[deliverable/linux.git] / drivers / regulator / pwm-regulator.c

/*
 * Regulator driver for PWM Regulators
 *
 * Copyright (C) 2014 - STMicroelectronics Inc.
 *
 * Author: Lee Jones <lee.jones@linaro.org>
 *
 * 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/delay.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/machine.h>
#include <linux/regulator/of_regulator.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/pwm.h>

struct pwm_regulator_data {
	/*  Shared */
	struct pwm_device *pwm;

	/* Voltage table */
	struct pwm_voltages *duty_cycle_table;

	/* regulator descriptor */
	struct regulator_desc desc;

	/* Regulator ops */
	struct regulator_ops ops;

	int state;

	/* Continuous voltage */
	int volt_uV;
};

struct pwm_voltages {
	unsigned int uV;
	unsigned int dutycycle;
};

/**
 * Voltage table call-backs
 */
static int pwm_regulator_get_voltage_sel(struct regulator_dev *rdev)
{
	struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev);

	return drvdata->state;
}

static int pwm_regulator_set_voltage_sel(struct regulator_dev *rdev,
					 unsigned selector)
{
	struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev);
	unsigned int pwm_reg_period;
	int dutycycle;
	int ret;

	pwm_reg_period = pwm_get_period(drvdata->pwm);

	dutycycle = (pwm_reg_period *
		    drvdata->duty_cycle_table[selector].dutycycle) / 100;

	ret = pwm_config(drvdata->pwm, dutycycle, pwm_reg_period);
	if (ret) {
		dev_err(&rdev->dev, "Failed to configure PWM\n");
		return ret;
	}

	drvdata->state = selector;

	return 0;
}

static int pwm_regulator_list_voltage(struct regulator_dev *rdev,
				      unsigned selector)
{
	struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev);

	if (selector >= rdev->desc->n_voltages)
		return -EINVAL;

	return drvdata->duty_cycle_table[selector].uV;
}

static int pwm_regulator_enable(struct regulator_dev *dev)
{
	struct pwm_regulator_data *drvdata = rdev_get_drvdata(dev);

	return pwm_enable(drvdata->pwm);
}

static int pwm_regulator_disable(struct regulator_dev *dev)
{
	struct pwm_regulator_data *drvdata = rdev_get_drvdata(dev);

	pwm_disable(drvdata->pwm);

	return 0;
}

static int pwm_regulator_is_enabled(struct regulator_dev *dev)
{
	struct pwm_regulator_data *drvdata = rdev_get_drvdata(dev);

	return pwm_is_enabled(drvdata->pwm);
}

/**
 * Continuous voltage call-backs
 */
static int pwm_voltage_to_duty_cycle_percentage(struct regulator_dev *rdev, int req_uV)
{
	int min_uV = rdev->constraints->min_uV;
	int max_uV = rdev->constraints->max_uV;
	int diff = max_uV - min_uV;

	return ((req_uV * 100) - (min_uV * 100)) / diff;
}

static int pwm_regulator_get_voltage(struct regulator_dev *rdev)
{
	struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev);

	return drvdata->volt_uV;
}

static int pwm_regulator_set_voltage(struct regulator_dev *rdev,
					int min_uV, int max_uV,
					unsigned *selector)
{
	struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev);
	unsigned int ramp_delay = rdev->constraints->ramp_delay;
	unsigned int period = pwm_get_period(drvdata->pwm);
	int duty_cycle;
	int ret;

	duty_cycle = pwm_voltage_to_duty_cycle_percentage(rdev, min_uV);

	ret = pwm_config(drvdata->pwm, (period / 100) * duty_cycle, period);
	if (ret) {
		dev_err(&rdev->dev, "Failed to configure PWM\n");
		return ret;
	}

	ret = pwm_enable(drvdata->pwm);
	if (ret) {
		dev_err(&rdev->dev, "Failed to enable PWM\n");
		return ret;
	}
	drvdata->volt_uV = min_uV;

