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
  30 /* In theory, these are HID usages. */
  31 static const struct key_entry intel_vbtn_keymap[] = {
  32         { KE_KEY, 0xC0, { KEY_POWER } },        /* power key press */
  33         { KE_IGNORE, 0xC1, { KEY_POWER } },     /* power key release */
  34         { KE_KEY, 0xC2, { KEY_LEFTMETA } },             /* 'Windows' key press */
  35         { KE_KEY, 0xC3, { KEY_LEFTMETA } },             /* 'Windows' key release */
  36         { KE_KEY, 0xC4, { KEY_VOLUMEUP } },             /* volume-up key press */
  37         { KE_IGNORE, 0xC5, { KEY_VOLUMEUP } },          /* volume-up key release */
  38         { KE_KEY, 0xC6, { KEY_VOLUMEDOWN } },           /* volume-down key press */
  39         { KE_IGNORE, 0xC7, { KEY_VOLUMEDOWN } },        /* volume-down key release */
  40         { KE_KEY,    0xC8, { KEY_ROTATE_LOCK_TOGGLE } },        /* rotate-lock key press */
  41         { KE_KEY,    0xC9, { KEY_ROTATE_LOCK_TOGGLE } },        /* rotate-lock key release */
  42 };
  43
  44 static const struct key_entry intel_vbtn_switchmap[] = {
  45         { KE_SW,     0xCA, { .sw = { SW_DOCK, 1 } } },          /* Docked */
  46         { KE_SW,     0xCB, { .sw = { SW_DOCK, 0 } } },          /* Undocked */
  47         { KE_SW,     0xCC, { .sw = { SW_TABLET_MODE, 1 } } },   /* Tablet */
  48         { KE_SW,     0xCD, { .sw = { SW_TABLET_MODE, 0 } } },   /* Laptop */
  49 };
  50
  51 #define KEYMAP_LEN \
  52         (ARRAY_SIZE(intel_vbtn_keymap) + ARRAY_SIZE(intel_vbtn_switchmap) + 1)
  53
  54 struct intel_vbtn_priv {
  55         struct key_entry keymap[KEYMAP_LEN];
  56         struct input_dev *input_dev;
  57         bool has_switches;
  58         bool wakeup_mode;
  59 };
  60
  61 static int intel_vbtn_input_setup(struct platform_device *device)
  62 {
  63         struct intel_vbtn_priv *priv = dev_get_drvdata(&device->dev);
  64         int ret, keymap_len = 0;
  65
  66         if (true) {
  67                 memcpy(&priv->keymap[keymap_len], intel_vbtn_keymap,
  68                        ARRAY_SIZE(intel_vbtn_keymap) *
  69                        sizeof(struct key_entry));
  70                 keymap_len += ARRAY_SIZE(intel_vbtn_keymap);
  71         }
  72
  73         if (priv->has_switches) {
  74                 memcpy(&priv->keymap[keymap_len], intel_vbtn_switchmap,
  75                        ARRAY_SIZE(intel_vbtn_switchmap) *
  76                        sizeof(struct key_entry));
  77                 keymap_len += ARRAY_SIZE(intel_vbtn_switchmap);
  78         }
  79
  80         priv->keymap[keymap_len].type = KE_END;
  81
  82         priv->input_dev = devm_input_allocate_device(&device->dev);
  83         if (!priv->input_dev)
  84                 return -ENOMEM;
  85
  86         ret = sparse_keymap_setup(priv->input_dev, priv->keymap, NULL);
  87         if (ret)
  88                 return ret;
  89
  90         priv->input_dev->dev.parent = &device->dev;
  91         priv->input_dev->name = "Intel Virtual Button driver";
  92         priv->input_dev->id.bustype = BUS_HOST;
  93
  94         return input_register_device(priv->input_dev);
  95 }
  96
  97 static void notify_handler(acpi_handle handle, u32 event, void *context)
  98 {
  99         struct platform_device *device = context;
 100         struct intel_vbtn_priv *priv = dev_get_drvdata(&device->dev);
 101         unsigned int val = !(event & 1); /* Even=press, Odd=release */
 102         const struct key_entry *ke, *ke_rel;
 103         bool autorelease;
 104
 105         if (priv->wakeup_mode) {
 106                 ke = sparse_keymap_entry_from_scancode(priv->input_dev, event);
 107                 if (ke) {
 108                         pm_wakeup_hard_event(&device->dev);
 109
 110                         /*
 111                          * Switch events like tablet mode will wake the device
 112                          * and report the new switch position to the input
 113                          * subsystem.
 114                          */
 115                         if (ke->type == KE_SW)
 116                                 sparse_keymap_report_event(priv->input_dev,
 117                                                            event,
 118                                                            val,
 119                                                            0);
 120                         return;
 121                 }
 122                 goto out_unknown;
 123         }
 124
 125         /*
 126          * Even press events are autorelease if there is no corresponding odd
 127          * release event, or if the odd event is KE_IGNORE.
