#include <linux/module.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/platform_device.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/machine.h>
#include <linux/regulator/of_regulator.h>
#include <linux/of.h>
#include <linux/pwm.h>
#include <linux/gpio/consumer.h>
struct pwm_continuous_reg_data {
unsigned int min_uV_dutycycle;
unsigned int max_uV_dutycycle;
unsigned int dutycycle_unit;
};
struct pwm_regulator_data {
struct pwm_device *pwm;
struct pwm_voltages *duty_cycle_table;
struct pwm_continuous_reg_data continuous;
struct regulator_desc desc;
int state;
struct gpio_desc *enb_gpio;
};
struct pwm_voltages {
unsigned int uV;
unsigned int dutycycle;
};
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_might_sleep(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);
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);
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);
unsigned int min_uV_duty = drvdata->continuous.min_uV_dutycycle;
unsigned int max_uV_duty = drvdata->continuous.max_uV_dutycycle;
unsigned int duty_unit = drvdata->continuous.dutycycle_unit;
int min_uV = rdev->constraints->min_uV;
int max_uV = rdev->constraints->max_uV;
int diff_uV = max_uV - min_uV;
struct pwm_state pstate;
unsigned int diff_duty;
unsigned int voltage;
pwm_get_state(drvdata->pwm, &pstate);
if (!pstate.enabled) {
if (pstate.polarity == PWM_POLARITY_INVERSED)
pstate.duty_cycle = pstate.period;
else
pstate.duty_cycle = 0;
}
voltage = pwm_get_relative_duty_cycle(&pstate, duty_unit);
if (voltage < min(max_uV_duty, min_uV_duty) ||
voltage > max(max_uV_duty, min_uV_duty))
return -ENOTRECOVERABLE;
if (max_uV_duty < min_uV_duty) {
voltage = min_uV_duty - voltage;
diff_duty = min_uV_duty - max_uV_duty;
} else {
voltage = voltage - min_uV_duty;
diff_duty = max_uV_duty - min_uV_duty;
}
voltage = DIV_ROUND_CLOSEST_ULL((u64)voltage * diff_uV, diff_duty);
return voltage + min_uV;
}
static int pwm_regulator_set_voltage(struct regulator_dev *rdev,
int req_min_uV, int req_max_uV,
unsigned int *selector)
{
struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev);
unsigned int min_uV_duty = drvdata->continuous.min_uV_dutycycle;
unsigned int max_uV_duty = drvdata->continuous.max_uV_dutycycle;
unsigned int duty_unit = drvdata->continuous.dutycycle_unit;
int min_uV = rdev->constraints->min_uV;
int max_uV = rdev->constraints->max_uV;
int diff_uV = max_uV - min_uV;
struct pwm_state pstate;
unsigned int diff_duty;
unsigned int dutycycle;
int ret;
pwm_init_state(drvdata->pwm, &pstate);
if (max_uV_duty < min_uV_duty)
diff_duty = min_uV_duty - max_uV_duty;
else
diff_duty = max_uV_duty - min_uV_duty;
dutycycle = DIV_ROUND_CLOSEST_ULL((u64)(req_min_uV - min_uV) *
diff_duty,
diff_uV);
if (max_uV_duty < min_uV_duty)
dutycycle = min_uV_duty - dutycycle;
else
dutycycle = min_uV_duty + dutycycle;
pwm_set_relative_duty_cycle(&pstate, dutycycle, duty_unit);
ret = pwm_apply_might_sleep(drvdata->pwm, &pstate);
if (ret) {
dev_err(&rdev->dev, "Failed to configure PWM: %d\n", ret);
return ret;
}
return 0;
}
static const 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 const 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 const 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)))
return dev_err_probe(&pdev->dev, -EINVAL,
"voltage-table length(%d) is invalid\n",
length);
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)
return dev_err_probe(&pdev->dev, ret,
"Failed to read voltage-table\n");
drvdata->state = -ENOTRECOVERABLE;
drvdata->duty_cycle_table = duty_cycle_table;
drvdata->desc.ops = &pwm_regulator_voltage_table_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)
{
u32 dutycycle_range[2] = { 0, 100 };
u32 dutycycle_unit = 100;
drvdata->desc.ops = &pwm_regulator_voltage_continuous_ops;
drvdata->desc.continuous_voltage_range = true;
of_property_read_u32_array(pdev->dev.of_node,
"pwm-dutycycle-range",
dutycycle_range, 2);
of_property_read_u32(pdev->dev.of_node, "pwm-dutycycle-unit",
&dutycycle_unit);
if (dutycycle_range[0] > dutycycle_unit ||
dutycycle_range[1] > dutycycle_unit)
return -EINVAL;
drvdata->continuous.dutycycle_unit = dutycycle_unit;
drvdata->continuous.min_uV_dutycycle = dutycycle_range[0];
drvdata->continuous.max_uV_dutycycle = dutycycle_range[1];
return 0;
}
static int pwm_regulator_init_boot_on(struct platform_device *pdev,
struct pwm_regulator_data *drvdata,
const struct regulator_init_data *init_data)
{
struct pwm_state pstate;
if (!init_data->constraints.boot_on || drvdata->enb_gpio)
return 0;
pwm_get_state(drvdata->pwm, &pstate);
if (pstate.enabled)
return 0;
if (pstate.polarity == PWM_POLARITY_INVERSED)
pstate.duty_cycle = pstate.period;
else
pstate.duty_cycle = 0;
return pwm_apply_might_sleep(drvdata->pwm, &pstate);
}
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)
return dev_err_probe(&pdev->dev, -EINVAL,
"Device Tree node missing\n");
drvdata = devm_kzalloc(&pdev->dev, sizeof(*drvdata), GFP_KERNEL);
if (!drvdata)
return -ENOMEM;
memcpy(&drvdata->desc, &pwm_regulator_desc, sizeof(drvdata->desc));
if (of_property_present(np, "voltage-table"))
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))
return dev_err_probe(&pdev->dev, PTR_ERR(drvdata->pwm),
"Failed to get PWM\n");
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);
return dev_err_probe(&pdev->dev, ret, "Failed to get enable GPIO\n");
}
ret = pwm_adjust_config(drvdata->pwm);
if (ret)
return ret;
ret = pwm_regulator_init_boot_on(pdev, drvdata, init_data);
if (ret)
return dev_err_probe(&pdev->dev, ret,
"Failed to apply boot_on settings\n");
regulator = devm_regulator_register(&pdev->dev,
&drvdata->desc, &config);
if (IS_ERR(regulator)) {
ret = PTR_ERR(regulator);
return dev_err_probe(&pdev->dev, ret,
"Failed to register regulator %s\n",
drvdata->desc.name);
}
return 0;
}
static const struct of_device_id __maybe_unused pwm_of_match[] = {
{ .compatible = "pwm-regulator" },
{ },
};
MODULE_DEVICE_TABLE(of, pwm_of_match);
static struct platform_driver pwm_regulator_driver = {
.driver = {
.name = "pwm-regulator",
.probe_type = PROBE_PREFER_ASYNCHRONOUS,
.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");
