[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/module.h>
#include <linux/kernel.h>
#include <linux/of.h>
#include <linux/platform_device.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 work_struct work;
	unsigned long period;
	bool suspended;
};

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

static void __pwm_beeper_set(struct pwm_beeper *beeper)
{
	unsigned long period = beeper->period;

	if (period) {
		pwm_config(beeper->pwm, period / 2, period);
		pwm_enable(beeper->pwm);
	} else
		pwm_disable(beeper->pwm);
}

static void pwm_beeper_work(struct work_struct *work)
{
	struct pwm_beeper *beeper =
		container_of(work, struct pwm_beeper, work);

	__pwm_beeper_set(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 ? 1000 : 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);

	if (beeper->period)
		pwm_disable(beeper->pwm);
}

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;
	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;
	}

	/*
	 * FIXME: pwm_apply_args() should be removed when switching to
	 * the atomic PWM API.
	 */
	pwm_apply_args(beeper->pwm);

	INIT_WORK(&beeper->work, pwm_beeper_work);

	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>
	17	#include <linux/module.h>
	18	#include <linux/kernel.h>
9dbe4c32	19	#include <linux/of.h>
e22739d0 LPC	20	#include <linux/platform_device.h>
	21	#include <linux/pwm.h>
	22	#include <linux/slab.h>
f49cf3b8	23	#include <linux/workqueue.h>
e22739d0 LPC	24
	25	struct pwm_beeper {
	26	struct input_dev *input;
	27	struct pwm_device *pwm;
f49cf3b8	28	struct work_struct work;
e22739d0	29	unsigned long period;
e9728f0d	30	bool suspended;
e22739d0 LPC	31	};
	32
	33	#define HZ_TO_NANOSECONDS(x) (1000000000UL/(x))
	34
f49cf3b8 MS	35	static void __pwm_beeper_set(struct pwm_beeper *beeper)
	36	{
	37	unsigned long period = beeper->period;
	38
	39	if (period) {
	40	pwm_config(beeper->pwm, period / 2, period);
	41	pwm_enable(beeper->pwm);
	42	} else
	43	pwm_disable(beeper->pwm);
	44	}
	45
	46	static void pwm_beeper_work(struct work_struct *work)
	47	{
	48	struct pwm_beeper *beeper =
	49	container_of(work, struct pwm_beeper, work);
	50
	51	__pwm_beeper_set(beeper);
	52	}
	53
e22739d0 LPC	54	static int pwm_beeper_event(struct input_dev *input,
	55	unsigned int type, unsigned int code, int value)
	56	{
e22739d0	57	struct pwm_beeper *beeper = input_get_drvdata(input);
e22739d0 LPC	58
	59	if (type != EV_SND \|\| value < 0)
	60	return -EINVAL;
	61
	62	switch (code) {
	63	case SND_BELL:
	64	value = value ? 1000 : 0;
	65	break;
	66	case SND_TONE:
	67	break;
	68	default:
	69	return -EINVAL;
	70	}
	71
f49cf3b8 MS	72	if (value == 0)
	73	beeper->period = 0;
	74	else
	75	beeper->period = HZ_TO_NANOSECONDS(value);
	76
e9728f0d DT	77	if (!beeper->suspended)
e9728f0d DT	78	schedule_work(&beeper->work);
e22739d0 LPC	79
	80	return 0;
	81	}
	82
f49cf3b8 MS	83	static void pwm_beeper_stop(struct pwm_beeper *beeper)
	84	{
	85	cancel_work_sync(&beeper->work);
	86
	87	if (beeper->period)
	88	pwm_disable(beeper->pwm);
	89	}
	90
	91	static void pwm_beeper_close(struct input_dev *input)
	92	{
	93	struct pwm_beeper *beeper = input_get_drvdata(input);
	94
	95	pwm_beeper_stop(beeper);
	96	}
	97
5298cc4c	98	static int pwm_beeper_probe(struct platform_device *pdev)
e22739d0	99	{
bcf4b046	100	struct device *dev = &pdev->dev;
e22739d0 LPC	101	struct pwm_beeper *beeper;
	102	int error;
	103
bcf4b046	104	beeper = devm_kzalloc(dev, sizeof(*beeper), GFP_KERNEL);
e22739d0 LPC	105	if (!beeper)
	106	return -ENOMEM;
	107
bcf4b046	108	beeper->pwm = devm_pwm_get(dev, NULL);