 128          */
 129         ke_rel = sparse_keymap_entry_from_scancode(priv->input_dev, event | 1);
 130         autorelease = val && (!ke_rel || ke_rel->type == KE_IGNORE);
 131
 132         if (sparse_keymap_report_event(priv->input_dev, event, val, autorelease))
 133                 return;
 134
 135 out_unknown:
 136         dev_dbg(&device->dev, "unknown event index 0x%x\n", event);
 137 }
 138
 139 static void detect_tablet_mode(struct platform_device *device)
 140 {
 141         struct intel_vbtn_priv *priv = dev_get_drvdata(&device->dev);
 142         acpi_handle handle = ACPI_HANDLE(&device->dev);
 143         unsigned long long vgbs;
 144         acpi_status status;
 145         int m;
 146
 147         status = acpi_evaluate_integer(handle, "VGBS", NULL, &vgbs);
 148         if (ACPI_FAILURE(status))
 149                 return;
 150
 151         m = !(vgbs & TABLET_MODE_FLAG);
 152         input_report_switch(priv->input_dev, SW_TABLET_MODE, m);
 153         m = (vgbs & DOCK_MODE_FLAG) ? 1 : 0;
 154         input_report_switch(priv->input_dev, SW_DOCK, m);
 155 }
 156
 157 static bool intel_vbtn_has_switches(acpi_handle handle)
 158 {
 159         const char *chassis_type = dmi_get_system_info(DMI_CHASSIS_TYPE);
 160         unsigned long long vgbs;
 161         acpi_status status;
 162
 163         /*
 164          * Some normal laptops have a VGBS method despite being non-convertible
 165          * and their VGBS method always returns 0, causing detect_tablet_mode()
 166          * to report SW_TABLET_MODE=1 to userspace, which causes issues.
 167          * These laptops have a DMI chassis_type of 9 ("Laptop"), do not report
 168          * switches on any devices with a DMI chassis_type of 9.
 169          */
 170         if (chassis_type && strcmp(chassis_type, "9") == 0)
 171                 return false;
 172
 173         status = acpi_evaluate_integer(handle, "VGBS", NULL, &vgbs);
 174         return ACPI_SUCCESS(status);
 175 }
 176
 177 static int intel_vbtn_probe(struct platform_device *device)
 178 {
 179         acpi_handle handle = ACPI_HANDLE(&device->dev);
 180         struct intel_vbtn_priv *priv;
 181         acpi_status status;
 182         int err;
 183
 184         status = acpi_evaluate_object(handle, "VBDL", NULL, NULL);
 185         if (ACPI_FAILURE(status)) {
 186                 dev_warn(&device->dev, "failed to read Intel Virtual Button driver\n");
 187                 return -ENODEV;
 188         }
 189
 190         priv = devm_kzalloc(&device->dev, sizeof(*priv), GFP_KERNEL);
 191         if (!priv)
 192                 return -ENOMEM;
 193         dev_set_drvdata(&device->dev, priv);
 194
 195         priv->has_switches = intel_vbtn_has_switches(handle);
 196
 197         err = intel_vbtn_input_setup(device);
 198         if (err) {
 199                 pr_err("Failed to setup Intel Virtual Button\n");
 200                 return err;
 201         }
 202
 203         if (priv->has_switches)
 204                 detect_tablet_mode(device);
 205
 206         status = acpi_install_notify_handler(handle,
 207                                              ACPI_DEVICE_NOTIFY,
 208                                              notify_handler,
 209                                              device);
 210         if (ACPI_FAILURE(status))
 211                 return -EBUSY;
 212
 213         device_init_wakeup(&device->dev, true);
 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         struct intel_vbtn_priv *priv = dev_get_drvdata(dev);
 234
 235         priv->wakeup_mode = true;
 236         return 0;
 237 }
 238
 239 static int intel_vbtn_pm_resume(struct device *dev)
 240 {
 241         struct intel_vbtn_priv *priv = dev_get_drvdata(dev);
 242
 243         priv->wakeup_mode = false;
 244         return 0;
 245 }
 246
 247 static const struct dev_pm_ops intel_vbtn_pm_ops = {
 248         .prepare = intel_vbtn_pm_prepare,
 249         .resume = intel_vbtn_pm_resume,
 250         .restore = intel_vbtn_pm_resume,
 251         .thaw = intel_vbtn_pm_resume,
 252 };
 253
 254 static struct platform_driver intel_vbtn_pl_driver = {
 255         .driver = {
 256                 .name = "intel-vbtn",
 257                 .acpi_match_table = intel_vbtn_ids,
 258                 .pm = &intel_vbtn_pm_ops,
 259         },
 260         .probe = intel_vbtn_probe,
 261         .remove = intel_vbtn_remove,
 262 };
 263 MODULE_DEVICE_TABLE(acpi, intel_vbtn_ids);
 264
 265 static acpi_status __init
 266 check_acpi_dev(acpi_handle handle, u32 lvl, void *context, void **rv)
 267 {
 268         const struct acpi_device_id *ids = context;
 269         struct acpi_device *dev;
 270
 271         if (acpi_bus_get_device(handle, &dev) != 0)
 272                 return AE_OK;
 273
 274         if (acpi_match_device_ids(dev, ids) == 0)
 275                 if (acpi_create_platform_device(dev, NULL))
 276                         dev_info(&dev->dev,
 277                                  "intel-vbtn: created platform device\n");
 278
 279         return AE_OK;
 280 }
 281
 282 static int __init intel_vbtn_init(void)
 283 {
 284         acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 285                             ACPI_UINT32_MAX, check_acpi_dev, NULL,
 286                             (void *)intel_vbtn_ids, NULL);
 287
 288         return platform_driver_register(&intel_vbtn_pl_driver);
 289 }
 290 module_init(intel_vbtn_init);
 291
 292 static void __exit intel_vbtn_exit(void)
 293 {
 294         platform_driver_unregister(&intel_vbtn_pl_driver);
 295 }
 296 module_exit(intel_vbtn_exit);