;
  	int id = rdev_get_id(rdev);
  	int ret, sel;
  
  	ret = verify_range(info, min_uV, max_uV);
  	if (ret < 0)
  		return ret;
  
  	if (min_uV < info->min_uV)
  		min_uV = info->min_uV;
  
  	if ((id == DA9052_ID_BUCK4) && (regulator->da9052->chip_id == DA9052)
  		&& (min_uV >= DA9052_CONST_3uV)) {
  			sel = DA9052_BUCK_PERI_REG_MAP_UPTO_3uV +
  			      DIV_ROUND_UP(min_uV - DA9052_CONST_3uV,
  					   DA9052_BUCK_PERI_3uV_STEP);
  	} else {
  		sel = DIV_ROUND_UP(min_uV - info->min_uV, info->step_uV);
  	}
  
  	ret = da9052_list_voltage(rdev, sel);
  	if (ret < 0)
  		return ret;
  
  	return sel;
  }
  
  static int da9052_regulator_set_voltage_sel(struct regulator_dev *rdev,
  					    unsigned int selector)
  {
  	struct da9052_regulator *regulator = rdev_get_drvdata(rdev);
  	struct da9052_regulator_info *info = regulator->info;
  	int id = rdev_get_id(rdev);
  	int ret;
  
  	ret = da9052_reg_update(regulator->da9052, rdev->desc->vsel_reg,
  				rdev->desc->vsel_mask, selector);
  	if (ret < 0)
  		return ret;
  
  	/* Some LDOs and DCDCs are DVC controlled which requires enabling of
  	 * the activate bit to implment the changes on the output.
  	 */
  	switch (id) {
  	case DA9052_ID_BUCK1:
  	case DA9052_ID_BUCK2:
  	case DA9052_ID_BUCK3:
  	case DA9052_ID_LDO2:
  	case DA9052_ID_LDO3:
  		ret = da9052_reg_update(regulator->da9052, DA9052_SUPPLY_REG,
  					info->activate_bit, info->activate_bit);
  		break;
  	}
  
  	return ret;
  }
  
  static int da9052_regulator_set_voltage_time_sel(struct regulator_dev *rdev,
  						 unsigned int old_sel,
  						 unsigned int new_sel)
  {
  	struct da9052_regulator *regulator = rdev_get_drvdata(rdev);
  	struct da9052_regulator_info *info = regulator->info;
  	int id = rdev_get_id(rdev);
  	int ret = 0;
  
  	/* The DVC controlled LDOs and DCDCs ramp with 6.25mV/µs after enabling
  	 * the activate bit.
  	 */
  	switch (id) {
  	case DA9052_ID_BUCK1:
  	case DA9052_ID_BUCK2:
  	case DA9052_ID_BUCK3:
  	case DA9052_ID_LDO2:
  	case DA9052_ID_LDO3:
  		ret = (new_sel - old_sel) * info->step_uV / 6250;
  		break;
  	}
  
  	return ret;
  }
  
  static struct regulator_ops da9052_dcdc_ops = {
  	.get_current_limit = da9052_dcdc_get_current_limit,
  	.set_current_limit = da9052_dcdc_set_current_limit,
  
  	.list_voltage = da9052_list_voltage,
  	.map_voltage = da9052_map_voltage,
  	.get_voltage_sel = regulator_get_voltage_sel_regmap,
  	.set_voltage_sel = da9052_regulator_set_voltage_sel,
  	.set_voltage_time_sel = da9052_regulator_set_voltage_time_sel,
  	.is_enabled = regulator_is_enabled_regmap,
  	.enable = regulator_enable_regmap,
  	.disable = regulator_disable_regmap,
  };
  
  static struct regulator_ops da9052_ldo_ops = {
  	.list_voltage = da9052_list_voltage,
  	.map_voltage = da9052_map_voltage,
  	.get_voltage_sel = regulator_get_voltage_sel_regmap,
  	.set_voltage_sel = da9052_regulator_set_voltage_sel,
  	.set_voltage_time_sel = da9052_regulator_set_voltage_time_sel,
  	.is_enabled = regulator_is_enabled_regmap,
  	.enable = regulator_enable_regmap,
  	.disable = regulator_disable_regmap,
  };
  
