1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 *  adv_swbutton.c - Software Button Interface Driver.
  4 *
  5 *  (C) Copyright 2020 Advantech Corporation, Inc
  6 *
  7 */
  8#include <linux/kernel.h>
  9#include <linux/module.h>
 10#include <linux/input.h>
 11#include <linux/acpi.h>
 12#include <linux/platform_device.h>
 13
 14#define ACPI_BUTTON_HID_SWBTN               "AHC0310"
 15
 16#define ACPI_BUTTON_NOTIFY_SWBTN_RELEASE    0x86
 17#define ACPI_BUTTON_NOTIFY_SWBTN_PRESSED    0x85
 18
 19struct adv_swbutton {
 20	struct input_dev *input;
 21	char phys[32];
 22};
 23
 24/*-------------------------------------------------------------------------
 25 *                               Driver Interface
 26 *--------------------------------------------------------------------------
 27 */
 28static void adv_swbutton_notify(acpi_handle handle, u32 event, void *context)
 29{
 30	struct platform_device *device = context;
 31	struct adv_swbutton *button = dev_get_drvdata(&device->dev);
 32
 33	switch (event) {
 34	case ACPI_BUTTON_NOTIFY_SWBTN_RELEASE:
 35		input_report_key(button->input, KEY_PROG1, 0);
 36		input_sync(button->input);
 37		break;
 38	case ACPI_BUTTON_NOTIFY_SWBTN_PRESSED:
 39		input_report_key(button->input, KEY_PROG1, 1);
 40		input_sync(button->input);
 41		break;
 42	default:
 43		dev_dbg(&device->dev, "Unsupported event [0x%x]\n", event);
 44	}
 45}
 46
 47static int adv_swbutton_probe(struct platform_device *device)
 48{
 49	struct adv_swbutton *button;
 50	struct input_dev *input;
 51	acpi_handle handle = ACPI_HANDLE(&device->dev);
 52	acpi_status status;
 53	int error;
 54
 55	button = devm_kzalloc(&device->dev, sizeof(*button), GFP_KERNEL);
 56	if (!button)
 57		return -ENOMEM;
 58
 59	dev_set_drvdata(&device->dev, button);
 60
 61	input = devm_input_allocate_device(&device->dev);
 62	if (!input)
 63		return -ENOMEM;
 64
 65	button->input = input;
 66	snprintf(button->phys, sizeof(button->phys), "%s/button/input0", ACPI_BUTTON_HID_SWBTN);
 67
 68	input->name = "Advantech Software Button";
 69	input->phys = button->phys;
 70	input->id.bustype = BUS_HOST;
 71	input->dev.parent = &device->dev;
 72	set_bit(EV_REP, input->evbit);
 73	input_set_capability(input, EV_KEY, KEY_PROG1);
 74
 75	error = input_register_device(input);
 76	if (error)
 77		return error;
 78
 79	device_init_wakeup(&device->dev, true);
 80
 81	status = acpi_install_notify_handler(handle,
 82					     ACPI_DEVICE_NOTIFY,
 83					     adv_swbutton_notify,
 84					     device);
 85	if (ACPI_FAILURE(status)) {
 86		dev_err(&device->dev, "Error installing notify handler\n");
 87		return -EIO;
 88	}
 89
 90	return 0;
 91}
 92
 93static int adv_swbutton_remove(struct platform_device *device)
 94{
 95	acpi_handle handle = ACPI_HANDLE(&device->dev);
 96
 97	acpi_remove_notify_handler(handle, ACPI_DEVICE_NOTIFY,
 98				   adv_swbutton_notify);
 99
100	return 0;
101}
102
103static const struct acpi_device_id button_device_ids[] = {
104	{ACPI_BUTTON_HID_SWBTN, 0},
105	{"", 0},
106};
107MODULE_DEVICE_TABLE(acpi, button_device_ids);
108
109static struct platform_driver adv_swbutton_driver = {
110	.driver = {
111		.name = "adv_swbutton",
112		.acpi_match_table = button_device_ids,
113	},
114	.probe = adv_swbutton_probe,
115	.remove = adv_swbutton_remove,
116};
117module_platform_driver(adv_swbutton_driver);
118
119MODULE_AUTHOR("Andrea Ho");
120MODULE_DESCRIPTION("Advantech ACPI SW Button Driver");
121MODULE_LICENSE("GPL v2");