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

/*
 *  Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
 *  PWM beeper driver
 *
 *  This program is free software; you can redistribute it and/or modify it
 *  under  the terms of the GNU General  Public License as published by the
 *  Free Software Foundation;  either version 2 of the License, or (at your
 *  option) any later version.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */

#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_state(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)) {
		error = PTR_ERR(beeper->pwm);
		if (error != -EPROBE_DEFER)
			dev_err(dev, "Failed to request PWM device: %d\n",
				error);
		return error;
	}

	/* Sync up PWM state and ensure it is off. */
	pwm_init_state(beeper->pwm, &state);
	state.enabled = false;
	error = pwm_apply_state(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)) {
		error = PTR_ERR(beeper->amplifier);
		if (error != -EPROBE_DEFER)
			dev_err(dev, "Failed to get 'amp' regulator: %d\n",
				error);
		return error;
	}

	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 __maybe_unused 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 __maybe_unused 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 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	= &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
e22739d0 LPC	1	/*
	2	* Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
	3	* PWM beeper driver
	4	*
	5	* This program is free software; you can redistribute it and/or modify it
	6	* under the terms of the GNU General Public License as published by the
	7	* Free Software Foundation; either version 2 of the License, or (at your
	8	* option) any later version.
	9	*
	10	* You should have received a copy of the GNU General Public License along
	11	* with this program; if not, write to the Free Software Foundation, Inc.,
	12	* 675 Mass Ave, Cambridge, MA 02139, USA.
	13	*
	14	*/
	15
	16	#include <linux/input.h>
9e549244	17	#include <linux/regulator/consumer.h>
e22739d0 LPC	18	#include <linux/module.h>
e22739d0 LPC	19	#include <linux/kernel.h>
9dbe4c32	20	#include <linux/of.h>
e22739d0	21	#include <linux/platform_device.h>
fad358a0	22	#include <linux/property.h>
e22739d0 LPC	23	#include <linux/pwm.h>
e22739d0 LPC	24	#include <linux/slab.h>
f49cf3b8	25	#include <linux/workqueue.h>
e22739d0 LPC	26
	27	struct pwm_beeper {
	28	struct input_dev *input;
	29	struct pwm_device *pwm;
9e549244	30	struct regulator *amplifier;
f49cf3b8	31	struct work_struct work;
e22739d0	32	unsigned long period;
fad358a0	33	unsigned int bell_frequency;
e9728f0d	34	bool suspended;
9e549244	35	bool amplifier_on;
e22739d0 LPC	36	};
	37
	38	#define HZ_TO_NANOSECONDS(x) (1000000000UL/(x))
	39
9e549244	40	static int pwm_beeper_on(struct pwm_beeper *beeper, unsigned long period)
f49cf3b8	41	{
2de8b411	42	struct pwm_state state;
9e549244 DL	43	int error;
9e549244 DL	44
2de8b411 DT	45	pwm_get_state(beeper->pwm, &state);
	46
	47	state.enabled = true;
	48	state.period = period;
	49	pwm_set_relative_duty_cycle(&state, 50, 100);
9e549244	50
2de8b411	51	error = pwm_apply_state(beeper->pwm, &state);
9e549244 DL	52	if (error)
	53	return error;
	54
	55	if (!beeper->amplifier_on) {
	56	error = regulator_enable(beeper->amplifier);
