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_switches;
  59         bool wakeup_mode;
  60 };
  61
  62 static int intel_vbtn_input_setup(struct platform_device *device)
  63 {
  64         struct intel_vbtn_priv *priv = dev_get_drvdata(&device->dev);
  65         int ret, keymap_len = 0;
  66
  67         if (true) {
  68                 memcpy(&priv->keymap[keymap_len], intel_vbtn_keymap,
  69                        ARRAY_SIZE(intel_vbtn_keymap) *
  70                        sizeof(struct key_entry));
  71                 keymap_len += ARRAY_SIZE(intel_vbtn_keymap);
  72         }
  73
  74         if (priv->has_switches) {
  75                 memcpy(&priv->keymap[keymap_len], intel_vbtn_switchmap,
  76                        ARRAY_SIZE(intel_vbtn_switchmap) *
  77                        sizeof(struct key_entry));
  78                 keymap_len += ARRAY_SIZE(intel_vbtn_switchmap);
  79         }
  80
  81         priv->keymap[keymap_len].type = KE_END;
  82
  83         priv->input_dev = devm_input_allocate_device(&device->dev);
  84         if (!priv->input_dev)
  85                 return -ENOMEM;
  86
  87         ret = sparse_keymap_setup(priv->input_dev, priv->keymap, NULL);
  88         if (ret)
  89                 return ret;
  90
  91         priv->input_dev->dev.parent = &device->dev;
  92         priv->input_dev->name = "Intel Virtual Button driver";
  93         priv->input_dev->id.bustype = BUS_HOST;
  94
  95         return input_register_device(priv->input_dev);
  96 }
  97
  98 static void notify_handler(acpi_handle handle, u32 event, void *context)
  99 {
 100         struct platform_device *device = context;
 101         struct intel_vbtn_priv *priv = dev_get_drvdata(&device->dev);
 102         unsigned int val = !(event & 1); /* Even=press, Odd=release */
 103         const struct key_entry *ke, *ke_rel;
 104         bool autorelease;
 105
 106         if (priv->wakeup_mode) {
 107                 ke = sparse_keymap_entry_from_scancode(priv->input_dev, event);
 108                 if (ke) {
 109                         pm_wakeup_hard_event(&device->dev);
 110
 111                         /*
 112                          * Switch events like tablet mode will wake the device
 113                          * and report the new switch position to the input
 114                          * subsystem.
 115                          */
 116                         if (ke->type == KE_SW)
 117                                 sparse_keymap_report_event(priv->input_dev,
 118                                                            event,
 119                                                            val,
 120                                                            0);
 121                         return;
 122                 }
 123                 goto out_unknown;
 124         }
 125
 126         /*
 127          * Even press events are autorelease if there is no corresponding odd
 128          * release event, or if the odd event is KE_IGNORE.
 129          */
 130         ke_rel = sparse_keymap_entry_from_scancode(priv->input_dev, event | 1);
 131         autorelease = val && (!ke_rel || ke_rel->type == KE_IGNORE);
 132
 133         if (sparse_keymap_report_event(priv->input_dev, event, val, autorelease))
 134                 return;
 135
 136 out_unknown:
 137         dev_dbg(&device->dev, "unknown event index 0x%x\n", event);
 138 }
 139
 140 static void detect_tablet_mode(struct platform_device *device)
 141 {
 142         struct intel_vbtn_priv *priv = dev_get_drvdata(&device->dev);
 143         acpi_handle handle = ACPI_HANDLE(&device->dev);
 144         unsigned long long vgbs;
 145         acpi_status status;
 146         int m;
 147
 148         status = acpi_evaluate_integer(handle, "VGBS", NULL, &vgbs);
 149         if (ACPI_FAILURE(status))
 150                 return;
 151
 152         m = !(vgbs & TABLET_MODE_FLAG);
 153         input_report_switch(priv->input_dev, SW_TABLET_MODE, m);
 154         m = (vgbs & DOCK_MODE_FLAG) ? 1 : 0;
 155         input_report_switch(priv->input_dev, SW_DOCK, m);
 156 }
 157
 158 static bool intel_vbtn_has_switches(acpi_handle handle)
 159 {
 160         const char *chassis_type = dmi_get_system_info(DMI_CHASSIS_TYPE);
 161         unsigned long long vgbs;
 162         acpi_status status;
 163
 164         /*
 165          * Some normal laptops have a VGBS method despite being non-convertible
 166          * and their VGBS method always returns 0, causing detect_tablet_mode()
 167          * to report SW_TABLET_MODE=1 to userspace, which causes issues.
 168          * These laptops have a DMI chassis_type of 9 ("Laptop"), do not report
 169          * switches on any devices with a DMI chassis_type of 9.
