linux/drivers/input/misc/pwm-beeper.c
Thomas Gleixner a912e80bd0 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 151
Based on 1 normalized pattern(s):

  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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 35 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Armijn Hemel <armijn@tjaldur.nl>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.655028468@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:28 -07:00

263 lines
5.8 KiB
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_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");