/*
  * Regulator driver for DA9055 PMIC
  *
  * Copyright(c) 2012 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/init.h>
  #include <linux/err.h>
  #include <linux/gpio.h>
  #include <linux/platform_device.h>
  #include <linux/regulator/driver.h>
  #include <linux/regulator/machine.h>
  
  #include <linux/mfd/da9055/core.h>
  #include <linux/mfd/da9055/reg.h>
  #include <linux/mfd/da9055/pdata.h>
  
  #define DA9055_MIN_UA		0
  #define DA9055_MAX_UA		3
  
  #define DA9055_LDO_MODE_SYNC	0
  #define DA9055_LDO_MODE_SLEEP	1
  
  #define DA9055_BUCK_MODE_SLEEP	1
  #define DA9055_BUCK_MODE_SYNC	2
  #define DA9055_BUCK_MODE_AUTO	3
  
  /* DA9055 REGULATOR IDs */
  #define DA9055_ID_BUCK1	0
  #define DA9055_ID_BUCK2	1
  #define DA9055_ID_LDO1		2
  #define DA9055_ID_LDO2		3
  #define DA9055_ID_LDO3		4
  #define DA9055_ID_LDO4		5
  #define DA9055_ID_LDO5		6
  #define DA9055_ID_LDO6		7
  
  /* DA9055 BUCK current limit */
  static const int da9055_current_limits[] = { 500000, 600000, 700000, 800000 };
  
  struct da9055_conf_reg {
  	int reg;
  	int sel_mask;
  	int en_mask;
  };
  
  struct da9055_volt_reg {
  	int reg_a;
  	int reg_b;
  	int sl_shift;

  	int v_mask;

  };
  
  struct da9055_mode_reg {
  	int reg;
  	int mask;
  	int shift;
  };
  
  struct da9055_regulator_info {
  	struct regulator_desc reg_desc;
  	struct da9055_conf_reg conf;
  	struct da9055_volt_reg volt;
  	struct da9055_mode_reg mode;
  };
  
  struct da9055_regulator {
  	struct da9055 *da9055;
  	struct da9055_regulator_info *info;
  	struct regulator_dev *rdev;
  	enum gpio_select reg_rselect;
  };
  
  static unsigned int da9055_buck_get_mode(struct regulator_dev *rdev)
  {
  	struct da9055_regulator *regulator = rdev_get_drvdata(rdev);
  	struct da9055_regulator_info *info = regulator->info;
  	int ret, mode = 0;
  
  	ret = da9055_reg_read(regulator->da9055, info->mode.reg);
  	if (ret < 0)
  		return ret;
  
  	switch ((ret & info->mode.mask) >> info->mode.shift) {
  	case DA9055_BUCK_MODE_SYNC:
  		mode = REGULATOR_MODE_FAST;
  		break;
  	case DA9055_BUCK_MODE_AUTO:
  		mode = REGULATOR_MODE_NORMAL;
  		break;
  	case DA9055_BUCK_MODE_SLEEP:
  		mode = REGULATOR_MODE_STANDBY;
  		break;
  	}
  
  	return mode;
  }
  
  static int da9055_buck_set_mode(struct regulator_dev *rdev,
  					unsigned int mode)
  {
  	struct da9055_regulator *regulator = rdev_get_drvdata(rdev);
  	struct da9055_regulator_info *info = regulator->info;
  	int val = 0;
  
  	switch (mode) {
  	case REGULATOR_MODE_FAST:
  		val = DA9055_BUCK_MODE_SYNC << info->mode.shift;
  		break;
  	case REGULATOR_MODE_NORMAL:
  		val = DA9055_BUCK_MODE_AUTO << info->mode.shift;
  		break;
  	case REGULATOR_MODE_STANDBY:
  		val = DA9055_BUCK_MODE_SLEEP << info->mode.shift;
  		break;
  	}
  
