Files
android_kernel_xiaomi_sm8450/drivers/regulator/pwm-regulator.c
Boris Brezillon 87248991a1 regulator: pwm: Properly initialize the ->state field
The ->state field is currently initialized to 0, thus referencing the
voltage selector at index 0, which might not reflect the current
voltage value.
If possible, retrieve the current voltage selector from the PWM state,
else return -EINVAL.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Tested-by: Brian Norris <briannorris@chromium.org>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-07-11 08:43:24 +02:00

359 lines
8.9 KiB
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>
#include <linux/gpio/consumer.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;
/* Enable GPIO */
struct gpio_desc *enb_gpio;
};
struct pwm_voltages {
unsigned int uV;
unsigned int dutycycle;
};
/**
* Voltage table call-backs
*/
static void pwm_regulator_init_state(struct regulator_dev *rdev)
{
struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev);
struct pwm_state pwm_state;
unsigned int dutycycle;
int i;
pwm_get_state(drvdata->pwm, &pwm_state);
dutycycle = pwm_get_relative_duty_cycle(&pwm_state, 100);
for (i = 0; i < rdev->desc->n_voltages; i++) {
if (dutycycle == drvdata->duty_cycle_table[i].dutycycle) {
drvdata->state = i;
return;
}
}
}
static int pwm_regulator_get_voltage_sel(struct regulator_dev *rdev)
{
struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev);
if (drvdata->state < 0)
pwm_regulator_init_state(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);
struct pwm_state pstate;
int ret;
pwm_init_state(drvdata->pwm, &pstate);
pwm_set_relative_duty_cycle(&pstate,
drvdata->duty_cycle_table[selector].dutycycle, 100);
ret = pwm_apply_state(drvdata->pwm, &pstate);
if (ret) {
dev_err(&rdev->dev, "Failed to configure PWM: %d\n", ret);
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);
if (drvdata->enb_gpio)
gpiod_set_value_cansleep(drvdata->enb_gpio, 1);
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);
if (drvdata->enb_gpio)
gpiod_set_value_cansleep(drvdata->enb_gpio, 0);
return 0;
}
static int pwm_regulator_is_enabled(struct regulator_dev *dev)
{
struct pwm_regulator_data *drvdata = rdev_get_drvdata(dev);
if (drvdata->enb_gpio && !gpiod_get_value_cansleep(drvdata->enb_gpio))
return false;
return pwm_is_enabled(drvdata->pwm);
}
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 req_diff = min_uV - rdev->constraints->min_uV;
struct pwm_state pstate;
unsigned int diff;
int old_uV = pwm_regulator_get_voltage(rdev);
int ret;
pwm_init_state(drvdata->pwm, &pstate);
diff = rdev->constraints->max_uV - rdev->constraints->min_uV;
/* We pass diff as the scale to get a uV precision. */
pwm_set_relative_duty_cycle(&pstate, req_diff, diff);
ret = pwm_apply_state(drvdata->pwm, &pstate);
if (ret) {
dev_err(&rdev->dev, "Failed to configure PWM: %d\n", ret);
return ret;
}
drvdata->volt_uV = min_uV;
if ((ramp_delay == 0) || !pwm_regulator_is_enabled(rdev))
return 0;
/* Ramp delay is in uV/uS. Adjust to uS and delay */
ramp_delay = DIV_ROUND_UP(abs(min_uV - old_uV), ramp_delay);
usleep_range(ramp_delay, ramp_delay + DIV_ROUND_UP(ramp_delay, 10));
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: %d\n", ret);
return ret;
}
drvdata->state = -EINVAL;
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;
enum gpiod_flags gpio_flags;
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)) {
ret = PTR_ERR(drvdata->pwm);
dev_err(&pdev->dev, "Failed to get PWM: %d\n", ret);
return ret;
}
if (init_data->constraints.boot_on || init_data->constraints.always_on)
gpio_flags = GPIOD_OUT_HIGH;
else
gpio_flags = GPIOD_OUT_LOW;
drvdata->enb_gpio = devm_gpiod_get_optional(&pdev->dev, "enable",
gpio_flags);
if (IS_ERR(drvdata->enb_gpio)) {
ret = PTR_ERR(drvdata->enb_gpio);
dev_err(&pdev->dev, "Failed to get enable GPIO: %d\n", ret);
return ret;
}
ret = pwm_adjust_config(drvdata->pwm);
if (ret)
return ret;
regulator = devm_regulator_register(&pdev->dev,
&drvdata->desc, &config);
if (IS_ERR(regulator)) {
ret = PTR_ERR(regulator);
dev_err(&pdev->dev, "Failed to register regulator %s: %d\n",
drvdata->desc.name, ret);
return ret;
}
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");