drivers/regulator/ltc3589.c - linux - Git at Google

 /*
  * Linear Technology LTC3589,LTC3589-1 regulator support
  *
  * Copyright (c) 2014 Philipp Zabel <p.zabel@pengutronix.de>, Pengutronix
  *
  * See file CREDITS for list of people who contributed to this
  * project.
  *
  * 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.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  */
 #include <linux/i2c.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/of.h>
 #include <linux/regmap.h>
 #include <linux/regulator/driver.h>
 #include <linux/regulator/of_regulator.h>

 #define DRIVER_NAME		"ltc3589"

 #define LTC3589_IRQSTAT		0x02
 #define LTC3589_SCR1		0x07
 #define LTC3589_OVEN		0x10
 #define LTC3589_SCR2		0x12
 #define LTC3589_PGSTAT		0x13
 #define LTC3589_VCCR		0x20
 #define LTC3589_CLIRQ		0x21
 #define LTC3589_B1DTV1		0x23
 #define LTC3589_B1DTV2		0x24
 #define LTC3589_VRRCR		0x25
 #define LTC3589_B2DTV1		0x26
 #define LTC3589_B2DTV2		0x27
 #define LTC3589_B3DTV1		0x29
 #define LTC3589_B3DTV2		0x2a
 #define LTC3589_L2DTV1		0x32
 #define LTC3589_L2DTV2		0x33

 #define LTC3589_IRQSTAT_PGOOD_TIMEOUT	BIT(3)
 #define LTC3589_IRQSTAT_UNDERVOLT_WARN	BIT(4)
 #define LTC3589_IRQSTAT_UNDERVOLT_FAULT	BIT(5)
 #define LTC3589_IRQSTAT_THERMAL_WARN	BIT(6)
 #define LTC3589_IRQSTAT_THERMAL_FAULT	BIT(7)

 #define LTC3589_OVEN_SW1		BIT(0)
 #define LTC3589_OVEN_SW2		BIT(1)
 #define LTC3589_OVEN_SW3		BIT(2)
 #define LTC3589_OVEN_BB_OUT		BIT(3)
 #define LTC3589_OVEN_LDO2		BIT(4)
 #define LTC3589_OVEN_LDO3		BIT(5)
 #define LTC3589_OVEN_LDO4		BIT(6)
 #define LTC3589_OVEN_SW_CTRL		BIT(7)

 #define LTC3589_VCCR_SW1_GO		BIT(0)
 #define LTC3589_VCCR_SW2_GO		BIT(2)
 #define LTC3589_VCCR_SW3_GO		BIT(4)
 #define LTC3589_VCCR_LDO2_GO		BIT(6)

 enum ltc3589_variant {
 	LTC3589,
 	LTC3589_1,
 	LTC3589_2,
 };

 enum ltc3589_reg {
 	LTC3589_SW1,
 	LTC3589_SW2,
 	LTC3589_SW3,
 	LTC3589_BB_OUT,
 	LTC3589_LDO1,
 	LTC3589_LDO2,
 	LTC3589_LDO3,
 	LTC3589_LDO4,
 	LTC3589_NUM_REGULATORS,
 };

 struct ltc3589_regulator {
 	struct regulator_desc desc;

 	/* External feedback voltage divider */
 	unsigned int r1;
 	unsigned int r2;
 };

 struct ltc3589 {
 	struct regmap *regmap;
 	struct device *dev;
 	enum ltc3589_variant variant;
 	struct ltc3589_regulator regulator_descs[LTC3589_NUM_REGULATORS];
 	struct regulator_dev *regulators[LTC3589_NUM_REGULATORS];
 };

 static const int ltc3589_ldo4[] = {
 	2800000, 2500000, 1800000, 3300000,
 };

 static const int ltc3589_12_ldo4[] = {
 	1200000, 1800000, 2500000, 3200000,
 };

 static int ltc3589_set_ramp_delay(struct regulator_dev *rdev, int ramp_delay)
 {
 	struct ltc3589 *ltc3589 = rdev_get_drvdata(rdev);
 	int sel, shift;

 	if (unlikely(ramp_delay <= 0))
 		return -EINVAL;

 	/* VRRCR slew rate offsets are the same as VCCR go bit offsets */
 	shift = ffs(rdev->desc->apply_bit) - 1;

 	/* The slew rate can be set to 0.88, 1.75, 3.5, or 7 mV/uS */
 	for (sel = 0; sel < 4; sel++) {
 		if ((880 << sel) >= ramp_delay) {
 			return regmap_update_bits(ltc3589->regmap,
 						  LTC3589_VRRCR,
 						  0x3 << shift, sel << shift);
 		}
 	}
 	return -EINVAL;
 }

 static int ltc3589_set_suspend_voltage(struct regulator_dev *rdev, int uV)
 {
 	struct ltc3589 *ltc3589 = rdev_get_drvdata(rdev);
 	int sel;

 	sel = regulator_map_voltage_linear(rdev, uV, uV);
 	if (sel < 0)
 		return sel;

 	/* DTV2 register follows right after the corresponding DTV1 register */
 	return regmap_update_bits(ltc3589->regmap, rdev->desc->vsel_reg + 1,
 				  rdev->desc->vsel_mask, sel);
 }

 static int ltc3589_set_suspend_mode(struct regulator_dev *rdev,
 				    unsigned int mode)
 {
 	struct ltc3589 *ltc3589 = rdev_get_drvdata(rdev);
 	int mask, bit = 0;

