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(desc: beep->desc, value: 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, on: 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(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(dev: input); |
56 | |
57 | cancel_work_sync(work: &beep->work); |
58 | gpio_beeper_toggle(beep, on: 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(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 |
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" ); |
115 | |