drivers/regulator/ab3100.c - linux - Git at Google

 /*
  * drivers/regulator/ab3100.c
  *
  * Copyright (C) 2008-2009 ST-Ericsson AB
  * License terms: GNU General Public License (GPL) version 2
  * Low-level control of the AB3100 IC Low Dropout (LDO)
  * regulators, external regulator and buck converter
  * Author: Mattias Wallin <mattias.wallin@stericsson.com>
  * Author: Linus Walleij <linus.walleij@stericsson.com>
  */

 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/err.h>
 #include <linux/platform_device.h>
 #include <linux/regulator/driver.h>
 #include <linux/mfd/ab3100.h>
 #include <linux/mfd/abx500.h>
 #include <linux/of.h>
 #include <linux/regulator/of_regulator.h>

 /* LDO registers and some handy masking definitions for AB3100 */
 #define AB3100_LDO_A		0x40
 #define AB3100_LDO_C		0x41
 #define AB3100_LDO_D		0x42
 #define AB3100_LDO_E		0x43
 #define AB3100_LDO_E_SLEEP	0x44
 #define AB3100_LDO_F		0x45
 #define AB3100_LDO_G		0x46
 #define AB3100_LDO_H		0x47
 #define AB3100_LDO_H_SLEEP_MODE	0
 #define AB3100_LDO_H_SLEEP_EN	2
 #define AB3100_LDO_ON		4
 #define AB3100_LDO_H_VSEL_AC	5
 #define AB3100_LDO_K		0x48
 #define AB3100_LDO_EXT		0x49
 #define AB3100_BUCK		0x4A
 #define AB3100_BUCK_SLEEP	0x4B
 #define AB3100_REG_ON_MASK	0x10

 /**
  * struct ab3100_regulator
  * A struct passed around the individual regulator functions
  * @platform_device: platform device holding this regulator
  * @dev: handle to the device
  * @plfdata: AB3100 platform data passed in at probe time
  * @regreg: regulator register number in the AB3100
  */
 struct ab3100_regulator {
 	struct device *dev;
 	struct ab3100_platform_data *plfdata;
 	u8 regreg;
 };

 /* The order in which registers are initialized */
 static const u8 ab3100_reg_init_order[AB3100_NUM_REGULATORS+2] = {
 	AB3100_LDO_A,
 	AB3100_LDO_C,
 	AB3100_LDO_E,
 	AB3100_LDO_E_SLEEP,
 	AB3100_LDO_F,
 	AB3100_LDO_G,
 	AB3100_LDO_H,
 	AB3100_LDO_K,
 	AB3100_LDO_EXT,
 	AB3100_BUCK,
 	AB3100_BUCK_SLEEP,
 	AB3100_LDO_D,
 };

 /* Preset (hardware defined) voltages for these regulators */
 #define LDO_A_VOLTAGE 2750000
 #define LDO_C_VOLTAGE 2650000
 #define LDO_D_VOLTAGE 2650000

 static const unsigned int ldo_e_buck_typ_voltages[] = {
 	1800000,
 	1400000,
 	1300000,
 	1200000,
 	1100000,
 	1050000,
 	900000,
 };

 static const unsigned int ldo_f_typ_voltages[] = {
 	1800000,
 	1400000,
 	1300000,
 	1200000,
 	1100000,
 	1050000,
 	2500000,
 	2650000,
 };

 static const unsigned int ldo_g_typ_voltages[] = {
 	2850000,
 	2750000,
 	1800000,
 	1500000,
 };

 static const unsigned int ldo_h_typ_voltages[] = {
 	2750000,
 	1800000,
 	1500000,
 	1200000,
 };

 static const unsigned int ldo_k_typ_voltages[] = {
 	2750000,
 	1800000,
 };


 /* The regulator devices */
 static struct ab3100_regulator
 ab3100_regulators[AB3100_NUM_REGULATORS] = {
 	{
 		.regreg = AB3100_LDO_A,
 	},
 	{
 		.regreg = AB3100_LDO_C,
 	},
 	{
 		.regreg = AB3100_LDO_D,
 	},
 	{
 		.regreg = AB3100_LDO_E,
 	},
 	{
 		.regreg = AB3100_LDO_F,
 	},
 	{
 		.regreg = AB3100_LDO_G,
 	},
 	{
 		.regreg = AB3100_LDO_H,
 	},
 	{
 		.regreg = AB3100_LDO_K,
 	},
 	{
 		.regreg = AB3100_LDO_EXT,
 		/* No voltages for the external regulator */
 	},
 	{
 		.regreg = AB3100_BUCK,
 	},
 };

 /*
  * General functions for enable, disable and is_enabled used for
  * LDO: A,C,E,F,G,H,K,EXT and BUCK
  */
 static int ab3100_enable_regulator(struct regulator_dev *reg)
 {
 	struct ab3100_regulator *abreg = rdev_get_drvdata(reg);
 	int err;
 	u8 regval;

 	err = abx500_get_register_interruptible(abreg->dev, 0, abreg->regreg,
 						&regval);
 	if (err) {
 		dev_warn(&reg->dev, "failed to get regid %d value\n",
 			 abreg->regreg);
 		return err;
 	}

 	/* The regulator is already on, no reason to go further */
 	if (regval & AB3100_REG_ON_MASK)
 		return 0;

 	regval |= AB3100_REG_ON_MASK;

 	err = abx500_set_register_interruptible(abreg->dev, 0, abreg->regreg,
 						regval);
 	if (err) {
 		dev_warn(&reg->dev, "failed to set regid %d value\n",
 			 abreg->regreg);
 		return err;
 	}

 	return 0;
 }

 static int ab3100_disable_regulator(struct regulator_dev *reg)
 {
 	struct ab3100_regulator *abreg = rdev_get_drvdata(reg);
 	int err;
 	u8 regval;

 	/*
 	 * LDO D is a special regulator. When it is disabled, the entire
 	 * system is shut down. So this is handled specially.
 	 */
 	pr_info("Called ab3100_disable_regulator\n");
 	if (abreg->regreg == AB3100_LDO_D) {
 		dev_info(&reg->dev, "disabling LDO D - shut down system\n");
 		/* Setting LDO D to 0x00 cuts the power to the SoC */
 		return abx500_set_register_interruptible(abreg->dev, 0,
 							 AB3100_LDO_D, 0x00U);
 	}