  	return da9055_reg_update(regulator->da9055, info->mode.reg,
  				 info->mode.mask, val);
  }
  
  static unsigned int da9055_ldo_get_mode(struct regulator_dev *rdev)
  {
  	struct da9055_regulator *regulator = rdev_get_drvdata(rdev);
  	struct da9055_regulator_info *info = regulator->info;
  	int ret;
  
  	ret = da9055_reg_read(regulator->da9055, info->volt.reg_b);
  	if (ret < 0)
  		return ret;
  
  	if (ret >> info->volt.sl_shift)
  		return REGULATOR_MODE_STANDBY;
  	else
  		return REGULATOR_MODE_NORMAL;
  }
  
  static int da9055_ldo_set_mode(struct regulator_dev *rdev, unsigned int mode)
  {
  	struct da9055_regulator *regulator = rdev_get_drvdata(rdev);
  	struct da9055_regulator_info *info = regulator->info;
  	struct da9055_volt_reg volt = info->volt;
  	int val = 0;
  
  	switch (mode) {
  	case REGULATOR_MODE_NORMAL:
  	case REGULATOR_MODE_FAST:
  		val = DA9055_LDO_MODE_SYNC;
  		break;
  	case REGULATOR_MODE_STANDBY:
  		val = DA9055_LDO_MODE_SLEEP;
  		break;
  	}
  
  	return da9055_reg_update(regulator->da9055, volt.reg_b,
  				 1 << volt.sl_shift,
  				 val << volt.sl_shift);
  }
  
  static int da9055_buck_get_current_limit(struct regulator_dev *rdev)
  {
  	struct da9055_regulator *regulator = rdev_get_drvdata(rdev);
  	struct da9055_regulator_info *info = regulator->info;
  	int ret;
  
  	ret = da9055_reg_read(regulator->da9055, DA9055_REG_BUCK_LIM);
  	if (ret < 0)
  		return ret;
  
  	ret &= info->mode.mask;
  	return da9055_current_limits[ret >> info->mode.shift];
  }
  
  static int da9055_buck_set_current_limit(struct regulator_dev *rdev, int min_uA,
  					 int max_uA)
  {
  	struct da9055_regulator *regulator = rdev_get_drvdata(rdev);
  	struct da9055_regulator_info *info = regulator->info;

  	int i;
  
  	for (i = ARRAY_SIZE(da9055_current_limits) - 1; i >= 0; i--) {
  		if ((min_uA <= da9055_current_limits[i]) &&
  		    (da9055_current_limits[i] <= max_uA))
  			return da9055_reg_update(regulator->da9055,
  						 DA9055_REG_BUCK_LIM,
  						 info->mode.mask,
  						 i << info->mode.shift);

  	}

  	return -EINVAL;

  }
  
  static int da9055_regulator_get_voltage_sel(struct regulator_dev *rdev)
  {
  	struct da9055_regulator *regulator = rdev_get_drvdata(rdev);
  	struct da9055_regulator_info *info = regulator->info;
  	struct da9055_volt_reg volt = info->volt;
  	int ret, sel;
  
  	/*
  	 * There are two voltage register set A & B for voltage ramping but
  	 * either one of then can be active therefore we first determine
  	 * the active register set.
  	 */
  	ret = da9055_reg_read(regulator->da9055, info->conf.reg);
  	if (ret < 0)
  		return ret;
  
  	ret &= info->conf.sel_mask;
  
  	/* Get the voltage for the active register set A/B */
  	if (ret == DA9055_REGUALTOR_SET_A)
  		ret = da9055_reg_read(regulator->da9055, volt.reg_a);
  	else
  		ret = da9055_reg_read(regulator->da9055, volt.reg_b);
  
  	if (ret < 0)
  		return ret;
  
  	sel = (ret & volt.v_mask);

  	return sel;

