/*
   * Regulator driver for National Semiconductors LP3972 PMIC chip
   *
   * Based on lp3971.c
   *
   * 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.
   *
   */
  
  #include <linux/bug.h>
  #include <linux/err.h>
  #include <linux/i2c.h>

  #include <linux/module.h>

  #include <linux/kernel.h>
  #include <linux/regulator/driver.h>
  #include <linux/regulator/lp3972.h>
  #include <linux/slab.h>
  
  struct lp3972 {
  	struct device *dev;
  	struct mutex io_lock;
  	struct i2c_client *i2c;

  };
  
  /* LP3972 Control Registers */
  #define LP3972_SCR_REG		0x07
  #define LP3972_OVER1_REG	0x10
  #define LP3972_OVSR1_REG	0x11
  #define LP3972_OVER2_REG	0x12
  #define LP3972_OVSR2_REG	0x13
  #define LP3972_VCC1_REG		0x20
  #define LP3972_ADTV1_REG	0x23
  #define LP3972_ADTV2_REG	0x24
  #define LP3972_AVRC_REG		0x25
  #define LP3972_CDTC1_REG	0x26
  #define LP3972_CDTC2_REG	0x27
  #define LP3972_SDTV1_REG	0x29
  #define LP3972_SDTV2_REG	0x2A
  #define LP3972_MDTV1_REG	0x32
  #define LP3972_MDTV2_REG	0x33
  #define LP3972_L2VCR_REG	0x39
  #define LP3972_L34VCR_REG	0x3A
  #define LP3972_SCR1_REG		0x80
  #define LP3972_SCR2_REG		0x81
  #define LP3972_OEN3_REG		0x82
  #define LP3972_OSR3_REG		0x83
  #define LP3972_LOER4_REG	0x84
  #define LP3972_B2TV_REG		0x85
  #define LP3972_B3TV_REG		0x86
  #define LP3972_B32RC_REG	0x87
  #define LP3972_ISRA_REG		0x88
  #define LP3972_BCCR_REG		0x89
  #define LP3972_II1RR_REG	0x8E
  #define LP3972_II2RR_REG	0x8F
  
  #define LP3972_SYS_CONTROL1_REG		LP3972_SCR1_REG
  /* System control register 1 initial value,
   * bits 5, 6 and 7 are EPROM programmable */
  #define SYS_CONTROL1_INIT_VAL		0x02
  #define SYS_CONTROL1_INIT_MASK		0x1F
  
  #define LP3972_VOL_CHANGE_REG		LP3972_VCC1_REG
  #define LP3972_VOL_CHANGE_FLAG_GO	0x01
  #define LP3972_VOL_CHANGE_FLAG_MASK	0x03
  
  /* LDO output enable mask */
  #define LP3972_OEN3_L1EN	BIT(0)
  #define LP3972_OVER2_LDO2_EN	BIT(2)
  #define LP3972_OVER2_LDO3_EN	BIT(3)
  #define LP3972_OVER2_LDO4_EN	BIT(4)
  #define LP3972_OVER1_S_EN	BIT(2)

  static const unsigned int ldo1_voltage_map[] = {
  	1700000, 1725000, 1750000, 1775000, 1800000, 1825000, 1850000, 1875000,
  	1900000, 1925000, 1950000, 1975000, 2000000,

  };

  static const unsigned int ldo23_voltage_map[] = {
  	1800000, 1900000, 2000000, 2100000, 2200000, 2300000, 2400000, 2500000,
  	2600000, 2700000, 2800000, 2900000, 3000000, 3100000, 3200000, 3300000,

  };

  static const unsigned int ldo4_voltage_map[] = {
  	1000000, 1050000, 1100000, 1150000, 1200000, 1250000, 1300000, 1350000,
  	1400000, 1500000, 1800000, 1900000, 2500000, 2800000, 3000000, 3300000,

