Quelle  adv_swbutton.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0
/*
 *  adv_swbutton.c - Software Button Interface Driver.
 *
 *  (C) Copyright 2020 Advantech Corporation, Inc
 *
 */
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/input.h>
#include <linux/acpi.h>
#include <linux/platform_device.h>

#define ACPI_BUTTON_HID_SWBTN               "AHC0310"

#define ACPI_BUTTON_NOTIFY_SWBTN_RELEASE    0x86
#define ACPI_BUTTON_NOTIFY_SWBTN_PRESSED    0x85

struct adv_swbutton {
 struct input_dev *input;
 char phys[32];
};

/*-------------------------------------------------------------------------
 *                               Driver Interface
 *--------------------------------------------------------------------------
 */
static void adv_swbutton_notify(acpi_handle handle, u32 event, void *context)
{
 struct platform_device *device = context;
 struct adv_swbutton *button = dev_get_drvdata(&device->dev);

 switch (event) {
 case ACPI_BUTTON_NOTIFY_SWBTN_RELEASE:
  input_report_key(button->input, KEY_PROG1, 0);
  input_sync(button->input);
  break;
 case ACPI_BUTTON_NOTIFY_SWBTN_PRESSED:
  input_report_key(button->input, KEY_PROG1, 1);
  input_sync(button->input);
  break;
 default:
  dev_dbg(&device->dev, "Unsupported event [0x%x]\n", event);
 }
}

static int adv_swbutton_probe(struct platform_device *device)
{
 struct adv_swbutton *button;
 struct input_dev *input;
 acpi_handle handle = ACPI_HANDLE(&device->dev);
 acpi_status status;
 int error;

 button = devm_kzalloc(&device->dev, sizeof(*button), GFP_KERNEL);
 if (!button)
  return -ENOMEM;

 dev_set_drvdata(&device->dev, button);

 input = devm_input_allocate_device(&device->dev);
 if (!input)
  return -ENOMEM;

 button->input = input;
 snprintf(button->phys, sizeof(button->phys), "%s/button/input0", ACPI_BUTTON_HID_SWBTN);

 input->name = "Advantech Software Button";
 input->phys = button->phys;
 input->id.bustype = BUS_HOST;
 input->dev.parent = &device->dev;
 set_bit(EV_REP, input->evbit);
 input_set_capability(input, EV_KEY, KEY_PROG1);

 error = input_register_device(input);
 if (error)
  return error;

 device_init_wakeup(&device->dev, true);

 status = acpi_install_notify_handler(handle,
          ACPI_DEVICE_NOTIFY,
          adv_swbutton_notify,
          device);
 if (ACPI_FAILURE(status)) {
  dev_err(&device->dev, "Error installing notify handler\n");
  return -EIO;
 }

 return 0;
}

static void adv_swbutton_remove(struct platform_device *device)
{
 acpi_handle handle = ACPI_HANDLE(&device->dev);

 acpi_remove_notify_handler(handle, ACPI_DEVICE_NOTIFY,
       adv_swbutton_notify);
}

static const struct acpi_device_id button_device_ids[] = {
 {ACPI_BUTTON_HID_SWBTN, 0},
 {"", 0},
};
MODULE_DEVICE_TABLE(acpi, button_device_ids);

static struct platform_driver adv_swbutton_driver = {
 .driver = {
  .name = "adv_swbutton",
  .acpi_match_table = button_device_ids,
 },
 .probe = adv_swbutton_probe,
 .remove = adv_swbutton_remove,
};
module_platform_driver(adv_swbutton_driver);

MODULE_AUTHOR("Andrea Ho");
MODULE_DESCRIPTION("Advantech ACPI SW Button Driver");
MODULE_LICENSE("GPL v2");