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, 4, { KEY_PAGEDOWN } },
  45         { KE_KEY, 4, { KEY_HOME } },
  46         { KE_KEY, 8, { KEY_RFKILL } },
  47         { KE_KEY, 9, { KEY_POWER } },
  48         { KE_KEY, 11, { KEY_SLEEP } },
  49         /* 13 has two different meanings in the spec -- ignore it. */
  50         { KE_KEY, 14, { KEY_STOPCD } },
  51         { KE_KEY, 15, { KEY_PLAYPAUSE } },
  52         { KE_KEY, 16, { KEY_MUTE } },
  53         { KE_KEY, 17, { KEY_VOLUMEUP } },
  54         { KE_KEY, 18, { KEY_VOLUMEDOWN } },
  55         { KE_KEY, 19, { KEY_BRIGHTNESSUP } },
  56         { KE_KEY, 20, { KEY_BRIGHTNESSDOWN } },
  57         /* 27: wake -- needs special handling */
  58         { KE_END },
  59 };
  60
  61 struct intel_hid_priv {
  62         struct input_dev *input_dev;
  63 };
  64
  65 static int intel_hid_set_enable(struct device *device, int enable)
  66 {
  67         union acpi_object arg0 = { ACPI_TYPE_INTEGER };
  68         struct acpi_object_list args = { 1, &arg0 };
  69         acpi_status status;
  70
  71         arg0.integer.value = enable;
  72         status = acpi_evaluate_object(ACPI_HANDLE(device), "HDSM", &args, NULL);
  73         if (!ACPI_SUCCESS(status)) {
  74                 dev_warn(device, "failed to %sable hotkeys\n",
  75                          enable ? "en" : "dis");
  76                 return -EIO;
  77         }
  78
  79         return 0;
  80 }
  81
  82 static int intel_hid_pl_suspend_handler(struct device *device)
  83 {
  84         intel_hid_set_enable(device, 0);
  85         return 0;
  86 }
  87
  88 static int intel_hid_pl_resume_handler(struct device *device)
  89 {
  90         intel_hid_set_enable(device, 1);
  91         return 0;
  92 }
  93
  94 static const struct dev_pm_ops intel_hid_pl_pm_ops = {
  95         .suspend  = intel_hid_pl_suspend_handler,
  96         .resume  = intel_hid_pl_resume_handler,
  97 };
  98
  99 static int intel_hid_input_setup(struct platform_device *device)
 100 {
 101         struct intel_hid_priv *priv = dev_get_drvdata(&device->dev);
 102         int ret;
 103
 104         priv->input_dev = input_allocate_device();
 105         if (!priv->input_dev)
 106                 return -ENOMEM;
 107
 108         ret = sparse_keymap_setup(priv->input_dev, intel_hid_keymap, NULL);
 109         if (ret)
 110                 goto err_free_device;
 111
 112         priv->input_dev->dev.parent = &device->dev;
 113         priv->input_dev->name = "Intel HID events";
 114         priv->input_dev->id.bustype = BUS_HOST;
 115         set_bit(KEY_RFKILL, priv->input_dev->keybit);
 116
 117         ret = input_register_device(priv->input_dev);
 118         if (ret)
 119                 goto err_free_device;
 120
 121         return 0;
 122
 123 err_free_device:
 124                 input_free_device(priv->input_dev);
 125                 return ret;
 126 }
 127
 128 static void intel_hid_input_destroy(struct platform_device *device)
 129 {
 130         struct intel_hid_priv *priv = dev_get_drvdata(&device->dev);
 131
 132         input_unregister_device(priv->input_dev);
 133 }
 134
 135 static void notify_handler(acpi_handle handle, u32 event, void *context)
 136 {
 137         struct platform_device *device = context;
 138         struct intel_hid_priv *priv = dev_get_drvdata(&device->dev);
 139         unsigned long long ev_index;
 140         acpi_status status;
 141
 142         /* The platform spec only defines one event code: 0xC0. */
 143         if (event != 0xc0) {
 144                 dev_warn(&device->dev, "received unknown event (0x%x)\n",
 145                          event);
 146                 return;
 147         }
 148
 149         status = acpi_evaluate_integer(handle, "HDEM", NULL, &ev_index);
