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 /* When NOT in tablet mode, VGBS returns with the flag 0x40 */
  19 #define TABLET_MODE_FLAG 0x40
  20 #define DOCK_MODE_FLAG   0x80
  21
  22 MODULE_LICENSE("GPL");
  23 MODULE_AUTHOR("AceLan Kao");
  24
  25 static const struct acpi_device_id intel_vbtn_ids[] = {
  26         {"INT33D6", 0},
  27         {"", 0},
  28 };
  29 MODULE_DEVICE_TABLE(acpi, intel_vbtn_ids);
  30
  31 /* In theory, these are HID usages. */
  32 static const struct key_entry intel_vbtn_keymap[] = {
  33         { KE_KEY, 0xC0, { KEY_POWER } },        /* power key press */
  34         { KE_IGNORE, 0xC1, { KEY_POWER } },     /* power key release */
  35         { KE_KEY, 0xC2, { KEY_LEFTMETA } },             /* 'Windows' key press */
  36         { KE_KEY, 0xC3, { KEY_LEFTMETA } },             /* 'Windows' key release */
  37         { KE_KEY, 0xC4, { KEY_VOLUMEUP } },             /* volume-up key press */
  38         { KE_IGNORE, 0xC5, { KEY_VOLUMEUP } },          /* volume-up key release */
  39         { KE_KEY, 0xC6, { KEY_VOLUMEDOWN } },           /* volume-down key press */
  40         { KE_IGNORE, 0xC7, { KEY_VOLUMEDOWN } },        /* volume-down key release */
  41         { KE_KEY,    0xC8, { KEY_ROTATE_LOCK_TOGGLE } },        /* rotate-lock key press */
  42         { KE_KEY,    0xC9, { KEY_ROTATE_LOCK_TOGGLE } },        /* rotate-lock key release */
  43 };
  44
  45 static const struct key_entry intel_vbtn_switchmap[] = {
  46         { KE_SW,     0xCA, { .sw = { SW_DOCK, 1 } } },          /* Docked */
  47         { KE_SW,     0xCB, { .sw = { SW_DOCK, 0 } } },          /* Undocked */
  48         { KE_SW,     0xCC, { .sw = { SW_TABLET_MODE, 1 } } },   /* Tablet */
  49         { KE_SW,     0xCD, { .sw = { SW_TABLET_MODE, 0 } } },   /* Laptop */
  50 };
  51
  52 #define KEYMAP_LEN \
  53         (ARRAY_SIZE(intel_vbtn_keymap) + ARRAY_SIZE(intel_vbtn_switchmap) + 1)
  54
  55 struct intel_vbtn_priv {
  56         struct key_entry keymap[KEYMAP_LEN];
  57         struct input_dev *input_dev;
  58         bool has_buttons;
  59         bool has_switches;
  60         bool wakeup_mode;
  61 };
  62
  63 static int intel_vbtn_input_setup(struct platform_device *device)
  64 {
  65         struct intel_vbtn_priv *priv = dev_get_drvdata(&device->dev);
  66         int ret, keymap_len = 0;
  67
  68         if (priv->has_buttons) {
  69                 memcpy(&priv->keymap[keymap_len], intel_vbtn_keymap,
  70                        ARRAY_SIZE(intel_vbtn_keymap) *
  71                        sizeof(struct key_entry));
  72                 keymap_len += ARRAY_SIZE(intel_vbtn_keymap);
  73         }
  74
  75         if (priv->has_switches) {
  76                 memcpy(&priv->keymap[keymap_len], intel_vbtn_switchmap,
  77                        ARRAY_SIZE(intel_vbtn_switchmap) *
  78                        sizeof(struct key_entry));
  79                 keymap_len += ARRAY_SIZE(intel_vbtn_switchmap);
  80         }
  81
  82         priv->keymap[keymap_len].type = KE_END;
  83
  84         priv->input_dev = devm_input_allocate_device(&device->dev);
  85         if (!priv->input_dev)
  86                 return -ENOMEM;
  87
  88         ret = sparse_keymap_setup(priv->input_dev, priv->keymap, NULL);
  89         if (ret)
  90                 return ret;
  91
  92         priv->input_dev->dev.parent = &device->dev;
  93         priv->input_dev->name = "Intel Virtual Button driver";
  94         priv->input_dev->id.bustype = BUS_HOST;
  95
  96         return input_register_device(priv->input_dev);
  97 }
  98
  99 static void notify_handler(acpi_handle handle, u32 event, void *context)
 100 {
 101         struct platform_device *device = context;
 102         struct intel_vbtn_priv *priv = dev_get_drvdata(&device->dev);
 103         unsigned int val = !(event & 1); /* Even=press, Odd=release */
 104         const struct key_entry *ke, *ke_rel;
 105         bool autorelease;
 106
 107         if (priv->wakeup_mode) {
 108                 ke = sparse_keymap_entry_from_scancode(priv->input_dev, event);
 109                 if (ke) {
 110                         pm_wakeup_hard_event(&device->dev);
 111
 112                         /*
 113                          * Switch events like tablet mode will wake the device
 114                          * and report the new switch position to the input
 115                          * subsystem.