  };

  static const unsigned int ldo5_voltage_map[] = {
  	      0,       0,       0,       0,       0,  850000,  875000,  900000,
  	 925000,  950000,  975000, 1000000, 1025000, 1050000, 1075000, 1100000,
  	1125000, 1150000, 1175000, 1200000, 1225000, 1250000, 1275000, 1300000,
  	1325000, 1350000, 1375000, 1400000, 1425000, 1450000, 1475000, 1500000,

  };

  static const unsigned int buck1_voltage_map[] = {
  	 725000,  750000,  775000,  800000,  825000,  850000,  875000,  900000,
  	 925000,  950000,  975000, 1000000, 1025000, 1050000, 1075000, 1100000,
  	1125000, 1150000, 1175000, 1200000, 1225000, 1250000, 1275000, 1300000,
  	1325000, 1350000, 1375000, 1400000, 1425000, 1450000, 1475000, 1500000,

  };

  static const unsigned int buck23_voltage_map[] = {
  	      0,  800000,  850000,  900000,  950000, 1000000, 1050000, 1100000,
  	1150000, 1200000, 1250000, 1300000, 1350000, 1400000, 1450000, 1500000,
  	1550000, 1600000, 1650000, 1700000, 1800000, 1900000, 2500000, 2800000,
  	3000000, 3300000,

  };
  
  static const int ldo_output_enable_mask[] = {
  	LP3972_OEN3_L1EN,
  	LP3972_OVER2_LDO2_EN,
  	LP3972_OVER2_LDO3_EN,
  	LP3972_OVER2_LDO4_EN,
  	LP3972_OVER1_S_EN,
  };
  
  static const int ldo_output_enable_addr[] = {
  	LP3972_OEN3_REG,
  	LP3972_OVER2_REG,
  	LP3972_OVER2_REG,
  	LP3972_OVER2_REG,
  	LP3972_OVER1_REG,
  };
  
  static const int ldo_vol_ctl_addr[] = {
  	LP3972_MDTV1_REG,
  	LP3972_L2VCR_REG,
  	LP3972_L34VCR_REG,
  	LP3972_L34VCR_REG,
  	LP3972_SDTV1_REG,
  };
  
  static const int buck_vol_enable_addr[] = {
  	LP3972_OVER1_REG,
  	LP3972_OEN3_REG,
  	LP3972_OEN3_REG,
  };
  
  static const int buck_base_addr[] = {
  	LP3972_ADTV1_REG,
  	LP3972_B2TV_REG,
  	LP3972_B3TV_REG,
  };

  #define LP3972_LDO_OUTPUT_ENABLE_MASK(x) (ldo_output_enable_mask[x])
  #define LP3972_LDO_OUTPUT_ENABLE_REG(x) (ldo_output_enable_addr[x])
  
  /*	LDO voltage control registers shift:
  	LP3972_LDO1 -> 0, LP3972_LDO2 -> 4
  	LP3972_LDO3 -> 0, LP3972_LDO4 -> 4
  	LP3972_LDO5 -> 0
  */
  #define LP3972_LDO_VOL_CONTR_SHIFT(x) (((x) & 1) << 2)
  #define LP3972_LDO_VOL_CONTR_REG(x) (ldo_vol_ctl_addr[x])
  #define LP3972_LDO_VOL_CHANGE_SHIFT(x) ((x) ? 4 : 6)
  
  #define LP3972_LDO_VOL_MASK(x) (((x) % 4) ? 0x0f : 0x1f)
  #define LP3972_LDO_VOL_MIN_IDX(x) (((x) == 4) ? 0x05 : 0x00)
  #define LP3972_LDO_VOL_MAX_IDX(x) ((x) ? (((x) == 4) ? 0x1f : 0x0f) : 0x0c)

  #define LP3972_BUCK_VOL_ENABLE_REG(x) (buck_vol_enable_addr[x])
  #define LP3972_BUCK_VOL1_REG(x) (buck_base_addr[x])
  #define LP3972_BUCK_VOL_MASK 0x1f

  
  static int lp3972_i2c_read(struct i2c_client *i2c, char reg, int count,
  	u16 *dest)
  {
  	int ret;
  
  	if (count != 1)
  		return -EIO;
  	ret = i2c_smbus_read_byte_data(i2c, reg);
  	if (ret < 0)

  		return ret;

