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(desc: beep->desc, value: 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, on: 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(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(dev: input);
56
57 cancel_work_sync(work: &beep->work);
58 gpio_beeper_toggle(beep, on: 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(dev: &pdev->dev, size: sizeof(*beep), GFP_KERNEL);
67 if (!beep)
68 return -ENOMEM;
69
70 beep->desc = devm_gpiod_get(dev: &pdev->dev, NULL, flags: GPIOD_OUT_LOW);
71 if (IS_ERR(ptr: beep->desc))
72 return PTR_ERR(ptr: 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(dev: input, EV_SND, SND_BELL);
89
90 input_set_drvdata(dev: input, data: 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 = "gpio-beeper", },
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

source code of linux/drivers/input/misc/gpio-beeper.c