 	/*
 	 * All other regulators are handled here
 	 */
 	err = abx500_get_register_interruptible(abreg->dev, 0, abreg->regreg,
 						&regval);
 	if (err) {
 		dev_err(&reg->dev, "unable to get register 0x%x\n",
 			abreg->regreg);
 		return err;
 	}
 	regval &= ~AB3100_REG_ON_MASK;
 	return abx500_set_register_interruptible(abreg->dev, 0, abreg->regreg,
 						 regval);
 }

 static int ab3100_is_enabled_regulator(struct regulator_dev *reg)
 {
 	struct ab3100_regulator *abreg = rdev_get_drvdata(reg);
 	u8 regval;
 	int err;

 	err = abx500_get_register_interruptible(abreg->dev, 0, abreg->regreg,
 						&regval);
 	if (err) {
 		dev_err(&reg->dev, "unable to get register 0x%x\n",
 			abreg->regreg);
 		return err;
 	}

 	return regval & AB3100_REG_ON_MASK;
 }

 static int ab3100_get_voltage_regulator(struct regulator_dev *reg)
 {
 	struct ab3100_regulator *abreg = rdev_get_drvdata(reg);
 	u8 regval;
 	int err;

 	/*
 	 * For variable types, read out setting and index into
 	 * supplied voltage list.
 	 */
 	err = abx500_get_register_interruptible(abreg->dev, 0,
 						abreg->regreg, &regval);
 	if (err) {
 		dev_warn(&reg->dev,
 			 "failed to get regulator value in register %02x\n",
 			 abreg->regreg);
 		return err;
 	}

 	/* The 3 highest bits index voltages */
 	regval &= 0xE0;
 	regval >>= 5;

 	if (regval >= reg->desc->n_voltages) {
 		dev_err(&reg->dev,
 			"regulator register %02x contains an illegal voltage setting\n",
 			abreg->regreg);
 		return -EINVAL;
 	}

 	return reg->desc->volt_table[regval];
 }

 static int ab3100_set_voltage_regulator_sel(struct regulator_dev *reg,
 					    unsigned selector)
 {
 	struct ab3100_regulator *abreg = rdev_get_drvdata(reg);
 	u8 regval;
 	int err;

 	err = abx500_get_register_interruptible(abreg->dev, 0,
 						abreg->regreg, &regval);
 	if (err) {
 		dev_warn(&reg->dev,
 			 "failed to get regulator register %02x\n",
 			 abreg->regreg);
 		return err;
 	}

 	/* The highest three bits control the variable regulators */
 	regval &= ~0xE0;
 	regval |= (selector << 5);

 	err = abx500_set_register_interruptible(abreg->dev, 0,
 						abreg->regreg, regval);
 	if (err)
 		dev_warn(&reg->dev, "failed to set regulator register %02x\n",
 			abreg->regreg);

 	return err;
 }

 static int ab3100_set_suspend_voltage_regulator(struct regulator_dev *reg,
 						int uV)
 {
 	struct ab3100_regulator *abreg = rdev_get_drvdata(reg);
 	u8 regval;
 	int err;
 	int bestindex;
 	u8 targetreg;

 	if (abreg->regreg == AB3100_LDO_E)
 		targetreg = AB3100_LDO_E_SLEEP;
 	else if (abreg->regreg == AB3100_BUCK)
 		targetreg = AB3100_BUCK_SLEEP;
 	else
 		return -EINVAL;

 	/* LDO E and BUCK have special suspend voltages you can set */
 	bestindex = regulator_map_voltage_iterate(reg, uV, uV);

 	err = abx500_get_register_interruptible(abreg->dev, 0,
 						targetreg, &regval);
 	if (err) {
 		dev_warn(&reg->dev,
 			 "failed to get regulator register %02x\n",
 			 targetreg);
 		return err;
 	}

 	/* The highest three bits control the variable regulators */
 	regval &= ~0xE0;
 	regval |= (bestindex << 5);

 	err = abx500_set_register_interruptible(abreg->dev, 0,
 						targetreg, regval);
 	if (err)
 		dev_warn(&reg->dev, "failed to set regulator register %02x\n",
 			abreg->regreg);

 	return err;
 }

 /*
  * The external regulator can just define a fixed voltage.
  */
 static int ab3100_get_voltage_regulator_external(struct regulator_dev *reg)
 {
 	struct ab3100_regulator *abreg = rdev_get_drvdata(reg);

 	if (abreg->plfdata)
 		return abreg->plfdata->external_voltage;
 	else
 		/* TODO: encode external voltage into device tree */
 		return 0;
 }

 static const struct regulator_ops regulator_ops_fixed = {
 	.enable      = ab3100_enable_regulator,
 	.disable     = ab3100_disable_regulator,
 	.is_enabled  = ab3100_is_enabled_regulator,
 };

 static const struct regulator_ops regulator_ops_variable = {
 	.enable      = ab3100_enable_regulator,
 	.disable     = ab3100_disable_regulator,
 	.is_enabled  = ab3100_is_enabled_regulator,
 	.get_voltage = ab3100_get_voltage_regulator,
 	.set_voltage_sel = ab3100_set_voltage_regulator_sel,
 	.list_voltage = regulator_list_voltage_table,
 };

 static const struct regulator_ops regulator_ops_variable_sleepable = {
 	.enable      = ab3100_enable_regulator,
 	.disable     = ab3100_disable_regulator,
 	.is_enabled  = ab3100_is_enabled_regulator,
 	.get_voltage = ab3100_get_voltage_regulator,
 	.set_voltage_sel = ab3100_set_voltage_regulator_sel,
 	.set_suspend_voltage = ab3100_set_suspend_voltage_regulator,
 	.list_voltage = regulator_list_voltage_table,
 };

