drivers/platform/x86/intel-vbtn.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  *  Intel Virtual Button driver for Windows 8.1+
   4  *
   5  *  Copyright (C) 2016 AceLan Kao <acelan.kao@canonical.com>
   6  *  Copyright (C) 2016 Alex Hung <alex.hung@canonical.com>
   7  */
   8
   9 #include <linux/acpi.h>
  10 #include <linux/dmi.h>
  11 #include <linux/input.h>
  12 #include <linux/input/sparse-keymap.h>
  13 #include <linux/kernel.h>
  14 #include <linux/module.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/suspend.h>
  17
  18 /* Returned when NOT in tablet mode on some HP Stream x360 11 models */
  19 #define VGBS_TABLET_MODE_FLAG_ALT       0x10
  20 /* When NOT in tablet mode, VGBS returns with the flag 0x40 */
  21 #define VGBS_TABLET_MODE_FLAG           0x40
  22 #define VGBS_DOCK_MODE_FLAG             0x80
  23
  24 #define VGBS_TABLET_MODE_FLAGS (VGBS_TABLET_MODE_FLAG | VGBS_TABLET_MODE_FLAG_ALT)
  25
  26 MODULE_LICENSE("GPL");
  27 MODULE_AUTHOR("AceLan Kao");
  28
  29 static const struct acpi_device_id intel_vbtn_ids[] = {
  30         {"INT33D6", 0},
  31         {"", 0},
  32 };
  33 MODULE_DEVICE_TABLE(acpi, intel_vbtn_ids);
  34
  35 /* In theory, these are HID usages. */
  36 static const struct key_entry intel_vbtn_keymap[] = {
  37         { KE_KEY, 0xC0, { KEY_POWER } },        /* power key press */
  38         { KE_IGNORE, 0xC1, { KEY_POWER } },     /* power key release */
  39         { KE_KEY, 0xC2, { KEY_LEFTMETA } },             /* 'Windows' key press */
  40         { KE_KEY, 0xC3, { KEY_LEFTMETA } },             /* 'Windows' 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_KEY,    0xC8, { KEY_ROTATE_LOCK_TOGGLE } },        /* rotate-lock key press */
  46         { KE_KEY,    0xC9, { KEY_ROTATE_LOCK_TOGGLE } },        /* rotate-lock key release */
  47 };
  48
  49 static const struct key_entry intel_vbtn_switchmap[] = {
  50         { KE_SW,     0xCA, { .sw = { SW_DOCK, 1 } } },          /* Docked */
  51         { KE_SW,     0xCB, { .sw = { SW_DOCK, 0 } } },          /* Undocked */
  52         { KE_SW,     0xCC, { .sw = { SW_TABLET_MODE, 1 } } },   /* Tablet */
  53         { KE_SW,     0xCD, { .sw = { SW_TABLET_MODE, 0 } } },   /* Laptop */
  54 };
  55
  56 #define KEYMAP_LEN \
  57         (ARRAY_SIZE(intel_vbtn_keymap) + ARRAY_SIZE(intel_vbtn_switchmap) + 1)
  58
  59 struct intel_vbtn_priv {
  60         struct key_entry keymap[KEYMAP_LEN];
  61         struct input_dev *input_dev;
  62         bool has_buttons;
  63         bool has_switches;
  64         bool wakeup_mode;
  65 };
  66
  67 static void detect_tablet_mode(struct platform_device *device)
  68 {
  69         struct intel_vbtn_priv *priv = dev_get_drvdata(&device->dev);
  70         acpi_handle handle = ACPI_HANDLE(&device->dev);
  71         unsigned long long vgbs;
  72         acpi_status status;
  73         int m;
  74
  75         status = acpi_evaluate_integer(handle, "VGBS", NULL, &vgbs);
  76         if (ACPI_FAILURE(status))
  77                 return;
  78
  79         m = !(vgbs & VGBS_TABLET_MODE_FLAGS);
  80         input_report_switch(priv->input_dev, SW_TABLET_MODE, m);
  81         m = (vgbs & VGBS_DOCK_MODE_FLAG) ? 1 : 0;
  82         input_report_switch(priv->input_dev, SW_DOCK, m);
  83 }
  84
  85 static int intel_vbtn_input_setup(struct platform_device *device)
  86 {
  87         struct intel_vbtn_priv *priv = dev_get_drvdata(&device->dev);
  88         int ret, keymap_len = 0;
  89
  90         if (priv->has_buttons) {
  91                 memcpy(&priv->keymap[keymap_len], intel_vbtn_keymap,
  92                        ARRAY_SIZE(intel_vbtn_keymap) *
  93                        sizeof(struct key_entry));
  94                 keymap_len += ARRAY_SIZE(intel_vbtn_keymap);
  95         }
  96
  97         if (priv->has_switches) {
  98                 memcpy(&priv->keymap[keymap_len], intel_vbtn_switchmap,
  99                        ARRAY_SIZE(intel_vbtn_switchmap) *
 100                        sizeof(struct key_entry));
 101                 keymap_len += ARRAY_SIZE(intel_vbtn_switchmap);
 102         }
 103
 104         priv->keymap[keymap_len].type = KE_END;
 105
 106         priv->input_dev = devm_input_allocate_device(&device->dev);
 107         if (!priv->input_dev)
 108                 return -ENOMEM;
 109
 110         ret = sparse_keymap_setup(priv->input_dev, priv->keymap, NULL);
 111         if (ret)
 112                 return ret;
 113
 114         priv->input_dev->dev.parent = &device->dev;
 115         priv->input_dev->name = "Intel Virtual Button driver";
 116         priv->input_dev->id.bustype = BUS_HOST;
 117
 118         if (priv->has_switches)
 119                 detect_tablet_mode(device);
 120
 121         return input_register_device(priv->input_dev);
 122 }
 123
 124 static void notify_handler(acpi_handle handle, u32 event, void *context)
 125 {
 126         struct platform_device *device = context;
 127         struct intel_vbtn_priv *priv = dev_get_drvdata(&device->dev);
 128         unsigned int val = !(event & 1); /* Even=press, Odd=release */
 129         const struct key_entry *ke, *ke_rel;
 130         bool autorelease;
 131
 132         if (priv->wakeup_mode) {
 133                 ke = sparse_keymap_entry_from_scancode(priv->input_dev, event);
 134                 if (ke) {
 135                         pm_wakeup_hard_event(&device->dev);
 136
 137                         /*
 138                          * Switch events like tablet mode will wake the device
 139                          * and report the new switch position to the input
 140                          * subsystem.