  #define DA9052_LDO(_id, step, min, max, sbits, ebits, abits) \
  {\
  	.reg_desc = {\
  		.name = #_id,\
  		.ops = &da9052_ldo_ops,\
  		.type = REGULATOR_VOLTAGE,\
  		.id = DA9052_ID_##_id,\
  		.n_voltages = (max - min) / step + 1, \
  		.owner = THIS_MODULE,\
  		.vsel_reg = DA9052_BUCKCORE_REG + DA9052_ID_##_id, \
  		.vsel_mask = (1 << (sbits)) - 1,\
  		.enable_reg = DA9052_BUCKCORE_REG + DA9052_ID_##_id, \
  		.enable_mask = 1 << (ebits),\
  	},\
  	.min_uV = (min) * 1000,\
  	.max_uV = (max) * 1000,\
  	.step_uV = (step) * 1000,\
  	.activate_bit = (abits),\
  }
  
  #define DA9052_DCDC(_id, step, min, max, sbits, ebits, abits) \
  {\
  	.reg_desc = {\
  		.name = #_id,\
  		.ops = &da9052_dcdc_ops,\
  		.type = REGULATOR_VOLTAGE,\
  		.id = DA9052_ID_##_id,\
  		.n_voltages = (max - min) / step + 1, \
  		.owner = THIS_MODULE,\
  		.vsel_reg = DA9052_BUCKCORE_REG + DA9052_ID_##_id, \
  		.vsel_mask = (1 << (sbits)) - 1,\
  		.enable_reg = DA9052_BUCKCORE_REG + DA9052_ID_##_id, \
  		.enable_mask = 1 << (ebits),\
  	},\
  	.min_uV = (min) * 1000,\
  	.max_uV = (max) * 1000,\
  	.step_uV = (step) * 1000,\
  	.activate_bit = (abits),\
  }
  
  static struct da9052_regulator_info da9052_regulator_info[] = {
  	DA9052_DCDC(BUCK1, 25, 500, 2075, 6, 6, DA9052_SUPPLY_VBCOREGO),
  	DA9052_DCDC(BUCK2, 25, 500, 2075, 6, 6, DA9052_SUPPLY_VBPROGO),
  	DA9052_DCDC(BUCK3, 25, 925, 2500, 6, 6, DA9052_SUPPLY_VBMEMGO),
  	DA9052_DCDC(BUCK4, 50, 1800, 3600, 5, 6, 0),
  	DA9052_LDO(LDO1, 50, 600, 1800, 5, 6, 0),
  	DA9052_LDO(LDO2, 25, 600, 1800, 6, 6, DA9052_SUPPLY_VLDO2GO),
  	DA9052_LDO(LDO3, 25, 1725, 3300, 6, 6, DA9052_SUPPLY_VLDO3GO),
  	DA9052_LDO(LDO4, 25, 1725, 3300, 6, 6, 0),
  	DA9052_LDO(LDO5, 50, 1200, 3600, 6, 6, 0),
  	DA9052_LDO(LDO6, 50, 1200, 3600, 6, 6, 0),
  	DA9052_LDO(LDO7, 50, 1200, 3600, 6, 6, 0),
  	DA9052_LDO(LDO8, 50, 1200, 3600, 6, 6, 0),
  	DA9052_LDO(LDO9, 50, 1250, 3650, 6, 6, 0),
  	DA9052_LDO(LDO10, 50, 1200, 3600, 6, 6, 0),
  };
  
  static struct da9052_regulator_info da9053_regulator_info[] = {
  	DA9052_DCDC(BUCK1, 25, 500, 2075, 6, 6, DA9052_SUPPLY_VBCOREGO),
  	DA9052_DCDC(BUCK2, 25, 500, 2075, 6, 6, DA9052_SUPPLY_VBPROGO),
  	DA9052_DCDC(BUCK3, 25, 925, 2500, 6, 6, DA9052_SUPPLY_VBMEMGO),
  	DA9052_DCDC(BUCK4, 25, 925, 2500, 6, 6, 0),
  	DA9052_LDO(LDO1, 50, 600, 1800, 5, 6, 0),
  	DA9052_LDO(LDO2, 25, 600, 1800, 6, 6, DA9052_SUPPLY_VLDO2GO),
  	DA9052_LDO(LDO3, 25, 1725, 3300, 6, 6, DA9052_SUPPLY_VLDO3GO),
  	DA9052_LDO(LDO4, 25, 1725, 3300, 6, 6, 0),
  	DA9052_LDO(LDO5, 50, 1200, 3600, 6, 6, 0),
  	DA9052_LDO(LDO6, 50, 1200, 3600, 6, 6, 0),
  	DA9052_LDO(LDO7, 50, 1200, 3600, 6, 6, 0),
  	DA9052_LDO(LDO8, 50, 1200, 3600, 6, 6, 0),
  	DA9052_LDO(LDO9, 50, 1250, 3650, 6, 6, 0),
  	DA9052_LDO(LDO10, 50, 1200, 3600, 6, 6, 0),
  };
  