	/* Delay required by PWM regulator to settle to the new voltage */
	usleep_range(ramp_delay, ramp_delay + 1000);

	return 0;
}

static struct regulator_ops pwm_regulator_voltage_table_ops = {
	.set_voltage_sel = pwm_regulator_set_voltage_sel,
	.get_voltage_sel = pwm_regulator_get_voltage_sel,
	.list_voltage    = pwm_regulator_list_voltage,
	.map_voltage     = regulator_map_voltage_iterate,
	.enable          = pwm_regulator_enable,
	.disable         = pwm_regulator_disable,
	.is_enabled      = pwm_regulator_is_enabled,
};

static struct regulator_ops pwm_regulator_voltage_continuous_ops = {
	.get_voltage = pwm_regulator_get_voltage,
	.set_voltage = pwm_regulator_set_voltage,
	.enable          = pwm_regulator_enable,
	.disable         = pwm_regulator_disable,
	.is_enabled      = pwm_regulator_is_enabled,
};

static struct regulator_desc pwm_regulator_desc = {
	.name		= "pwm-regulator",
	.type		= REGULATOR_VOLTAGE,
	.owner		= THIS_MODULE,
	.supply_name    = "pwm",
};

static int pwm_regulator_init_table(struct platform_device *pdev,
				    struct pwm_regulator_data *drvdata)
{
	struct device_node *np = pdev->dev.of_node;
	struct pwm_voltages *duty_cycle_table;
	unsigned int length = 0;
	int ret;

	of_find_property(np, "voltage-table", &length);

	if ((length < sizeof(*duty_cycle_table)) ||
	    (length % sizeof(*duty_cycle_table))) {
		dev_err(&pdev->dev,
			"voltage-table length(%d) is invalid\n",
			length);
		return -EINVAL;
	}

	duty_cycle_table = devm_kzalloc(&pdev->dev, length, GFP_KERNEL);
	if (!duty_cycle_table)
		return -ENOMEM;

	ret = of_property_read_u32_array(np, "voltage-table",
					 (u32 *)duty_cycle_table,
					 length / sizeof(u32));
	if (ret) {
		dev_err(&pdev->dev, "Failed to read voltage-table\n");
		return ret;
	}

	drvdata->duty_cycle_table	= duty_cycle_table;
	memcpy(&drvdata->ops, &pwm_regulator_voltage_table_ops,
	       sizeof(drvdata->ops));
	drvdata->desc.ops = &drvdata->ops;
	drvdata->desc.n_voltages	= length / sizeof(*duty_cycle_table);

	return 0;
}

static int pwm_regulator_init_continuous(struct platform_device *pdev,
					 struct pwm_regulator_data *drvdata)
{
	memcpy(&drvdata->ops, &pwm_regulator_voltage_continuous_ops,
	       sizeof(drvdata->ops));
	drvdata->desc.ops = &drvdata->ops;
	drvdata->desc.continuous_voltage_range = true;

	return 0;
}

static int pwm_regulator_probe(struct platform_device *pdev)
{
	const struct regulator_init_data *init_data;
	struct pwm_regulator_data *drvdata;
	struct regulator_dev *regulator;
	struct regulator_config config = { };
	struct device_node *np = pdev->dev.of_node;
	int ret;

	if (!np) {
		dev_err(&pdev->dev, "Device Tree node missing\n");
		return -EINVAL;
	}

	drvdata = devm_kzalloc(&pdev->dev, sizeof(*drvdata), GFP_KERNEL);
	if (!drvdata)
		return -ENOMEM;

	memcpy(&drvdata->desc, &pwm_regulator_desc, sizeof(drvdata->desc));

	if (of_find_property(np, "voltage-table", NULL))
		ret = pwm_regulator_init_table(pdev, drvdata);
	else
		ret = pwm_regulator_init_continuous(pdev, drvdata);
	if (ret)
		return ret;

	init_data = of_get_regulator_init_data(&pdev->dev, np,
					       &drvdata->desc);
	if (!init_data)
		return -ENOMEM;

	config.of_node = np;
	config.dev = &pdev->dev;
	config.driver_data = drvdata;
	config.init_data = init_data;

	drvdata->pwm = devm_pwm_get(&pdev->dev, NULL);
	if (IS_ERR(drvdata->pwm)) {
		dev_err(&pdev->dev, "Failed to get PWM\n");
		return PTR_ERR(drvdata->pwm);
	}

	regulator = devm_regulator_register(&pdev->dev,
					    &drvdata->desc, &config);
	if (IS_ERR(regulator)) {
		dev_err(&pdev->dev, "Failed to register regulator %s\n",
			drvdata->desc.name);
		return PTR_ERR(regulator);
	}

	return 0;
}

static const struct of_device_id pwm_of_match[] = {
	{ .compatible = "pwm-regulator" },
	{ },
};
MODULE_DEVICE_TABLE(of, pwm_of_match);

static struct platform_driver pwm_regulator_driver = {
	.driver = {
		.name		= "pwm-regulator",
		.of_match_table = of_match_ptr(pwm_of_match),
	},
	.probe = pwm_regulator_probe,
};

