| Kyle Swenson | 8d8f654 | 2021-03-15 11:02:55 -0600 | [diff] [blame] | 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 | |
| 21 | struct gpio_beeper { |
| 22 | struct work_struct work; |
| 23 | struct gpio_desc *desc; |
| 24 | bool beeping; |
| 25 | }; |
| 26 | |
| 27 | static void gpio_beeper_toggle(struct gpio_beeper *beep, bool on) |
| 28 | { |
| 29 | gpiod_set_value_cansleep(beep->desc, on); |
| 30 | } |
| 31 | |
| 32 | static 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 | |
| 39 | static 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 | |
| 57 | static 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 | |
| 65 | static 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 |
| 100 | static const struct of_device_id gpio_beeper_of_match[] = { |
| 101 | { .compatible = BEEPER_MODNAME, }, |
| 102 | { } |
| 103 | }; |
| 104 | MODULE_DEVICE_TABLE(of, gpio_beeper_of_match); |
| 105 | #endif |
| 106 | |
| 107 | static 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 | }; |
| 114 | module_platform_driver(gpio_beeper_platform_driver); |
| 115 | |
| 116 | MODULE_LICENSE("GPL"); |
| 117 | MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>"); |
| 118 | MODULE_DESCRIPTION("Generic GPIO beeper driver"); |