 /*
  * LDO EXT is an external regulator so it is really
  * not possible to set any voltage locally here, AB3100
  * is an on/off switch plain an simple. The external
  * voltage is defined in the board set-up if any.
  */
 static const struct regulator_ops regulator_ops_external = {
 	.enable      = ab3100_enable_regulator,
 	.disable     = ab3100_disable_regulator,
 	.is_enabled  = ab3100_is_enabled_regulator,
 	.get_voltage = ab3100_get_voltage_regulator_external,
 };

 static const struct regulator_desc
 ab3100_regulator_desc[AB3100_NUM_REGULATORS] = {
 	{
 		.name = "LDO_A",
 		.id   = AB3100_LDO_A,
 		.ops  = &regulator_ops_fixed,
 		.n_voltages = 1,
 		.type = REGULATOR_VOLTAGE,
 		.owner = THIS_MODULE,
 		.fixed_uV = LDO_A_VOLTAGE,
 		.enable_time = 200,
 	},
 	{
 		.name = "LDO_C",
 		.id   = AB3100_LDO_C,
 		.ops  = &regulator_ops_fixed,
 		.n_voltages = 1,
 		.type = REGULATOR_VOLTAGE,
 		.owner = THIS_MODULE,
 		.fixed_uV = LDO_C_VOLTAGE,
 		.enable_time = 200,
 	},
 	{
 		.name = "LDO_D",
 		.id   = AB3100_LDO_D,
 		.ops  = &regulator_ops_fixed,
 		.n_voltages = 1,
 		.type = REGULATOR_VOLTAGE,
 		.owner = THIS_MODULE,
 		.fixed_uV = LDO_D_VOLTAGE,
 		.enable_time = 200,
 	},
 	{
 		.name = "LDO_E",
 		.id   = AB3100_LDO_E,
 		.ops  = &regulator_ops_variable_sleepable,
 		.n_voltages = ARRAY_SIZE(ldo_e_buck_typ_voltages),
 		.volt_table = ldo_e_buck_typ_voltages,
 		.type = REGULATOR_VOLTAGE,
 		.owner = THIS_MODULE,
 		.enable_time = 200,
 	},
 	{
 		.name = "LDO_F",
 		.id   = AB3100_LDO_F,
 		.ops  = &regulator_ops_variable,
 		.n_voltages = ARRAY_SIZE(ldo_f_typ_voltages),
 		.volt_table = ldo_f_typ_voltages,
 		.type = REGULATOR_VOLTAGE,
 		.owner = THIS_MODULE,
 		.enable_time = 600,
 	},
 	{
 		.name = "LDO_G",
 		.id   = AB3100_LDO_G,
 		.ops  = &regulator_ops_variable,
 		.n_voltages = ARRAY_SIZE(ldo_g_typ_voltages),
 		.volt_table = ldo_g_typ_voltages,
 		.type = REGULATOR_VOLTAGE,
 		.owner = THIS_MODULE,
 		.enable_time = 400,
 	},
 	{
 		.name = "LDO_H",
 		.id   = AB3100_LDO_H,
 		.ops  = &regulator_ops_variable,
 		.n_voltages = ARRAY_SIZE(ldo_h_typ_voltages),
 		.volt_table = ldo_h_typ_voltages,
 		.type = REGULATOR_VOLTAGE,
 		.owner = THIS_MODULE,
 		.enable_time = 200,
 	},
 	{
 		.name = "LDO_K",
 		.id   = AB3100_LDO_K,
 		.ops  = &regulator_ops_variable,
 		.n_voltages = ARRAY_SIZE(ldo_k_typ_voltages),
 		.volt_table = ldo_k_typ_voltages,
 		.type = REGULATOR_VOLTAGE,
 		.owner = THIS_MODULE,
 		.enable_time = 200,
 	},
 	{
 		.name = "LDO_EXT",
 		.id   = AB3100_LDO_EXT,
 		.ops  = &regulator_ops_external,
 		.type = REGULATOR_VOLTAGE,
 		.owner = THIS_MODULE,
 	},
 	{
 		.name = "BUCK",
 		.id   = AB3100_BUCK,
 		.ops  = &regulator_ops_variable_sleepable,
 		.n_voltages = ARRAY_SIZE(ldo_e_buck_typ_voltages),
 		.volt_table = ldo_e_buck_typ_voltages,
 		.type = REGULATOR_VOLTAGE,
 		.owner = THIS_MODULE,
 		.enable_time = 1000,
 	},
 };

 static int ab3100_regulator_register(struct platform_device *pdev,
 				     struct ab3100_platform_data *plfdata,
 				     struct regulator_init_data *init_data,
 				     struct device_node *np,
 				     unsigned long id)
 {
 	const struct regulator_desc *desc;
 	struct ab3100_regulator *reg;
 	struct regulator_dev *rdev;
 	struct regulator_config config = { };
 	int err, i;

 	for (i = 0; i < AB3100_NUM_REGULATORS; i++) {
 		desc = &ab3100_regulator_desc[i];
 		if (desc->id == id)
 			break;
 	}
 	if (desc->id != id)
 		return -ENODEV;

 	/* Same index used for this array */
 	reg = &ab3100_regulators[i];

 	/*
 	 * Initialize per-regulator struct.
 	 * Inherit platform data, this comes down from the
 	 * i2c boarddata, from the machine. So if you want to
 	 * see what it looks like for a certain machine, go
 	 * into the machine I2C setup.
 	 */
 	reg->dev = &pdev->dev;
 	if (plfdata) {
 		reg->plfdata = plfdata;
 		config.init_data = &plfdata->reg_constraints[i];
 	} else if (np) {
 		config.of_node = np;
 		config.init_data = init_data;
 	}
 	config.dev = &pdev->dev;
 	config.driver_data = reg;

 	rdev = devm_regulator_register(&pdev->dev, desc, &config);
 	if (IS_ERR(rdev)) {
 		err = PTR_ERR(rdev);
 		dev_err(&pdev->dev,
 			"%s: failed to register regulator %s err %d\n",
 			__func__, desc->name,
 			err);
 		return err;
 	}

 	return 0;
 }

 static struct of_regulator_match ab3100_regulator_matches[] = {
 	{ .name = "ab3100_ldo_a", .driver_data = (void *) AB3100_LDO_A, },
 	{ .name = "ab3100_ldo_c", .driver_data = (void *) AB3100_LDO_C, },
 	{ .name = "ab3100_ldo_d", .driver_data = (void *) AB3100_LDO_D, },
 	{ .name = "ab3100_ldo_e", .driver_data = (void *) AB3100_LDO_E, },
 	{ .name = "ab3100_ldo_f", .driver_data = (void *) AB3100_LDO_F },
 	{ .name = "ab3100_ldo_g", .driver_data = (void *) AB3100_LDO_G },
 	{ .name = "ab3100_ldo_h", .driver_data = (void *) AB3100_LDO_H },
 	{ .name = "ab3100_ldo_k", .driver_data = (void *) AB3100_LDO_K },
 	{ .name = "ab3100_ext", .driver_data = (void *) AB3100_LDO_EXT },
 	{ .name = "ab3100_buck", .driver_data = (void *) AB3100_BUCK },
 };