module_platform_driver(pwm_regulator_driver);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Lee Jones <lee.jones@linaro.org>");
MODULE_DESCRIPTION("PWM Regulator Driver");
MODULE_ALIAS("platform:pwm-regulator");
Commit	Line	Data
aa66cc66 CZ	1	/*
	2	* Regulator driver for PWM Regulators
	3	*
	4	* Copyright (C) 2014 - STMicroelectronics Inc.
	5	*
	6	* Author: Lee Jones <lee.jones@linaro.org>
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License version 2 as
	10	* published by the Free Software Foundation.
	11	*/
	12
4773be18	13	#include <linux/delay.h>
aa66cc66 CZ	14	#include <linux/module.h>
	15	#include <linux/init.h>
	16	#include <linux/err.h>
	17	#include <linux/regulator/driver.h>
	18	#include <linux/regulator/machine.h>
	19	#include <linux/regulator/of_regulator.h>
	20	#include <linux/of.h>
	21	#include <linux/of_device.h>
	22	#include <linux/pwm.h>
	23
	24	struct pwm_regulator_data {
4773be18	25	/* Shared */
aa66cc66	26	struct pwm_device *pwm;
4773be18 LJ	27
	28	/* Voltage table */
	29	struct pwm_voltages *duty_cycle_table;
f907a0a9 LD	30
	31	/* regulator descriptor */
	32	struct regulator_desc desc;
	33
	34	/* Regulator ops */
	35	struct regulator_ops ops;
	36
aa66cc66	37	int state;
4773be18 LJ	38
4773be18 LJ	39	/* Continuous voltage */
4773be18	40	int volt_uV;
aa66cc66 CZ	41	};
	42
	43	struct pwm_voltages {
	44	unsigned int uV;
	45	unsigned int dutycycle;
	46	};
	47
4773be18 LJ	48	/**
	49	* Voltage table call-backs
	50	*/
ab101e35	51	static int pwm_regulator_get_voltage_sel(struct regulator_dev *rdev)
aa66cc66	52	{
ab101e35	53	struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev);
aa66cc66 CZ	54
	55	return drvdata->state;
	56	}
	57
ab101e35	58	static int pwm_regulator_set_voltage_sel(struct regulator_dev *rdev,
aa66cc66 CZ	59	unsigned selector)
aa66cc66 CZ	60	{
ab101e35	61	struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev);
aa66cc66 CZ	62	unsigned int pwm_reg_period;
	63	int dutycycle;
	64	int ret;
	65
	66	pwm_reg_period = pwm_get_period(drvdata->pwm);
	67
	68	dutycycle = (pwm_reg_period *
	69	drvdata->duty_cycle_table[selector].dutycycle) / 100;
	70
	71	ret = pwm_config(drvdata->pwm, dutycycle, pwm_reg_period);
	72	if (ret) {
ab101e35	73	dev_err(&rdev->dev, "Failed to configure PWM\n");
aa66cc66 CZ	74	return ret;
	75	}
	76
	77	drvdata->state = selector;
	78
aa66cc66 CZ	79	return 0;
	80	}
	81
ab101e35	82	static int pwm_regulator_list_voltage(struct regulator_dev *rdev,
aa66cc66 CZ	83	unsigned selector)
aa66cc66 CZ	84	{
ab101e35	85	struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev);
aa66cc66	86
ab101e35	87	if (selector >= rdev->desc->n_voltages)
aa66cc66 CZ	88	return -EINVAL;
	89
	90	return drvdata->duty_cycle_table[selector].uV;
	91	}
4773be18	92
1de7d802 BB	93	static int pwm_regulator_enable(struct regulator_dev *dev)
	94	{
	95	struct pwm_regulator_data *drvdata = rdev_get_drvdata(dev);
	96
	97	return pwm_enable(drvdata->pwm);
	98	}
	99
	100	static int pwm_regulator_disable(struct regulator_dev *dev)
	101	{
	102	struct pwm_regulator_data *drvdata = rdev_get_drvdata(dev);
	103
	104	pwm_disable(drvdata->pwm);
	105
	106	return 0;
	107	}
	108
	109	static int pwm_regulator_is_enabled(struct regulator_dev *dev)
	110	{
	111	struct pwm_regulator_data *drvdata = rdev_get_drvdata(dev);
	112
