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