  }

  static int da9055_regulator_set_voltage_sel(struct regulator_dev *rdev,
  					    unsigned int selector)
  {
  	struct da9055_regulator *regulator = rdev_get_drvdata(rdev);
  	struct da9055_regulator_info *info = regulator->info;
  	int ret;
  
  	/*
  	 * Regulator register set A/B is not selected through GPIO therefore
  	 * we use default register set A for voltage ramping.
  	 */
  	if (regulator->reg_rselect == NO_GPIO) {
  		/* Select register set A */
  		ret = da9055_reg_update(regulator->da9055, info->conf.reg,
  					info->conf.sel_mask, DA9055_SEL_REG_A);
  		if (ret < 0)
  			return ret;
  
  		/* Set the voltage */

  		return da9055_reg_update(regulator->da9055, info->volt.reg_a,
  					 info->volt.v_mask, selector);

  	}
  
  	/*
  	 * Here regulator register set A/B is selected through GPIO.
  	 * Therefore we first determine the selected register set A/B and
  	 * then set the desired voltage for that register set A/B.
  	 */
  	ret = da9055_reg_read(regulator->da9055, info->conf.reg);
  	if (ret < 0)
  		return ret;
  
  	ret &= info->conf.sel_mask;
  
  	/* Set the voltage */
  	if (ret == DA9055_REGUALTOR_SET_A)

  		return da9055_reg_update(regulator->da9055, info->volt.reg_a,
  					 info->volt.v_mask, selector);

  	else

  		return da9055_reg_update(regulator->da9055, info->volt.reg_b,
  					 info->volt.v_mask, selector);

  }
  
  static int da9055_regulator_set_suspend_voltage(struct regulator_dev *rdev,
  						int uV)
  {
  	struct da9055_regulator *regulator = rdev_get_drvdata(rdev);
  	struct da9055_regulator_info *info = regulator->info;
  	int ret;
  
  	/* Select register set B for suspend voltage ramping. */
  	if (regulator->reg_rselect == NO_GPIO) {
  		ret = da9055_reg_update(regulator->da9055, info->conf.reg,
  					info->conf.sel_mask, DA9055_SEL_REG_B);
  		if (ret < 0)
  			return ret;
  	}

  	ret = regulator_map_voltage_linear(rdev, uV, uV);

  	if (ret < 0)
  		return ret;

  	return da9055_reg_update(regulator->da9055, info->volt.reg_b,
  				 info->volt.v_mask, ret);

  }
  
  static int da9055_suspend_enable(struct regulator_dev *rdev)
  {
  	struct da9055_regulator *regulator = rdev_get_drvdata(rdev);
  	struct da9055_regulator_info *info = regulator->info;
  
  	/* Select register set B for voltage ramping. */
  	if (regulator->reg_rselect == NO_GPIO)
  		return da9055_reg_update(regulator->da9055, info->conf.reg,
  					info->conf.sel_mask, DA9055_SEL_REG_B);
  	else
  		return 0;
  }
  
  static int da9055_suspend_disable(struct regulator_dev *rdev)
  {
  	struct da9055_regulator *regulator = rdev_get_drvdata(rdev);
  	struct da9055_regulator_info *info = regulator->info;
  
  	/* Diselect register set B. */
  	if (regulator->reg_rselect == NO_GPIO)
  		return da9055_reg_update(regulator->da9055, info->conf.reg,
  					info->conf.sel_mask, DA9055_SEL_REG_A);
  	else
  		return 0;
  }
  
  static struct regulator_ops da9055_buck_ops = {
  	.get_mode = da9055_buck_get_mode,
  	.set_mode = da9055_buck_set_mode,
  
  	.get_current_limit = da9055_buck_get_current_limit,
  	.set_current_limit = da9055_buck_set_current_limit,
  
  	.get_voltage_sel = da9055_regulator_get_voltage_sel,
  	.set_voltage_sel = da9055_regulator_set_voltage_sel,

  	.list_voltage = regulator_list_voltage_linear,
  	.map_voltage = regulator_map_voltage_linear,