	113	return pwm_is_enabled(drvdata->pwm);
	114	}
	115
4773be18 LJ	116	/**
	117	* Continuous voltage call-backs
	118	*/
f3f6439d	119	static int pwm_voltage_to_duty_cycle_percentage(struct regulator_dev *rdev, int req_uV)
4773be18	120	{
cae897de LJ	121	int min_uV = rdev->constraints->min_uV;
	122	int max_uV = rdev->constraints->max_uV;
	123	int diff = max_uV - min_uV;
	124
1aaab348	125	return ((req_uV * 100) - (min_uV * 100)) / diff;
4773be18 LJ	126	}
	127
	128	static int pwm_regulator_get_voltage(struct regulator_dev *rdev)
	129	{
	130	struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev);
	131
	132	return drvdata->volt_uV;
	133	}
	134
	135	static int pwm_regulator_set_voltage(struct regulator_dev *rdev,
	136	int min_uV, int max_uV,
	137	unsigned *selector)
	138	{
	139	struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev);
	140	unsigned int ramp_delay = rdev->constraints->ramp_delay;
f3f6439d	141	unsigned int period = pwm_get_period(drvdata->pwm);
4773be18 LJ	142	int duty_cycle;
	143	int ret;
	144
f3f6439d	145	duty_cycle = pwm_voltage_to_duty_cycle_percentage(rdev, min_uV);
4773be18	146
f3f6439d	147	ret = pwm_config(drvdata->pwm, (period / 100) * duty_cycle, period);
4773be18 LJ	148	if (ret) {
	149	dev_err(&rdev->dev, "Failed to configure PWM\n");
	150	return ret;
	151	}
	152
	153	ret = pwm_enable(drvdata->pwm);
	154	if (ret) {
	155	dev_err(&rdev->dev, "Failed to enable PWM\n");
	156	return ret;
	157	}
	158	drvdata->volt_uV = min_uV;
	159
	160	/* Delay required by PWM regulator to settle to the new voltage */
	161	usleep_range(ramp_delay, ramp_delay + 1000);
	162
	163	return 0;
	164	}
	165
f9178dad	166	static struct regulator_ops pwm_regulator_voltage_table_ops = {
aa66cc66 CZ	167	.set_voltage_sel = pwm_regulator_set_voltage_sel,
	168	.get_voltage_sel = pwm_regulator_get_voltage_sel,
	169	.list_voltage = pwm_regulator_list_voltage,
	170	.map_voltage = regulator_map_voltage_iterate,
1de7d802 BB	171	.enable = pwm_regulator_enable,
	172	.disable = pwm_regulator_disable,
	173	.is_enabled = pwm_regulator_is_enabled,
aa66cc66 CZ	174	};
aa66cc66 CZ	175
4773be18 LJ	176	static struct regulator_ops pwm_regulator_voltage_continuous_ops = {
	177	.get_voltage = pwm_regulator_get_voltage,
	178	.set_voltage = pwm_regulator_set_voltage,
1de7d802 BB	179	.enable = pwm_regulator_enable,
	180	.disable = pwm_regulator_disable,
	181	.is_enabled = pwm_regulator_is_enabled,
4773be18 LJ	182	};
4773be18 LJ	183
b6f55e74	184	static struct regulator_desc pwm_regulator_desc = {
aa66cc66	185	.name = "pwm-regulator",
aa66cc66 CZ	186	.type = REGULATOR_VOLTAGE,
	187	.owner = THIS_MODULE,
	188	.supply_name = "pwm",
	189	};
	190
f9178dad LJ	191	static int pwm_regulator_init_table(struct platform_device *pdev,
	192	struct pwm_regulator_data *drvdata)
	193	{
	194	struct device_node *np = pdev->dev.of_node;
	195	struct pwm_voltages *duty_cycle_table;
60cb65eb	196	unsigned int length = 0;
f9178dad LJ	197	int ret;
	198
	199	of_find_property(np, "voltage-table", &length);
	200
	201	if ((length < sizeof(*duty_cycle_table)) \|\|
	202	(length % sizeof(*duty_cycle_table))) {
	203	dev_err(&pdev->dev,
	204	"voltage-table length(%d) is invalid\n",
	205	length);
	206	return -EINVAL;
	207	}
	208
	209	duty_cycle_table = devm_kzalloc(&pdev->dev, length, GFP_KERNEL);
	210	if (!duty_cycle_table)