 	/* VCCR reference selects are right next to the VCCR go bits */
 	mask = rdev->desc->apply_bit << 1;

 	if (mode == REGULATOR_MODE_STANDBY)
 		bit = mask;	/* Select DTV2 */

 	mask |= rdev->desc->apply_bit;
 	bit |= rdev->desc->apply_bit;
 	return regmap_update_bits(ltc3589->regmap, LTC3589_VCCR, mask, bit);
 }

 /* SW1, SW2, SW3, LDO2 */
 static struct regulator_ops ltc3589_linear_regulator_ops = {
 	.enable = regulator_enable_regmap,
 	.disable = regulator_disable_regmap,
 	.is_enabled = regulator_is_enabled_regmap,
 	.list_voltage = regulator_list_voltage_linear,
 	.set_voltage_sel = regulator_set_voltage_sel_regmap,
 	.get_voltage_sel = regulator_get_voltage_sel_regmap,
 	.set_ramp_delay = ltc3589_set_ramp_delay,
 	.set_voltage_time_sel = regulator_set_voltage_time_sel,
 	.set_suspend_voltage = ltc3589_set_suspend_voltage,
 	.set_suspend_mode = ltc3589_set_suspend_mode,
 };

 /* BB_OUT, LDO3 */
 static struct regulator_ops ltc3589_fixed_regulator_ops = {
 	.enable = regulator_enable_regmap,
 	.disable = regulator_disable_regmap,
 	.is_enabled = regulator_is_enabled_regmap,
 };

 /* LDO1 */
 static struct regulator_ops ltc3589_fixed_standby_regulator_ops = {
 };

 /* LDO4 */
 static struct regulator_ops ltc3589_table_regulator_ops = {
 	.enable = regulator_enable_regmap,
 	.disable = regulator_disable_regmap,
 	.is_enabled = regulator_is_enabled_regmap,
 	.list_voltage = regulator_list_voltage_table,
 	.set_voltage_sel = regulator_set_voltage_sel_regmap,
 	.get_voltage_sel = regulator_get_voltage_sel_regmap,
 };


 #define LTC3589_REG(_name, _ops, en_bit, dtv1_reg, dtv_mask, go_bit)	\
 	[LTC3589_ ## _name] = {						\
 		.desc = {						\
 			.name = #_name,					\
 			.n_voltages = (dtv_mask) + 1,			\
 			.min_uV = (go_bit) ? 362500 : 0,		\
 			.uV_step = (go_bit) ? 12500 : 0,		\
 			.ramp_delay = (go_bit) ? 1750 : 0,		\
 			.fixed_uV = (dtv_mask) ? 0 : 800000,		\
 			.ops = &ltc3589_ ## _ops ## _regulator_ops,	\
 			.type = REGULATOR_VOLTAGE,			\
 			.id = LTC3589_ ## _name,			\
 			.owner = THIS_MODULE,				\
 			.vsel_reg = (dtv1_reg),			\
 			.vsel_mask = (dtv_mask),			\
 			.apply_reg = (go_bit) ? LTC3589_VCCR : 0,	\
 			.apply_bit = (go_bit),				\
 			.enable_reg = (en_bit) ? LTC3589_OVEN : 0,	\
 			.enable_mask = (en_bit),			\
 		},							\
 	}

 #define LTC3589_LINEAR_REG(_name, _dtv1)				\
 	LTC3589_REG(_name, linear, LTC3589_OVEN_ ## _name,		\
 		    LTC3589_ ## _dtv1, 0x1f,				\
 		    LTC3589_VCCR_ ## _name ## _GO)

 #define LTC3589_FIXED_REG(_name) \
 	LTC3589_REG(_name, fixed, LTC3589_OVEN_ ## _name, 0, 0, 0)

 static struct ltc3589_regulator ltc3589_regulators[LTC3589_NUM_REGULATORS] = {
 	LTC3589_LINEAR_REG(SW1, B1DTV1),
 	LTC3589_LINEAR_REG(SW2, B2DTV1),
 	LTC3589_LINEAR_REG(SW3, B3DTV1),
 	LTC3589_FIXED_REG(BB_OUT),
 	LTC3589_REG(LDO1, fixed_standby, 0, 0, 0, 0),
 	LTC3589_LINEAR_REG(LDO2, L2DTV1),
 	LTC3589_FIXED_REG(LDO3),
 	LTC3589_REG(LDO4, table, LTC3589_OVEN_LDO4, LTC3589_L2DTV2, 0x60, 0),
 };

 #ifdef CONFIG_OF
 static struct of_regulator_match ltc3589_matches[LTC3589_NUM_REGULATORS] = {
 	{ .name = "sw1",    },
 	{ .name = "sw2",    },
 	{ .name = "sw3",    },
 	{ .name = "bb-out", },
 	{ .name = "ldo1",   }, /* standby */
 	{ .name = "ldo2",   },
 	{ .name = "ldo3",   },
 	{ .name = "ldo4",   },
 };

 static int ltc3589_parse_regulators_dt(struct ltc3589 *ltc3589)
 {
 	struct device *dev = ltc3589->dev;
 	struct device_node *node;
 	int i, ret;

 	node = of_find_node_by_name(dev->of_node, "regulators");
 	if (!node) {
 		dev_err(dev, "regulators node not found\n");
 		return -EINVAL;
 	}

 	ret = of_regulator_match(dev, node, ltc3589_matches,
 				 ARRAY_SIZE(ltc3589_matches));
 	of_node_put(node);
 	if (ret < 0) {
 		dev_err(dev, "Error parsing regulator init data: %d\n", ret);
 		return ret;
 	}
 	if (ret != LTC3589_NUM_REGULATORS) {
 		dev_err(dev, "Only %d regulators described in device tree\n",
 			ret);
 		return -EINVAL;
 	}

