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         if (!(chassis_type && strcmp(chassis_type, "31") == 0))
 165                 return false;
 166
 167         status = acpi_evaluate_integer(handle, "VGBS", NULL, &vgbs);
 168         return ACPI_SUCCESS(status);
 169 }
 170
 171 static int intel_vbtn_probe(struct platform_device *device)
 172 {
 173         acpi_handle handle = ACPI_HANDLE(&device->dev);
 174         struct intel_vbtn_priv *priv;
 175         acpi_status status;
 176         int err;
 177
 178         status = acpi_evaluate_object(handle, "VBDL", NULL, NULL);
 179         if (ACPI_FAILURE(status)) {
 180                 dev_warn(&device->dev, "failed to read Intel Virtual Button driver\n");
 181                 return -ENODEV;
 182         }
 183
 184         priv = devm_kzalloc(&device->dev, sizeof(*priv), GFP_KERNEL);
 185         if (!priv)
 186                 return -ENOMEM;
 187         dev_set_drvdata(&device->dev, priv);
 188
 189         priv->has_switches = intel_vbtn_has_switches(handle);
 190
 191         err = intel_vbtn_input_setup(device);
 192         if (err) {
 193                 pr_err("Failed to setup Intel Virtual Button\n");
 194                 return err;
 195         }
 196
 197         if (priv->has_switches)
 198                 detect_tablet_mode(device);
 199
 200         status = acpi_install_notify_handler(handle,
 201                                              ACPI_DEVICE_NOTIFY,
 202                                              notify_handler,
 203                                              device);
 204         if (ACPI_FAILURE(status))
 205                 return -EBUSY;
 206
 207         device_init_wakeup(&device->dev, true);
 208         /*
 209          * In order for system wakeup to work, the EC GPE has to be marked as
 210          * a wakeup one, so do that here (this setting will persist, but it has
 211          * no effect until the wakeup mask is set for the EC GPE).
 212          */
 213         acpi_ec_mark_gpe_for_wake();
 214         return 0;
 215 }
 216
 217 static int intel_vbtn_remove(struct platform_device *device)
 218 {
 219         acpi_handle handle = ACPI_HANDLE(&device->dev);
 220
 221         device_init_wakeup(&device->dev, false);
 222         acpi_remove_notify_handler(handle, ACPI_DEVICE_NOTIFY, notify_handler);
 223
 224         /*
 225          * Even if we failed to shut off the event stream, we can still
 226          * safely detach from the device.
 227          */
 228         return 0;
 229 }
 230
 231 static int intel_vbtn_pm_prepare(struct device *dev)
 232 {
 233         if (device_may_wakeup(dev)) {
 234                 struct intel_vbtn_priv *priv = dev_get_drvdata(dev);
 235
 236                 priv->wakeup_mode = true;
 237         }
 238         return 0;
 239 }
 240
 241 static void intel_vbtn_pm_complete(struct device *dev)
 242 {
 243         struct intel_vbtn_priv *priv = dev_get_drvdata(dev);
 244
 245         priv->wakeup_mode = false;
 246 }
 247
 248 static int intel_vbtn_pm_resume(struct device *dev)
 249 {
 250         intel_vbtn_pm_complete(dev);
 251         return 0;
 252 }
 253
 254 static const struct dev_pm_ops intel_vbtn_pm_ops = {
 255         .prepare = intel_vbtn_pm_prepare,
 256         .complete = intel_vbtn_pm_complete,
 257         .resume = intel_vbtn_pm_resume,
 258         .restore = intel_vbtn_pm_resume,
 259         .thaw = intel_vbtn_pm_resume,
 260 };
 261
 262 static struct platform_driver intel_vbtn_pl_driver = {
 263         .driver = {
 264                 .name = "intel-vbtn",
 265                 .acpi_match_table = intel_vbtn_ids,
 266                 .pm = &intel_vbtn_pm_ops,
 267         },
 268         .probe = intel_vbtn_probe,
 269         .remove = intel_vbtn_remove,
 270 };
 271
 272 static acpi_status __init
 273 check_acpi_dev(acpi_handle handle, u32 lvl, void *context, void **rv)
 274 {
 275         const struct acpi_device_id *ids = context;
 276         struct acpi_device *dev;
 277
 278         if (acpi_bus_get_device(handle, &dev) != 0)
 279                 return AE_OK;
 280
 281         if (acpi_match_device_ids(dev, ids) == 0)
 282                 if (acpi_create_platform_device(dev, NULL))
 283                         dev_info(&dev->dev,
 284                                  "intel-vbtn: created platform device\n");
 285
 286         return AE_OK;
 287 }
 288
 289 static int __init intel_vbtn_init(void)
 290 {
 291         acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 292                             ACPI_UINT32_MAX, check_acpi_dev, NULL,
 293                             (void *)intel_vbtn_ids, NULL);
 294
 295         return platform_driver_register(&intel_vbtn_pl_driver);
 296 }
 297 module_init(intel_vbtn_init);
 298
 299 static void __exit intel_vbtn_exit(void)
 300 {
 301         platform_driver_unregister(&intel_vbtn_pl_driver);
 302 }
 303 module_exit(intel_vbtn_exit);