[linux-2.6-block.git] / drivers / input / misc / pwm-beeper.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
 *  PWM beeper driver
 */

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

struct pwm_beeper {
	struct input_dev *input;
	struct pwm_device *pwm;
	struct regulator *amplifier;
	struct work_struct work;
	unsigned long period;
	unsigned int bell_frequency;
	bool suspended;
	bool amplifier_on;
};

#define HZ_TO_NANOSECONDS(x) (1000000000UL/(x))

static int pwm_beeper_on(struct pwm_beeper *beeper, unsigned long period)
{
	struct pwm_state state;
	int error;

	pwm_get_state(beeper->pwm, &state);

	state.enabled = true;
	state.period = period;
	pwm_set_relative_duty_cycle(&state, 50, 100);

	error = pwm_apply_might_sleep(beeper->pwm, &state);
	if (error)
		return error;

	if (!beeper->amplifier_on) {
		error = regulator_enable(beeper->amplifier);
		if (error) {
			pwm_disable(beeper->pwm);
			return error;
		}

		beeper->amplifier_on = true;
	}

	return 0;
}

static void pwm_beeper_off(struct pwm_beeper *beeper)
{
	if (beeper->amplifier_on) {
		regulator_disable(beeper->amplifier);
		beeper->amplifier_on = false;
	}

	pwm_disable(beeper->pwm);
}

static void pwm_beeper_work(struct work_struct *work)
{
	struct pwm_beeper *beeper = container_of(work, struct pwm_beeper, work);
	unsigned long period = READ_ONCE(beeper->period);

	if (period)
		pwm_beeper_on(beeper, period);
	else
		pwm_beeper_off(beeper);
}

static int pwm_beeper_event(struct input_dev *input,
			    unsigned int type, unsigned int code, int value)
{
	struct pwm_beeper *beeper = input_get_drvdata(input);

	if (type != EV_SND || value < 0)
		return -EINVAL;

	switch (code) {
	case SND_BELL:
		value = value ? beeper->bell_frequency : 0;
		break;
	case SND_TONE:
		break;
	default:
		return -EINVAL;
	}

	if (value == 0)
		beeper->period = 0;
	else
		beeper->period = HZ_TO_NANOSECONDS(value);

	if (!beeper->suspended)
		schedule_work(&beeper->work);

	return 0;
}

static void pwm_beeper_stop(struct pwm_beeper *beeper)
{
	cancel_work_sync(&beeper->work);
	pwm_beeper_off(beeper);
}

static void pwm_beeper_close(struct input_dev *input)
{
	struct pwm_beeper *beeper = input_get_drvdata(input);

	pwm_beeper_stop(beeper);
}

static int pwm_beeper_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct pwm_beeper *beeper;
	struct pwm_state state;
	u32 bell_frequency;
	int error;

	beeper = devm_kzalloc(dev, sizeof(*beeper), GFP_KERNEL);
	if (!beeper)
		return -ENOMEM;

	beeper->pwm = devm_pwm_get(dev, NULL);
	if (IS_ERR(beeper->pwm))
		return dev_err_probe(dev, PTR_ERR(beeper->pwm), "Failed to request PWM device\n");

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

	beeper->amplifier = devm_regulator_get(dev, "amp");
	if (IS_ERR(beeper->amplifier))
		return dev_err_probe(dev, PTR_ERR(beeper->amplifier),
				     "Failed to get 'amp' regulator\n");

	INIT_WORK(&beeper->work, pwm_beeper_work);

	error = device_property_read_u32(dev, "beeper-hz", &bell_frequency);
	if (error) {
		bell_frequency = 1000;
		dev_dbg(dev,
			"failed to parse 'beeper-hz' property, using default: %uHz\n",
			bell_frequency);
	}

	beeper->bell_frequency = bell_frequency;

	beeper->input = devm_input_allocate_device(dev);
	if (!beeper->input) {
		dev_err(dev, "Failed to allocate input device\n");
		return -ENOMEM;
	}

	beeper->input->name = "pwm-beeper";
	beeper->input->phys = "pwm/input0";
	beeper->input->id.bustype = BUS_HOST;
	beeper->input->id.vendor = 0x001f;
	beeper->input->id.product = 0x0001;
	beeper->input->id.version = 0x0100;

	input_set_capability(beeper->input, EV_SND, SND_TONE);
	input_set_capability(beeper->input, EV_SND, SND_BELL);

	beeper->input->event = pwm_beeper_event;
	beeper->input->close = pwm_beeper_close;

	input_set_drvdata(beeper->input, beeper);

	error = input_register_device(beeper->input);
	if (error) {
		dev_err(dev, "Failed to register input device: %d\n", error);
		return error;
	}

	platform_set_drvdata(pdev, beeper);

	return 0;
}

static int pwm_beeper_suspend(struct device *dev)
{
	struct pwm_beeper *beeper = dev_get_drvdata(dev);

