/* * Generic GPIO beeper driver * * Copyright (C) 2013-2014 Alexander Shiyan <shc_work@mail.ru> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. */ #include <linux/input.h> #include <linux/module.h> #include <linux/gpio/consumer.h> #include <linux/of.h> #include <linux/workqueue.h> #include <linux/platform_device.h> #define BEEPER_MODNAME "gpio-beeper" struct gpio_beeper { struct work_struct work; struct gpio_desc *desc; bool beeping; }; static void gpio_beeper_toggle(struct gpio_beeper *beep, bool on) { gpiod_set_value_cansleep(beep->desc, on); } static void gpio_beeper_work(struct work_struct *work) { struct gpio_beeper *beep = container_of(work, struct gpio_beeper, work); gpio_beeper_toggle(beep, beep->beeping); } static int gpio_beeper_event(struct input_dev *dev, unsigned int type, unsigned int code, int value) { struct gpio_beeper *beep = input_get_drvdata(dev); if (type != EV_SND || code != SND_BELL) return -ENOTSUPP; if (value < 0) return -EINVAL; beep->beeping = value; /* Schedule work to actually turn the beeper on or off */ schedule_work(&beep->work); return 0; } static void gpio_beeper_close(struct input_dev *input) { struct gpio_beeper *beep = input_get_drvdata(input); cancel_work_sync(&beep->work); gpio_beeper_toggle(beep, false); } static int gpio_beeper_probe(struct platform_device *pdev) { struct gpio_beeper *beep; struct input_dev *input; beep = devm_kzalloc(&pdev->dev, sizeof(*beep), GFP_KERNEL); if (!beep) return -ENOMEM; beep->desc = devm_gpiod_get(&pdev->dev, NULL, GPIOD_OUT_LOW); if (IS_ERR(beep->desc)) return PTR_ERR(beep->desc); input = devm_input_allocate_device(&pdev->dev); if (!input) return -ENOMEM; INIT_WORK(&beep->work, gpio_beeper_work); input->name = pdev->name; input->id.bustype = BUS_HOST; input->id.vendor = 0x0001; input->id.product = 0x0001; input->id.version = 0x0100; input->close = gpio_beeper_close; input->event = gpio_beeper_event; input_set_capability(input, EV_SND, SND_BELL); input_set_drvdata(input, beep); return input_register_device(input); } #ifdef CONFIG_OF static const struct of_device_id gpio_beeper_of_match[] = { { .compatible = BEEPER_MODNAME, }, { } }; MODULE_DEVICE_TABLE(of, gpio_beeper_of_match); #endif static struct platform_driver gpio_beeper_platform_driver = { .driver = { .name = BEEPER_MODNAME, .of_match_table = of_match_ptr(gpio_beeper_of_match), }, .probe = gpio_beeper_probe, }; module_platform_driver(gpio_beeper_platform_driver); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>"); MODULE_DESCRIPTION("Generic GPIO beeper driver");