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"); 119