 170          */
 171         if (chassis_type && strcmp(chassis_type, "9") == 0)
 172                 return false;
 173
 174         status = acpi_evaluate_integer(handle, "VGBS", NULL, &vgbs);
 175         return ACPI_SUCCESS(status);
 176 }
 177
 178 static int intel_vbtn_probe(struct platform_device *device)
 179 {
 180         acpi_handle handle = ACPI_HANDLE(&device->dev);
 181         struct intel_vbtn_priv *priv;
 182         acpi_status status;
 183         int err;
 184
 185         status = acpi_evaluate_object(handle, "VBDL", NULL, NULL);
 186         if (ACPI_FAILURE(status)) {
 187                 dev_warn(&device->dev, "failed to read Intel Virtual Button driver\n");
 188                 return -ENODEV;
 189         }
 190
 191         priv = devm_kzalloc(&device->dev, sizeof(*priv), GFP_KERNEL);
 192         if (!priv)
 193                 return -ENOMEM;
 194         dev_set_drvdata(&device->dev, priv);
 195
 196         priv->has_switches = intel_vbtn_has_switches(handle);
 197
 198         err = intel_vbtn_input_setup(device);
 199         if (err) {
 200                 pr_err("Failed to setup Intel Virtual Button\n");
 201                 return err;
 202         }
 203
 204         if (priv->has_switches)
 205                 detect_tablet_mode(device);
 206
 207         status = acpi_install_notify_handler(handle,
 208                                              ACPI_DEVICE_NOTIFY,
 209                                              notify_handler,
 210                                              device);
 211         if (ACPI_FAILURE(status))
 212                 return -EBUSY;
 213
 214         device_init_wakeup(&device->dev, true);
 215         /*
 216          * In order for system wakeup to work, the EC GPE has to be marked as
 217          * a wakeup one, so do that here (this setting will persist, but it has
 218          * no effect until the wakeup mask is set for the EC GPE).
 219          */
 220         acpi_ec_mark_gpe_for_wake();
 221         return 0;
 222 }
 223
 224 static int intel_vbtn_remove(struct platform_device *device)
 225 {
 226         acpi_handle handle = ACPI_HANDLE(&device->dev);
 227
 228         device_init_wakeup(&device->dev, false);
 229         acpi_remove_notify_handler(handle, ACPI_DEVICE_NOTIFY, notify_handler);
 230
 231         /*
 232          * Even if we failed to shut off the event stream, we can still
 233          * safely detach from the device.
 234          */
 235         return 0;
 236 }
 237
 238 static int intel_vbtn_pm_prepare(struct device *dev)
 239 {
 240         if (device_may_wakeup(dev)) {
 241                 struct intel_vbtn_priv *priv = dev_get_drvdata(dev);
 242
 243                 priv->wakeup_mode = true;
 244         }
 245         return 0;
 246 }
 247
 248 static void intel_vbtn_pm_complete(struct device *dev)
 249 {
 250         struct intel_vbtn_priv *priv = dev_get_drvdata(dev);
 251
 252         priv->wakeup_mode = false;
 253 }
 254
 255 static int intel_vbtn_pm_resume(struct device *dev)
 256 {
 257         intel_vbtn_pm_complete(dev);
 258         return 0;
 259 }
 260
 261 static const struct dev_pm_ops intel_vbtn_pm_ops = {
 262         .prepare = intel_vbtn_pm_prepare,
 263         .complete = intel_vbtn_pm_complete,
 264         .resume = intel_vbtn_pm_resume,
 265         .restore = intel_vbtn_pm_resume,
 266         .thaw = intel_vbtn_pm_resume,
 267 };
 268
 269 static struct platform_driver intel_vbtn_pl_driver = {
 270         .driver = {
 271                 .name = "intel-vbtn",
 272                 .acpi_match_table = intel_vbtn_ids,
 273                 .pm = &intel_vbtn_pm_ops,
 274         },
 275         .probe = intel_vbtn_probe,
 276         .remove = intel_vbtn_remove,
 277 };
 278
 279 static acpi_status __init
 280 check_acpi_dev(acpi_handle handle, u32 lvl, void *context, void **rv)
 281 {
 282         const struct acpi_device_id *ids = context;
 283         struct acpi_device *dev;
 284
 285         if (acpi_bus_get_device(handle, &dev) != 0)
 286                 return AE_OK;
 287
 288         if (acpi_match_device_ids(dev, ids) == 0)
 289                 if (acpi_create_platform_device(dev, NULL))
 290                         dev_info(&dev->dev,
 291                                  "intel-vbtn: created platform device\n");
 292
 293         return AE_OK;
 294 }
 295
 296 static int __init intel_vbtn_init(void)
 297 {
 298         acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 299                             ACPI_UINT32_MAX, check_acpi_dev, NULL,
 300                             (void *)intel_vbtn_ids, NULL);
 301
 302         return platform_driver_register(&intel_vbtn_pl_driver);
 303 }
 304 module_init(intel_vbtn_init);
 305
 306 static void __exit intel_vbtn_exit(void)
 307 {
 308         platform_driver_unregister(&intel_vbtn_pl_driver);
 309 }
 310 module_exit(intel_vbtn_exit);