  
  	*dest = ret;
  	return 0;
  }
  
  static int lp3972_i2c_write(struct i2c_client *i2c, char reg, int count,
  	const u16 *src)
  {
  	if (count != 1)
  		return -EIO;
  	return i2c_smbus_write_byte_data(i2c, reg, *src);
  }
  
  static u8 lp3972_reg_read(struct lp3972 *lp3972, u8 reg)
  {
  	u16 val = 0;
  
  	mutex_lock(&lp3972->io_lock);
  
  	lp3972_i2c_read(lp3972->i2c, reg, 1, &val);
  
  	dev_dbg(lp3972->dev, "reg read 0x%02x -> 0x%02x
  ", (int)reg,

  		(unsigned)val & 0xff);

  
  	mutex_unlock(&lp3972->io_lock);
  
  	return val & 0xff;
  }
  
  static int lp3972_set_bits(struct lp3972 *lp3972, u8 reg, u16 mask, u16 val)
  {
  	u16 tmp;
  	int ret;
  
  	mutex_lock(&lp3972->io_lock);
  
  	ret = lp3972_i2c_read(lp3972->i2c, reg, 1, &tmp);
  	tmp = (tmp & ~mask) | val;
  	if (ret == 0) {
  		ret = lp3972_i2c_write(lp3972->i2c, reg, 1, &tmp);
  		dev_dbg(lp3972->dev, "reg write 0x%02x -> 0x%02x
  ", (int)reg,

  			(unsigned)val & 0xff);

  	}
  	mutex_unlock(&lp3972->io_lock);
  
  	return ret;
  }

  static int lp3972_ldo_is_enabled(struct regulator_dev *dev)
  {
  	struct lp3972 *lp3972 = rdev_get_drvdata(dev);
  	int ldo = rdev_get_id(dev) - LP3972_LDO1;
  	u16 mask = LP3972_LDO_OUTPUT_ENABLE_MASK(ldo);
  	u16 val;
  
  	val = lp3972_reg_read(lp3972, LP3972_LDO_OUTPUT_ENABLE_REG(ldo));
  	return !!(val & mask);
  }
  
  static int lp3972_ldo_enable(struct regulator_dev *dev)
  {
  	struct lp3972 *lp3972 = rdev_get_drvdata(dev);
  	int ldo = rdev_get_id(dev) - LP3972_LDO1;
  	u16 mask = LP3972_LDO_OUTPUT_ENABLE_MASK(ldo);
  
  	return lp3972_set_bits(lp3972, LP3972_LDO_OUTPUT_ENABLE_REG(ldo),
  				mask, mask);
  }
  
  static int lp3972_ldo_disable(struct regulator_dev *dev)
  {
  	struct lp3972 *lp3972 = rdev_get_drvdata(dev);
  	int ldo = rdev_get_id(dev) - LP3972_LDO1;
  	u16 mask = LP3972_LDO_OUTPUT_ENABLE_MASK(ldo);
  
  	return lp3972_set_bits(lp3972, LP3972_LDO_OUTPUT_ENABLE_REG(ldo),
  				mask, 0);
  }

  static int lp3972_ldo_get_voltage_sel(struct regulator_dev *dev)

  {
  	struct lp3972 *lp3972 = rdev_get_drvdata(dev);
  	int ldo = rdev_get_id(dev) - LP3972_LDO1;
  	u16 mask = LP3972_LDO_VOL_MASK(ldo);
  	u16 val, reg;
  
  	reg = lp3972_reg_read(lp3972, LP3972_LDO_VOL_CONTR_REG(ldo));
  	val = (reg >> LP3972_LDO_VOL_CONTR_SHIFT(ldo)) & mask;

  	return val;

  }

  static int lp3972_ldo_set_voltage_sel(struct regulator_dev *dev,
  				      unsigned int selector)

