gpio-beeper.c
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/*
* Generic GPIO beeper driver
*
* Copyright (C) 2013-2014 Alexander Shiyan <shc_work@mail.ru>
*
* 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.
*/
#include <linux/input.h>
#include <linux/module.h>
#include <linux/gpio/consumer.h>
#include <linux/of.h>
#include <linux/workqueue.h>
#include <linux/platform_device.h>
#define BEEPER_MODNAME "gpio-beeper"
struct gpio_beeper {
struct work_struct work;
struct gpio_desc *desc;
bool beeping;
};
static void gpio_beeper_toggle(struct gpio_beeper *beep, bool on)
{
gpiod_set_value_cansleep(beep->desc, on);
}
static void gpio_beeper_work(struct work_struct *work)
{
struct gpio_beeper *beep = container_of(work, struct gpio_beeper, work);
gpio_beeper_toggle(beep, beep->beeping);
}
static int gpio_beeper_event(struct input_dev *dev, unsigned int type,
unsigned int code, int value)
{
struct gpio_beeper *beep = input_get_drvdata(dev);
if (type != EV_SND || code != SND_BELL)
return -ENOTSUPP;
if (value < 0)
return -EINVAL;
beep->beeping = value;
/* Schedule work to actually turn the beeper on or off */
schedule_work(&beep->work);
return 0;
}
static void gpio_beeper_close(struct input_dev *input)
{
struct gpio_beeper *beep = input_get_drvdata(input);
cancel_work_sync(&beep->work);
gpio_beeper_toggle(beep, false);
}
static int gpio_beeper_probe(struct platform_device *pdev)
{
struct gpio_beeper *beep;
struct input_dev *input;
beep = devm_kzalloc(&pdev->dev, sizeof(*beep), GFP_KERNEL);
if (!beep)
return -ENOMEM;
beep->desc = devm_gpiod_get(&pdev->dev, NULL, GPIOD_OUT_LOW);
if (IS_ERR(beep->desc))
return PTR_ERR(beep->desc);
input = devm_input_allocate_device(&pdev->dev);
if (!input)
return -ENOMEM;
INIT_WORK(&beep->work, gpio_beeper_work);
input->name = pdev->name;
input->id.bustype = BUS_HOST;
input->id.vendor = 0x0001;
input->id.product = 0x0001;
input->id.version = 0x0100;
input->close = gpio_beeper_close;
input->event = gpio_beeper_event;
input_set_capability(input, EV_SND, SND_BELL);
input_set_drvdata(input, beep);
return input_register_device(input);
}
#ifdef CONFIG_OF
static const struct of_device_id gpio_beeper_of_match[] = {
{ .compatible = BEEPER_MODNAME, },
{ }
};
MODULE_DEVICE_TABLE(of, gpio_beeper_of_match);
#endif
static struct platform_driver gpio_beeper_platform_driver = {
.driver = {
.name = BEEPER_MODNAME,
.of_match_table = of_match_ptr(gpio_beeper_of_match),
},
.probe = gpio_beeper_probe,
};
module_platform_driver(gpio_beeper_platform_driver);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
MODULE_DESCRIPTION("Generic GPIO beeper driver");