 /*
  * Initial settings of ab3100 registers.
  * Common for below LDO regulator settings are that
  * bit 7-5 controls voltage. Bit 4 turns regulator ON(1) or OFF(0).
  * Bit 3-2 controls sleep enable and bit 1-0 controls sleep mode.
  */
 /* LDO_A 0x16: 2.75V, ON, SLEEP_A, SLEEP OFF GND */
 #define LDO_A_SETTING		0x16
 /* LDO_C 0x10: 2.65V, ON, SLEEP_A or B, SLEEP full power */
 #define LDO_C_SETTING		0x10
 /* LDO_D 0x10: 2.65V, ON, sleep mode not used */
 #define LDO_D_SETTING		0x10
 /* LDO_E 0x10: 1.8V, ON, SLEEP_A or B, SLEEP full power */
 #define LDO_E_SETTING		0x10
 /* LDO_E SLEEP 0x00: 1.8V, not used, SLEEP_A or B, not used */
 #define LDO_E_SLEEP_SETTING	0x00
 /* LDO_F 0xD0: 2.5V, ON, SLEEP_A or B, SLEEP full power */
 #define LDO_F_SETTING		0xD0
 /* LDO_G 0x00: 2.85V, OFF, SLEEP_A or B, SLEEP full power */
 #define LDO_G_SETTING		0x00
 /* LDO_H 0x18: 2.75V, ON, SLEEP_B, SLEEP full power */
 #define LDO_H_SETTING		0x18
 /* LDO_K 0x00: 2.75V, OFF, SLEEP_A or B, SLEEP full power */
 #define LDO_K_SETTING		0x00
 /* LDO_EXT 0x00: Voltage not set, OFF, not used, not used */
 #define LDO_EXT_SETTING		0x00
 /* BUCK 0x7D: 1.2V, ON, SLEEP_A and B, SLEEP low power */
 #define BUCK_SETTING	0x7D
 /* BUCK SLEEP 0xAC: 1.05V, Not used, SLEEP_A and B, Not used */
 #define BUCK_SLEEP_SETTING	0xAC

 static const u8 ab3100_reg_initvals[] = {
 	LDO_A_SETTING,
 	LDO_C_SETTING,
 	LDO_E_SETTING,
 	LDO_E_SLEEP_SETTING,
 	LDO_F_SETTING,
 	LDO_G_SETTING,
 	LDO_H_SETTING,
 	LDO_K_SETTING,
 	LDO_EXT_SETTING,
 	BUCK_SETTING,
 	BUCK_SLEEP_SETTING,
 	LDO_D_SETTING,
 };

 static int
 ab3100_regulator_of_probe(struct platform_device *pdev, struct device_node *np)
 {
 	int err, i;

 	/*
 	 * Set up the regulator registers, as was previously done with
 	 * platform data.
 	 */
 	/* Set up regulators */
 	for (i = 0; i < ARRAY_SIZE(ab3100_reg_init_order); i++) {
 		err = abx500_set_register_interruptible(&pdev->dev, 0,
 					ab3100_reg_init_order[i],
 					ab3100_reg_initvals[i]);
 		if (err) {
 			dev_err(&pdev->dev, "regulator initialization failed with error %d\n",
 				err);
 			return err;
 		}
 	}

 	for (i = 0; i < ARRAY_SIZE(ab3100_regulator_matches); i++) {
 		err = ab3100_regulator_register(
 			pdev, NULL, ab3100_regulator_matches[i].init_data,
 			ab3100_regulator_matches[i].of_node,
 			(unsigned long)ab3100_regulator_matches[i].driver_data);
 		if (err)
 			return err;
 	}

 	return 0;
 }


 static int ab3100_regulators_probe(struct platform_device *pdev)
 {
 	struct ab3100_platform_data *plfdata = dev_get_platdata(&pdev->dev);
 	struct device_node *np = pdev->dev.of_node;
 	int err = 0;
 	u8 data;
 	int i;

 	/* Check chip state */
 	err = abx500_get_register_interruptible(&pdev->dev, 0,
 						AB3100_LDO_D, &data);
 	if (err) {
 		dev_err(&pdev->dev, "could not read initial status of LDO_D\n");
 		return err;
 	}
 	if (data & 0x10)
 		dev_notice(&pdev->dev,
 			   "chip is already in active mode (Warm start)\n");
 	else
 		dev_notice(&pdev->dev,
 			   "chip is in inactive mode (Cold start)\n");

 	if (np) {
 		err = of_regulator_match(&pdev->dev, np,
 					 ab3100_regulator_matches,
 					 ARRAY_SIZE(ab3100_regulator_matches));
 		if (err < 0) {
 			dev_err(&pdev->dev,
 				"Error parsing regulator init data: %d\n", err);
 			return err;
 		}
 		return ab3100_regulator_of_probe(pdev, np);
 	}

 	/* Set up regulators */
 	for (i = 0; i < ARRAY_SIZE(ab3100_reg_init_order); i++) {
 		err = abx500_set_register_interruptible(&pdev->dev, 0,
 					ab3100_reg_init_order[i],
 					plfdata->reg_initvals[i]);
 		if (err) {
 			dev_err(&pdev->dev, "regulator initialization failed with error %d\n",
 				err);
 			return err;
 		}
 	}

 	/* Register the regulators */
 	for (i = 0; i < AB3100_NUM_REGULATORS; i++) {
 		const struct regulator_desc *desc = &ab3100_regulator_desc[i];

 		err = ab3100_regulator_register(pdev, plfdata, NULL, NULL,
 						desc->id);
 		if (err)
 			return err;
 	}

 	return 0;
 }

 static struct platform_driver ab3100_regulators_driver = {
 	.driver = {
 		.name  = "ab3100-regulators",
 	},
 	.probe = ab3100_regulators_probe,
 };

 static __init int ab3100_regulators_init(void)
 {
 	return platform_driver_register(&ab3100_regulators_driver);
 }

 static __exit void ab3100_regulators_exit(void)
 {
 	platform_driver_unregister(&ab3100_regulators_driver);
 }

 subsys_initcall(ab3100_regulators_init);
 module_exit(ab3100_regulators_exit);

