1/*
2 * Generic GPIO beeper driver
3 *
4 * Copyright (C) 2013-2014 Alexander Shiyan <shc_work@mail.ru>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 */
11
12#include <linux/input.h>
13#include <linux/module.h>
14#include <linux/gpio/consumer.h>
15#include <linux/of.h>
16#include <linux/workqueue.h>
17#include <linux/platform_device.h>
18
19#define BEEPER_MODNAME		"gpio-beeper"
20
21struct gpio_beeper {
22	struct work_struct	work;
23	struct gpio_desc	*desc;
24	bool			beeping;
25};
26
27static void gpio_beeper_toggle(struct gpio_beeper *beep, bool on)
28{
29	gpiod_set_value_cansleep(beep->desc, on);
30}
31
32static void gpio_beeper_work(struct work_struct *work)
33{
34	struct gpio_beeper *beep = container_of(work, struct gpio_beeper, work);
35
36	gpio_beeper_toggle(beep, beep->beeping);
37}
38
39static int gpio_beeper_event(struct input_dev *dev, unsigned int type,
40			     unsigned int code, int value)
41{
42	struct gpio_beeper *beep = input_get_drvdata(dev);
43
44	if (type != EV_SND || code != SND_BELL)
45		return -ENOTSUPP;
46
47	if (value < 0)
48		return -EINVAL;
49
50	beep->beeping = value;
51	/* Schedule work to actually turn the beeper on or off */
52	schedule_work(&beep->work);
53
54	return 0;
55}
56
57static void gpio_beeper_close(struct input_dev *input)
58{
59	struct gpio_beeper *beep = input_get_drvdata(input);
60
61	cancel_work_sync(&beep->work);
62	gpio_beeper_toggle(beep, false);
63}
64
65static int gpio_beeper_probe(struct platform_device *pdev)
66{
67	struct gpio_beeper *beep;
68	struct input_dev *input;
69
70	beep = devm_kzalloc(&pdev->dev, sizeof(*beep), GFP_KERNEL);
71	if (!beep)
72		return -ENOMEM;
73
74	beep->desc = devm_gpiod_get(&pdev->dev, NULL, GPIOD_OUT_LOW);
75	if (IS_ERR(beep->desc))
76		return PTR_ERR(beep->desc);
77
78	input = devm_input_allocate_device(&pdev->dev);
79	if (!input)
80		return -ENOMEM;
81
82	INIT_WORK(&beep->work, gpio_beeper_work);
83
84	input->name		= pdev->name;
85	input->id.bustype	= BUS_HOST;
86	input->id.vendor	= 0x0001;
87	input->id.product	= 0x0001;
88	input->id.version	= 0x0100;
89	input->close		= gpio_beeper_close;
90	input->event		= gpio_beeper_event;
91
92	input_set_capability(input, EV_SND, SND_BELL);
93
94	input_set_drvdata(input, beep);
95
96	return input_register_device(input);
97}
98
99#ifdef CONFIG_OF
100static const struct of_device_id gpio_beeper_of_match[] = {
101	{ .compatible = BEEPER_MODNAME, },
102	{ }
103};
104MODULE_DEVICE_TABLE(of, gpio_beeper_of_match);
105#endif
106
107static struct platform_driver gpio_beeper_platform_driver = {
108	.driver	= {
109		.name		= BEEPER_MODNAME,
110		.of_match_table	= of_match_ptr(gpio_beeper_of_match),
111	},
112	.probe	= gpio_beeper_probe,
113};
114module_platform_driver(gpio_beeper_platform_driver);
115
116MODULE_LICENSE("GPL");
117MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
118MODULE_DESCRIPTION("Generic GPIO beeper driver");
119