  {
  	struct lp3972 *lp3972 = rdev_get_drvdata(dev);
  	int ldo = rdev_get_id(dev) - LP3972_LDO1;

  	int shift, ret;

  	shift = LP3972_LDO_VOL_CONTR_SHIFT(ldo);
  	ret = lp3972_set_bits(lp3972, LP3972_LDO_VOL_CONTR_REG(ldo),

  		LP3972_LDO_VOL_MASK(ldo) << shift, selector << shift);

  
  	if (ret)
  		return ret;

  	/*
  	 * LDO1 and LDO5 support voltage control by either target voltage1
  	 * or target voltage2 register.
  	 * We use target voltage1 register for LDO1 and LDO5 in this driver.
  	 * We need to update voltage change control register(0x20) to enable
  	 * LDO1 and LDO5 to change to their programmed target values.
  	 */

  	switch (ldo) {
  	case LP3972_LDO1:
  	case LP3972_LDO5:
  		shift = LP3972_LDO_VOL_CHANGE_SHIFT(ldo);
  		ret = lp3972_set_bits(lp3972, LP3972_VOL_CHANGE_REG,
  			LP3972_VOL_CHANGE_FLAG_MASK << shift,
  			LP3972_VOL_CHANGE_FLAG_GO << shift);
  		if (ret)
  			return ret;
  
  		ret = lp3972_set_bits(lp3972, LP3972_VOL_CHANGE_REG,
  			LP3972_VOL_CHANGE_FLAG_MASK << shift, 0);
  		break;
  	}
  
  	return ret;
  }
  
  static struct regulator_ops lp3972_ldo_ops = {

  	.list_voltage = regulator_list_voltage_table,

  	.map_voltage = regulator_map_voltage_ascend,

  	.is_enabled = lp3972_ldo_is_enabled,
  	.enable = lp3972_ldo_enable,
  	.disable = lp3972_ldo_disable,

  	.get_voltage_sel = lp3972_ldo_get_voltage_sel,

  	.set_voltage_sel = lp3972_ldo_set_voltage_sel,

  };

  static int lp3972_dcdc_is_enabled(struct regulator_dev *dev)
  {
  	struct lp3972 *lp3972 = rdev_get_drvdata(dev);
  	int buck = rdev_get_id(dev) - LP3972_DCDC1;
  	u16 mask = 1 << (buck * 2);
  	u16 val;
  
  	val = lp3972_reg_read(lp3972, LP3972_BUCK_VOL_ENABLE_REG(buck));
  	return !!(val & mask);
  }
  
  static int lp3972_dcdc_enable(struct regulator_dev *dev)
  {
  	struct lp3972 *lp3972 = rdev_get_drvdata(dev);
  	int buck = rdev_get_id(dev) - LP3972_DCDC1;
  	u16 mask = 1 << (buck * 2);
  	u16 val;
  
  	val = lp3972_set_bits(lp3972, LP3972_BUCK_VOL_ENABLE_REG(buck),
  				mask, mask);
  	return val;
  }
  
  static int lp3972_dcdc_disable(struct regulator_dev *dev)
  {
  	struct lp3972 *lp3972 = rdev_get_drvdata(dev);
  	int buck = rdev_get_id(dev) - LP3972_DCDC1;
  	u16 mask = 1 << (buck * 2);
  	u16 val;
  
  	val = lp3972_set_bits(lp3972, LP3972_BUCK_VOL_ENABLE_REG(buck),
  				mask, 0);
  	return val;
  }

  static int lp3972_dcdc_get_voltage_sel(struct regulator_dev *dev)

  {
  	struct lp3972 *lp3972 = rdev_get_drvdata(dev);
  	int buck = rdev_get_id(dev) - LP3972_DCDC1;
  	u16 reg;

  
  	reg = lp3972_reg_read(lp3972, LP3972_BUCK_VOL1_REG(buck));
  	reg &= LP3972_BUCK_VOL_MASK;

  	return reg;