	/*
	 * Spinlock is taken here is not to protect write to
	 * beeper->suspended, but to ensure that pwm_beeper_event
	 * does not re-submit work once flag is set.
	 */
	spin_lock_irq(&beeper->input->event_lock);
	beeper->suspended = true;
	spin_unlock_irq(&beeper->input->event_lock);

	pwm_beeper_stop(beeper);

	return 0;
}

static int pwm_beeper_resume(struct device *dev)
{
	struct pwm_beeper *beeper = dev_get_drvdata(dev);

	spin_lock_irq(&beeper->input->event_lock);
	beeper->suspended = false;
	spin_unlock_irq(&beeper->input->event_lock);

	/* Let worker figure out if we should resume beeping */
	schedule_work(&beeper->work);

	return 0;
}

static DEFINE_SIMPLE_DEV_PM_OPS(pwm_beeper_pm_ops,
				pwm_beeper_suspend, pwm_beeper_resume);

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

static struct platform_driver pwm_beeper_driver = {
	.probe	= pwm_beeper_probe,
	.driver = {
		.name	= "pwm-beeper",
		.pm	= pm_sleep_ptr(&pwm_beeper_pm_ops),
		.of_match_table = of_match_ptr(pwm_beeper_match),
	},
};
module_platform_driver(pwm_beeper_driver);

MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
MODULE_DESCRIPTION("PWM beeper driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:pwm-beeper");
Commit	Line	Data
	1	// SPDX-License-Identifier: GPL-2.0-or-later
	2	/*
	3	* Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
	4	* PWM beeper driver
	5	*/
	6
	7	#include <linux/input.h>
	8	#include <linux/regulator/consumer.h>
	9	#include <linux/module.h>
	10	#include <linux/kernel.h>
	11	#include <linux/of.h>
	12	#include <linux/platform_device.h>
	13	#include <linux/property.h>
	14	#include <linux/pwm.h>
	15	#include <linux/slab.h>
	16	#include <linux/workqueue.h>
	17
	18	struct pwm_beeper {
	19	struct input_dev *input;
	20	struct pwm_device *pwm;
	21	struct regulator *amplifier;
	22	struct work_struct work;
	23	unsigned long period;
	24	unsigned int bell_frequency;
	25	bool suspended;
	26	bool amplifier_on;
	27	};
	28
	29	#define HZ_TO_NANOSECONDS(x) (1000000000UL/(x))
	30
	31	static int pwm_beeper_on(struct pwm_beeper *beeper, unsigned long period)
	32	{
	33	struct pwm_state state;
	34	int error;
	35
	36	pwm_get_state(beeper->pwm, &state);
	37
	38	state.enabled = true;
	39	state.period = period;
	40	pwm_set_relative_duty_cycle(&state, 50, 100);
	41
	42	error = pwm_apply_might_sleep(beeper->pwm, &state);
	43	if (error)
	44	return error;
	45
	46	if (!beeper->amplifier_on) {
	47	error = regulator_enable(beeper->amplifier);
	48	if (error) {
	49	pwm_disable(beeper->pwm);
	50	return error;
	51	}
	52
	53	beeper->amplifier_on = true;
	54	}
	55
	56	return 0;
	57	}
	58
	59	static void pwm_beeper_off(struct pwm_beeper *beeper)
	60	{
	61	if (beeper->amplifier_on) {
	62	regulator_disable(beeper->amplifier);
	63	beeper->amplifier_on = false;
	64	}
	65
	66	pwm_disable(beeper->pwm);
	67	}
	68
	69	static void pwm_beeper_work(struct work_struct *work)
	70	{
	71	struct pwm_beeper *beeper = container_of(work, struct pwm_beeper, work);
	72	unsigned long period = READ_ONCE(beeper->period);
	73
	74	if (period)
	75	pwm_beeper_on(beeper, period);
	76	else
	77	pwm_beeper_off(beeper);
	78	}
	79
	80	static int pwm_beeper_event(struct input_dev *input,
	81	unsigned int type, unsigned int code, int value)
	82	{
	83	struct pwm_beeper *beeper = input_get_drvdata(input);
	84
	85	if (type != EV_SND \|\| value < 0)
	86	return -EINVAL;
	87
	88	switch (code) {
	89	case SND_BELL:
	90	value = value ? beeper->bell_frequency : 0;
	91	break;
	92	case SND_TONE:
	93	break;
	94	default:
	95	return -EINVAL;
	96	}
	97
	98	if (value == 0)
	99	beeper->period = 0;
	100	else
	101	beeper->period = HZ_TO_NANOSECONDS(value);
	102
	103	if (!beeper->suspended)
	104	schedule_work(&beeper->work);
	105
	106	return 0;
	107	}
	108
	109	static void pwm_beeper_stop(struct pwm_beeper *beeper)
	110	{
	111	cancel_work_sync(&beeper->work);
	112	pwm_beeper_off(beeper);
	113	}
	114
	115	static void pwm_beeper_close(struct input_dev *input)
	116	{
	117	struct pwm_beeper *beeper = input_get_drvdata(input);
	118
	119	pwm_beeper_stop(beeper);
	120	}
	121
	122	static int pwm_beeper_probe(struct platform_device *pdev)
	123	{
	124	struct device *dev = &pdev->dev;
	125	struct pwm_beeper *beeper;
	126	struct pwm_state state;
	127	u32 bell_frequency;
	128	int error;
	129
	130	beeper = devm_kzalloc(dev, sizeof(*beeper), GFP_KERNEL);
	131	if (!beeper)
	132	return -ENOMEM;
	133
	134	beeper->pwm = devm_pwm_get(dev, NULL);
	135	if (IS_ERR(beeper->pwm))
	136	return dev_err_probe(dev, PTR_ERR(beeper->pwm), "Failed to request PWM device\n");
	137
	138	/* Sync up PWM state and ensure it is off. */
	139	pwm_init_state(beeper->pwm, &state);
	140	state.enabled = false;
	141	error = pwm_apply_might_sleep(beeper->pwm, &state);
	142	if (error) {
	143	dev_err(dev, "failed to apply initial PWM state: %d\n",
	144	error);
	145	return error;
	146	}
	147
	148	beeper->amplifier = devm_regulator_get(dev, "amp");
	149	if (IS_ERR(beeper->amplifier))
	150	return dev_err_probe(dev, PTR_ERR(beeper->amplifier),
	151	"Failed to get 'amp' regulator\n");
	152
	153	INIT_WORK(&beeper->work, pwm_beeper_work);
	154
	155	error = device_property_read_u32(dev, "beeper-hz", &bell_frequency);
	156	if (error) {
	157	bell_frequency = 1000;
	158	dev_dbg(dev,
	159	"failed to parse 'beeper-hz' property, using default: %uHz\n",
	160	bell_frequency);
	161	}
	162
	163	beeper->bell_frequency = bell_frequency;
	164
	165	beeper->input = devm_input_allocate_device(dev);
	166	if (!beeper->input) {
	167	dev_err(dev, "Failed to allocate input device\n");
	168	return -ENOMEM;
	169	}
	170
	171	beeper->input->name = "pwm-beeper";
	172	beeper->input->phys = "pwm/input0";
	173	beeper->input->id.bustype = BUS_HOST;
	174	beeper->input->id.vendor = 0x001f;
	175	beeper->input->id.product = 0x0001;
	176	beeper->input->id.version = 0x0100;
	177
	178	input_set_capability(beeper->input, EV_SND, SND_TONE);
	179	input_set_capability(beeper->input, EV_SND, SND_BELL);
	180
	181	beeper->input->event = pwm_beeper_event;
	182	beeper->input->close = pwm_beeper_close;
	183
	184	input_set_drvdata(beeper->input, beeper);
	185
	186	error = input_register_device(beeper->input);
	187	if (error) {
	188	dev_err(dev, "Failed to register input device: %d\n", error);
	189	return error;
	190	}
	191
	192	platform_set_drvdata(pdev, beeper);
	193
	194	return 0;
	195	}
	196
	197	static int pwm_beeper_suspend(struct device *dev)
	198	{
	199	struct pwm_beeper *beeper = dev_get_drvdata(dev);
	200
	201	/*
	202	* Spinlock is taken here is not to protect write to
	203	* beeper->suspended, but to ensure that pwm_beeper_event
	204	* does not re-submit work once flag is set.
	205	*/
	206	spin_lock_irq(&beeper->input->event_lock);
	207	beeper->suspended = true;
	208	spin_unlock_irq(&beeper->input->event_lock);
	209
	210	pwm_beeper_stop(beeper);
	211
	212	return 0;
	213	}
	214
	215	static int pwm_beeper_resume(struct device *dev)
	216	{
	217	struct pwm_beeper *beeper = dev_get_drvdata(dev);
	218
	219	spin_lock_irq(&beeper->input->event_lock);
	220	beeper->suspended = false;
	221	spin_unlock_irq(&beeper->input->event_lock);
	222
	223	/* Let worker figure out if we should resume beeping */
	224	schedule_work(&beeper->work);
	225
	226	return 0;
	227	}
	228
	229	static DEFINE_SIMPLE_DEV_PM_OPS(pwm_beeper_pm_ops,
	230	pwm_beeper_suspend, pwm_beeper_resume);
	231
	232	#ifdef CONFIG_OF
	233	static const struct of_device_id pwm_beeper_match[] = {
	234	{ .compatible = "pwm-beeper", },
	235	{ },
	236	};
	237	MODULE_DEVICE_TABLE(of, pwm_beeper_match);
	238	#endif
	239
	240	static struct platform_driver pwm_beeper_driver = {
	241	.probe = pwm_beeper_probe,
	242	.driver = {
	243	.name = "pwm-beeper",
	244	.pm = pm_sleep_ptr(&pwm_beeper_pm_ops),
	245	.of_match_table = of_match_ptr(pwm_beeper_match),
	246	},
	247	};
	248	module_platform_driver(pwm_beeper_driver);
	249
	250	MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
	251	MODULE_DESCRIPTION("PWM beeper driver");
	252	MODULE_LICENSE("GPL");
	253	MODULE_ALIAS("platform:pwm-beeper");