/*
   * Regulator driver for TPS6524x PMIC
   *
   * Copyright (C) 2010 Texas Instruments
   *
   * 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 version 2.
   *
   * This program is distributed "as is" WITHOUT ANY WARRANTY of any kind,
   * whether express or implied; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   * General Public License for more details.
   */
  
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/err.h>
  #include <linux/errno.h>
  #include <linux/slab.h>
  #include <linux/spi/spi.h>
  #include <linux/regulator/driver.h>
  #include <linux/regulator/machine.h>
  
  #define REG_LDO_SET		0x0
  #define LDO_ILIM_MASK		1	/* 0 = 400-800, 1 = 900-1500 */
  #define LDO_VSEL_MASK		0x0f
  #define LDO2_ILIM_SHIFT		12
  #define LDO2_VSEL_SHIFT		4
  #define LDO1_ILIM_SHIFT		8
  #define LDO1_VSEL_SHIFT		0
  
  #define REG_BLOCK_EN		0x1
  #define BLOCK_MASK		1
  #define BLOCK_LDO1_SHIFT	0
  #define BLOCK_LDO2_SHIFT	1
  #define BLOCK_LCD_SHIFT		2
  #define BLOCK_USB_SHIFT		3
  
  #define REG_DCDC_SET		0x2
  #define DCDC_VDCDC_MASK		0x1f
  #define DCDC_VDCDC1_SHIFT	0
  #define DCDC_VDCDC2_SHIFT	5
  #define DCDC_VDCDC3_SHIFT	10
  
  #define REG_DCDC_EN		0x3
  #define DCDCDCDC_EN_MASK	0x1
  #define DCDCDCDC1_EN_SHIFT	0
  #define DCDCDCDC1_PG_MSK	BIT(1)
  #define DCDCDCDC2_EN_SHIFT	2
  #define DCDCDCDC2_PG_MSK	BIT(3)
  #define DCDCDCDC3_EN_SHIFT	4
  #define DCDCDCDC3_PG_MSK	BIT(5)
  
  #define REG_USB			0x4
  #define USB_ILIM_SHIFT		0
  #define USB_ILIM_MASK		0x3
  #define USB_TSD_SHIFT		2
  #define USB_TSD_MASK		0x3
  #define USB_TWARN_SHIFT		4
  #define USB_TWARN_MASK		0x3
  #define USB_IWARN_SD		BIT(6)
  #define USB_FAST_LOOP		BIT(7)
  
  #define REG_ALARM		0x5
  #define ALARM_LDO1		BIT(0)
  #define ALARM_DCDC1		BIT(1)
  #define ALARM_DCDC2		BIT(2)
  #define ALARM_DCDC3		BIT(3)
  #define ALARM_LDO2		BIT(4)
  #define ALARM_USB_WARN		BIT(5)
  #define ALARM_USB_ALARM		BIT(6)
  #define ALARM_LCD		BIT(9)
  #define ALARM_TEMP_WARM		BIT(10)
  #define ALARM_TEMP_HOT		BIT(11)
  #define ALARM_NRST		BIT(14)
  #define ALARM_POWERUP		BIT(15)
  
  #define REG_INT_ENABLE		0x6
  #define INT_LDO1		BIT(0)
  #define INT_DCDC1		BIT(1)
  #define INT_DCDC2		BIT(2)
  #define INT_DCDC3		BIT(3)
  #define INT_LDO2		BIT(4)
  #define INT_USB_WARN		BIT(5)
  #define INT_USB_ALARM		BIT(6)
  #define INT_LCD			BIT(9)
  #define INT_TEMP_WARM		BIT(10)
  #define INT_TEMP_HOT		BIT(11)
  #define INT_GLOBAL_EN		BIT(15)
  
  #define REG_INT_STATUS		0x7
  #define STATUS_LDO1		BIT(0)
  #define STATUS_DCDC1		BIT(1)
  #define STATUS_DCDC2		BIT(2)
  #define STATUS_DCDC3		BIT(3)
  #define STATUS_LDO2		BIT(4)
  #define STATUS_USB_WARN		BIT(5)
  #define STATUS_USB_ALARM	BIT(6)
  #define STATUS_LCD		BIT(9)
  #define STATUS_TEMP_WARM	BIT(10)
  #define STATUS_TEMP_HOT		BIT(11)
  
  #define REG_SOFTWARE_RESET	0xb
  #define REG_WRITE_ENABLE	0xd
  #define REG_REV_ID		0xf
  
  #define N_DCDC			3
  #define N_LDO			2
  #define N_SWITCH		2

  #define N_REGULATORS		(N_DCDC + N_LDO + N_SWITCH)