  	.is_enabled = regulator_is_enabled_regmap,
  	.enable = regulator_enable_regmap,
  	.disable = regulator_disable_regmap,
  
  	.set_suspend_voltage = da9055_regulator_set_suspend_voltage,
  	.set_suspend_enable = da9055_suspend_enable,
  	.set_suspend_disable = da9055_suspend_disable,
  	.set_suspend_mode = da9055_buck_set_mode,
  };
  
  static struct regulator_ops da9055_ldo_ops = {
  	.get_mode = da9055_ldo_get_mode,
  	.set_mode = da9055_ldo_set_mode,
  
  	.get_voltage_sel = da9055_regulator_get_voltage_sel,
  	.set_voltage_sel = da9055_regulator_set_voltage_sel,

  	.list_voltage = regulator_list_voltage_linear,
  	.map_voltage = regulator_map_voltage_linear,

  	.is_enabled = regulator_is_enabled_regmap,
  	.enable = regulator_enable_regmap,
  	.disable = regulator_disable_regmap,
  
  	.set_suspend_voltage = da9055_regulator_set_suspend_voltage,
  	.set_suspend_enable = da9055_suspend_enable,
  	.set_suspend_disable = da9055_suspend_disable,
  	.set_suspend_mode = da9055_ldo_set_mode,
  
  };
  
  #define DA9055_LDO(_id, step, min, max, vbits, voffset) \
  {\
  	.reg_desc = {\
  		.name = #_id,\
  		.ops = &da9055_ldo_ops,\
  		.type = REGULATOR_VOLTAGE,\
  		.id = DA9055_ID_##_id,\

  		.n_voltages = (max - min) / step + 1 + (voffset), \

  		.enable_reg = DA9055_REG_BCORE_CONT + DA9055_ID_##_id, \
  		.enable_mask = 1, \
  		.min_uV = (min) * 1000,\
  		.uV_step = (step) * 1000,\

  		.linear_min_sel = (voffset),\

  		.owner = THIS_MODULE,\
  	},\
  	.conf = {\
  		.reg = DA9055_REG_BCORE_CONT + DA9055_ID_##_id, \
  		.sel_mask = (1 << 4),\
  		.en_mask = 1,\
  	},\
  	.volt = {\
  		.reg_a = DA9055_REG_VBCORE_A + DA9055_ID_##_id, \
  		.reg_b = DA9055_REG_VBCORE_B + DA9055_ID_##_id, \
  		.sl_shift = 7,\

  		.v_mask = (1 << (vbits)) - 1,\

  	},\
  }
  
  #define DA9055_BUCK(_id, step, min, max, vbits, voffset, mbits, sbits) \
  {\
  	.reg_desc = {\
  		.name = #_id,\
  		.ops = &da9055_buck_ops,\
  		.type = REGULATOR_VOLTAGE,\
  		.id = DA9055_ID_##_id,\

  		.n_voltages = (max - min) / step + 1 + (voffset), \

  		.enable_reg = DA9055_REG_BCORE_CONT + DA9055_ID_##_id, \
  		.enable_mask = 1,\
  		.min_uV = (min) * 1000,\
  		.uV_step = (step) * 1000,\

  		.linear_min_sel = (voffset),\

  		.owner = THIS_MODULE,\
  	},\
  	.conf = {\
  		.reg = DA9055_REG_BCORE_CONT + DA9055_ID_##_id, \
  		.sel_mask = (1 << 4),\
  		.en_mask = 1,\
  	},\
  	.volt = {\
  		.reg_a = DA9055_REG_VBCORE_A + DA9055_ID_##_id, \
  		.reg_b = DA9055_REG_VBCORE_B + DA9055_ID_##_id, \
  		.sl_shift = 7,\