 	/* Parse feedback voltage dividers. LDO3 and LDO4 don't have them */
 	for (i = 0; i < LTC3589_LDO3; i++) {
 		struct ltc3589_regulator *desc = &ltc3589->regulator_descs[i];
 		struct device_node *np = ltc3589_matches[i].of_node;
 		u32 vdiv[2];

 		ret = of_property_read_u32_array(np, "lltc,fb-voltage-divider",
 						 vdiv, 2);
 		if (ret) {
 			dev_err(dev, "Failed to parse voltage divider: %d\n",
 				ret);
 			return ret;
 		}

 		desc->r1 = vdiv[0];
 		desc->r2 = vdiv[1];
 	}

 	return 0;
 }

 static inline struct regulator_init_data *match_init_data(int index)
 {
 	return ltc3589_matches[index].init_data;
 }

 static inline struct device_node *match_of_node(int index)
 {
 	return ltc3589_matches[index].of_node;
 }
 #else
 static inline int ltc3589_parse_regulators_dt(struct ltc3589 *ltc3589)
 {
 	return 0;
 }

 static inline struct regulator_init_data *match_init_data(int index)
 {
 	return NULL;
 }

 static inline struct device_node *match_of_node(int index)
 {
 	return NULL;
 }
 #endif

 static bool ltc3589_writeable_reg(struct device *dev, unsigned int reg)
 {
 	switch (reg) {
 	case LTC3589_IRQSTAT:
 	case LTC3589_SCR1:
 	case LTC3589_OVEN:
 	case LTC3589_SCR2:
 	case LTC3589_VCCR:
 	case LTC3589_CLIRQ:
 	case LTC3589_B1DTV1:
 	case LTC3589_B1DTV2:
 	case LTC3589_VRRCR:
 	case LTC3589_B2DTV1:
 	case LTC3589_B2DTV2:
 	case LTC3589_B3DTV1:
 	case LTC3589_B3DTV2:
 	case LTC3589_L2DTV1:
 	case LTC3589_L2DTV2:
 		return true;
 	}
 	return false;
 }

 static bool ltc3589_readable_reg(struct device *dev, unsigned int reg)
 {
 	switch (reg) {
 	case LTC3589_IRQSTAT:
 	case LTC3589_SCR1:
 	case LTC3589_OVEN:
 	case LTC3589_SCR2:
 	case LTC3589_PGSTAT:
 	case LTC3589_VCCR:
 	case LTC3589_B1DTV1:
 	case LTC3589_B1DTV2:
 	case LTC3589_VRRCR:
 	case LTC3589_B2DTV1:
 	case LTC3589_B2DTV2:
 	case LTC3589_B3DTV1:
 	case LTC3589_B3DTV2:
 	case LTC3589_L2DTV1:
 	case LTC3589_L2DTV2:
 		return true;
 	}
 	return false;
 }

 static bool ltc3589_volatile_reg(struct device *dev, unsigned int reg)
 {
 	switch (reg) {
 	case LTC3589_IRQSTAT:
 	case LTC3589_PGSTAT:
 		return true;
 	}
 	return false;
 }

 static struct reg_default ltc3589_reg_defaults[] = {
 	{ LTC3589_SCR1,   0x00 },
 	{ LTC3589_OVEN,   0x00 },
 	{ LTC3589_SCR2,   0x00 },
 	{ LTC3589_VCCR,   0x00 },
 	{ LTC3589_B1DTV1, 0x19 },
 	{ LTC3589_B1DTV2, 0x19 },
 	{ LTC3589_VRRCR,  0xff },
 	{ LTC3589_B2DTV1, 0x19 },
 	{ LTC3589_B2DTV2, 0x19 },
 	{ LTC3589_B3DTV1, 0x19 },
 	{ LTC3589_B3DTV2, 0x19 },
 	{ LTC3589_L2DTV1, 0x19 },
 	{ LTC3589_L2DTV2, 0x19 },
 };

 static const struct regmap_config ltc3589_regmap_config = {
 	.reg_bits = 8,
 	.val_bits = 8,
 	.writeable_reg = ltc3589_writeable_reg,
 	.readable_reg = ltc3589_readable_reg,
 	.volatile_reg = ltc3589_volatile_reg,
 	.max_register = LTC3589_L2DTV2,
 	.reg_defaults = ltc3589_reg_defaults,
 	.num_reg_defaults = ARRAY_SIZE(ltc3589_reg_defaults),
 	.use_single_rw = true,
 	.cache_type = REGCACHE_RBTREE,
 };


 static irqreturn_t ltc3589_isr(int irq, void *dev_id)
 {
 	struct ltc3589 *ltc3589 = dev_id;
 	unsigned int i, irqstat, event;

