// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  PWM vibrator driver
 *
 *  Copyright (C) 2017 Collabora Ltd.
 *
 *  Based on previous work from:
 *  Copyright (C) 2012 Dmitry Torokhov <dmitry.torokhov@gmail.com>
 *
 *  Based on PWM beeper driver:
 *  Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
 */

#include <linux/input.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/property.h>
#include <linux/pwm.h>
#include <linux/regulator/consumer.h>
#include <linux/slab.h>

struct pwm_vibrator {
        struct input_dev *input;
        struct pwm_device *pwm;
        struct pwm_device *pwm_dir;
        struct regulator *vcc;

        struct work_struct play_work;
        u16 level;
        u32 direction_duty_cycle;
        bool vcc_on;
};

static int pwm_vibrator_start(struct pwm_vibrator *vibrator)
{
        struct device *pdev = vibrator->input->dev.parent;
        struct pwm_state state;
        int err;

        if (!vibrator->vcc_on) {
                err = regulator_enable(vibrator->vcc);
                if (err) {
                        dev_err(pdev, "failed to enable regulator: %d", err);
                        return err;
                }
                vibrator->vcc_on = true;
        }

        pwm_get_state(vibrator->pwm, &state);
        pwm_set_relative_duty_cycle(&state, vibrator->level, 0xffff);
        state.enabled = true;

        err = pwm_apply_state(vibrator->pwm, &state);
        if (err) {
                dev_err(pdev, "failed to apply pwm state: %d", err);
                return err;
        }

        if (vibrator->pwm_dir) {
                pwm_get_state(vibrator->pwm_dir, &state);
                state.duty_cycle = vibrator->direction_duty_cycle;
                state.enabled = true;

                err = pwm_apply_state(vibrator->pwm_dir, &state);
                if (err) {
                        dev_err(pdev, "failed to apply dir-pwm state: %d", err);
                        pwm_disable(vibrator->pwm);
                        return err;
                }
        }

        return 0;
}

static void pwm_vibrator_stop(struct pwm_vibrator *vibrator)
{
        if (vibrator->pwm_dir)
                pwm_disable(vibrator->pwm_dir);
        pwm_disable(vibrator->pwm);

        if (vibrator->vcc_on) {
                regulator_disable(vibrator->vcc);
                vibrator->vcc_on = false;
        }
}

static void pwm_vibrator_play_work(struct work_struct *work)
{
        struct pwm_vibrator *vibrator = container_of(work,
                                        struct pwm_vibrator, play_work);

        if (vibrator->level)
                pwm_vibrator_start(vibrator);
        else
                pwm_vibrator_stop(vibrator);
}

static int pwm_vibrator_play_effect(struct input_dev *dev, void *data,
                                    struct ff_effect *effect)
{
        struct pwm_vibrator *vibrator = input_get_drvdata(dev);

        vibrator->level = effect->u.rumble.strong_magnitude;
        if (!vibrator->level)
                vibrator->level = effect->u.rumble.weak_magnitude;

        schedule_work(&vibrator->play_work);

        return 0;
}

static void pwm_vibrator_close(struct input_dev *input)
{
        struct pwm_vibrator *vibrator = input_get_drvdata(input);

        cancel_work_sync(&vibrator->play_work);
        pwm_vibrator_stop(vibrator);
}

static int pwm_vibrator_probe(struct platform_device *pdev)
{
        struct pwm_vibrator *vibrator;
        struct pwm_state state;
        int err;

        vibrator = devm_kzalloc(&pdev->dev, sizeof(*vibrator), GFP_KERNEL);
        if (!vibrator)
                return -ENOMEM;

        vibrator->input = devm_input_allocate_device(&pdev->dev);
        if (!vibrator->input)
                return -ENOMEM;

        vibrator->vcc = devm_regulator_get(&pdev->dev, "vcc");
        err = PTR_ERR_OR_ZERO(vibrator->vcc);
        if (err) {
                if (err != -EPROBE_DEFER)
                        dev_err(&pdev->dev, "Failed to request regulator: %d",
                                err);
                return err;
        }

        vibrator->pwm = devm_pwm_get(&pdev->dev, "enable");
        err = PTR_ERR_OR_ZERO(vibrator->pwm);
        if (err) {
                if (err != -EPROBE_DEFER)
                        dev_err(&pdev->dev, "Failed to request main pwm: %d",
                                err);
                return err;
        }