  #define CMD_READ(reg)		((reg) << 6)
  #define CMD_WRITE(reg)		(BIT(5) | (reg) << 6)
  #define STAT_CLK		BIT(3)
  #define STAT_WRITE		BIT(2)
  #define STAT_INVALID		BIT(1)
  #define STAT_WP			BIT(0)
  
  struct field {
  	int		reg;
  	int		shift;
  	int		mask;
  };
  
  struct supply_info {
  	const char	*name;
  	int		n_voltages;

  	const unsigned int *voltages;

  	int		n_ilimsels;

  	const unsigned int *ilimsels;

  	struct field	enable, voltage, ilimsel;
  };
  
  struct tps6524x {
  	struct device		*dev;
  	struct spi_device	*spi;
  	struct mutex		lock;
  	struct regulator_desc	desc[N_REGULATORS];

  };
  
  static int __read_reg(struct tps6524x *hw, int reg)
  {
  	int error = 0;
  	u16 cmd = CMD_READ(reg), in;
  	u8 status;
  	struct spi_message m;
  	struct spi_transfer t[3];
  
  	spi_message_init(&m);
  	memset(t, 0, sizeof(t));
  
  	t[0].tx_buf = &cmd;
  	t[0].len = 2;
  	t[0].bits_per_word = 12;
  	spi_message_add_tail(&t[0], &m);
  
  	t[1].rx_buf = ∈
  	t[1].len = 2;
  	t[1].bits_per_word = 16;
  	spi_message_add_tail(&t[1], &m);
  
  	t[2].rx_buf = &status;
  	t[2].len = 1;
  	t[2].bits_per_word = 4;
  	spi_message_add_tail(&t[2], &m);
  
  	error = spi_sync(hw->spi, &m);
  	if (error < 0)
  		return error;
  
  	dev_dbg(hw->dev, "read reg %d, data %x, status %x
  ",
  		reg, in, status);
  
  	if (!(status & STAT_CLK) || (status & STAT_WRITE))
  		return -EIO;
  
  	if (status & STAT_INVALID)
  		return -EINVAL;
  
  	return in;
  }
  
  static int read_reg(struct tps6524x *hw, int reg)
  {
  	int ret;
  
  	mutex_lock(&hw->lock);
  	ret = __read_reg(hw, reg);
  	mutex_unlock(&hw->lock);
  
  	return ret;
  }
  
  static int __write_reg(struct tps6524x *hw, int reg, int val)
  {
  	int error = 0;
  	u16 cmd = CMD_WRITE(reg), out = val;
  	u8 status;
  	struct spi_message m;
  	struct spi_transfer t[3];
  
  	spi_message_init(&m);
  	memset(t, 0, sizeof(t));
  
  	t[0].tx_buf = &cmd;
  	t[0].len = 2;
  	t[0].bits_per_word = 12;
  	spi_message_add_tail(&t[0], &m);
  
  	t[1].tx_buf = &out;
  	t[1].len = 2;
  	t[1].bits_per_word = 16;
  	spi_message_add_tail(&t[1], &m);
  
  	t[2].rx_buf = &status;
  	t[2].len = 1;
  	t[2].bits_per_word = 4;
  	spi_message_add_tail(&t[2], &m);
  
  	error = spi_sync(hw->spi, &m);
  	if (error < 0)
  		return error;
  
  	dev_dbg(hw->dev, "wrote reg %d, data %x, status %x
  ",
  		reg, out, status);
  
  	if (!(status & STAT_CLK) || !(status & STAT_WRITE))
  		return -EIO;
  
  	if (status & (STAT_INVALID | STAT_WP))
  		return -EINVAL;
  
  	return error;
  }
  
  static int __rmw_reg(struct tps6524x *hw, int reg, int mask, int val)
  {
  	int ret;
  
  	ret = __read_reg(hw, reg);
  	if (ret < 0)
  		return ret;
  
  	ret &= ~mask;
  	ret |= val;
  
  	ret = __write_reg(hw, reg, ret);
  
  	return (ret < 0) ? ret : 0;
  }
  
  static int rmw_protect(struct tps6524x *hw, int reg, int mask, int val)
  {
  	int ret;
  
  	mutex_lock(&hw->lock);
  
  	ret = __write_reg(hw, REG_WRITE_ENABLE, 1);
  	if (ret) {
  		dev_err(hw->dev, "failed to set write enable
  ");
  		goto error;
  	}
  
  	ret = __rmw_reg(hw, reg, mask, val);
  	if (ret)
  		dev_err(hw->dev, "failed to rmw register %d
  ", reg);
  
