drivers/platform/x86/intel-hid.c

   1 /*
   2  *  Intel HID event driver for Windows 8
   3  *
   4  *  Copyright (C) 2015 Alex Hung <alex.hung@canonical.com>
   5  *  Copyright (C) 2015 Andrew Lutomirski <luto@kernel.org>
   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 <acpi/acpi_bus.h>
  27
  28 MODULE_LICENSE("GPL");
  29 MODULE_AUTHOR("Alex Hung");
  30
  31 static const struct acpi_device_id intel_hid_ids[] = {
  32         {"INT33D5", 0},
  33         {"", 0},
  34 };
  35
  36 /* In theory, these are HID usages. */
  37 static const struct key_entry intel_hid_keymap[] = {
  38         /* 1: LSuper (Page 0x07, usage 0xE3) -- unclear what to do */
  39         /* 2: Toggle SW_ROTATE_LOCK -- easy to implement if seen in wild */
  40         { KE_KEY, 3, { KEY_NUMLOCK } },
  41         { KE_KEY, 4, { KEY_HOME } },
  42         { KE_KEY, 5, { KEY_END } },
  43         { KE_KEY, 6, { KEY_PAGEUP } },
  44         { KE_KEY, 7, { KEY_PAGEDOWN } },
  45         { KE_KEY, 8, { KEY_RFKILL } },
  46         { KE_KEY, 9, { KEY_POWER } },
  47         { KE_KEY, 11, { KEY_SLEEP } },
  48         /* 13 has two different meanings in the spec -- ignore it. */
  49         { KE_KEY, 14, { KEY_STOPCD } },
  50         { KE_KEY, 15, { KEY_PLAYPAUSE } },
  51         { KE_KEY, 16, { KEY_MUTE } },
  52         { KE_KEY, 17, { KEY_VOLUMEUP } },
  53         { KE_KEY, 18, { KEY_VOLUMEDOWN } },
  54         { KE_KEY, 19, { KEY_BRIGHTNESSUP } },
  55         { KE_KEY, 20, { KEY_BRIGHTNESSDOWN } },
  56         /* 27: wake -- needs special handling */
  57         { KE_END },
  58 };
  59
  60 struct intel_hid_priv {
  61         struct input_dev *input_dev;
  62 };
  63
  64 static int intel_hid_set_enable(struct device *device, int enable)
  65 {
  66         union acpi_object arg0 = { ACPI_TYPE_INTEGER };
  67         struct acpi_object_list args = { 1, &arg0 };
  68         acpi_status status;
  69
  70         arg0.integer.value = enable;
  71         status = acpi_evaluate_object(ACPI_HANDLE(device), "HDSM", &args, NULL);
  72         if (!ACPI_SUCCESS(status)) {
  73                 dev_warn(device, "failed to %sable hotkeys\n",
  74                          enable ? "en" : "dis");
  75                 return -EIO;
  76         }
  77
  78         return 0;
  79 }
  80
  81 static int intel_hid_pl_suspend_handler(struct device *device)
  82 {
  83         intel_hid_set_enable(device, 0);
  84         return 0;
  85 }
  86
  87 static int intel_hid_pl_resume_handler(struct device *device)
  88 {
  89         intel_hid_set_enable(device, 1);
  90         return 0;
  91 }
  92
  93 static const struct dev_pm_ops intel_hid_pl_pm_ops = {
  94         .freeze  = intel_hid_pl_suspend_handler,
  95         .restore  = intel_hid_pl_resume_handler,
  96         .suspend  = intel_hid_pl_suspend_handler,
  97         .resume  = intel_hid_pl_resume_handler,
  98 };
  99
 100 static int intel_hid_input_setup(struct platform_device *device)
 101 {
 102         struct intel_hid_priv *priv = dev_get_drvdata(&device->dev);
 103         int ret;
 104
 105         priv->input_dev = input_allocate_device();
 106         if (!priv->input_dev)
 107                 return -ENOMEM;
 108
 109         ret = sparse_keymap_setup(priv->input_dev, intel_hid_keymap, NULL);
 110         if (ret)
 111                 goto err_free_device;
 112
 113         priv->input_dev->dev.parent = &device->dev;
 114         priv->input_dev->name = "Intel HID events";
 115         priv->input_dev->id.bustype = BUS_HOST;
 116         set_bit(KEY_RFKILL, priv->input_dev->keybit);
 117
 118         ret = input_register_device(priv->input_dev);
 119         if (ret)
 120                 goto err_free_device;
 121
 122         return 0;
 123
 124 err_free_device:
 125         input_free_device(priv->input_dev);
 126         return ret;
 127 }
 128
 129 static void intel_hid_input_destroy(struct platform_device *device)
 130 {
 131         struct intel_hid_priv *priv = dev_get_drvdata(&device->dev);
 132
 133         input_unregister_device(priv->input_dev);
 134 }
 135
 136 static void notify_handler(acpi_handle handle, u32 event, void *context)
 137 {
 138         struct platform_device *device = context;
 139         struct intel_hid_priv *priv = dev_get_drvdata(&device->dev);
 140         unsigned long long ev_index;
 141         acpi_status status;
 142
 143         /* The platform spec only defines one event code: 0xC0. */
 144         if (event != 0xc0) {
 145                 dev_warn(&device->dev, "received unknown event (0x%x)\n",
 146                          event);
 147                 return;
 148         }
 149
 150         status = acpi_evaluate_integer(handle, "HDEM", NULL, &ev_index);
 151         if (!ACPI_SUCCESS(status)) {
 152                 dev_warn(&device->dev, "failed to get event index\n");
 153                 return;
 154         }
 155
 156         if (!sparse_keymap_report_event(priv->input_dev, ev_index, 1, true))
 157                 dev_info(&device->dev, "unknown event index 0x%llx\n",
 158                          ev_index);
 159 }
 160
 161 static int intel_hid_probe(struct platform_device *device)
 162 {
 163         acpi_handle handle = ACPI_HANDLE(&device->dev);
 164         struct intel_hid_priv *priv;
 165         unsigned long long mode;
 166         acpi_status status;
 167         int err;
 168
 169         status = acpi_evaluate_integer(handle, "HDMM", NULL, &mode);
 170         if (!ACPI_SUCCESS(status)) {
 171                 dev_warn(&device->dev, "failed to read mode\n");
 172                 return -ENODEV;
 173         }
 174
 175         if (mode != 0) {
 176                 /*
 177                  * This driver only implements "simple" mode.  There appear
 178                  * to be no other modes, but we should be paranoid and check
 179                  * for compatibility.
