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/*
* Regulator driver for ST's 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>
#define ST_PWM_REG_PERIOD 8448
struct st_pwm_regulator_pdata {
const struct regulator_desc *desc;
struct st_pwm_voltages *duty_cycle_table;
};
struct st_pwm_regulator_data {
const struct st_pwm_regulator_pdata *pdata;
struct pwm_device *pwm;
bool enabled;
int state;
};
struct st_pwm_voltages {
unsigned int uV;
unsigned int dutycycle;
};
static int st_pwm_regulator_get_voltage_sel(struct regulator_dev *dev)
{
struct st_pwm_regulator_data *drvdata = rdev_get_drvdata(dev);
return drvdata->state;
}
static int st_pwm_regulator_set_voltage_sel(struct regulator_dev *dev,
unsigned selector)
{
struct st_pwm_regulator_data *drvdata = rdev_get_drvdata(dev);
int dutycycle;
int ret;
dutycycle = (ST_PWM_REG_PERIOD / 100) *
drvdata->pdata->duty_cycle_table[selector].dutycycle;
ret = pwm_config(drvdata->pwm, dutycycle, ST_PWM_REG_PERIOD);
if (ret) {
dev_err(&dev->dev, "Failed to configure PWM\n");
return ret;
}
drvdata->state = selector;
if (!drvdata->enabled) {
ret = pwm_enable(drvdata->pwm);
if (ret) {
dev_err(&dev->dev, "Failed to enable PWM\n");
return ret;
}
drvdata->enabled = true;
}
return 0;
}
static int st_pwm_regulator_list_voltage(struct regulator_dev *dev,
unsigned selector)
{
struct st_pwm_regulator_data *drvdata = rdev_get_drvdata(dev);
if (selector >= dev->desc->n_voltages)
return -EINVAL;
return drvdata->pdata->duty_cycle_table[selector].uV;
}
static struct regulator_ops st_pwm_regulator_voltage_ops = {
.set_voltage_sel = st_pwm_regulator_set_voltage_sel,
.get_voltage_sel = st_pwm_regulator_get_voltage_sel,
.list_voltage = st_pwm_regulator_list_voltage,
.map_voltage = regulator_map_voltage_iterate,
};
static struct st_pwm_voltages b2105_duty_cycle_table[] = {
{ .uV = 1114000, .dutycycle = 0, },
{ .uV = 1095000, .dutycycle = 10, },
{ .uV = 1076000, .dutycycle = 20, },
{ .uV = 1056000, .dutycycle = 30, },
{ .uV = 1036000, .dutycycle = 40, },
{ .uV = 1016000, .dutycycle = 50, },
/* WARNING: Values above 50% duty-cycle cause boot failures. */
};
static const struct regulator_desc b2105_desc = {
.name = "b2105-pwm-regulator",
.ops = &st_pwm_regulator_voltage_ops,
.type = REGULATOR_VOLTAGE,
.owner = THIS_MODULE,
.n_voltages = ARRAY_SIZE(b2105_duty_cycle_table),
.supply_name = "pwm",
};
static const struct st_pwm_regulator_pdata b2105_info = {
.desc = &b2105_desc,
.duty_cycle_table = b2105_duty_cycle_table,
};
static const struct of_device_id st_pwm_of_match[] = {
{ .compatible = "st,b2105-pwm-regulator", .data = &b2105_info, },
{ },
};
MODULE_DEVICE_TABLE(of, st_pwm_of_match);
static int st_pwm_regulator_probe(struct platform_device *pdev)
{
struct st_pwm_regulator_data *drvdata;
struct regulator_dev *regulator;
struct regulator_config config = { };
struct device_node *np = pdev->dev.of_node;
const struct of_device_id *of_match;
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;
of_match = of_match_device(st_pwm_of_match, &pdev->dev);
if (!of_match) {
dev_err(&pdev->dev, "failed to match of device\n");
return -ENODEV;
}
drvdata->pdata = of_match->data;
config.init_data = of_get_regulator_init_data(&pdev->dev, np);
if (!config.init_data)
return -ENOMEM;
config.of_node = np;
config.dev = &pdev->dev;
config.driver_data = drvdata;
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->pdata->desc, &config);
if (IS_ERR(regulator)) {
dev_err(&pdev->dev, "Failed to register regulator %s\n",
drvdata->pdata->desc->name);
return PTR_ERR(regulator);
}
return 0;
}
static struct platform_driver st_pwm_regulator_driver = {
.driver = {
.name = "st-pwm-regulator",
.owner = THIS_MODULE,
.of_match_table = of_match_ptr(st_pwm_of_match),
},
.probe = st_pwm_regulator_probe,
};
module_platform_driver(st_pwm_regulator_driver);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Lee Jones <lee.jones@linaro.org>");
MODULE_DESCRIPTION("ST PWM Regulator Driver");
MODULE_ALIAS("platform:st_pwm-regulator");
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