  	ret = __write_reg(hw, REG_WRITE_ENABLE, 0);
  	if (ret) {
  		dev_err(hw->dev, "failed to clear write enable
  ");
  		goto error;
  	}
  
  error:
  	mutex_unlock(&hw->lock);
  
  	return ret;
  }
  
  static int read_field(struct tps6524x *hw, const struct field *field)
  {
  	int tmp;
  
  	tmp = read_reg(hw, field->reg);
  	if (tmp < 0)
  		return tmp;
  
  	return (tmp >> field->shift) & field->mask;
  }
  
  static int write_field(struct tps6524x *hw, const struct field *field,
  		       int val)
  {
  	if (val & ~field->mask)
  		return -EOVERFLOW;
  
  	return rmw_protect(hw, field->reg,
  				    field->mask << field->shift,
  				    val << field->shift);
  }

  static const unsigned int dcdc1_voltages[] = {

  	 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, 1525000, 1550000, 1575000,
  };

  static const unsigned int dcdc2_voltages[] = {

  	1400000, 1450000, 1500000, 1550000,
  	1600000, 1650000, 1700000, 1750000,
  	1800000, 1850000, 1900000, 1950000,
  	2000000, 2050000, 2100000, 2150000,
  	2200000, 2250000, 2300000, 2350000,
  	2400000, 2450000, 2500000, 2550000,
  	2600000, 2650000, 2700000, 2750000,
  	2800000, 2850000, 2900000, 2950000,
  };

  static const unsigned int dcdc3_voltages[] = {

  	2400000, 2450000, 2500000, 2550000, 2600000,
  	2650000, 2700000, 2750000, 2800000, 2850000,
  	2900000, 2950000, 3000000, 3050000, 3100000,
  	3150000, 3200000, 3250000, 3300000, 3350000,
  	3400000, 3450000, 3500000, 3550000, 3600000,
  };

  static const unsigned int ldo1_voltages[] = {

  	4300000, 4350000, 4400000, 4450000,
  	4500000, 4550000, 4600000, 4650000,
  	4700000, 4750000, 4800000, 4850000,
  	4900000, 4950000, 5000000, 5050000,
  };

  static const unsigned int ldo2_voltages[] = {

  	1100000, 1150000, 1200000, 1250000,
  	1300000, 1700000, 1750000, 1800000,
  	1850000, 1900000, 3150000, 3200000,
  	3250000, 3300000, 3350000, 3400000,
  };

  static const unsigned int fixed_5000000_voltage[] = {
  	5000000
  };

  static const unsigned int ldo_ilimsel[] = {

  	400000, 1500000
  };

  static const unsigned int usb_ilimsel[] = {

  	200000, 400000, 800000, 1000000
  };

  static const unsigned int fixed_2400000_ilimsel[] = {
  	2400000
  };
  
  static const unsigned int fixed_1200000_ilimsel[] = {
  	1200000
  };
  
  static const unsigned int fixed_400000_ilimsel[] = {
  	400000
  };

  #define __MK_FIELD(_reg, _mask, _shift) \
  	{ .reg = (_reg), .mask = (_mask), .shift = (_shift), }
  
  static const struct supply_info supply_info[N_REGULATORS] = {
  	{
  		.name		= "DCDC1",

  		.n_voltages	= ARRAY_SIZE(dcdc1_voltages),
  		.voltages	= dcdc1_voltages,

  		.n_ilimsels	= ARRAY_SIZE(fixed_2400000_ilimsel),
  		.ilimsels	= fixed_2400000_ilimsel,

  		.enable		= __MK_FIELD(REG_DCDC_EN, DCDCDCDC_EN_MASK,
  					     DCDCDCDC1_EN_SHIFT),
  		.voltage	= __MK_FIELD(REG_DCDC_SET, DCDC_VDCDC_MASK,
  					     DCDC_VDCDC1_SHIFT),
  	},
  	{
  		.name		= "DCDC2",

  		.n_voltages	= ARRAY_SIZE(dcdc2_voltages),
  		.voltages	= dcdc2_voltages,

  		.n_ilimsels	= ARRAY_SIZE(fixed_1200000_ilimsel),
  		.ilimsels	= fixed_1200000_ilimsel,

  		.enable		= __MK_FIELD(REG_DCDC_EN, DCDCDCDC_EN_MASK,
  					     DCDCDCDC2_EN_SHIFT),
  		.voltage	= __MK_FIELD(REG_DCDC_SET, DCDC_VDCDC_MASK,
  					     DCDC_VDCDC2_SHIFT),
  	},
  	{
  		.name		= "DCDC3",