	57	if (error) {
	58	pwm_disable(beeper->pwm);
	59	return error;
	60	}
f49cf3b8	61
9e549244 DL	62	beeper->amplifier_on = true;
	63	}
	64
	65	return 0;
	66	}
	67
	68	static void pwm_beeper_off(struct pwm_beeper *beeper)
	69	{
	70	if (beeper->amplifier_on) {
	71	regulator_disable(beeper->amplifier);
	72	beeper->amplifier_on = false;
	73	}
	74
	75	pwm_disable(beeper->pwm);
f49cf3b8 MS	76	}
	77
	78	static void pwm_beeper_work(struct work_struct *work)
	79	{
9e549244 DL	80	struct pwm_beeper *beeper = container_of(work, struct pwm_beeper, work);
9e549244 DL	81	unsigned long period = READ_ONCE(beeper->period);
f49cf3b8	82
9e549244 DL	83	if (period)
	84	pwm_beeper_on(beeper, period);
	85	else
	86	pwm_beeper_off(beeper);
f49cf3b8 MS	87	}
f49cf3b8 MS	88
e22739d0 LPC	89	static int pwm_beeper_event(struct input_dev *input,
	90	unsigned int type, unsigned int code, int value)
	91	{
e22739d0	92	struct pwm_beeper *beeper = input_get_drvdata(input);
e22739d0 LPC	93
	94	if (type != EV_SND \|\| value < 0)
	95	return -EINVAL;
	96
	97	switch (code) {
	98	case SND_BELL:
fad358a0	99	value = value ? beeper->bell_frequency : 0;
e22739d0 LPC	100	break;
	101	case SND_TONE:
	102	break;
	103	default:
	104	return -EINVAL;
	105	}
	106
f49cf3b8 MS	107	if (value == 0)
	108	beeper->period = 0;
	109	else
	110	beeper->period = HZ_TO_NANOSECONDS(value);
	111
e9728f0d DT	112	if (!beeper->suspended)
e9728f0d DT	113	schedule_work(&beeper->work);
e22739d0 LPC	114
	115	return 0;
	116	}
	117
f49cf3b8 MS	118	static void pwm_beeper_stop(struct pwm_beeper *beeper)
	119	{
	120	cancel_work_sync(&beeper->work);
9e549244	121	pwm_beeper_off(beeper);
f49cf3b8 MS	122	}
	123
	124	static void pwm_beeper_close(struct input_dev *input)
	125	{
	126	struct pwm_beeper *beeper = input_get_drvdata(input);
	127
	128	pwm_beeper_stop(beeper);
	129	}
	130
5298cc4c	131	static int pwm_beeper_probe(struct platform_device *pdev)
e22739d0	132	{
bcf4b046	133	struct device *dev = &pdev->dev;
e22739d0	134	struct pwm_beeper *beeper;
2de8b411	135	struct pwm_state state;
fad358a0	136	u32 bell_frequency;
e22739d0 LPC	137	int error;
e22739d0 LPC	138
bcf4b046	139	beeper = devm_kzalloc(dev, sizeof(*beeper), GFP_KERNEL);
e22739d0 LPC	140	if (!beeper)
	141	return -ENOMEM;
	142
bcf4b046	143	beeper->pwm = devm_pwm_get(dev, NULL);
e22739d0 LPC	144	if (IS_ERR(beeper->pwm)) {
e22739d0 LPC	145	error = PTR_ERR(beeper->pwm);
62481881 DL	146	if (error != -EPROBE_DEFER)
	147	dev_err(dev, "Failed to request PWM device: %d\n",
	148	error);
bcf4b046	149	return error;
e22739d0 LPC	150	}
e22739d0 LPC	151
2de8b411 DT	152	/* Sync up PWM state and ensure it is off. */
	153	pwm_init_state(beeper->pwm, &state);
	154	state.enabled = false;
	155	error = pwm_apply_state(beeper->pwm, &state);
	156	if (error) {
	157	dev_err(dev, "failed to apply initial PWM state: %d\n",
	158	error);
	159	return error;
	160	}
cfae56f1	161
9e549244 DL	162	beeper->amplifier = devm_regulator_get(dev, "amp");
	163	if (IS_ERR(beeper->amplifier)) {
	164	error = PTR_ERR(beeper->amplifier);
	165	if (error != -EPROBE_DEFER)
	166	dev_err(dev, "Failed to get 'amp' regulator: %d\n",
	167	error);
	168	return error;
	169	}
	170
f49cf3b8 MS	171	INIT_WORK(&beeper->work, pwm_beeper_work);
f49cf3b8 MS	172
fad358a0 GB	173	error = device_property_read_u32(dev, "beeper-hz", &bell_frequency);