 180                  */
 181                 dev_info(&device->dev, "platform is not in simple mode\n");
 182                 return -ENODEV;
 183         }
 184
 185         priv = devm_kzalloc(&device->dev, sizeof(*priv), GFP_KERNEL);
 186         if (!priv)
 187                 return -ENOMEM;
 188         dev_set_drvdata(&device->dev, priv);
 189
 190         err = intel_hid_input_setup(device);
 191         if (err) {
 192                 pr_err("Failed to setup Intel HID hotkeys\n");
 193                 return err;
 194         }
 195
 196         status = acpi_install_notify_handler(handle,
 197                                              ACPI_DEVICE_NOTIFY,
 198                                              notify_handler,
 199                                              device);
 200         if (ACPI_FAILURE(status)) {
 201                 err = -EBUSY;
 202                 goto err_remove_input;
 203         }
 204
 205         err = intel_hid_set_enable(&device->dev, 1);
 206         if (err)
 207                 goto err_remove_notify;
 208
 209         return 0;
 210
 211 err_remove_notify:
 212         acpi_remove_notify_handler(handle, ACPI_DEVICE_NOTIFY, notify_handler);
 213
 214 err_remove_input:
 215         intel_hid_input_destroy(device);
 216
 217         return err;
 218 }
 219
 220 static int intel_hid_remove(struct platform_device *device)
 221 {
 222         acpi_handle handle = ACPI_HANDLE(&device->dev);
 223
 224         acpi_remove_notify_handler(handle, ACPI_DEVICE_NOTIFY, notify_handler);
 225         intel_hid_input_destroy(device);
 226         intel_hid_set_enable(&device->dev, 0);
 227
 228         /*
 229          * Even if we failed to shut off the event stream, we can still
 230          * safely detach from the device.
 231          */
 232         return 0;
 233 }
 234
 235 static struct platform_driver intel_hid_pl_driver = {
 236         .driver = {
 237                 .name = "intel-hid",
 238                 .acpi_match_table = intel_hid_ids,
 239                 .pm = &intel_hid_pl_pm_ops,
 240         },
 241         .probe = intel_hid_probe,
 242         .remove = intel_hid_remove,
 243 };
 244 MODULE_DEVICE_TABLE(acpi, intel_hid_ids);
 245
 246 /*
 247  * Unfortunately, some laptops provide a _HID="INT33D5" device with
 248  * _CID="PNP0C02".  This causes the pnpacpi scan driver to claim the
 249  * ACPI node, so no platform device will be created.  The pnpacpi
 250  * driver rejects this device in subsequent processing, so no physical
 251  * node is created at all.
 252  *
 253  * As a workaround until the ACPI core figures out how to handle
 254  * this corner case, manually ask the ACPI platform device code to
 255  * claim the ACPI node.
 256  */
 257 static acpi_status __init
 258 check_acpi_dev(acpi_handle handle, u32 lvl, void *context, void **rv)
 259 {
 260         const struct acpi_device_id *ids = context;
 261         struct acpi_device *dev;
 262
 263         if (acpi_bus_get_device(handle, &dev) != 0)
 264                 return AE_OK;
 265
 266         if (acpi_match_device_ids(dev, ids) == 0)
 267                 if (acpi_create_platform_device(dev))
 268                         dev_info(&dev->dev,
 269                                  "intel-hid: created platform device\n");
 270
 271         return AE_OK;
 272 }
 273
 274 static int __init intel_hid_init(void)
 275 {
 276         acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 277                             ACPI_UINT32_MAX, check_acpi_dev, NULL,
 278                             (void *)intel_hid_ids, NULL);
 279
 280         return platform_driver_register(&intel_hid_pl_driver);
 281 }
 282 module_init(intel_hid_init);
 283
 284 static void __exit intel_hid_exit(void)
 285 {
 286         platform_driver_unregister(&intel_hid_pl_driver);
 287 }
 288 module_exit(intel_hid_exit);