  		.n_voltages	= ARRAY_SIZE(dcdc3_voltages),
  		.voltages	= dcdc3_voltages,

  		.n_ilimsels	= ARRAY_SIZE(fixed_1200000_ilimsel),
  		.ilimsels	= fixed_1200000_ilimsel,

  		.enable		= __MK_FIELD(REG_DCDC_EN, DCDCDCDC_EN_MASK,
  					DCDCDCDC3_EN_SHIFT),
  		.voltage	= __MK_FIELD(REG_DCDC_SET, DCDC_VDCDC_MASK,
  					     DCDC_VDCDC3_SHIFT),
  	},
  	{
  		.name		= "LDO1",
  		.n_voltages	= ARRAY_SIZE(ldo1_voltages),
  		.voltages	= ldo1_voltages,
  		.n_ilimsels	= ARRAY_SIZE(ldo_ilimsel),
  		.ilimsels	= ldo_ilimsel,
  		.enable		= __MK_FIELD(REG_BLOCK_EN, BLOCK_MASK,
  					     BLOCK_LDO1_SHIFT),
  		.voltage	= __MK_FIELD(REG_LDO_SET, LDO_VSEL_MASK,
  					     LDO1_VSEL_SHIFT),
  		.ilimsel	= __MK_FIELD(REG_LDO_SET, LDO_ILIM_MASK,
  					     LDO1_ILIM_SHIFT),
  	},
  	{
  		.name		= "LDO2",
  		.n_voltages	= ARRAY_SIZE(ldo2_voltages),
  		.voltages	= ldo2_voltages,
  		.n_ilimsels	= ARRAY_SIZE(ldo_ilimsel),
  		.ilimsels	= ldo_ilimsel,
  		.enable		= __MK_FIELD(REG_BLOCK_EN, BLOCK_MASK,
  					     BLOCK_LDO2_SHIFT),
  		.voltage	= __MK_FIELD(REG_LDO_SET, LDO_VSEL_MASK,
  					     LDO2_VSEL_SHIFT),
  		.ilimsel	= __MK_FIELD(REG_LDO_SET, LDO_ILIM_MASK,
  					     LDO2_ILIM_SHIFT),
  	},
  	{
  		.name		= "USB",

  		.n_voltages	= ARRAY_SIZE(fixed_5000000_voltage),
  		.voltages	= fixed_5000000_voltage,

  		.n_ilimsels	= ARRAY_SIZE(usb_ilimsel),
  		.ilimsels	= usb_ilimsel,
  		.enable		= __MK_FIELD(REG_BLOCK_EN, BLOCK_MASK,
  					     BLOCK_USB_SHIFT),
  		.ilimsel	= __MK_FIELD(REG_USB, USB_ILIM_MASK,
  					     USB_ILIM_SHIFT),
  	},
  	{
  		.name		= "LCD",

  		.n_voltages	= ARRAY_SIZE(fixed_5000000_voltage),
  		.voltages	= fixed_5000000_voltage,

  		.n_ilimsels	= ARRAY_SIZE(fixed_400000_ilimsel),
  		.ilimsels	= fixed_400000_ilimsel,

  		.enable		= __MK_FIELD(REG_BLOCK_EN, BLOCK_MASK,
  					     BLOCK_LCD_SHIFT),
  	},
  };

  static int set_voltage_sel(struct regulator_dev *rdev, unsigned selector)

  {
  	const struct supply_info *info;
  	struct tps6524x *hw;

  
  	hw	= rdev_get_drvdata(rdev);
  	info	= &supply_info[rdev_get_id(rdev)];

  	if (rdev->desc->n_voltages == 1)

  		return -EINVAL;

  	return write_field(hw, &info->voltage, selector);

  }

  static int get_voltage_sel(struct regulator_dev *rdev)

  {
  	const struct supply_info *info;
  	struct tps6524x *hw;
  	int ret;
  
  	hw	= rdev_get_drvdata(rdev);
  	info	= &supply_info[rdev_get_id(rdev)];

  	if (rdev->desc->n_voltages == 1)

  		return 0;

  
  	ret = read_field(hw, &info->voltage);
  	if (ret < 0)
  		return ret;
  	if (WARN_ON(ret >= info->n_voltages))
  		return -EIO;

  	return ret;

