[mirror_ubuntu-zesty-kernel.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;
	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 100 - (((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;
	pwm_regulator_desc.ops		= &pwm_regulator_voltage_table_ops;
	pwm_regulator_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)
{
	pwm_regulator_desc.ops = &pwm_regulator_voltage_continuous_ops;
	pwm_regulator_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;

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