 MODULE_AUTHOR("Mattias Wallin <mattias.wallin@stericsson.com>");
 MODULE_DESCRIPTION("AB3100 Regulator driver");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS("platform:ab3100-regulators");
	/*
	* drivers/regulator/ab3100.c
	*
	* Copyright (C) 2008-2009 ST-Ericsson AB
	* License terms: GNU General Public License (GPL) version 2
	* Low-level control of the AB3100 IC Low Dropout (LDO)
	* regulators, external regulator and buck converter
	* Author: Mattias Wallin <mattias.wallin@stericsson.com>
	* Author: Linus Walleij <linus.walleij@stericsson.com>
	*/

	#include <linux/module.h>
	#include <linux/kernel.h>
	#include <linux/init.h>
	#include <linux/err.h>
	#include <linux/platform_device.h>
	#include <linux/regulator/driver.h>
	#include <linux/mfd/ab3100.h>
	#include <linux/mfd/abx500.h>
	#include <linux/of.h>
	#include <linux/regulator/of_regulator.h>

	/* LDO registers and some handy masking definitions for AB3100 */
	#define AB3100_LDO_A 0x40
	#define AB3100_LDO_C 0x41
	#define AB3100_LDO_D 0x42
	#define AB3100_LDO_E 0x43
	#define AB3100_LDO_E_SLEEP 0x44
	#define AB3100_LDO_F 0x45
	#define AB3100_LDO_G 0x46
	#define AB3100_LDO_H 0x47
	#define AB3100_LDO_H_SLEEP_MODE 0
	#define AB3100_LDO_H_SLEEP_EN 2
	#define AB3100_LDO_ON 4
	#define AB3100_LDO_H_VSEL_AC 5
	#define AB3100_LDO_K 0x48
	#define AB3100_LDO_EXT 0x49
	#define AB3100_BUCK 0x4A
	#define AB3100_BUCK_SLEEP 0x4B
	#define AB3100_REG_ON_MASK 0x10

	/**
	* struct ab3100_regulator
	* A struct passed around the individual regulator functions
	* @platform_device: platform device holding this regulator
	* @dev: handle to the device
	* @plfdata: AB3100 platform data passed in at probe time
	* @regreg: regulator register number in the AB3100
	*/
	struct ab3100_regulator {
	struct device *dev;
	struct ab3100_platform_data *plfdata;
	u8 regreg;
	};

	/* The order in which registers are initialized */
	static const u8 ab3100_reg_init_order[AB3100_NUM_REGULATORS+2] = {
	AB3100_LDO_A,
	AB3100_LDO_C,
	AB3100_LDO_E,
	AB3100_LDO_E_SLEEP,
	AB3100_LDO_F,
	AB3100_LDO_G,
	AB3100_LDO_H,
	AB3100_LDO_K,
	AB3100_LDO_EXT,
	AB3100_BUCK,
	AB3100_BUCK_SLEEP,
	AB3100_LDO_D,
	};

	/* Preset (hardware defined) voltages for these regulators */
	#define LDO_A_VOLTAGE 2750000
	#define LDO_C_VOLTAGE 2650000
	#define LDO_D_VOLTAGE 2650000

	static const unsigned int ldo_e_buck_typ_voltages[] = {
	1800000,
	1400000,
	1300000,
	1200000,
	1100000,
	1050000,
	900000,
	};

	static const unsigned int ldo_f_typ_voltages[] = {
	1800000,
	1400000,
	1300000,
	1200000,
	1100000,
	1050000,
	2500000,
	2650000,
	};

	static const unsigned int ldo_g_typ_voltages[] = {
	2850000,
	2750000,
	1800000,
	1500000,
	};

	static const unsigned int ldo_h_typ_voltages[] = {
	2750000,
	1800000,
	1500000,
	1200000,
	};

	static const unsigned int ldo_k_typ_voltages[] = {
	2750000,
	1800000,
	};


	/* The regulator devices */
	static struct ab3100_regulator
	ab3100_regulators[AB3100_NUM_REGULATORS] = {
	{
	.regreg = AB3100_LDO_A,
	},
	{
	.regreg = AB3100_LDO_C,
	},
	{
	.regreg = AB3100_LDO_D,
	},
	{
	.regreg = AB3100_LDO_E,
	},
	{
	.regreg = AB3100_LDO_F,
	},
	{
	.regreg = AB3100_LDO_G,
	},
	{
	.regreg = AB3100_LDO_H,
	},
	{
	.regreg = AB3100_LDO_K,
	},
	{
	.regreg = AB3100_LDO_EXT,
	/* No voltages for the external regulator */
	},
	{
	.regreg = AB3100_BUCK,
	},
	};

	/*
	* General functions for enable, disable and is_enabled used for
	* LDO: A,C,E,F,G,H,K,EXT and BUCK
	*/
	static int ab3100_enable_regulator(struct regulator_dev *reg)
	{
	struct ab3100_regulator *abreg = rdev_get_drvdata(reg);
	int err;
	u8 regval;

	err = abx500_get_register_interruptible(abreg->dev, 0, abreg->regreg,
	&regval);
	if (err) {
	dev_warn(&reg->dev, "failed to get regid %d value\n",
	abreg->regreg);
	return err;
	}

	/* The regulator is already on, no reason to go further */
	if (regval & AB3100_REG_ON_MASK)
	return 0;

	regval \|= AB3100_REG_ON_MASK;

	err = abx500_set_register_interruptible(abreg->dev, 0, abreg->regreg,
	regval);
	if (err) {
	dev_warn(&reg->dev, "failed to set regid %d value\n",
	abreg->regreg);
	return err;
	}

	return 0;
	}

	static int ab3100_disable_regulator(struct regulator_dev *reg)
	{
	struct ab3100_regulator *abreg = rdev_get_drvdata(reg);
	int err;
	u8 regval;