 141                          */
 142                         if (ke->type == KE_SW)
 143                                 sparse_keymap_report_event(priv->input_dev,
 144                                                            event,
 145                                                            val,
 146                                                            0);
 147                         return;
 148                 }
 149                 goto out_unknown;
 150         }
 151
 152         /*
 153          * Even press events are autorelease if there is no corresponding odd
 154          * release event, or if the odd event is KE_IGNORE.
 155          */
 156         ke_rel = sparse_keymap_entry_from_scancode(priv->input_dev, event | 1);
 157         autorelease = val && (!ke_rel || ke_rel->type == KE_IGNORE);
 158
 159         if (sparse_keymap_report_event(priv->input_dev, event, val, autorelease))
 160                 return;
 161
 162 out_unknown:
 163         dev_dbg(&device->dev, "unknown event index 0x%x\n", event);
 164 }
 165
 166 static bool intel_vbtn_has_buttons(acpi_handle handle)
 167 {
 168         acpi_status status;
 169
 170         status = acpi_evaluate_object(handle, "VBDL", NULL, NULL);
 171         return ACPI_SUCCESS(status);
 172 }
 173
 174 /*
 175  * There are several laptops (non 2-in-1) models out there which support VGBS,
 176  * but simply always return 0, which we translate to SW_TABLET_MODE=1. This in
 177  * turn causes userspace (libinput) to suppress events from the builtin
 178  * keyboard and touchpad, making the laptop essentially unusable.
 179  *
 180  * Since the problem of wrongly reporting SW_TABLET_MODE=1 in combination
 181  * with libinput, leads to a non-usable system. Where as OTOH many people will
 182  * not even notice when SW_TABLET_MODE is not being reported, a DMI based allow
 183  * list is used here. This list mainly matches on the chassis-type of 2-in-1s.
 184  *
 185  * There are also some 2-in-1s which use the intel-vbtn ACPI interface to report
 186  * SW_TABLET_MODE with a chassis-type of 8 ("Portable") or 10 ("Notebook"),
 187  * these are matched on a per model basis, since many normal laptops with a
 188  * possible broken VGBS ACPI-method also use these chassis-types.
 189  */
 190 static const struct dmi_system_id dmi_switches_allow_list[] = {
 191         {
 192                 .matches = {
 193                         DMI_EXACT_MATCH(DMI_CHASSIS_TYPE, "31" /* Convertible */),
 194                 },
 195         },
 196         {
 197                 .matches = {
 198                         DMI_EXACT_MATCH(DMI_CHASSIS_TYPE, "32" /* Detachable */),
 199                 },
 200         },
 201         {
 202                 .matches = {
 203                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 204                         DMI_MATCH(DMI_PRODUCT_NAME, "Venue 11 Pro 7130"),
 205                 },
 206         },
 207         {
 208                 .matches = {
 209                         DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 210                         DMI_MATCH(DMI_PRODUCT_NAME, "HP Stream x360 Convertible PC 11"),
 211                 },
 212         },
 213         {
 214                 .matches = {
 215                         DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 216                         DMI_MATCH(DMI_PRODUCT_NAME, "HP Pavilion 13 x360 PC"),
 217                 },
 218         },
 219         {
 220                 .matches = {
 221                         DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
 222                         DMI_MATCH(DMI_PRODUCT_NAME, "Switch SA5-271"),
 223                 },
 224         },
 225         {} /* Array terminator */
 226 };
 227
 228 static bool intel_vbtn_has_switches(acpi_handle handle)
 229 {
 230         unsigned long long vgbs;
 231         acpi_status status;
 232
 233         if (!dmi_check_system(dmi_switches_allow_list))
 234                 return false;
 235
 236         status = acpi_evaluate_integer(handle, "VGBS", NULL, &vgbs);
 237         return ACPI_SUCCESS(status);
 238 }
 239
 240 static int intel_vbtn_probe(struct platform_device *device)
 241 {
 242         acpi_handle handle = ACPI_HANDLE(&device->dev);
 243         bool has_buttons, has_switches;
 244         struct intel_vbtn_priv *priv;
 245         acpi_status status;
 246         int err;
 247