  }

  static int lp3972_dcdc_set_voltage_sel(struct regulator_dev *dev,
  				       unsigned int selector)

  {
  	struct lp3972 *lp3972 = rdev_get_drvdata(dev);
  	int buck = rdev_get_id(dev) - LP3972_DCDC1;

  	int ret;

  	ret = lp3972_set_bits(lp3972, LP3972_BUCK_VOL1_REG(buck),

  				LP3972_BUCK_VOL_MASK, selector);

  	if (ret)
  		return ret;
  
  	if (buck != 0)
  		return ret;
  
  	ret = lp3972_set_bits(lp3972, LP3972_VOL_CHANGE_REG,
  		LP3972_VOL_CHANGE_FLAG_MASK, LP3972_VOL_CHANGE_FLAG_GO);
  	if (ret)
  		return ret;
  
  	return lp3972_set_bits(lp3972, LP3972_VOL_CHANGE_REG,
  				LP3972_VOL_CHANGE_FLAG_MASK, 0);
  }
  
  static struct regulator_ops lp3972_dcdc_ops = {

  	.list_voltage = regulator_list_voltage_table,

  	.map_voltage = regulator_map_voltage_ascend,

  	.is_enabled = lp3972_dcdc_is_enabled,
  	.enable = lp3972_dcdc_enable,
  	.disable = lp3972_dcdc_disable,

  	.get_voltage_sel = lp3972_dcdc_get_voltage_sel,

  	.set_voltage_sel = lp3972_dcdc_set_voltage_sel,

  };

  static const struct regulator_desc regulators[] = {

  	{
  		.name = "LDO1",
  		.id = LP3972_LDO1,
  		.ops = &lp3972_ldo_ops,
  		.n_voltages = ARRAY_SIZE(ldo1_voltage_map),

  		.volt_table = ldo1_voltage_map,

  		.type = REGULATOR_VOLTAGE,
  		.owner = THIS_MODULE,
  	},
  	{
  		.name = "LDO2",
  		.id = LP3972_LDO2,
  		.ops = &lp3972_ldo_ops,
  		.n_voltages = ARRAY_SIZE(ldo23_voltage_map),

  		.volt_table = ldo23_voltage_map,

  		.type = REGULATOR_VOLTAGE,
  		.owner = THIS_MODULE,
  	},
  	{
  		.name = "LDO3",
  		.id = LP3972_LDO3,
  		.ops = &lp3972_ldo_ops,
  		.n_voltages = ARRAY_SIZE(ldo23_voltage_map),

  		.volt_table = ldo23_voltage_map,

  		.type = REGULATOR_VOLTAGE,
  		.owner = THIS_MODULE,
  	},
  	{
  		.name = "LDO4",
  		.id = LP3972_LDO4,
  		.ops = &lp3972_ldo_ops,
  		.n_voltages = ARRAY_SIZE(ldo4_voltage_map),

  		.volt_table = ldo4_voltage_map,

  		.type = REGULATOR_VOLTAGE,
  		.owner = THIS_MODULE,
  	},
  	{
  		.name = "LDO5",
  		.id = LP3972_LDO5,
  		.ops = &lp3972_ldo_ops,
  		.n_voltages = ARRAY_SIZE(ldo5_voltage_map),

  		.volt_table = ldo5_voltage_map,

  		.type = REGULATOR_VOLTAGE,
  		.owner = THIS_MODULE,
  	},
  	{
  		.name = "DCDC1",
  		.id = LP3972_DCDC1,
  		.ops = &lp3972_dcdc_ops,
  		.n_voltages = ARRAY_SIZE(buck1_voltage_map),

  		.volt_table = buck1_voltage_map,

  		.type = REGULATOR_VOLTAGE,
  		.owner = THIS_MODULE,
  	},
  	{
  		.name = "DCDC2",
  		.id = LP3972_DCDC2,
  		.ops = &lp3972_dcdc_ops,
  		.n_voltages = ARRAY_SIZE(buck23_voltage_map),

