drivers/platform/x86/intel-vbtn.c

   1 /*
   2  *  Intel Virtual Button driver for Windows 8.1+
   3  *
   4  *  Copyright (C) 2016 AceLan Kao <acelan.kao@canonical.com>
   5  *  Copyright (C) 2016 Alex Hung <alex.hung@canonical.com>
   6  *
   7  *  This program is free software; you can redistribute it and/or modify
   8  *  it under the terms of the GNU General Public License as published by
   9  *  the Free Software Foundation; either version 2 of the License, or
  10  *  (at your option) any later version.
  11  *
  12  *  This program is distributed in the hope that it will be useful,
  13  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *  GNU General Public License for more details.
  16  *
  17  */
  18
  19 #include <linux/kernel.h>
  20 #include <linux/module.h>
  21 #include <linux/init.h>
  22 #include <linux/input.h>
  23 #include <linux/platform_device.h>
  24 #include <linux/input/sparse-keymap.h>
  25 #include <linux/acpi.h>
  26 #include <linux/suspend.h>
  27 #include <acpi/acpi_bus.h>
  28
  29 MODULE_LICENSE("GPL");
  30 MODULE_AUTHOR("AceLan Kao");
  31
  32 static const struct acpi_device_id intel_vbtn_ids[] = {
  33         {"INT33D6", 0},
  34         {"", 0},
  35 };
  36
  37 /* In theory, these are HID usages. */
  38 static const struct key_entry intel_vbtn_keymap[] = {
  39         { KE_KEY, 0xC0, { KEY_POWER } },        /* power key press */
  40         { KE_IGNORE, 0xC1, { KEY_POWER } },     /* power key release */
  41         { KE_KEY, 0xC4, { KEY_VOLUMEUP } },             /* volume-up key press */
  42         { KE_IGNORE, 0xC5, { KEY_VOLUMEUP } },          /* volume-up key release */
  43         { KE_KEY, 0xC6, { KEY_VOLUMEDOWN } },           /* volume-down key press */
  44         { KE_IGNORE, 0xC7, { KEY_VOLUMEDOWN } },        /* volume-down key release */
  45         { KE_END },
  46 };
  47
  48 struct intel_vbtn_priv {
  49         struct input_dev *input_dev;
  50         bool wakeup_mode;
  51 };
  52
  53 static int intel_vbtn_input_setup(struct platform_device *device)
  54 {
  55         struct intel_vbtn_priv *priv = dev_get_drvdata(&device->dev);
  56         int ret;
  57
  58         priv->input_dev = devm_input_allocate_device(&device->dev);
  59         if (!priv->input_dev)
  60                 return -ENOMEM;
  61
  62         ret = sparse_keymap_setup(priv->input_dev, intel_vbtn_keymap, NULL);
  63         if (ret)
  64                 return ret;
  65
  66         priv->input_dev->dev.parent = &device->dev;
  67         priv->input_dev->name = "Intel Virtual Button driver";
  68         priv->input_dev->id.bustype = BUS_HOST;
  69
  70         return input_register_device(priv->input_dev);
  71 }
  72
  73 static void notify_handler(acpi_handle handle, u32 event, void *context)
  74 {
  75         struct platform_device *device = context;
  76         struct intel_vbtn_priv *priv = dev_get_drvdata(&device->dev);
  77
  78         if (priv->wakeup_mode) {
  79                 if (sparse_keymap_entry_from_scancode(priv->input_dev, event)) {
  80                         pm_wakeup_hard_event(&device->dev);
  81                         return;
  82                 }
  83         } else if (sparse_keymap_report_event(priv->input_dev, event, 1, true)) {
  84                 return;
  85         }
  86         dev_info(&device->dev, "unknown event index 0x%x\n", event);
  87 }
  88
  89 static int intel_vbtn_probe(struct platform_device *device)
  90 {
  91         acpi_handle handle = ACPI_HANDLE(&device->dev);
  92         struct intel_vbtn_priv *priv;
  93         acpi_status status;
  94         int err;
  95