 248         has_buttons = intel_vbtn_has_buttons(handle);
 249         has_switches = intel_vbtn_has_switches(handle);
 250
 251         if (!has_buttons && !has_switches) {
 252                 dev_warn(&device->dev, "failed to read Intel Virtual Button driver\n");
 253                 return -ENODEV;
 254         }
 255
 256         priv = devm_kzalloc(&device->dev, sizeof(*priv), GFP_KERNEL);
 257         if (!priv)
 258                 return -ENOMEM;
 259         dev_set_drvdata(&device->dev, priv);
 260
 261         priv->has_buttons = has_buttons;
 262         priv->has_switches = has_switches;
 263
 264         err = intel_vbtn_input_setup(device);
 265         if (err) {
 266                 pr_err("Failed to setup Intel Virtual Button\n");
 267                 return err;
 268         }
 269
 270         status = acpi_install_notify_handler(handle,
 271                                              ACPI_DEVICE_NOTIFY,
 272                                              notify_handler,
 273                                              device);
 274         if (ACPI_FAILURE(status))
 275                 return -EBUSY;
 276
 277         device_init_wakeup(&device->dev, true);
 278         /*
 279          * In order for system wakeup to work, the EC GPE has to be marked as
 280          * a wakeup one, so do that here (this setting will persist, but it has
 281          * no effect until the wakeup mask is set for the EC GPE).
 282          */
 283         acpi_ec_mark_gpe_for_wake();
 284         return 0;
 285 }
 286
 287 static int intel_vbtn_remove(struct platform_device *device)
 288 {
 289         acpi_handle handle = ACPI_HANDLE(&device->dev);
 290
 291         device_init_wakeup(&device->dev, false);
 292         acpi_remove_notify_handler(handle, ACPI_DEVICE_NOTIFY, notify_handler);
 293
 294         /*
 295          * Even if we failed to shut off the event stream, we can still
 296          * safely detach from the device.
 297          */
 298         return 0;
 299 }
 300
 301 static int intel_vbtn_pm_prepare(struct device *dev)
 302 {
 303         if (device_may_wakeup(dev)) {
 304                 struct intel_vbtn_priv *priv = dev_get_drvdata(dev);
 305
 306                 priv->wakeup_mode = true;
 307         }
 308         return 0;
 309 }
 310
 311 static void intel_vbtn_pm_complete(struct device *dev)
 312 {
 313         struct intel_vbtn_priv *priv = dev_get_drvdata(dev);
 314
 315         priv->wakeup_mode = false;
 316 }
 317
 318 static int intel_vbtn_pm_resume(struct device *dev)
 319 {
 320         intel_vbtn_pm_complete(dev);
 321         return 0;
 322 }
 323
 324 static const struct dev_pm_ops intel_vbtn_pm_ops = {
 325         .prepare = intel_vbtn_pm_prepare,
 326         .complete = intel_vbtn_pm_complete,
 327         .resume = intel_vbtn_pm_resume,
 328         .restore = intel_vbtn_pm_resume,
 329         .thaw = intel_vbtn_pm_resume,
 330 };
 331
 332 static struct platform_driver intel_vbtn_pl_driver = {
 333         .driver = {
 334                 .name = "intel-vbtn",
 335                 .acpi_match_table = intel_vbtn_ids,
 336                 .pm = &intel_vbtn_pm_ops,
 337         },
 338         .probe = intel_vbtn_probe,
 339         .remove = intel_vbtn_remove,
 340 };
 341
 342 static acpi_status __init
 343 check_acpi_dev(acpi_handle handle, u32 lvl, void *context, void **rv)
 344 {
 345         const struct acpi_device_id *ids = context;
 346         struct acpi_device *dev;
 347
 348         if (acpi_bus_get_device(handle, &dev) != 0)
 349                 return AE_OK;
 350
 351         if (acpi_match_device_ids(dev, ids) == 0)
 352                 if (!IS_ERR_OR_NULL(acpi_create_platform_device(dev, NULL)))
 353                         dev_info(&dev->dev,
 354                                  "intel-vbtn: created platform device\n");
 355
 356         return AE_OK;
 357 }
 358
 359 static int __init intel_vbtn_init(void)
 360 {
 361         acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 362                             ACPI_UINT32_MAX, check_acpi_dev, NULL,
 363                             (void *)intel_vbtn_ids, NULL);
 364
 365         return platform_driver_register(&intel_vbtn_pl_driver);
 366 }
 367 module_init(intel_vbtn_init);
 368
 369 static void __exit intel_vbtn_exit(void)
 370 {
 371         platform_driver_unregister(&intel_vbtn_pl_driver);
 372 }
 373 module_exit(intel_vbtn_exit);