 	regmap_read(ltc3589->regmap, LTC3589_IRQSTAT, &irqstat);

 	if (irqstat & LTC3589_IRQSTAT_THERMAL_WARN) {
 		event = REGULATOR_EVENT_OVER_TEMP;
 		for (i = 0; i < LTC3589_NUM_REGULATORS; i++)
 			regulator_notifier_call_chain(ltc3589->regulators[i],
 						      event, NULL);
 	}

 	if (irqstat & LTC3589_IRQSTAT_UNDERVOLT_WARN) {
 		event = REGULATOR_EVENT_UNDER_VOLTAGE;
 		for (i = 0; i < LTC3589_NUM_REGULATORS; i++)
 			regulator_notifier_call_chain(ltc3589->regulators[i],
 						      event, NULL);
 	}

 	/* Clear warning condition */
 	regmap_write(ltc3589->regmap, LTC3589_CLIRQ, 0);

 	return IRQ_HANDLED;
 }

 static inline unsigned int ltc3589_scale(unsigned int uV, u32 r1, u32 r2)
 {
 	uint64_t tmp;
 	if (uV == 0)
 		return 0;
 	tmp = (uint64_t)uV * r1;
 	do_div(tmp, r2);
 	return uV + (unsigned int)tmp;
 }

 static void ltc3589_apply_fb_voltage_divider(struct ltc3589_regulator *rdesc)
 {
 	struct regulator_desc *desc = &rdesc->desc;

 	if (!rdesc->r1 || !rdesc->r2)
 		return;

 	desc->min_uV = ltc3589_scale(desc->min_uV, rdesc->r1, rdesc->r2);
 	desc->uV_step = ltc3589_scale(desc->uV_step, rdesc->r1, rdesc->r2);
 	desc->fixed_uV = ltc3589_scale(desc->fixed_uV, rdesc->r1, rdesc->r2);
 }

 static int ltc3589_probe(struct i2c_client *client,
 			 const struct i2c_device_id *id)
 {
 	struct device *dev = &client->dev;
 	struct ltc3589_regulator *descs;
 	struct ltc3589 *ltc3589;
 	int i, ret;

 	ltc3589 = devm_kzalloc(dev, sizeof(*ltc3589), GFP_KERNEL);
 	if (!ltc3589)
 		return -ENOMEM;

 	i2c_set_clientdata(client, ltc3589);
 	ltc3589->variant = id->driver_data;
 	ltc3589->dev = dev;

 	descs = ltc3589->regulator_descs;
 	memcpy(descs, ltc3589_regulators, sizeof(ltc3589_regulators));
 	if (ltc3589->variant == LTC3589) {
 		descs[LTC3589_LDO3].desc.fixed_uV = 1800000;
 		descs[LTC3589_LDO4].desc.volt_table = ltc3589_ldo4;
 	} else {
 		descs[LTC3589_LDO3].desc.fixed_uV = 2800000;
 		descs[LTC3589_LDO4].desc.volt_table = ltc3589_12_ldo4;
 	}

 	ltc3589->regmap = devm_regmap_init_i2c(client, &ltc3589_regmap_config);
 	if (IS_ERR(ltc3589->regmap)) {
 		ret = PTR_ERR(ltc3589->regmap);
 		dev_err(dev, "failed to initialize regmap: %d\n", ret);
 		return ret;
 	}

 	ret = ltc3589_parse_regulators_dt(ltc3589);
 	if (ret)
 		return ret;

 	for (i = 0; i < LTC3589_NUM_REGULATORS; i++) {
 		struct ltc3589_regulator *rdesc = &ltc3589->regulator_descs[i];
 		struct regulator_desc *desc = &rdesc->desc;
 		struct regulator_init_data *init_data;
 		struct regulator_config config = { };

 		init_data = match_init_data(i);

 		if (i < LTC3589_LDO3)
 			ltc3589_apply_fb_voltage_divider(rdesc);

 		config.dev = dev;
 		config.init_data = init_data;
 		config.driver_data = ltc3589;
 		config.of_node = match_of_node(i);

 		ltc3589->regulators[i] = devm_regulator_register(dev, desc,
 								 &config);
 		if (IS_ERR(ltc3589->regulators[i])) {
 			ret = PTR_ERR(ltc3589->regulators[i]);
 			dev_err(dev, "failed to register regulator %s: %d\n",
 				desc->name, ret);
 			return ret;
 		}
 	}

 	ret = devm_request_threaded_irq(dev, client->irq, NULL, ltc3589_isr,
 					IRQF_TRIGGER_LOW | IRQF_ONESHOT,
 					client->name, ltc3589);
 	if (ret) {
 		dev_err(dev, "Failed to request IRQ: %d\n", ret);
 		return ret;
 	}

 	return 0;
 }

 static struct i2c_device_id ltc3589_i2c_id[] = {
 	{ "ltc3589",   LTC3589   },
 	{ "ltc3589-1", LTC3589_1 },
 	{ "ltc3589-2", LTC3589_2 },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, ltc3589_i2c_id);

 static struct i2c_driver ltc3589_driver = {
 	.driver = {
 		.name = DRIVER_NAME,
 		.owner = THIS_MODULE,
 	},
 	.probe = ltc3589_probe,
 	.id_table = ltc3589_i2c_id,
 };
 module_i2c_driver(ltc3589_driver);