 116                          */
 117                         if (ke->type == KE_SW)
 118                                 sparse_keymap_report_event(priv->input_dev,
 119                                                            event,
 120                                                            val,
 121                                                            0);
 122                         return;
 123                 }
 124                 goto out_unknown;
 125         }
 126
 127         /*
 128          * Even press events are autorelease if there is no corresponding odd
 129          * release event, or if the odd event is KE_IGNORE.
 130          */
 131         ke_rel = sparse_keymap_entry_from_scancode(priv->input_dev, event | 1);
 132         autorelease = val && (!ke_rel || ke_rel->type == KE_IGNORE);
 133
 134         if (sparse_keymap_report_event(priv->input_dev, event, val, autorelease))
 135                 return;
 136
 137 out_unknown:
 138         dev_dbg(&device->dev, "unknown event index 0x%x\n", event);
 139 }
 140
 141 static void detect_tablet_mode(struct platform_device *device)
 142 {
 143         struct intel_vbtn_priv *priv = dev_get_drvdata(&device->dev);
 144         acpi_handle handle = ACPI_HANDLE(&device->dev);
 145         unsigned long long vgbs;
 146         acpi_status status;
 147         int m;
 148
 149         status = acpi_evaluate_integer(handle, "VGBS", NULL, &vgbs);
 150         if (ACPI_FAILURE(status))
 151                 return;
 152
 153         m = !(vgbs & TABLET_MODE_FLAG);
 154         input_report_switch(priv->input_dev, SW_TABLET_MODE, m);
 155         m = (vgbs & DOCK_MODE_FLAG) ? 1 : 0;
 156         input_report_switch(priv->input_dev, SW_DOCK, m);
 157 }
 158
 159 static bool intel_vbtn_has_buttons(acpi_handle handle)
 160 {
 161         acpi_status status;
 162
 163         status = acpi_evaluate_object(handle, "VBDL", NULL, NULL);
 164         return ACPI_SUCCESS(status);
 165 }
 166
 167 static bool intel_vbtn_has_switches(acpi_handle handle)
 168 {
 169         const char *chassis_type = dmi_get_system_info(DMI_CHASSIS_TYPE);
 170         unsigned long chassis_type_int;
 171         unsigned long long vgbs;
 172         acpi_status status;
 173
 174         if (kstrtoul(chassis_type, 10, &chassis_type_int))
 175                 return false;
 176
 177         switch (chassis_type_int) {
 178         case  8: /* Portable */
 179         case 31: /* Convertible */
 180         case 32: /* Detachable */
 181                 break;
 182         default:
 183                 return false;
 184         }
 185
 186         status = acpi_evaluate_integer(handle, "VGBS", NULL, &vgbs);
 187         return ACPI_SUCCESS(status);
 188 }
 189
 190 static int intel_vbtn_probe(struct platform_device *device)
 191 {
 192         acpi_handle handle = ACPI_HANDLE(&device->dev);
 193         bool has_buttons, has_switches;
 194         struct intel_vbtn_priv *priv;
 195         acpi_status status;
 196         int err;
 197
 198         has_buttons = intel_vbtn_has_buttons(handle);
 199         has_switches = intel_vbtn_has_switches(handle);
 200
 201         if (!has_buttons && !has_switches) {
 202                 dev_warn(&device->dev, "failed to read Intel Virtual Button driver\n");
 203                 return -ENODEV;
 204         }
 205
 206         priv = devm_kzalloc(&device->dev, sizeof(*priv), GFP_KERNEL);
 207         if (!priv)
 208                 return -ENOMEM;
 209         dev_set_drvdata(&device->dev, priv);
 210
 211         priv->has_buttons = has_buttons;
 212         priv->has_switches = has_switches;
 213
 214         err = intel_vbtn_input_setup(device);
 215         if (err) {
 216                 pr_err("Failed to setup Intel Virtual Button\n");
 217                 return err;
 218         }
 219
 220         if (priv->has_switches)
 221                 detect_tablet_mode(device);
 222
 223         status = acpi_install_notify_handler(handle,
 224                                              ACPI_DEVICE_NOTIFY,
 225                                              notify_handler,
 226                                              device);
 227         if (ACPI_FAILURE(status))
 228                 return -EBUSY;
 229
 230         device_init_wakeup(&device->dev, true);
 231         /*
 232          * In order for system wakeup to work, the EC GPE has to be marked as
 233          * a wakeup one, so do that here (this setting will persist, but it has
 234          * no effect until the wakeup mask is set for the EC GPE).