	/*
	* LDO D is a special regulator. When it is disabled, the entire
	* system is shut down. So this is handled specially.
	*/
	pr_info("Called ab3100_disable_regulator\n");
	if (abreg->regreg == AB3100_LDO_D) {
	dev_info(&reg->dev, "disabling LDO D - shut down system\n");
	/* Setting LDO D to 0x00 cuts the power to the SoC */
	return abx500_set_register_interruptible(abreg->dev, 0,
	AB3100_LDO_D, 0x00U);
	}

	/*
	* All other regulators are handled here
	*/
	err = abx500_get_register_interruptible(abreg->dev, 0, abreg->regreg,
	&regval);
	if (err) {
	dev_err(&reg->dev, "unable to get register 0x%x\n",
	abreg->regreg);
	return err;
	}
	regval &= ~AB3100_REG_ON_MASK;
	return abx500_set_register_interruptible(abreg->dev, 0, abreg->regreg,
	regval);
	}

	static int ab3100_is_enabled_regulator(struct regulator_dev *reg)
	{
	struct ab3100_regulator *abreg = rdev_get_drvdata(reg);
	u8 regval;
	int err;

	err = abx500_get_register_interruptible(abreg->dev, 0, abreg->regreg,
	&regval);
	if (err) {
	dev_err(&reg->dev, "unable to get register 0x%x\n",
	abreg->regreg);
	return err;
	}

	return regval & AB3100_REG_ON_MASK;
	}

	static int ab3100_get_voltage_regulator(struct regulator_dev *reg)
	{
	struct ab3100_regulator *abreg = rdev_get_drvdata(reg);
	u8 regval;
	int err;

	/*
	* For variable types, read out setting and index into
	* supplied voltage list.
	*/
	err = abx500_get_register_interruptible(abreg->dev, 0,
	abreg->regreg, &regval);
	if (err) {
	dev_warn(&reg->dev,
	"failed to get regulator value in register %02x\n",
	abreg->regreg);
	return err;
	}

	/* The 3 highest bits index voltages */
	regval &= 0xE0;
	regval >>= 5;

	if (regval >= reg->desc->n_voltages) {
	dev_err(&reg->dev,
	"regulator register %02x contains an illegal voltage setting\n",
	abreg->regreg);
	return -EINVAL;
	}

	return reg->desc->volt_table[regval];
	}

	static int ab3100_set_voltage_regulator_sel(struct regulator_dev *reg,
	unsigned selector)
	{
	struct ab3100_regulator *abreg = rdev_get_drvdata(reg);
	u8 regval;
	int err;

	err = abx500_get_register_interruptible(abreg->dev, 0,
	abreg->regreg, &regval);
	if (err) {
	dev_warn(&reg->dev,
	"failed to get regulator register %02x\n",
	abreg->regreg);
	return err;
	}

	/* The highest three bits control the variable regulators */
	regval &= ~0xE0;
	regval \|= (selector << 5);

	err = abx500_set_register_interruptible(abreg->dev, 0,
	abreg->regreg, regval);
	if (err)
	dev_warn(&reg->dev, "failed to set regulator register %02x\n",
	abreg->regreg);

	return err;
	}

	static int ab3100_set_suspend_voltage_regulator(struct regulator_dev *reg,
	int uV)
	{
	struct ab3100_regulator *abreg = rdev_get_drvdata(reg);
	u8 regval;
	int err;
	int bestindex;
	u8 targetreg;

	if (abreg->regreg == AB3100_LDO_E)
	targetreg = AB3100_LDO_E_SLEEP;
	else if (abreg->regreg == AB3100_BUCK)
	targetreg = AB3100_BUCK_SLEEP;
	else
	return -EINVAL;

	/* LDO E and BUCK have special suspend voltages you can set */
	bestindex = regulator_map_voltage_iterate(reg, uV, uV);

	err = abx500_get_register_interruptible(abreg->dev, 0,
	targetreg, &regval);
	if (err) {
	dev_warn(&reg->dev,
	"failed to get regulator register %02x\n",
	targetreg);
	return err;
	}

	/* The highest three bits control the variable regulators */
	regval &= ~0xE0;
	regval \|= (bestindex << 5);

	err = abx500_set_register_interruptible(abreg->dev, 0,
	targetreg, regval);
	if (err)
	dev_warn(&reg->dev, "failed to set regulator register %02x\n",
	abreg->regreg);

	return err;
	}

	/*
	* The external regulator can just define a fixed voltage.
	*/
	static int ab3100_get_voltage_regulator_external(struct regulator_dev *reg)
	{
	struct ab3100_regulator *abreg = rdev_get_drvdata(reg);

	if (abreg->plfdata)
	return abreg->plfdata->external_voltage;
	else
	/* TODO: encode external voltage into device tree */
	return 0;
	}

	static const struct regulator_ops regulator_ops_fixed = {
	.enable = ab3100_enable_regulator,
	.disable = ab3100_disable_regulator,
	.is_enabled = ab3100_is_enabled_regulator,
	};

	static const struct regulator_ops regulator_ops_variable = {
	.enable = ab3100_enable_regulator,
	.disable = ab3100_disable_regulator,
	.is_enabled = ab3100_is_enabled_regulator,
	.get_voltage = ab3100_get_voltage_regulator,
	.set_voltage_sel = ab3100_set_voltage_regulator_sel,
	.list_voltage = regulator_list_voltage_table,
	};

	static const struct regulator_ops regulator_ops_variable_sleepable = {
	.enable = ab3100_enable_regulator,
	.disable = ab3100_disable_regulator,
	.is_enabled = ab3100_is_enabled_regulator,
	.get_voltage = ab3100_get_voltage_regulator,
	.set_voltage_sel = ab3100_set_voltage_regulator_sel,
	.set_suspend_voltage = ab3100_set_suspend_voltage_regulator,
	.list_voltage = regulator_list_voltage_table,
	};