  96         status = acpi_evaluate_object(handle, "VBDL", NULL, NULL);
  97         if (ACPI_FAILURE(status)) {
  98                 dev_warn(&device->dev, "failed to read Intel Virtual Button driver\n");
  99                 return -ENODEV;
 100         }
 101
 102         priv = devm_kzalloc(&device->dev, sizeof(*priv), GFP_KERNEL);
 103         if (!priv)
 104                 return -ENOMEM;
 105         dev_set_drvdata(&device->dev, priv);
 106
 107         err = intel_vbtn_input_setup(device);
 108         if (err) {
 109                 pr_err("Failed to setup Intel Virtual Button\n");
 110                 return err;
 111         }
 112
 113         status = acpi_install_notify_handler(handle,
 114                                              ACPI_DEVICE_NOTIFY,
 115                                              notify_handler,
 116                                              device);
 117         if (ACPI_FAILURE(status))
 118                 return -EBUSY;
 119
 120         device_init_wakeup(&device->dev, true);
 121         return 0;
 122 }
 123
 124 static int intel_vbtn_remove(struct platform_device *device)
 125 {
 126         acpi_handle handle = ACPI_HANDLE(&device->dev);
 127
 128         acpi_remove_notify_handler(handle, ACPI_DEVICE_NOTIFY, notify_handler);
 129
 130         /*
 131          * Even if we failed to shut off the event stream, we can still
 132          * safely detach from the device.
 133          */
 134         return 0;
 135 }
 136
 137 static int intel_vbtn_pm_prepare(struct device *dev)
 138 {
 139         struct intel_vbtn_priv *priv = dev_get_drvdata(dev);
 140
 141         priv->wakeup_mode = true;
 142         return 0;
 143 }
 144
 145 static int intel_vbtn_pm_resume(struct device *dev)
 146 {
 147         struct intel_vbtn_priv *priv = dev_get_drvdata(dev);
 148
 149         priv->wakeup_mode = false;
 150         return 0;
 151 }
 152
 153 static const struct dev_pm_ops intel_vbtn_pm_ops = {
 154         .prepare = intel_vbtn_pm_prepare,
 155         .resume = intel_vbtn_pm_resume,
 156         .restore = intel_vbtn_pm_resume,
 157         .thaw = intel_vbtn_pm_resume,
 158 };
 159
 160 static struct platform_driver intel_vbtn_pl_driver = {
 161         .driver = {
 162                 .name = "intel-vbtn",
 163                 .acpi_match_table = intel_vbtn_ids,
 164                 .pm = &intel_vbtn_pm_ops,
 165         },
 166         .probe = intel_vbtn_probe,
 167         .remove = intel_vbtn_remove,
 168 };
 169 MODULE_DEVICE_TABLE(acpi, intel_vbtn_ids);
 170
 171 static acpi_status __init
 172 check_acpi_dev(acpi_handle handle, u32 lvl, void *context, void **rv)
 173 {
 174         const struct acpi_device_id *ids = context;
 175         struct acpi_device *dev;
 176
 177         if (acpi_bus_get_device(handle, &dev) != 0)
 178                 return AE_OK;
 179
 180         if (acpi_match_device_ids(dev, ids) == 0)
 181                 if (acpi_create_platform_device(dev, NULL))
 182                         dev_info(&dev->dev,
 183                                  "intel-vbtn: created platform device\n");
 184
 185         return AE_OK;
 186 }
 187
 188 static int __init intel_vbtn_init(void)
 189 {
 190         acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 191                             ACPI_UINT32_MAX, check_acpi_dev, NULL,
 192                             (void *)intel_vbtn_ids, NULL);
 193
 194         return platform_driver_register(&intel_vbtn_pl_driver);
 195 }
 196 module_init(intel_vbtn_init);
 197
 198 static void __exit intel_vbtn_exit(void)
 199 {
 200         platform_driver_unregister(&intel_vbtn_pl_driver);
 201 }
 202 module_exit(intel_vbtn_exit);