	174	if (error) {
	175	bell_frequency = 1000;
	176	dev_dbg(dev,
	177	"failed to parse 'beeper-hz' property, using default: %uHz\n",
	178	bell_frequency);
	179	}
	180
	181	beeper->bell_frequency = bell_frequency;
	182
bcf4b046	183	beeper->input = devm_input_allocate_device(dev);
e22739d0	184	if (!beeper->input) {
bcf4b046 DT	185	dev_err(dev, "Failed to allocate input device\n");
bcf4b046 DT	186	return -ENOMEM;
e22739d0	187	}
e22739d0 LPC	188
	189	beeper->input->name = "pwm-beeper";
	190	beeper->input->phys = "pwm/input0";
	191	beeper->input->id.bustype = BUS_HOST;
	192	beeper->input->id.vendor = 0x001f;
	193	beeper->input->id.product = 0x0001;
	194	beeper->input->id.version = 0x0100;
	195
48a55d7d DT	196	input_set_capability(beeper->input, EV_SND, SND_TONE);
48a55d7d DT	197	input_set_capability(beeper->input, EV_SND, SND_BELL);
e22739d0 LPC	198
e22739d0 LPC	199	beeper->input->event = pwm_beeper_event;
f49cf3b8	200	beeper->input->close = pwm_beeper_close;
e22739d0 LPC	201
	202	input_set_drvdata(beeper->input, beeper);
	203
	204	error = input_register_device(beeper->input);
	205	if (error) {
bcf4b046 DT	206	dev_err(dev, "Failed to register input device: %d\n", error);
bcf4b046 DT	207	return error;
e22739d0 LPC	208	}
	209
	210	platform_set_drvdata(pdev, beeper);
	211
e22739d0 LPC	212	return 0;
	213	}
	214
97a652a8	215	static int __maybe_unused pwm_beeper_suspend(struct device *dev)
e22739d0 LPC	216	{
	217	struct pwm_beeper *beeper = dev_get_drvdata(dev);
	218
e9728f0d DT	219	/*
	220	* Spinlock is taken here is not to protect write to
	221	* beeper->suspended, but to ensure that pwm_beeper_event
	222	* does not re-submit work once flag is set.
	223	*/
	224	spin_lock_irq(&beeper->input->event_lock);
	225	beeper->suspended = true;
	226	spin_unlock_irq(&beeper->input->event_lock);
	227
f49cf3b8	228	pwm_beeper_stop(beeper);
e22739d0 LPC	229
	230	return 0;
	231	}
	232
97a652a8	233	static int __maybe_unused pwm_beeper_resume(struct device *dev)
e22739d0 LPC	234	{
	235	struct pwm_beeper *beeper = dev_get_drvdata(dev);
	236
e9728f0d DT	237	spin_lock_irq(&beeper->input->event_lock);
	238	beeper->suspended = false;
	239	spin_unlock_irq(&beeper->input->event_lock);
	240
	241	/* Let worker figure out if we should resume beeping */
	242	schedule_work(&beeper->work);
e22739d0 LPC	243
	244	return 0;
	245	}
	246
	247	static SIMPLE_DEV_PM_OPS(pwm_beeper_pm_ops,
	248	pwm_beeper_suspend, pwm_beeper_resume);
	249
d56a289b SH	250	#ifdef CONFIG_OF
	251	static const struct of_device_id pwm_beeper_match[] = {
	252	{ .compatible = "pwm-beeper", },
	253	{ },
	254	};
544edf56	255	MODULE_DEVICE_TABLE(of, pwm_beeper_match);
d56a289b SH	256	#endif
d56a289b SH	257
e22739d0 LPC	258	static struct platform_driver pwm_beeper_driver = {
e22739d0 LPC	259	.probe = pwm_beeper_probe,
e22739d0 LPC	260	.driver = {
e22739d0 LPC	261	.name = "pwm-beeper",
ceb5b6c8	262	.pm = &pwm_beeper_pm_ops,
d56a289b	263	.of_match_table = of_match_ptr(pwm_beeper_match),
e22739d0 LPC	264	},
e22739d0 LPC	265	};
840a746b	266	module_platform_driver(pwm_beeper_driver);
e22739d0 LPC	267
	268	MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
	269	MODULE_DESCRIPTION("PWM beeper driver");
	270	MODULE_LICENSE("GPL");
	271	MODULE_ALIAS("platform:pwm-beeper");