#include <linux/input.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_data/regulator-haptic.h>
#include <linux/platform_device.h>
#include <linux/regulator/consumer.h>
#include <linux/slab.h>
#include <linux/string_choices.h>
#define MAX_MAGNITUDE_SHIFT 16
struct regulator_haptic {
struct device *dev;
struct input_dev *input_dev;
struct regulator *regulator;
struct work_struct work;
struct mutex mutex;
bool active;
bool suspended;
unsigned int max_volt;
unsigned int min_volt;
unsigned int magnitude;
};
static int regulator_haptic_toggle(struct regulator_haptic *haptic, bool on)
{
int error;
if (haptic->active != on) {
error = on ? regulator_enable(haptic->regulator) :
regulator_disable(haptic->regulator);
if (error) {
dev_err(haptic->dev,
"failed to switch regulator %s: %d\n",
str_on_off(on), error);
return error;
}
haptic->active = on;
}
return 0;
}
static int regulator_haptic_set_voltage(struct regulator_haptic *haptic,
unsigned int magnitude)
{
u64 volt_mag_multi;
unsigned int intensity;
int error;
volt_mag_multi = (u64)(haptic->max_volt - haptic->min_volt) * magnitude;
intensity = (unsigned int)(volt_mag_multi >> MAX_MAGNITUDE_SHIFT);
error = regulator_set_voltage(haptic->regulator,
intensity + haptic->min_volt,
haptic->max_volt);
if (error) {
dev_err(haptic->dev, "cannot set regulator voltage to %d: %d\n",
intensity + haptic->min_volt, error);
return error;
}
regulator_haptic_toggle(haptic, !!magnitude);
return 0;
}
static void regulator_haptic_work(struct work_struct *work)
{
struct regulator_haptic *haptic = container_of(work,
struct regulator_haptic, work);
guard(mutex)(&haptic->mutex);
if (!haptic->suspended)
regulator_haptic_set_voltage(haptic, haptic->magnitude);
}
static int regulator_haptic_play_effect(struct input_dev *input, void *data,
struct ff_effect *effect)
{
struct regulator_haptic *haptic = input_get_drvdata(input);
haptic->magnitude = effect->u.rumble.strong_magnitude;
if (!haptic->magnitude)
haptic->magnitude = effect->u.rumble.weak_magnitude;
schedule_work(&haptic->work);
return 0;
}
static void regulator_haptic_close(struct input_dev *input)
{
struct regulator_haptic *haptic = input_get_drvdata(input);
cancel_work_sync(&haptic->work);
regulator_haptic_set_voltage(haptic, 0);
}
static int __maybe_unused
regulator_haptic_parse_dt(struct device *dev, struct regulator_haptic *haptic)
{
struct device_node *node;
int error;
node = dev->of_node;
if(!node) {
dev_err(dev, "Missing device tree data\n");
return -EINVAL;
}
error = of_property_read_u32(node, "max-microvolt", &haptic->max_volt);
if (error) {
dev_err(dev, "cannot parse max-microvolt\n");
return error;
}
error = of_property_read_u32(node, "min-microvolt", &haptic->min_volt);
if (error) {
dev_err(dev, "cannot parse min-microvolt\n");
return error;
}
return 0;
}
static int regulator_haptic_probe(struct platform_device *pdev)
{
const struct regulator_haptic_data *pdata = dev_get_platdata(&pdev->dev);
struct regulator_haptic *haptic;
struct input_dev *input_dev;
int error;
haptic = devm_kzalloc(&pdev->dev, sizeof(*haptic), GFP_KERNEL);
if (!haptic)
return -ENOMEM;
platform_set_drvdata(pdev, haptic);
haptic->dev = &pdev->dev;
mutex_init(&haptic->mutex);
INIT_WORK(&haptic->work, regulator_haptic_work);
if (pdata) {
haptic->max_volt = pdata->max_volt;
haptic->min_volt = pdata->min_volt;
} else if (IS_ENABLED(CONFIG_OF)) {
error = regulator_haptic_parse_dt(&pdev->dev, haptic);
if (error)
return error;
} else {
dev_err(&pdev->dev, "Missing platform data\n");
return -EINVAL;
}
haptic->regulator = devm_regulator_get_exclusive(&pdev->dev, "haptic");
if (IS_ERR(haptic->regulator)) {
dev_err(&pdev->dev, "failed to get regulator\n");
return PTR_ERR(haptic->regulator);
}
input_dev = devm_input_allocate_device(&pdev->dev);
if (!input_dev)
return -ENOMEM;
haptic->input_dev = input_dev;
haptic->input_dev->name = "regulator-haptic";
haptic->input_dev->dev.parent = &pdev->dev;
haptic->input_dev->close = regulator_haptic_close;
input_set_drvdata(haptic->input_dev, haptic);
input_set_capability(haptic->input_dev, EV_FF, FF_RUMBLE);
error = input_ff_create_memless(input_dev, NULL,
regulator_haptic_play_effect);
if (error) {
dev_err(&pdev->dev, "failed to create force-feedback\n");
return error;
}
error = input_register_device(haptic->input_dev);
if (error) {
dev_err(&pdev->dev, "failed to register input device\n");
return error;
}
return 0;
}
static int regulator_haptic_suspend(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
struct regulator_haptic *haptic = platform_get_drvdata(pdev);
scoped_guard(mutex_intr, &haptic->mutex) {
regulator_haptic_set_voltage(haptic, 0);
haptic->suspended = true;
return 0;
}
return -EINTR;
}
static int regulator_haptic_resume(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
struct regulator_haptic *haptic = platform_get_drvdata(pdev);
unsigned int magnitude;
guard(mutex)(&haptic->mutex);
haptic->suspended = false;
magnitude = READ_ONCE(haptic->magnitude);
if (magnitude)
regulator_haptic_set_voltage(haptic, magnitude);
return 0;
}
static DEFINE_SIMPLE_DEV_PM_OPS(regulator_haptic_pm_ops,
regulator_haptic_suspend, regulator_haptic_resume);
static const struct of_device_id regulator_haptic_dt_match[] = {
{ .compatible = "regulator-haptic" },
{ },
};
MODULE_DEVICE_TABLE(of, regulator_haptic_dt_match);
static struct platform_driver regulator_haptic_driver = {
.probe = regulator_haptic_probe,
.driver = {
.name = "regulator-haptic",
.of_match_table = regulator_haptic_dt_match,
.pm = pm_sleep_ptr(®ulator_haptic_pm_ops),
},
};
module_platform_driver(regulator_haptic_driver);
MODULE_AUTHOR("Jaewon Kim <jaewon02.kim@samsung.com>");
MODULE_AUTHOR("Hyunhee Kim <hyunhee.kim@samsung.com>");
MODULE_DESCRIPTION("Regulator haptic driver");
MODULE_LICENSE("GPL");