 MODULE_AUTHOR("Philipp Zabel <p.zabel@pengutronix.de>");
 MODULE_DESCRIPTION("Regulator driver for Linear Technology LTC3589(-1,2)");
 MODULE_LICENSE("GPL v2");
 MODULE_ALIAS("i2c:ltc3589");
	/*
	* Linear Technology LTC3589,LTC3589-1 regulator support
	*
	* Copyright (c) 2014 Philipp Zabel <p.zabel@pengutronix.de>, Pengutronix
	*
	* See file CREDITS for list of people who contributed to this
	* project.
	*
	* 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.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	*/
	#include <linux/i2c.h>
	#include <linux/init.h>
	#include <linux/interrupt.h>
	#include <linux/module.h>
	#include <linux/kernel.h>
	#include <linux/of.h>
	#include <linux/regmap.h>
	#include <linux/regulator/driver.h>
	#include <linux/regulator/of_regulator.h>

	#define DRIVER_NAME "ltc3589"

	#define LTC3589_IRQSTAT 0x02
	#define LTC3589_SCR1 0x07
	#define LTC3589_OVEN 0x10
	#define LTC3589_SCR2 0x12
	#define LTC3589_PGSTAT 0x13
	#define LTC3589_VCCR 0x20
	#define LTC3589_CLIRQ 0x21
	#define LTC3589_B1DTV1 0x23
	#define LTC3589_B1DTV2 0x24
	#define LTC3589_VRRCR 0x25
	#define LTC3589_B2DTV1 0x26
	#define LTC3589_B2DTV2 0x27
	#define LTC3589_B3DTV1 0x29
	#define LTC3589_B3DTV2 0x2a
	#define LTC3589_L2DTV1 0x32
	#define LTC3589_L2DTV2 0x33

	#define LTC3589_IRQSTAT_PGOOD_TIMEOUT BIT(3)
	#define LTC3589_IRQSTAT_UNDERVOLT_WARN BIT(4)
	#define LTC3589_IRQSTAT_UNDERVOLT_FAULT BIT(5)
	#define LTC3589_IRQSTAT_THERMAL_WARN BIT(6)
	#define LTC3589_IRQSTAT_THERMAL_FAULT BIT(7)

	#define LTC3589_OVEN_SW1 BIT(0)
	#define LTC3589_OVEN_SW2 BIT(1)
	#define LTC3589_OVEN_SW3 BIT(2)
	#define LTC3589_OVEN_BB_OUT BIT(3)
	#define LTC3589_OVEN_LDO2 BIT(4)
	#define LTC3589_OVEN_LDO3 BIT(5)
	#define LTC3589_OVEN_LDO4 BIT(6)
	#define LTC3589_OVEN_SW_CTRL BIT(7)

	#define LTC3589_VCCR_SW1_GO BIT(0)
	#define LTC3589_VCCR_SW2_GO BIT(2)
	#define LTC3589_VCCR_SW3_GO BIT(4)
	#define LTC3589_VCCR_LDO2_GO BIT(6)

	enum ltc3589_variant {
	LTC3589,
	LTC3589_1,
	LTC3589_2,
	};

	enum ltc3589_reg {
	LTC3589_SW1,
	LTC3589_SW2,
	LTC3589_SW3,
	LTC3589_BB_OUT,
	LTC3589_LDO1,
	LTC3589_LDO2,
	LTC3589_LDO3,
	LTC3589_LDO4,
	LTC3589_NUM_REGULATORS,
	};

	struct ltc3589_regulator {
	struct regulator_desc desc;

	/* External feedback voltage divider */
	unsigned int r1;
	unsigned int r2;
	};

	struct ltc3589 {
	struct regmap *regmap;
	struct device *dev;
	enum ltc3589_variant variant;
	struct ltc3589_regulator regulator_descs[LTC3589_NUM_REGULATORS];
	struct regulator_dev *regulators[LTC3589_NUM_REGULATORS];
	};

	static const int ltc3589_ldo4[] = {
	2800000, 2500000, 1800000, 3300000,
	};

	static const int ltc3589_12_ldo4[] = {
	1200000, 1800000, 2500000, 3200000,
	};

	static int ltc3589_set_ramp_delay(struct regulator_dev *rdev, int ramp_delay)
	{
	struct ltc3589 *ltc3589 = rdev_get_drvdata(rdev);
	int sel, shift;

	if (unlikely(ramp_delay <= 0))
	return -EINVAL;

	/* VRRCR slew rate offsets are the same as VCCR go bit offsets */
	shift = ffs(rdev->desc->apply_bit) - 1;

	/* The slew rate can be set to 0.88, 1.75, 3.5, or 7 mV/uS */
	for (sel = 0; sel < 4; sel++) {
	if ((880 << sel) >= ramp_delay) {
	return regmap_update_bits(ltc3589->regmap,
	LTC3589_VRRCR,
	0x3 << shift, sel << shift);
	}
	}
	return -EINVAL;
	}

	static int ltc3589_set_suspend_voltage(struct regulator_dev *rdev, int uV)
	{
	struct ltc3589 *ltc3589 = rdev_get_drvdata(rdev);
	int sel;

	sel = regulator_map_voltage_linear(rdev, uV, uV);
	if (sel < 0)
	return sel;