	/*
	* LDO EXT is an external regulator so it is really
	* not possible to set any voltage locally here, AB3100
	* is an on/off switch plain an simple. The external
	* voltage is defined in the board set-up if any.
	*/
	static const struct regulator_ops regulator_ops_external = {
	.enable = ab3100_enable_regulator,
	.disable = ab3100_disable_regulator,
	.is_enabled = ab3100_is_enabled_regulator,
	.get_voltage = ab3100_get_voltage_regulator_external,
	};

	static const struct regulator_desc
	ab3100_regulator_desc[AB3100_NUM_REGULATORS] = {
	{
	.name = "LDO_A",
	.id = AB3100_LDO_A,
	.ops = &regulator_ops_fixed,
	.n_voltages = 1,
	.type = REGULATOR_VOLTAGE,
	.owner = THIS_MODULE,
	.fixed_uV = LDO_A_VOLTAGE,
	.enable_time = 200,
	},
	{
	.name = "LDO_C",
	.id = AB3100_LDO_C,
	.ops = &regulator_ops_fixed,
	.n_voltages = 1,
	.type = REGULATOR_VOLTAGE,
	.owner = THIS_MODULE,
	.fixed_uV = LDO_C_VOLTAGE,
	.enable_time = 200,
	},
	{
	.name = "LDO_D",
	.id = AB3100_LDO_D,
	.ops = &regulator_ops_fixed,
	.n_voltages = 1,
	.type = REGULATOR_VOLTAGE,
	.owner = THIS_MODULE,
	.fixed_uV = LDO_D_VOLTAGE,
	.enable_time = 200,
	},
	{
	.name = "LDO_E",
	.id = AB3100_LDO_E,
	.ops = &regulator_ops_variable_sleepable,
	.n_voltages = ARRAY_SIZE(ldo_e_buck_typ_voltages),
	.volt_table = ldo_e_buck_typ_voltages,
	.type = REGULATOR_VOLTAGE,
	.owner = THIS_MODULE,
	.enable_time = 200,
	},
	{
	.name = "LDO_F",
	.id = AB3100_LDO_F,
	.ops = &regulator_ops_variable,
	.n_voltages = ARRAY_SIZE(ldo_f_typ_voltages),
	.volt_table = ldo_f_typ_voltages,
	.type = REGULATOR_VOLTAGE,
	.owner = THIS_MODULE,
	.enable_time = 600,
	},
	{
	.name = "LDO_G",
	.id = AB3100_LDO_G,
	.ops = &regulator_ops_variable,
	.n_voltages = ARRAY_SIZE(ldo_g_typ_voltages),
	.volt_table = ldo_g_typ_voltages,
	.type = REGULATOR_VOLTAGE,
	.owner = THIS_MODULE,
	.enable_time = 400,
	},
	{
	.name = "LDO_H",
	.id = AB3100_LDO_H,
	.ops = &regulator_ops_variable,
	.n_voltages = ARRAY_SIZE(ldo_h_typ_voltages),
	.volt_table = ldo_h_typ_voltages,
	.type = REGULATOR_VOLTAGE,
	.owner = THIS_MODULE,
	.enable_time = 200,
	},
	{
	.name = "LDO_K",
	.id = AB3100_LDO_K,
	.ops = &regulator_ops_variable,
	.n_voltages = ARRAY_SIZE(ldo_k_typ_voltages),
	.volt_table = ldo_k_typ_voltages,
	.type = REGULATOR_VOLTAGE,
	.owner = THIS_MODULE,
	.enable_time = 200,
	},
	{
	.name = "LDO_EXT",
	.id = AB3100_LDO_EXT,
	.ops = &regulator_ops_external,
	.type = REGULATOR_VOLTAGE,
	.owner = THIS_MODULE,
	},
	{
	.name = "BUCK",
	.id = AB3100_BUCK,
	.ops = &regulator_ops_variable_sleepable,
	.n_voltages = ARRAY_SIZE(ldo_e_buck_typ_voltages),
	.volt_table = ldo_e_buck_typ_voltages,
	.type = REGULATOR_VOLTAGE,
	.owner = THIS_MODULE,
	.enable_time = 1000,
	},
	};

	static int ab3100_regulator_register(struct platform_device *pdev,
	struct ab3100_platform_data *plfdata,
	struct regulator_init_data *init_data,
	struct device_node *np,
	unsigned long id)
	{
	const struct regulator_desc *desc;
	struct ab3100_regulator *reg;
	struct regulator_dev *rdev;
	struct regulator_config config = { };
	int err, i;

	for (i = 0; i < AB3100_NUM_REGULATORS; i++) {
	desc = &ab3100_regulator_desc[i];
	if (desc->id == id)
	break;
	}
	if (desc->id != id)
	return -ENODEV;

	/* Same index used for this array */
	reg = &ab3100_regulators[i];

	/*
	* Initialize per-regulator struct.
	* Inherit platform data, this comes down from the
	* i2c boarddata, from the machine. So if you want to
	* see what it looks like for a certain machine, go
	* into the machine I2C setup.
	*/
	reg->dev = &pdev->dev;
	if (plfdata) {
	reg->plfdata = plfdata;
	config.init_data = &plfdata->reg_constraints[i];
	} else if (np) {
	config.of_node = np;
	config.init_data = init_data;
	}
	config.dev = &pdev->dev;
	config.driver_data = reg;

	rdev = devm_regulator_register(&pdev->dev, desc, &config);
	if (IS_ERR(rdev)) {
	err = PTR_ERR(rdev);
	dev_err(&pdev->dev,
	"%s: failed to register regulator %s err %d\n",
	__func__, desc->name,
	err);
	return err;
	}

	return 0;
	}

	static struct of_regulator_match ab3100_regulator_matches[] = {
	{ .name = "ab3100_ldo_a", .driver_data = (void *) AB3100_LDO_A, },
	{ .name = "ab3100_ldo_c", .driver_data = (void *) AB3100_LDO_C, },
	{ .name = "ab3100_ldo_d", .driver_data = (void *) AB3100_LDO_D, },
	{ .name = "ab3100_ldo_e", .driver_data = (void *) AB3100_LDO_E, },
	{ .name = "ab3100_ldo_f", .driver_data = (void *) AB3100_LDO_F },
	{ .name = "ab3100_ldo_g", .driver_data = (void *) AB3100_LDO_G },
	{ .name = "ab3100_ldo_h", .driver_data = (void *) AB3100_LDO_H },
	{ .name = "ab3100_ldo_k", .driver_data = (void *) AB3100_LDO_K },
	{ .name = "ab3100_ext", .driver_data = (void *) AB3100_LDO_EXT },
	{ .name = "ab3100_buck", .driver_data = (void *) AB3100_BUCK },
	};