  		.v_mask = (1 << (vbits)) - 1,\

  	},\
  	.mode = {\
  		.reg = DA9055_REG_BCORE_MODE,\
  		.mask = (mbits),\
  		.shift = (sbits),\
  	},\
  }
  
  static struct da9055_regulator_info da9055_regulator_info[] = {
  	DA9055_BUCK(BUCK1, 25, 725, 2075, 6, 9, 0xc, 2),
  	DA9055_BUCK(BUCK2, 25, 925, 2500, 6, 0, 3, 0),
  	DA9055_LDO(LDO1, 50, 900, 3300, 6, 2),
  	DA9055_LDO(LDO2, 50, 900, 3300, 6, 3),
  	DA9055_LDO(LDO3, 50, 900, 3300, 6, 2),
  	DA9055_LDO(LDO4, 50, 900, 3300, 6, 2),
  	DA9055_LDO(LDO5, 50, 900, 2750, 6, 2),
  	DA9055_LDO(LDO6, 20, 900, 3300, 7, 0),
  };
  
  /*
   * Configures regulator to be controlled either through GPIO 1 or 2.
   * GPIO can control regulator state and/or select the regulator register
   * set A/B for voltage ramping.
   */

  static int da9055_gpio_init(struct da9055_regulator *regulator,
  			    struct regulator_config *config,
  			    struct da9055_pdata *pdata, int id)

  {
  	struct da9055_regulator_info *info = regulator->info;
  	int ret = 0;
  
  	if (pdata->gpio_ren && pdata->gpio_ren[id]) {
  		char name[18];
  		int gpio_mux = pdata->gpio_ren[id];
  
  		config->ena_gpio = pdata->ena_gpio[id];
  		config->ena_gpio_flags = GPIOF_OUT_INIT_HIGH;
  		config->ena_gpio_invert = 1;
  
  		/*
  		 * GPI pin is muxed with regulator to control the
  		 * regulator state.
  		 */
  		sprintf(name, "DA9055 GPI %d", gpio_mux);
  		ret = devm_gpio_request_one(config->dev, gpio_mux, GPIOF_DIR_IN,
  					    name);
  		if (ret < 0)
  			goto err;
  
  		/*
  		 * Let the regulator know that its state is controlled
  		 * through GPI.
  		 */
  		ret = da9055_reg_update(regulator->da9055, info->conf.reg,
  					DA9055_E_GPI_MASK,
  					pdata->reg_ren[id]
  					<< DA9055_E_GPI_SHIFT);
  		if (ret < 0)
  			goto err;
  	}

  	if (pdata->gpio_rsel && pdata->gpio_rsel[id]) {

  		char name[18];
  		int gpio_mux = pdata->gpio_rsel[id];
  
  		regulator->reg_rselect = pdata->reg_rsel[id];
  
  		/*
  		 * GPI pin is muxed with regulator to select the
  		 * regulator register set A/B for voltage ramping.
  		 */
  		sprintf(name, "DA9055 GPI %d", gpio_mux);
  		ret = devm_gpio_request_one(config->dev, gpio_mux, GPIOF_DIR_IN,
  					    name);
  		if (ret < 0)
  			goto err;
  
  		/*
  		 * Let the regulator know that its register set A/B
  		 * will be selected through GPI for voltage ramping.
  		 */
  		ret = da9055_reg_update(regulator->da9055, info->conf.reg,
  					DA9055_V_GPI_MASK,
  					pdata->reg_rsel[id]
  					<< DA9055_V_GPI_SHIFT);
  	}
  
  err:
  	return ret;
  }
  
  static irqreturn_t da9055_ldo5_6_oc_irq(int irq, void *data)
  {
  	struct da9055_regulator *regulator = data;
  
  	regulator_notifier_call_chain(regulator->rdev,
  				      REGULATOR_EVENT_OVER_CURRENT, NULL);
  
  	return IRQ_HANDLED;
  }
  
  static inline struct da9055_regulator_info *find_regulator_info(int id)
  {
  	struct da9055_regulator_info *info;
  	int i;
  
  	for (i = 0; i < ARRAY_SIZE(da9055_regulator_info); i++) {
  		info = &da9055_regulator_info[i];
  		if (info->reg_desc.id == id)
  			return info;
  	}
  
  	return NULL;
  }

  static int da9055_regulator_probe(struct platform_device *pdev)