	/* DTV2 register follows right after the corresponding DTV1 register */
	return regmap_update_bits(ltc3589->regmap, rdev->desc->vsel_reg + 1,
	rdev->desc->vsel_mask, sel);
	}

	static int ltc3589_set_suspend_mode(struct regulator_dev *rdev,
	unsigned int mode)
	{
	struct ltc3589 *ltc3589 = rdev_get_drvdata(rdev);
	int mask, bit = 0;

	/* VCCR reference selects are right next to the VCCR go bits */
	mask = rdev->desc->apply_bit << 1;

	if (mode == REGULATOR_MODE_STANDBY)
	bit = mask; /* Select DTV2 */

	mask \|= rdev->desc->apply_bit;
	bit \|= rdev->desc->apply_bit;
	return regmap_update_bits(ltc3589->regmap, LTC3589_VCCR, mask, bit);
	}

	/* SW1, SW2, SW3, LDO2 */
	static struct regulator_ops ltc3589_linear_regulator_ops = {
	.enable = regulator_enable_regmap,
	.disable = regulator_disable_regmap,
	.is_enabled = regulator_is_enabled_regmap,
	.list_voltage = regulator_list_voltage_linear,
	.set_voltage_sel = regulator_set_voltage_sel_regmap,
	.get_voltage_sel = regulator_get_voltage_sel_regmap,
	.set_ramp_delay = ltc3589_set_ramp_delay,
	.set_voltage_time_sel = regulator_set_voltage_time_sel,
	.set_suspend_voltage = ltc3589_set_suspend_voltage,
	.set_suspend_mode = ltc3589_set_suspend_mode,
	};

	/* BB_OUT, LDO3 */
	static struct regulator_ops ltc3589_fixed_regulator_ops = {
	.enable = regulator_enable_regmap,
	.disable = regulator_disable_regmap,
	.is_enabled = regulator_is_enabled_regmap,
	};

	/* LDO1 */
	static struct regulator_ops ltc3589_fixed_standby_regulator_ops = {
	};

	/* LDO4 */
	static struct regulator_ops ltc3589_table_regulator_ops = {
	.enable = regulator_enable_regmap,
	.disable = regulator_disable_regmap,
	.is_enabled = regulator_is_enabled_regmap,
	.list_voltage = regulator_list_voltage_table,
	.set_voltage_sel = regulator_set_voltage_sel_regmap,
	.get_voltage_sel = regulator_get_voltage_sel_regmap,
	};


	#define LTC3589_REG(_name, _ops, en_bit, dtv1_reg, dtv_mask, go_bit) \
	[LTC3589_ ## _name] = { \
	.desc = { \
	.name = #_name, \
	.n_voltages = (dtv_mask) + 1, \
	.min_uV = (go_bit) ? 362500 : 0, \
	.uV_step = (go_bit) ? 12500 : 0, \
	.ramp_delay = (go_bit) ? 1750 : 0, \
	.fixed_uV = (dtv_mask) ? 0 : 800000, \
	.ops = &ltc3589_ ## _ops ## _regulator_ops, \
	.type = REGULATOR_VOLTAGE, \
	.id = LTC3589_ ## _name, \
	.owner = THIS_MODULE, \
	.vsel_reg = (dtv1_reg), \
	.vsel_mask = (dtv_mask), \
	.apply_reg = (go_bit) ? LTC3589_VCCR : 0, \
	.apply_bit = (go_bit), \
	.enable_reg = (en_bit) ? LTC3589_OVEN : 0, \
	.enable_mask = (en_bit), \
	}, \
	}

	#define LTC3589_LINEAR_REG(_name, _dtv1) \
	LTC3589_REG(_name, linear, LTC3589_OVEN_ ## _name, \
	LTC3589_ ## _dtv1, 0x1f, \
	LTC3589_VCCR_ ## _name ## _GO)

	#define LTC3589_FIXED_REG(_name) \
	LTC3589_REG(_name, fixed, LTC3589_OVEN_ ## _name, 0, 0, 0)

	static struct ltc3589_regulator ltc3589_regulators[LTC3589_NUM_REGULATORS] = {
	LTC3589_LINEAR_REG(SW1, B1DTV1),
	LTC3589_LINEAR_REG(SW2, B2DTV1),
	LTC3589_LINEAR_REG(SW3, B3DTV1),
	LTC3589_FIXED_REG(BB_OUT),
	LTC3589_REG(LDO1, fixed_standby, 0, 0, 0, 0),
	LTC3589_LINEAR_REG(LDO2, L2DTV1),
	LTC3589_FIXED_REG(LDO3),
	LTC3589_REG(LDO4, table, LTC3589_OVEN_LDO4, LTC3589_L2DTV2, 0x60, 0),
	};