 150         if (!ACPI_SUCCESS(status)) {
 151                 dev_warn(&device->dev, "failed to get event index\n");
 152                 return;
 153         }
 154
 155         if (!sparse_keymap_report_event(priv->input_dev, ev_index, 1, true))
 156                 dev_info(&device->dev, "unknown event index 0x%llx\n",
 157                          ev_index);
 158 }
 159
 160 static int intel_hid_probe(struct platform_device *device)
 161 {
 162         acpi_handle handle = ACPI_HANDLE(&device->dev);
 163         struct intel_hid_priv *priv;
 164         unsigned long long mode;
 165         acpi_status status;
 166         int err;
 167
 168         status = acpi_evaluate_integer(handle, "HDMM", NULL, &mode);
 169         if (!ACPI_SUCCESS(status)) {
 170                 dev_warn(&device->dev, "failed to read mode\n");
 171                 return -ENODEV;
 172         }
 173
 174         if (mode != 0) {
 175                 /*
 176                  * This driver only implements "simple" mode.  There appear
 177                  * to be no other modes, but we should be paranoid and check
 178                  * for compatibility.
 179                  */
 180                 dev_info(&device->dev, "platform is not in simple mode\n");
 181                 return -ENODEV;
 182         }
 183
 184         priv = devm_kzalloc(&device->dev,
 185                             sizeof(struct intel_hid_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         acpi_remove_notify_handler(handle, ACPI_DEVICE_NOTIFY, notify_handler);
 228
 229         /*
 230          * Even if we failed to shut off the event stream, we can still
 231          * safely detach from the device.
 232          */
 233         return 0;
 234 }
 235
 236 static struct platform_driver intel_hid_pl_driver = {
 237         .driver = {
 238                 .name = "intel-hid",
 239                 .acpi_match_table = intel_hid_ids,
 240                 .pm = &intel_hid_pl_pm_ops,
 241         },
 242         .probe = intel_hid_probe,
 243         .remove = intel_hid_remove,
 244 };
 245 MODULE_DEVICE_TABLE(acpi, intel_hid_ids);
 246
 247 /*
 248  * Unfortunately, some laptops provide a _HID="INT33D5" device with
 249  * _CID="PNP0C02".  This causes the pnpacpi scan driver to claim the
 250  * ACPI node, so no platform device will be created.  The pnpacpi
 251  * driver rejects this device in subsequent processing, so no physical
 252  * node is created at all.
 253  *
 254  * As a workaround until the ACPI core figures out how to handle
 255  * this corner case, manually ask the ACPI platform device code to
 256  * claim the ACPI node.
 257  */
 258 static acpi_status __init
 259 check_acpi_dev(acpi_handle handle, u32 lvl, void *context, void **rv)
 260 {
 261         const struct acpi_device_id *ids = context;
 262         struct acpi_device *dev;
 263
 264         if (acpi_bus_get_device(handle, &dev) != 0)
 265                 return AE_OK;
 266
 267         if (acpi_match_device_ids(dev, ids) == 0)
 268                 if (acpi_create_platform_device(dev))
 269                         dev_info(&dev->dev,
 270                                  "intel-hid: created platform device\n");
 271
 272         return AE_OK;
 273 }
 274
 275 static int __init intel_hid_init(void)
 276 {
 277         acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 278                             ACPI_UINT32_MAX, check_acpi_dev, NULL,
 279                             (void *)intel_hid_ids, NULL);
 280
 281         return platform_driver_register(&intel_hid_pl_driver);
 282 }
 283 module_init(intel_hid_init);
 284
 285 static void __exit intel_hid_exit(void)
 286 {
 287         platform_driver_unregister(&intel_hid_pl_driver);
 288 }
 289 module_exit(intel_hid_exit);