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(beep->desc, 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, 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(&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(input); 56 57 cancel_work_sync(&beep->work); 58 gpio_beeper_toggle(beep, 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(&pdev->dev, sizeof(*beep), GFP_KERNEL); 67 if (!beep) 68 return -ENOMEM; 69 70 beep->desc = devm_gpiod_get(&pdev->dev, NULL, GPIOD_OUT_LOW); 71 if (IS_ERR(beep->desc)) 72 return PTR_ERR(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(input, EV_SND, SND_BELL); 89 90 input_set_drvdata(input, 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