drivers/platform/x86/adv_swbutton.c

   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
  19 struct adv_swbutton {
  20         struct input_dev *input;
  21         char phys[32];
  22 };
  23
  24 /*-------------------------------------------------------------------------
  25  *                               Driver Interface
  26  *--------------------------------------------------------------------------
  27  */
  28 static 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
  47 static 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
  93 static 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
 103 static const struct acpi_device_id button_device_ids[] = {
 104         {ACPI_BUTTON_HID_SWBTN, 0},
 105         {"", 0},
 106 };
 107 MODULE_DEVICE_TABLE(acpi, button_device_ids);
 108
 109 static 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 };
 117 module_platform_driver(adv_swbutton_driver);
 118
 119 MODULE_AUTHOR("Andrea Ho");
 120 MODULE_DESCRIPTION("Advantech ACPI SW Button Driver");
 121 MODULE_LICENSE("GPL v2");