        INIT_WORK(&vibrator->play_work, pwm_vibrator_play_work);

        /* Sync up PWM state and ensure it is off. */
        pwm_init_state(vibrator->pwm, &state);
        state.enabled = false;
        err = pwm_apply_state(vibrator->pwm, &state);
        if (err) {
                dev_err(&pdev->dev, "failed to apply initial PWM state: %d",
                        err);
                return err;
        }

        vibrator->pwm_dir = devm_pwm_get(&pdev->dev, "direction");
        err = PTR_ERR_OR_ZERO(vibrator->pwm_dir);
        switch (err) {
        case 0:
                /* Sync up PWM state and ensure it is off. */
                pwm_init_state(vibrator->pwm_dir, &state);
                state.enabled = false;
                err = pwm_apply_state(vibrator->pwm_dir, &state);
                if (err) {
                        dev_err(&pdev->dev, "failed to apply initial PWM state: %d",
                                err);
                        return err;
                }

                vibrator->direction_duty_cycle =
                        pwm_get_period(vibrator->pwm_dir) / 2;
                device_property_read_u32(&pdev->dev, "direction-duty-cycle-ns",
                                         &vibrator->direction_duty_cycle);
                break;

        case -ENODATA:
                /* Direction PWM is optional */
                vibrator->pwm_dir = NULL;
                break;

        default:
                dev_err(&pdev->dev, "Failed to request direction pwm: %d", err);
                /* Fall through */

        case -EPROBE_DEFER:
                return err;
        }

        vibrator->input->name = "pwm-vibrator";
        vibrator->input->id.bustype = BUS_HOST;
        vibrator->input->dev.parent = &pdev->dev;
        vibrator->input->close = pwm_vibrator_close;

        input_set_drvdata(vibrator->input, vibrator);
        input_set_capability(vibrator->input, EV_FF, FF_RUMBLE);

        err = input_ff_create_memless(vibrator->input, NULL,
                                      pwm_vibrator_play_effect);
        if (err) {
                dev_err(&pdev->dev, "Couldn't create FF dev: %d", err);
                return err;
        }

        err = input_register_device(vibrator->input);
        if (err) {
                dev_err(&pdev->dev, "Couldn't register input dev: %d", err);
                return err;
        }

        platform_set_drvdata(pdev, vibrator);

        return 0;
}

static int __maybe_unused pwm_vibrator_suspend(struct device *dev)
{
        struct pwm_vibrator *vibrator = dev_get_drvdata(dev);

        cancel_work_sync(&vibrator->play_work);
        if (vibrator->level)
                pwm_vibrator_stop(vibrator);

        return 0;
}

static int __maybe_unused pwm_vibrator_resume(struct device *dev)
{
        struct pwm_vibrator *vibrator = dev_get_drvdata(dev);

        if (vibrator->level)
                pwm_vibrator_start(vibrator);

        return 0;
}

static SIMPLE_DEV_PM_OPS(pwm_vibrator_pm_ops,
                         pwm_vibrator_suspend, pwm_vibrator_resume);

#ifdef CONFIG_OF
static const struct of_device_id pwm_vibra_dt_match_table[] = {
        { .compatible = "pwm-vibrator" },
        {},
};
MODULE_DEVICE_TABLE(of, pwm_vibra_dt_match_table);
#endif

static struct platform_driver pwm_vibrator_driver = {
        .probe  = pwm_vibrator_probe,
        .driver = {
                .name   = "pwm-vibrator",
                .pm     = &pwm_vibrator_pm_ops,
                .of_match_table = of_match_ptr(pwm_vibra_dt_match_table),
        },
};
module_platform_driver(pwm_vibrator_driver);

MODULE_AUTHOR("Sebastian Reichel <sre@kernel.org>");
MODULE_DESCRIPTION("PWM vibrator driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:pwm-vibrator");