LXR linux/drivers/input/misc/gpio-beeper.c

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * Generic GPIO beeper driver
   4 *
   5 * Copyright (C) 2013-2014 Alexander Shiyan <shc_work@mail.ru>
   6 */
   7
   8#include <linux/input.h>
   9#include <linux/module.h>
  10#include <linux/gpio/consumer.h>
  11#include <linux/of.h>
  12#include <linux/workqueue.h>
  13#include <linux/platform_device.h>
  14
  15#define BEEPER_MODNAME          "gpio-beeper"
  16
  17struct gpio_beeper {
  18        struct work_struct      work;
  19        struct gpio_desc        *desc;
  20        bool                    beeping;
  21};
  22
  23static void gpio_beeper_toggle(struct gpio_beeper *beep, bool on)
  24{
  25        gpiod_set_value_cansleep(beep->desc, on);
  26}
  27
  28static void gpio_beeper_work(struct work_struct *work)
  29{
  30        struct gpio_beeper *beep = container_of(work, struct gpio_beeper, work);
  31
  32        gpio_beeper_toggle(beep, beep->beeping);
  33}
  34
  35static int gpio_beeper_event(struct input_dev *dev, unsigned int type,
  36                             unsigned int code, int value)
  37{
  38        struct gpio_beeper *beep = input_get_drvdata(dev);
  39
  40        if (type != EV_SND || code != SND_BELL)
  41                return -ENOTSUPP;
  42
  43        if (value < 0)
  44                return -EINVAL;
  45
  46        beep->beeping = value;
  47        /* Schedule work to actually turn the beeper on or off */
  48        schedule_work(&beep->work);
  49
  50        return 0;
  51}
  52
  53static void gpio_beeper_close(struct input_dev *input)
  54{
  55        struct gpio_beeper *beep = input_get_drvdata(input);
  56
  57        cancel_work_sync(&beep->work);
  58        gpio_beeper_toggle(beep, false);
  59}
  60
  61static int gpio_beeper_probe(struct platform_device *pdev)
  62{
  63        struct gpio_beeper *beep;
  64        struct input_dev *input;
  65
  66        beep = devm_kzalloc(&pdev->dev, sizeof(*beep), GFP_KERNEL);
  67        if (!beep)
  68                return -ENOMEM;
  69
  70        beep->desc = devm_gpiod_get(&pdev->dev, NULL, GPIOD_OUT_LOW);
  71        if (IS_ERR(beep->desc))
  72                return PTR_ERR(beep->desc);
  73
  74        input = devm_input_allocate_device(&pdev->dev);
  75        if (!input)
  76                return -ENOMEM;
  77
  78        INIT_WORK(&beep->work, gpio_beeper_work);
  79
  80        input->name             = pdev->name;
  81        input->id.bustype       = BUS_HOST;
  82        input->id.vendor        = 0x0001;
  83        input->id.product       = 0x0001;
  84        input->id.version       = 0x0100;
  85        input->close            = gpio_beeper_close;
  86        input->event            = gpio_beeper_event;
  87
  88        input_set_capability(input, EV_SND, SND_BELL);
  89
  90        input_set_drvdata(input, beep);
  91
  92        return input_register_device(input);
  93}
  94
  95#ifdef CONFIG_OF
  96static const struct of_device_id gpio_beeper_of_match[] = {
  97        { .compatible = BEEPER_MODNAME, },
  98        { }
  99};
 100MODULE_DEVICE_TABLE(of, gpio_beeper_of_match);
 101#endif
 102
 103static struct platform_driver gpio_beeper_platform_driver = {
 104        .driver = {
 105                .name           = BEEPER_MODNAME,
 106                .of_match_table = of_match_ptr(gpio_beeper_of_match),
 107        },
 108        .probe  = gpio_beeper_probe,
 109};
 110module_platform_driver(gpio_beeper_platform_driver);
 111
 112MODULE_LICENSE("GPL");
 113MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
 114MODULE_DESCRIPTION("Generic GPIO beeper driver");
 115