	211	return -ENOMEM;
	212
	213	ret = of_property_read_u32_array(np, "voltage-table",
	214	(u32 *)duty_cycle_table,
	215	length / sizeof(u32));
	216	if (ret) {
	217	dev_err(&pdev->dev, "Failed to read voltage-table\n");
	218	return ret;
	219	}
	220
	221	drvdata->duty_cycle_table = duty_cycle_table;
f907a0a9 LD	222	memcpy(&drvdata->ops, &pwm_regulator_voltage_table_ops,
	223	sizeof(drvdata->ops));
	224	drvdata->desc.ops = &drvdata->ops;
	225	drvdata->desc.n_voltages = length / sizeof(*duty_cycle_table);
f9178dad LJ	226
	227	return 0;
	228	}
	229
4773be18 LJ	230	static int pwm_regulator_init_continuous(struct platform_device *pdev,
	231	struct pwm_regulator_data *drvdata)
	232	{
f907a0a9 LD	233	memcpy(&drvdata->ops, &pwm_regulator_voltage_continuous_ops,
	234	sizeof(drvdata->ops));
	235	drvdata->desc.ops = &drvdata->ops;
	236	drvdata->desc.continuous_voltage_range = true;
4773be18 LJ	237
	238	return 0;
	239	}
	240
aa66cc66 CZ	241	static int pwm_regulator_probe(struct platform_device *pdev)
aa66cc66 CZ	242	{
5ad2cb14	243	const struct regulator_init_data *init_data;
aa66cc66	244	struct pwm_regulator_data *drvdata;
aa66cc66 CZ	245	struct regulator_dev *regulator;
	246	struct regulator_config config = { };
	247	struct device_node *np = pdev->dev.of_node;
f9178dad	248	int ret;
aa66cc66 CZ	249
	250	if (!np) {
	251	dev_err(&pdev->dev, "Device Tree node missing\n");
	252	return -EINVAL;
	253	}
	254
	255	drvdata = devm_kzalloc(&pdev->dev, sizeof(*drvdata), GFP_KERNEL);
	256	if (!drvdata)
	257	return -ENOMEM;
	258
f907a0a9 LD	259	memcpy(&drvdata->desc, &pwm_regulator_desc, sizeof(drvdata->desc));
f907a0a9 LD	260
4773be18	261	if (of_find_property(np, "voltage-table", NULL))
f9178dad	262	ret = pwm_regulator_init_table(pdev, drvdata);
4773be18 LJ	263	else
	264	ret = pwm_regulator_init_continuous(pdev, drvdata);
	265	if (ret)
	266	return ret;
aa66cc66	267
5ad2cb14	268	init_data = of_get_regulator_init_data(&pdev->dev, np,
f907a0a9	269	&drvdata->desc);
5ad2cb14	270	if (!init_data)
aa66cc66 CZ	271	return -ENOMEM;
	272
	273	config.of_node = np;
	274	config.dev = &pdev->dev;
	275	config.driver_data = drvdata;
5ad2cb14	276	config.init_data = init_data;
aa66cc66 CZ	277
	278	drvdata->pwm = devm_pwm_get(&pdev->dev, NULL);
	279	if (IS_ERR(drvdata->pwm)) {
	280	dev_err(&pdev->dev, "Failed to get PWM\n");
	281	return PTR_ERR(drvdata->pwm);
	282	}
	283
	284	regulator = devm_regulator_register(&pdev->dev,
f907a0a9	285	&drvdata->desc, &config);
aa66cc66 CZ	286	if (IS_ERR(regulator)) {
aa66cc66 CZ	287	dev_err(&pdev->dev, "Failed to register regulator %s\n",
f907a0a9	288	drvdata->desc.name);
aa66cc66 CZ	289	return PTR_ERR(regulator);
	290	}
	291
	292	return 0;
	293	}
	294
	295	static const struct of_device_id pwm_of_match[] = {
	296	{ .compatible = "pwm-regulator" },
	297	{ },
	298	};
	299	MODULE_DEVICE_TABLE(of, pwm_of_match);
	300
	301	static struct platform_driver pwm_regulator_driver = {
	302	.driver = {
	303	.name = "pwm-regulator",
aa66cc66 CZ	304	.of_match_table = of_match_ptr(pwm_of_match),
	305	},
	306	.probe = pwm_regulator_probe,
	307	};
	308
	309	module_platform_driver(pwm_regulator_driver);
	310
	311	MODULE_LICENSE("GPL");
	312	MODULE_AUTHOR("Lee Jones <lee.jones@linaro.org>");
	313	MODULE_DESCRIPTION("PWM Regulator Driver");
	314	MODULE_ALIAS("platform:pwm-regulator");