  {
  	struct regulator_config config = { };
  	struct da9055_regulator *regulator;
  	struct da9055 *da9055 = dev_get_drvdata(pdev->dev.parent);
  	struct da9055_pdata *pdata = da9055->dev->platform_data;
  	int ret, irq;
  
  	if (pdata == NULL || pdata->regulators[pdev->id] == NULL)
  		return -ENODEV;
  
  	regulator = devm_kzalloc(&pdev->dev, sizeof(struct da9055_regulator),
  				 GFP_KERNEL);
  	if (!regulator)
  		return -ENOMEM;
  
  	regulator->info = find_regulator_info(pdev->id);
  	if (regulator->info == NULL) {
  		dev_err(&pdev->dev, "invalid regulator ID specified
  ");
  		return -EINVAL;
  	}
  
  	regulator->da9055 = da9055;
  	config.dev = &pdev->dev;
  	config.driver_data = regulator;
  	config.regmap = da9055->regmap;
  
  	if (pdata && pdata->regulators)
  		config.init_data = pdata->regulators[pdev->id];
  
  	ret = da9055_gpio_init(regulator, &config, pdata, pdev->id);
  	if (ret < 0)
  		return ret;
  
  	regulator->rdev = regulator_register(&regulator->info->reg_desc,
  					     &config);
  	if (IS_ERR(regulator->rdev)) {
  		dev_err(&pdev->dev, "Failed to register regulator %s
  ",
  			regulator->info->reg_desc.name);
  		ret = PTR_ERR(regulator->rdev);
  		return ret;
  	}
  
  	/* Only LDO 5 and 6 has got the over current interrupt */
  	if (pdev->id == DA9055_ID_LDO5 || pdev->id ==  DA9055_ID_LDO6) {
  		irq = platform_get_irq_byname(pdev, "REGULATOR");
  		irq = regmap_irq_get_virq(da9055->irq_data, irq);
  		ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
  						da9055_ldo5_6_oc_irq,
  						IRQF_TRIGGER_HIGH |
  						IRQF_ONESHOT |
  						IRQF_PROBE_SHARED,
  						pdev->name, regulator);
  		if (ret != 0) {
  			if (ret != -EBUSY) {
  				dev_err(&pdev->dev,
  				"Failed to request Regulator IRQ %d: %d
  ",
  				irq, ret);
  				goto err_regulator;
  			}
  		}
  	}
  
  	platform_set_drvdata(pdev, regulator);
  
  	return 0;
  
  err_regulator:
  	regulator_unregister(regulator->rdev);
  	return ret;
  }

  static int da9055_regulator_remove(struct platform_device *pdev)

  {
  	struct da9055_regulator *regulator = platform_get_drvdata(pdev);
  
  	regulator_unregister(regulator->rdev);
  
  	return 0;
  }
  
  static struct platform_driver da9055_regulator_driver = {
  	.probe = da9055_regulator_probe,

  	.remove = da9055_regulator_remove,

  	.driver = {
  		.name = "da9055-regulator",
  		.owner = THIS_MODULE,
  	},
  };
  
  static int __init da9055_regulator_init(void)
  {
  	return platform_driver_register(&da9055_regulator_driver);
  }
  subsys_initcall(da9055_regulator_init);
  
  static void __exit da9055_regulator_exit(void)
  {
  	platform_driver_unregister(&da9055_regulator_driver);
  }
  module_exit(da9055_regulator_exit);
  
  MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");
  MODULE_DESCRIPTION("Power Regulator driver for Dialog DA9055 PMIC");
  MODULE_LICENSE("GPL");
  MODULE_ALIAS("platform:da9055-regulator");