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