root/drivers/input/misc/gpio-beeper.c

DEFINITIONS

1. gpio_beeper_toggle
2. gpio_beeper_work
3. gpio_beeper_event
4. gpio_beeper_close
5. gpio_beeper_probe

   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 
  17 struct gpio_beeper {
  18         struct work_struct      work;
  19         struct gpio_desc        *desc;
  20         bool                    beeping;
  21 };
  22 
  23 static void gpio_beeper_toggle(struct gpio_beeper *beep, bool on)
  24 {
  25         gpiod_set_value_cansleep(beep->desc, on);
  26 }
  27 
  28 static 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 
  35 static 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 
  53 static 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 
  61 static 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
  96 static const struct of_device_id gpio_beeper_of_match[] = {
  97         { .compatible = BEEPER_MODNAME, },
  98         { }
  99 };
 100 MODULE_DEVICE_TABLE(of, gpio_beeper_of_match);
 101 #endif
 102 
 103 static 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 };
 110 module_platform_driver(gpio_beeper_platform_driver);
 111 
 112 MODULE_LICENSE("GPL");
 113 MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
 114 MODULE_DESCRIPTION("Generic GPIO beeper driver");