e22739d0 LPC	109	if (IS_ERR(beeper->pwm)) {
e22739d0 LPC	110	error = PTR_ERR(beeper->pwm);
62481881 DL	111	if (error != -EPROBE_DEFER)
	112	dev_err(dev, "Failed to request PWM device: %d\n",
	113	error);
bcf4b046	114	return error;
e22739d0 LPC	115	}
e22739d0 LPC	116
cfae56f1 BB	117	/*
	118	* FIXME: pwm_apply_args() should be removed when switching to
	119	* the atomic PWM API.
	120	*/
	121	pwm_apply_args(beeper->pwm);
	122
f49cf3b8 MS	123	INIT_WORK(&beeper->work, pwm_beeper_work);
f49cf3b8 MS	124
bcf4b046	125	beeper->input = devm_input_allocate_device(dev);
e22739d0	126	if (!beeper->input) {
bcf4b046 DT	127	dev_err(dev, "Failed to allocate input device\n");
bcf4b046 DT	128	return -ENOMEM;
e22739d0	129	}
e22739d0 LPC	130
	131	beeper->input->name = "pwm-beeper";
	132	beeper->input->phys = "pwm/input0";
	133	beeper->input->id.bustype = BUS_HOST;
	134	beeper->input->id.vendor = 0x001f;
	135	beeper->input->id.product = 0x0001;
	136	beeper->input->id.version = 0x0100;
	137
48a55d7d DT	138	input_set_capability(beeper->input, EV_SND, SND_TONE);
48a55d7d DT	139	input_set_capability(beeper->input, EV_SND, SND_BELL);
e22739d0 LPC	140
e22739d0 LPC	141	beeper->input->event = pwm_beeper_event;
f49cf3b8	142	beeper->input->close = pwm_beeper_close;
e22739d0 LPC	143
	144	input_set_drvdata(beeper->input, beeper);
	145
	146	error = input_register_device(beeper->input);
	147	if (error) {
bcf4b046 DT	148	dev_err(dev, "Failed to register input device: %d\n", error);
bcf4b046 DT	149	return error;
e22739d0 LPC	150	}
	151
	152	platform_set_drvdata(pdev, beeper);
	153
e22739d0 LPC	154	return 0;
	155	}
	156
97a652a8	157	static int __maybe_unused pwm_beeper_suspend(struct device *dev)
e22739d0 LPC	158	{
	159	struct pwm_beeper *beeper = dev_get_drvdata(dev);
	160
e9728f0d DT	161	/*
	162	* Spinlock is taken here is not to protect write to
	163	* beeper->suspended, but to ensure that pwm_beeper_event
	164	* does not re-submit work once flag is set.
	165	*/
	166	spin_lock_irq(&beeper->input->event_lock);
	167	beeper->suspended = true;
	168	spin_unlock_irq(&beeper->input->event_lock);
	169
f49cf3b8	170	pwm_beeper_stop(beeper);
e22739d0 LPC	171
	172	return 0;
	173	}
	174
97a652a8	175	static int __maybe_unused pwm_beeper_resume(struct device *dev)
e22739d0 LPC	176	{
	177	struct pwm_beeper *beeper = dev_get_drvdata(dev);
	178
e9728f0d DT	179	spin_lock_irq(&beeper->input->event_lock);
	180	beeper->suspended = false;
	181	spin_unlock_irq(&beeper->input->event_lock);
	182
	183	/* Let worker figure out if we should resume beeping */
	184	schedule_work(&beeper->work);
e22739d0 LPC	185
	186	return 0;
	187	}
	188
	189	static SIMPLE_DEV_PM_OPS(pwm_beeper_pm_ops,
	190	pwm_beeper_suspend, pwm_beeper_resume);
	191
d56a289b SH	192	#ifdef CONFIG_OF
	193	static const struct of_device_id pwm_beeper_match[] = {
	194	{ .compatible = "pwm-beeper", },
	195	{ },
	196	};
544edf56	197	MODULE_DEVICE_TABLE(of, pwm_beeper_match);
d56a289b SH	198	#endif
d56a289b SH	199
e22739d0 LPC	200	static struct platform_driver pwm_beeper_driver = {
e22739d0 LPC	201	.probe = pwm_beeper_probe,
e22739d0 LPC	202	.driver = {
e22739d0 LPC	203	.name = "pwm-beeper",
ceb5b6c8	204	.pm = &pwm_beeper_pm_ops,
d56a289b	205	.of_match_table = of_match_ptr(pwm_beeper_match),
e22739d0 LPC	206	},
e22739d0 LPC	207	};
840a746b	208	module_platform_driver(pwm_beeper_driver);
e22739d0 LPC	209
	210	MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
	211	MODULE_DESCRIPTION("PWM beeper driver");
	212	MODULE_LICENSE("GPL");
	213	MODULE_ALIAS("platform:pwm-beeper");