  		.volt_table = buck23_voltage_map,

  		.type = REGULATOR_VOLTAGE,
  		.owner = THIS_MODULE,
  	},
  	{
  		.name = "DCDC3",
  		.id = LP3972_DCDC3,
  		.ops = &lp3972_dcdc_ops,
  		.n_voltages = ARRAY_SIZE(buck23_voltage_map),

  		.volt_table = buck23_voltage_map,

  		.type = REGULATOR_VOLTAGE,
  		.owner = THIS_MODULE,
  	},
  };

  static int setup_regulators(struct lp3972 *lp3972,

  	struct lp3972_platform_data *pdata)
  {
  	int i, err;

  	/* Instantiate the regulators */
  	for (i = 0; i < pdata->num_regulators; i++) {
  		struct lp3972_regulator_subdev *reg = &pdata->regulators[i];

  		struct regulator_config config = { };

  		struct regulator_dev *rdev;

  
  		config.dev = lp3972->dev;
  		config.init_data = reg->initdata;
  		config.driver_data = lp3972;

  		rdev = devm_regulator_register(lp3972->dev,
  					       &regulators[reg->id], &config);
  		if (IS_ERR(rdev)) {
  			err = PTR_ERR(rdev);

  			dev_err(lp3972->dev, "regulator init failed: %d
  ",
  				err);

  			return err;

  		}
  	}
  
  	return 0;

  }

  static int lp3972_i2c_probe(struct i2c_client *i2c,

  			    const struct i2c_device_id *id)
  {
  	struct lp3972 *lp3972;

  	struct lp3972_platform_data *pdata = dev_get_platdata(&i2c->dev);

  	int ret;
  	u16 val;
  
  	if (!pdata) {
  		dev_dbg(&i2c->dev, "No platform init data supplied
  ");
  		return -ENODEV;
  	}

  	lp3972 = devm_kzalloc(&i2c->dev, sizeof(struct lp3972), GFP_KERNEL);

  	if (!lp3972)
  		return -ENOMEM;
  
  	lp3972->i2c = i2c;
  	lp3972->dev = &i2c->dev;
  
  	mutex_init(&lp3972->io_lock);
  
  	/* Detect LP3972 */
  	ret = lp3972_i2c_read(i2c, LP3972_SYS_CONTROL1_REG, 1, &val);

  	if (ret == 0 &&
  		(val & SYS_CONTROL1_INIT_MASK) != SYS_CONTROL1_INIT_VAL) {

  		ret = -ENODEV;

  		dev_err(&i2c->dev, "chip reported: val = 0x%x
  ", val);
  	}

  	if (ret < 0) {

  		dev_err(&i2c->dev, "failed to detect device. ret = %d
  ", ret);

  		return ret;

  	}
  
  	ret = setup_regulators(lp3972, pdata);
  	if (ret < 0)

  		return ret;

  
  	i2c_set_clientdata(i2c, lp3972);
  	return 0;

  }

  static const struct i2c_device_id lp3972_i2c_id[] = {
  	{ "lp3972", 0 },
  	{ }
  };
  MODULE_DEVICE_TABLE(i2c, lp3972_i2c_id);
  
  static struct i2c_driver lp3972_i2c_driver = {
  	.driver = {
  		.name = "lp3972",
  		.owner = THIS_MODULE,
  	},
  	.probe    = lp3972_i2c_probe,

  	.id_table = lp3972_i2c_id,
  };
  
  static int __init lp3972_module_init(void)
  {
  	return i2c_add_driver(&lp3972_i2c_driver);
  }
  subsys_initcall(lp3972_module_init);
  
  static void __exit lp3972_module_exit(void)
  {
  	i2c_del_driver(&lp3972_i2c_driver);
  }
  module_exit(lp3972_module_exit);
  
  MODULE_LICENSE("GPL");
  MODULE_AUTHOR("Axel Lin <axel.lin@gmail.com>");
  MODULE_DESCRIPTION("LP3972 PMIC driver");