	/*
	* Initial settings of ab3100 registers.
	* Common for below LDO regulator settings are that
	* bit 7-5 controls voltage. Bit 4 turns regulator ON(1) or OFF(0).
	* Bit 3-2 controls sleep enable and bit 1-0 controls sleep mode.
	*/
	/* LDO_A 0x16: 2.75V, ON, SLEEP_A, SLEEP OFF GND */
	#define LDO_A_SETTING 0x16
	/* LDO_C 0x10: 2.65V, ON, SLEEP_A or B, SLEEP full power */
	#define LDO_C_SETTING 0x10
	/* LDO_D 0x10: 2.65V, ON, sleep mode not used */
	#define LDO_D_SETTING 0x10
	/* LDO_E 0x10: 1.8V, ON, SLEEP_A or B, SLEEP full power */
	#define LDO_E_SETTING 0x10
	/* LDO_E SLEEP 0x00: 1.8V, not used, SLEEP_A or B, not used */
	#define LDO_E_SLEEP_SETTING 0x00
	/* LDO_F 0xD0: 2.5V, ON, SLEEP_A or B, SLEEP full power */
	#define LDO_F_SETTING 0xD0
	/* LDO_G 0x00: 2.85V, OFF, SLEEP_A or B, SLEEP full power */
	#define LDO_G_SETTING 0x00
	/* LDO_H 0x18: 2.75V, ON, SLEEP_B, SLEEP full power */
	#define LDO_H_SETTING 0x18
	/* LDO_K 0x00: 2.75V, OFF, SLEEP_A or B, SLEEP full power */
	#define LDO_K_SETTING 0x00
	/* LDO_EXT 0x00: Voltage not set, OFF, not used, not used */
	#define LDO_EXT_SETTING 0x00
	/* BUCK 0x7D: 1.2V, ON, SLEEP_A and B, SLEEP low power */
	#define BUCK_SETTING 0x7D
	/* BUCK SLEEP 0xAC: 1.05V, Not used, SLEEP_A and B, Not used */
	#define BUCK_SLEEP_SETTING 0xAC

	static const u8 ab3100_reg_initvals[] = {
	LDO_A_SETTING,
	LDO_C_SETTING,
	LDO_E_SETTING,
	LDO_E_SLEEP_SETTING,
	LDO_F_SETTING,
	LDO_G_SETTING,
	LDO_H_SETTING,
	LDO_K_SETTING,
	LDO_EXT_SETTING,
	BUCK_SETTING,
	BUCK_SLEEP_SETTING,
	LDO_D_SETTING,
	};

	static int
	ab3100_regulator_of_probe(struct platform_device pdev, struct device_node np)
	{
	int err, i;

	/*
	* Set up the regulator registers, as was previously done with
	* platform data.
	*/
	/* Set up regulators */
	for (i = 0; i < ARRAY_SIZE(ab3100_reg_init_order); i++) {
	err = abx500_set_register_interruptible(&pdev->dev, 0,
	ab3100_reg_init_order[i],
	ab3100_reg_initvals[i]);
	if (err) {
	dev_err(&pdev->dev, "regulator initialization failed with error %d\n",
	err);
	return err;
	}
	}

	for (i = 0; i < ARRAY_SIZE(ab3100_regulator_matches); i++) {
	err = ab3100_regulator_register(
	pdev, NULL, ab3100_regulator_matches[i].init_data,
	ab3100_regulator_matches[i].of_node,
	(unsigned long)ab3100_regulator_matches[i].driver_data);
	if (err)
	return err;
	}

	return 0;
	}


	static int ab3100_regulators_probe(struct platform_device *pdev)
	{
	struct ab3100_platform_data *plfdata = dev_get_platdata(&pdev->dev);
	struct device_node *np = pdev->dev.of_node;
	int err = 0;
	u8 data;
	int i;

	/* Check chip state */
	err = abx500_get_register_interruptible(&pdev->dev, 0,
	AB3100_LDO_D, &data);
	if (err) {
	dev_err(&pdev->dev, "could not read initial status of LDO_D\n");
	return err;
	}
	if (data & 0x10)
	dev_notice(&pdev->dev,
	"chip is already in active mode (Warm start)\n");
	else
	dev_notice(&pdev->dev,
	"chip is in inactive mode (Cold start)\n");

	if (np) {
	err = of_regulator_match(&pdev->dev, np,
	ab3100_regulator_matches,
	ARRAY_SIZE(ab3100_regulator_matches));
	if (err < 0) {
	dev_err(&pdev->dev,
	"Error parsing regulator init data: %d\n", err);
	return err;
	}
	return ab3100_regulator_of_probe(pdev, np);
	}

	/* Set up regulators */
	for (i = 0; i < ARRAY_SIZE(ab3100_reg_init_order); i++) {
	err = abx500_set_register_interruptible(&pdev->dev, 0,
	ab3100_reg_init_order[i],
	plfdata->reg_initvals[i]);
	if (err) {
	dev_err(&pdev->dev, "regulator initialization failed with error %d\n",
	err);
	return err;
	}
	}

	/* Register the regulators */
	for (i = 0; i < AB3100_NUM_REGULATORS; i++) {
	const struct regulator_desc *desc = &ab3100_regulator_desc[i];

	err = ab3100_regulator_register(pdev, plfdata, NULL, NULL,
	desc->id);
	if (err)
	return err;
	}

	return 0;
	}

	static struct platform_driver ab3100_regulators_driver = {
	.driver = {
	.name = "ab3100-regulators",
	},
	.probe = ab3100_regulators_probe,
	};

	static __init int ab3100_regulators_init(void)
	{
	return platform_driver_register(&ab3100_regulators_driver);
	}

	static __exit void ab3100_regulators_exit(void)
	{
	platform_driver_unregister(&ab3100_regulators_driver);
	}

	subsys_initcall(ab3100_regulators_init);
	module_exit(ab3100_regulators_exit);

	MODULE_AUTHOR("Mattias Wallin <mattias.wallin@stericsson.com>");
	MODULE_DESCRIPTION("AB3100 Regulator driver");
	MODULE_LICENSE("GPL");
	MODULE_ALIAS("platform:ab3100-regulators");