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/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 {
	struct pwm_voltages *duty_cycle_table;
	struct pwm_device *pwm;
	int state;
};

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

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;

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

	return 0;
}