 235          */
 236         acpi_ec_mark_gpe_for_wake();
 237         return 0;
 238 }
 239
 240 static int intel_vbtn_remove(struct platform_device *device)
 241 {
 242         acpi_handle handle = ACPI_HANDLE(&device->dev);
 243
 244         device_init_wakeup(&device->dev, false);
 245         acpi_remove_notify_handler(handle, ACPI_DEVICE_NOTIFY, notify_handler);
 246
 247         /*
 248          * Even if we failed to shut off the event stream, we can still
 249          * safely detach from the device.
 250          */
 251         return 0;
 252 }
 253
 254 static int intel_vbtn_pm_prepare(struct device *dev)
 255 {
 256         if (device_may_wakeup(dev)) {
 257                 struct intel_vbtn_priv *priv = dev_get_drvdata(dev);
 258
 259                 priv->wakeup_mode = true;
 260         }
 261         return 0;
 262 }
 263
 264 static void intel_vbtn_pm_complete(struct device *dev)
 265 {
 266         struct intel_vbtn_priv *priv = dev_get_drvdata(dev);
 267
 268         priv->wakeup_mode = false;
 269 }
 270
 271 static int intel_vbtn_pm_resume(struct device *dev)
 272 {
 273         intel_vbtn_pm_complete(dev);
 274         return 0;
 275 }
 276
 277 static const struct dev_pm_ops intel_vbtn_pm_ops = {
 278         .prepare = intel_vbtn_pm_prepare,
 279         .complete = intel_vbtn_pm_complete,
 280         .resume = intel_vbtn_pm_resume,
 281         .restore = intel_vbtn_pm_resume,
 282         .thaw = intel_vbtn_pm_resume,
 283 };
 284
 285 static struct platform_driver intel_vbtn_pl_driver = {
 286         .driver = {
 287                 .name = "intel-vbtn",
 288                 .acpi_match_table = intel_vbtn_ids,
 289                 .pm = &intel_vbtn_pm_ops,
 290         },
 291         .probe = intel_vbtn_probe,
 292         .remove = intel_vbtn_remove,
 293 };
 294
 295 static acpi_status __init
 296 check_acpi_dev(acpi_handle handle, u32 lvl, void *context, void **rv)
 297 {
 298         const struct acpi_device_id *ids = context;
 299         struct acpi_device *dev;
 300
 301         if (acpi_bus_get_device(handle, &dev) != 0)
 302                 return AE_OK;
 303
 304         if (acpi_match_device_ids(dev, ids) == 0)
 305                 if (acpi_create_platform_device(dev, NULL))
 306                         dev_info(&dev->dev,
 307                                  "intel-vbtn: created platform device\n");
 308
 309         return AE_OK;
 310 }
 311
 312 static int __init intel_vbtn_init(void)
 313 {
 314         acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 315                             ACPI_UINT32_MAX, check_acpi_dev, NULL,
 316                             (void *)intel_vbtn_ids, NULL);
 317
 318         return platform_driver_register(&intel_vbtn_pl_driver);
 319 }
 320 module_init(intel_vbtn_init);
 321
 322 static void __exit intel_vbtn_exit(void)
 323 {
 324         platform_driver_unregister(&intel_vbtn_pl_driver);
 325 }
 326 module_exit(intel_vbtn_exit);