  }
  
  static int set_current_limit(struct regulator_dev *rdev, int min_uA,
  			     int max_uA)
  {
  	const struct supply_info *info;
  	struct tps6524x *hw;
  	int i;
  
  	hw	= rdev_get_drvdata(rdev);
  	info	= &supply_info[rdev_get_id(rdev)];

  	if (info->n_ilimsels == 1)

  		return -EINVAL;

  	for (i = info->n_ilimsels - 1; i >= 0; i--) {

  		if (min_uA <= info->ilimsels[i] &&
  		    max_uA >= info->ilimsels[i])

  			return write_field(hw, &info->ilimsel, i);
  	}

  	return -EINVAL;

  }
  
  static int get_current_limit(struct regulator_dev *rdev)
  {
  	const struct supply_info *info;
  	struct tps6524x *hw;
  	int ret;
  
  	hw	= rdev_get_drvdata(rdev);
  	info	= &supply_info[rdev_get_id(rdev)];

  	if (info->n_ilimsels == 1)
  		return info->ilimsels[0];

  
  	ret = read_field(hw, &info->ilimsel);
  	if (ret < 0)
  		return ret;
  	if (WARN_ON(ret >= info->n_ilimsels))
  		return -EIO;
  
  	return info->ilimsels[ret];
  }
  
  static int enable_supply(struct regulator_dev *rdev)
  {
  	const struct supply_info *info;
  	struct tps6524x *hw;
  
  	hw	= rdev_get_drvdata(rdev);
  	info	= &supply_info[rdev_get_id(rdev)];
  
  	return write_field(hw, &info->enable, 1);
  }
  
  static int disable_supply(struct regulator_dev *rdev)
  {
  	const struct supply_info *info;
  	struct tps6524x *hw;
  
  	hw	= rdev_get_drvdata(rdev);
  	info	= &supply_info[rdev_get_id(rdev)];
  
  	return write_field(hw, &info->enable, 0);
  }
  
  static int is_supply_enabled(struct regulator_dev *rdev)
  {
  	const struct supply_info *info;
  	struct tps6524x *hw;
  
  	hw	= rdev_get_drvdata(rdev);
  	info	= &supply_info[rdev_get_id(rdev)];
  
  	return read_field(hw, &info->enable);
  }

  static const struct regulator_ops regulator_ops = {

  	.is_enabled		= is_supply_enabled,
  	.enable			= enable_supply,
  	.disable		= disable_supply,

  	.get_voltage_sel	= get_voltage_sel,

  	.set_voltage_sel	= set_voltage_sel,

  	.list_voltage		= regulator_list_voltage_table,

  	.map_voltage		= regulator_map_voltage_ascend,

  	.set_current_limit	= set_current_limit,
  	.get_current_limit	= get_current_limit,
  };

  static int pmic_probe(struct spi_device *spi)

  {
  	struct tps6524x *hw;
  	struct device *dev = &spi->dev;
  	const struct supply_info *info = supply_info;
  	struct regulator_init_data *init_data;

  	struct regulator_config config = { };

  	struct regulator_dev *rdev;

  	int i;

  	init_data = dev_get_platdata(dev);

  	if (!init_data) {
  		dev_err(dev, "could not find regulator platform data
  ");
  		return -EINVAL;
  	}

  	hw = devm_kzalloc(&spi->dev, sizeof(struct tps6524x), GFP_KERNEL);

  	if (!hw)

  		return -ENOMEM;

  	spi_set_drvdata(spi, hw);
  
  	memset(hw, 0, sizeof(struct tps6524x));
  	hw->dev = dev;

  	hw->spi = spi;

  	mutex_init(&hw->lock);
  
  	for (i = 0; i < N_REGULATORS; i++, info++, init_data++) {
  		hw->desc[i].name	= info->name;
  		hw->desc[i].id		= i;
  		hw->desc[i].n_voltages	= info->n_voltages;

  		hw->desc[i].volt_table	= info->voltages;

  		hw->desc[i].ops		= &regulator_ops;
  		hw->desc[i].type	= REGULATOR_VOLTAGE;
  		hw->desc[i].owner	= THIS_MODULE;

  		config.dev = dev;
  		config.init_data = init_data;
  		config.driver_data = hw;

  		rdev = devm_regulator_register(dev, &hw->desc[i], &config);
  		if (IS_ERR(rdev))
  			return PTR_ERR(rdev);

  	}
  
  	return 0;

  }
  
  static struct spi_driver pmic_driver = {
  	.probe		= pmic_probe,

  	.driver		= {
  		.name	= "tps6524x",

  	},
  };

  module_spi_driver(pmic_driver);

  
  MODULE_DESCRIPTION("TPS6524X PMIC Driver");
  MODULE_AUTHOR("Cyril Chemparathy");
  MODULE_LICENSE("GPL");
  MODULE_ALIAS("spi:tps6524x");