  static inline struct da9052_regulator_info *find_regulator_info(u8 chip_id,
  								 int id)
  {
  	struct da9052_regulator_info *info;
  	int i;
  
  	switch (chip_id) {
  	case DA9052:
  		for (i = 0; i < ARRAY_SIZE(da9052_regulator_info); i++) {
  			info = &da9052_regulator_info[i];
  			if (info->reg_desc.id == id)
  				return info;
  		}
  		break;
  	case DA9053_AA:
  	case DA9053_BA:
  	case DA9053_BB:
  	case DA9053_BC:
  		for (i = 0; i < ARRAY_SIZE(da9053_regulator_info); i++) {
  			info = &da9053_regulator_info[i];
  			if (info->reg_desc.id == id)
  				return info;
  		}
  		break;
  	}
  
  	return NULL;
  }
  
  static int da9052_regulator_probe(struct platform_device *pdev)
  {
  	const struct mfd_cell *cell = mfd_get_cell(pdev);
  	struct regulator_config config = { };
  	struct da9052_regulator *regulator;
  	struct da9052 *da9052;
  	struct da9052_pdata *pdata;
  
  	regulator = devm_kzalloc(&pdev->dev, sizeof(struct da9052_regulator),
  				 GFP_KERNEL);
  	if (!regulator)
  		return -ENOMEM;
  
  	da9052 = dev_get_drvdata(pdev->dev.parent);
  	pdata = dev_get_platdata(da9052->dev);
  	regulator->da9052 = da9052;
  
  	regulator->info = find_regulator_info(regulator->da9052->chip_id,
  					      cell->id);
  	if (regulator->info == NULL) {
  		dev_err(&pdev->dev, "invalid regulator ID specified
  ");
  		return -EINVAL;
  	}
  
  	config.dev = &pdev->dev;
  	config.driver_data = regulator;
  	config.regmap = da9052->regmap;
  	if (pdata && pdata->regulators) {
  		config.init_data = pdata->regulators[cell->id];
  	} else {
  #ifdef CONFIG_OF
  		struct device_node *nproot = da9052->dev->of_node;
  		struct device_node *np;
  
  		if (!nproot)
  			return -ENODEV;
  
  		nproot = of_get_child_by_name(nproot, "regulators");
  		if (!nproot)
  			return -ENODEV;
  
  		for_each_child_of_node(nproot, np) {
  			if (!of_node_cmp(np->name,
  					 regulator->info->reg_desc.name)) {
  				config.init_data = of_get_regulator_init_data(
  					&pdev->dev, np,
  					&regulator->info->reg_desc);
  				config.of_node = np;
  				break;
  			}
  		}
  		of_node_put(nproot);
  #endif
  	}
  
  	regulator->rdev = devm_regulator_register(&pdev->dev,
  						  &regulator->info->reg_desc,
  						  &config);
  	if (IS_ERR(regulator->rdev)) {
  		dev_err(&pdev->dev, "failed to register regulator %s
  ",
  			regulator->info->reg_desc.name);
  		return PTR_ERR(regulator->rdev);
  	}
  
  	platform_set_drvdata(pdev, regulator);
  
  	return 0;
  }
  
  static struct platform_driver da9052_regulator_driver = {
  	.probe = da9052_regulator_probe,
  	.driver = {
  		.name = "da9052-regulator",
  	},
  };
  
  static int __init da9052_regulator_init(void)
  {
  	return platform_driver_register(&da9052_regulator_driver);
  }
  subsys_initcall(da9052_regulator_init);
  
  static void __exit da9052_regulator_exit(void)
  {
  	platform_driver_unregister(&da9052_regulator_driver);
  }
  module_exit(da9052_regulator_exit);
  
  MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");
  MODULE_DESCRIPTION("Power Regulator driver for Dialog DA9052 PMIC");
  MODULE_LICENSE("GPL");
  MODULE_ALIAS("platform:da9052-regulator");