	#ifdef CONFIG_OF
	static struct of_regulator_match ltc3589_matches[LTC3589_NUM_REGULATORS] = {
	{ .name = "sw1", },
	{ .name = "sw2", },
	{ .name = "sw3", },
	{ .name = "bb-out", },
	{ .name = "ldo1", }, /* standby */
	{ .name = "ldo2", },
	{ .name = "ldo3", },
	{ .name = "ldo4", },
	};

	static int ltc3589_parse_regulators_dt(struct ltc3589 *ltc3589)
	{
	struct device *dev = ltc3589->dev;
	struct device_node *node;
	int i, ret;

	node = of_find_node_by_name(dev->of_node, "regulators");
	if (!node) {
	dev_err(dev, "regulators node not found\n");
	return -EINVAL;
	}

	ret = of_regulator_match(dev, node, ltc3589_matches,
	ARRAY_SIZE(ltc3589_matches));
	of_node_put(node);
	if (ret < 0) {
	dev_err(dev, "Error parsing regulator init data: %d\n", ret);
	return ret;
	}
	if (ret != LTC3589_NUM_REGULATORS) {
	dev_err(dev, "Only %d regulators described in device tree\n",
	ret);
	return -EINVAL;
	}

	/* Parse feedback voltage dividers. LDO3 and LDO4 don't have them */
	for (i = 0; i < LTC3589_LDO3; i++) {
	struct ltc3589_regulator *desc = &ltc3589->regulator_descs[i];
	struct device_node *np = ltc3589_matches[i].of_node;
	u32 vdiv[2];

	ret = of_property_read_u32_array(np, "lltc,fb-voltage-divider",
	vdiv, 2);
	if (ret) {
	dev_err(dev, "Failed to parse voltage divider: %d\n",
	ret);
	return ret;
	}

	desc->r1 = vdiv[0];
	desc->r2 = vdiv[1];
	}

	return 0;
	}

	static inline struct regulator_init_data *match_init_data(int index)
	{
	return ltc3589_matches[index].init_data;
	}

	static inline struct device_node *match_of_node(int index)
	{
	return ltc3589_matches[index].of_node;
	}
	#else
	static inline int ltc3589_parse_regulators_dt(struct ltc3589 *ltc3589)
	{
	return 0;
	}

	static inline struct regulator_init_data *match_init_data(int index)
	{
	return NULL;
	}

	static inline struct device_node *match_of_node(int index)
	{
	return NULL;
	}
	#endif

	static bool ltc3589_writeable_reg(struct device *dev, unsigned int reg)
	{
	switch (reg) {
	case LTC3589_IRQSTAT:
	case LTC3589_SCR1:
	case LTC3589_OVEN:
	case LTC3589_SCR2:
	case LTC3589_VCCR:
	case LTC3589_CLIRQ:
	case LTC3589_B1DTV1:
	case LTC3589_B1DTV2:
	case LTC3589_VRRCR:
	case LTC3589_B2DTV1:
	case LTC3589_B2DTV2:
	case LTC3589_B3DTV1:
	case LTC3589_B3DTV2:
	case LTC3589_L2DTV1:
	case LTC3589_L2DTV2:
	return true;
	}
	return false;
	}

	static bool ltc3589_readable_reg(struct device *dev, unsigned int reg)
	{
	switch (reg) {
	case LTC3589_IRQSTAT:
	case LTC3589_SCR1:
	case LTC3589_OVEN:
	case LTC3589_SCR2:
	case LTC3589_PGSTAT:
	case LTC3589_VCCR:
	case LTC3589_B1DTV1:
	case LTC3589_B1DTV2:
	case LTC3589_VRRCR:
	case LTC3589_B2DTV1:
	case LTC3589_B2DTV2:
	case LTC3589_B3DTV1:
	case LTC3589_B3DTV2:
	case LTC3589_L2DTV1:
	case LTC3589_L2DTV2:
	return true;
	}
	return false;
	}

	static bool ltc3589_volatile_reg(struct device *dev, unsigned int reg)
	{
	switch (reg) {
	case LTC3589_IRQSTAT:
	case LTC3589_PGSTAT:
	return true;
	}
	return false;
	}

	static struct reg_default ltc3589_reg_defaults[] = {
	{ LTC3589_SCR1, 0x00 },
	{ LTC3589_OVEN, 0x00 },
	{ LTC3589_SCR2, 0x00 },
	{ LTC3589_VCCR, 0x00 },
	{ LTC3589_B1DTV1, 0x19 },
	{ LTC3589_B1DTV2, 0x19 },
	{ LTC3589_VRRCR, 0xff },
	{ LTC3589_B2DTV1, 0x19 },
	{ LTC3589_B2DTV2, 0x19 },
	{ LTC3589_B3DTV1, 0x19 },
	{ LTC3589_B3DTV2, 0x19 },
	{ LTC3589_L2DTV1, 0x19 },
	{ LTC3589_L2DTV2, 0x19 },
	};

	static const struct regmap_config ltc3589_regmap_config = {
	.reg_bits = 8,
	.val_bits = 8,
	.writeable_reg = ltc3589_writeable_reg,
	.readable_reg = ltc3589_readable_reg,
	.volatile_reg = ltc3589_volatile_reg,
	.max_register = LTC3589_L2DTV2,
	.reg_defaults = ltc3589_reg_defaults,
	.num_reg_defaults = ARRAY_SIZE(ltc3589_reg_defaults),
	.use_single_rw = true,
	.cache_type = REGCACHE_RBTREE,
	};


	static irqreturn_t ltc3589_isr(int irq, void *dev_id)
	{
	struct ltc3589 *ltc3589 = dev_id;
	unsigned int i, irqstat, event;

	regmap_read(ltc3589->regmap, LTC3589_IRQSTAT, &irqstat);

	if (irqstat & LTC3589_IRQSTAT_THERMAL_WARN) {
	event = REGULATOR_EVENT_OVER_TEMP;
	for (i = 0; i < LTC3589_NUM_REGULATORS; i++)
	regulator_notifier_call_chain(ltc3589->regulators[i],
	event, NULL);
	}

	if (irqstat & LTC3589_IRQSTAT_UNDERVOLT_WARN) {
	event = REGULATOR_EVENT_UNDER_VOLTAGE;
	for (i = 0; i < LTC3589_NUM_REGULATORS; i++)
	regulator_notifier_call_chain(ltc3589->regulators[i],
	event, NULL);
	}

	/* Clear warning condition */
	regmap_write(ltc3589->regmap, LTC3589_CLIRQ, 0);

	return IRQ_HANDLED;
	}

	static inline unsigned int ltc3589_scale(unsigned int uV, u32 r1, u32 r2)
	{
	uint64_t tmp;
	if (uV == 0)
	return 0;
	tmp = (uint64_t)uV * r1;
	do_div(tmp, r2);
	return uV + (unsigned int)tmp;
	}

	static void ltc3589_apply_fb_voltage_divider(struct ltc3589_regulator *rdesc)
	{
	struct regulator_desc *desc = &rdesc->desc;

	if (!rdesc->r1 \|\| !rdesc->r2)
	return;

	desc->min_uV = ltc3589_scale(desc->min_uV, rdesc->r1, rdesc->r2);
	desc->uV_step = ltc3589_scale(desc->uV_step, rdesc->r1, rdesc->r2);
	desc->fixed_uV = ltc3589_scale(desc->fixed_uV, rdesc->r1, rdesc->r2);
	}

	static int ltc3589_probe(struct i2c_client *client,
	const struct i2c_device_id *id)
	{
	struct device *dev = &client->dev;
	struct ltc3589_regulator *descs;
	struct ltc3589 *ltc3589;
	int i, ret;

	ltc3589 = devm_kzalloc(dev, sizeof(*ltc3589), GFP_KERNEL);
	if (!ltc3589)
	return -ENOMEM;

	i2c_set_clientdata(client, ltc3589);
	ltc3589->variant = id->driver_data;
	ltc3589->dev = dev;

	descs = ltc3589->regulator_descs;
	memcpy(descs, ltc3589_regulators, sizeof(ltc3589_regulators));
	if (ltc3589->variant == LTC3589) {
	descs[LTC3589_LDO3].desc.fixed_uV = 1800000;
	descs[LTC3589_LDO4].desc.volt_table = ltc3589_ldo4;
	} else {
	descs[LTC3589_LDO3].desc.fixed_uV = 2800000;
	descs[LTC3589_LDO4].desc.volt_table = ltc3589_12_ldo4;
	}

	ltc3589->regmap = devm_regmap_init_i2c(client, &ltc3589_regmap_config);
	if (IS_ERR(ltc3589->regmap)) {
	ret = PTR_ERR(ltc3589->regmap);
	dev_err(dev, "failed to initialize regmap: %d\n", ret);
	return ret;
	}

	ret = ltc3589_parse_regulators_dt(ltc3589);
	if (ret)
	return ret;

	for (i = 0; i < LTC3589_NUM_REGULATORS; i++) {
	struct ltc3589_regulator *rdesc = &ltc3589->regulator_descs[i];
	struct regulator_desc *desc = &rdesc->desc;
	struct regulator_init_data *init_data;
	struct regulator_config config = { };

	init_data = match_init_data(i);

	if (i < LTC3589_LDO3)
	ltc3589_apply_fb_voltage_divider(rdesc);

	config.dev = dev;
	config.init_data = init_data;
	config.driver_data = ltc3589;
	config.of_node = match_of_node(i);

	ltc3589->regulators[i] = devm_regulator_register(dev, desc,
	&config);
	if (IS_ERR(ltc3589->regulators[i])) {
	ret = PTR_ERR(ltc3589->regulators[i]);
	dev_err(dev, "failed to register regulator %s: %d\n",
	desc->name, ret);
	return ret;
	}
	}

	ret = devm_request_threaded_irq(dev, client->irq, NULL, ltc3589_isr,
	IRQF_TRIGGER_LOW \| IRQF_ONESHOT,
	client->name, ltc3589);
	if (ret) {
	dev_err(dev, "Failed to request IRQ: %d\n", ret);
	return ret;
	}

	return 0;
	}

	static struct i2c_device_id ltc3589_i2c_id[] = {
	{ "ltc3589", LTC3589 },
	{ "ltc3589-1", LTC3589_1 },
	{ "ltc3589-2", LTC3589_2 },
	{ }
	};
	MODULE_DEVICE_TABLE(i2c, ltc3589_i2c_id);

	static struct i2c_driver ltc3589_driver = {
	.driver = {
	.name = DRIVER_NAME,
	.owner = THIS_MODULE,
	},
	.probe = ltc3589_probe,
	.id_table = ltc3589_i2c_id,
	};
	module_i2c_driver(ltc3589_driver);

	MODULE_AUTHOR("Philipp Zabel <p.zabel@pengutronix.de>");
	MODULE_DESCRIPTION("Regulator driver for Linear Technology LTC3589(-1,2)");
	MODULE_LICENSE("GPL v2");
	MODULE_ALIAS("i2c:ltc3589");