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         { KE_SW,     0xCA, { .sw = { SW_DOCK, 1 } } },          /* Docked */
  43         { KE_SW,     0xCB, { .sw = { SW_DOCK, 0 } } },          /* Undocked */
  44         { KE_SW,     0xCC, { .sw = { SW_TABLET_MODE, 1 } } },   /* Tablet */
  45         { KE_SW,     0xCD, { .sw = { SW_TABLET_MODE, 0 } } },   /* Laptop */
  46         { KE_END },
  47 };
  48
  49 struct intel_vbtn_priv {
  50         struct input_dev *input_dev;
  51         bool wakeup_mode;
  52 };
  53
  54 static int intel_vbtn_input_setup(struct platform_device *device)
  55 {
  56         struct intel_vbtn_priv *priv = dev_get_drvdata(&device->dev);
  57         int ret;
  58
  59         priv->input_dev = devm_input_allocate_device(&device->dev);
  60         if (!priv->input_dev)
  61                 return -ENOMEM;
  62
  63         ret = sparse_keymap_setup(priv->input_dev, intel_vbtn_keymap, NULL);
  64         if (ret)
  65                 return ret;
  66
  67         priv->input_dev->dev.parent = &device->dev;
  68         priv->input_dev->name = "Intel Virtual Button driver";
  69         priv->input_dev->id.bustype = BUS_HOST;
  70
  71         return input_register_device(priv->input_dev);
  72 }
  73
  74 static void notify_handler(acpi_handle handle, u32 event, void *context)
  75 {
  76         struct platform_device *device = context;
  77         struct intel_vbtn_priv *priv = dev_get_drvdata(&device->dev);
  78         unsigned int val = !(event & 1); /* Even=press, Odd=release */
  79         const struct key_entry *ke_rel;
  80         bool autorelease;
  81
  82         if (priv->wakeup_mode) {
  83                 if (sparse_keymap_entry_from_scancode(priv->input_dev, event)) {
  84                         pm_wakeup_hard_event(&device->dev);
  85                         return;
  86                 }
  87                 goto out_unknown;
  88         }
  89
  90         /*
  91          * Even press events are autorelease if there is no corresponding odd
  92          * release event, or if the odd event is KE_IGNORE.
  93          */
  94         ke_rel = sparse_keymap_entry_from_scancode(priv->input_dev, event | 1);
  95         autorelease = val && (!ke_rel || ke_rel->type == KE_IGNORE);
  96
  97         if (sparse_keymap_report_event(priv->input_dev, event, val, autorelease))
  98                 return;
  99
 100 out_unknown:
 101         dev_dbg(&device->dev, "unknown event index 0x%x\n", event);
 102 }
 103
 104 static void detect_tablet_mode(struct platform_device *device)
 105 {
 106         const char *chassis_type = dmi_get_system_info(DMI_CHASSIS_TYPE);
 107         struct intel_vbtn_priv *priv = dev_get_drvdata(&device->dev);
 108         acpi_handle handle = ACPI_HANDLE(&device->dev);
 109         struct acpi_buffer vgbs_output = { ACPI_ALLOCATE_BUFFER, NULL };
 110         union acpi_object *obj;
 111         acpi_status status;
 112         int m;
 113
 114         if (!(chassis_type && strcmp(chassis_type, "31") == 0))
 115                 goto out;
 116
 117         status = acpi_evaluate_object(handle, "VGBS", NULL, &vgbs_output);
 118         if (ACPI_FAILURE(status))
 119                 goto out;
 120
 121         obj = vgbs_output.pointer;
 122         if (!(obj && obj->type == ACPI_TYPE_INTEGER))
 123                 goto out;
 124
 125         m = !(obj->integer.value & TABLET_MODE_FLAG);
 126         input_report_switch(priv->input_dev, SW_TABLET_MODE, m);
 127         m = (obj->integer.value & DOCK_MODE_FLAG) ? 1 : 0;
 128         input_report_switch(priv->input_dev, SW_DOCK, m);
 129 out:
 130         kfree(vgbs_output.pointer);
 131 }
 132
 133 static int intel_vbtn_probe(struct platform_device *device)
 134 {
 135         acpi_handle handle = ACPI_HANDLE(&device->dev);
 136         struct intel_vbtn_priv *priv;
 137         acpi_status status;
 138         int err;
 139
 140         status = acpi_evaluate_object(handle, "VBDL", NULL, NULL);
 141         if (ACPI_FAILURE(status)) {
 142                 dev_warn(&device->dev, "failed to read Intel Virtual Button driver\n");
 143                 return -ENODEV;
 144         }
 145
 146         priv = devm_kzalloc(&device->dev, sizeof(*priv), GFP_KERNEL);
 147         if (!priv)
 148                 return -ENOMEM;
 149         dev_set_drvdata(&device->dev, priv);
 150
 151         err = intel_vbtn_input_setup(device);
 152         if (err) {
 153                 pr_err("Failed to setup Intel Virtual Button\n");
 154                 return err;
 155         }
 156
 157         detect_tablet_mode(device);
 158
 159         status = acpi_install_notify_handler(handle,
 160                                              ACPI_DEVICE_NOTIFY,
 161                                              notify_handler,
 162                                              device);
 163         if (ACPI_FAILURE(status))
 164                 return -EBUSY;
 165
 166         device_init_wakeup(&device->dev, true);
 167         return 0;
 168 }
 169
 170 static int intel_vbtn_remove(struct platform_device *device)
 171 {
 172         acpi_handle handle = ACPI_HANDLE(&device->dev);
 173
 174         device_init_wakeup(&device->dev, false);
 175         acpi_remove_notify_handler(handle, ACPI_DEVICE_NOTIFY, notify_handler);
 176
 177         /*
 178          * Even if we failed to shut off the event stream, we can still
 179          * safely detach from the device.
 180          */
 181         return 0;
 182 }
 183
 184 static int intel_vbtn_pm_prepare(struct device *dev)
 185 {
 186         struct intel_vbtn_priv *priv = dev_get_drvdata(dev);
 187
 188         priv->wakeup_mode = true;
 189         return 0;
 190 }
 191
 192 static int intel_vbtn_pm_resume(struct device *dev)
 193 {
 194         struct intel_vbtn_priv *priv = dev_get_drvdata(dev);
 195
 196         priv->wakeup_mode = false;
 197         return 0;
 198 }
 199
 200 static const struct dev_pm_ops intel_vbtn_pm_ops = {
 201         .prepare = intel_vbtn_pm_prepare,
 202         .resume = intel_vbtn_pm_resume,
 203         .restore = intel_vbtn_pm_resume,
 204         .thaw = intel_vbtn_pm_resume,
 205 };
 206
 207 static struct platform_driver intel_vbtn_pl_driver = {
 208         .driver = {
 209                 .name = "intel-vbtn",
 210                 .acpi_match_table = intel_vbtn_ids,
 211                 .pm = &intel_vbtn_pm_ops,
 212         },
 213         .probe = intel_vbtn_probe,
 214         .remove = intel_vbtn_remove,
 215 };
 216 MODULE_DEVICE_TABLE(acpi, intel_vbtn_ids);
 217
 218 static acpi_status __init
 219 check_acpi_dev(acpi_handle handle, u32 lvl, void *context, void **rv)
 220 {
 221         const struct acpi_device_id *ids = context;
 222         struct acpi_device *dev;
 223
 224         if (acpi_bus_get_device(handle, &dev) != 0)
 225                 return AE_OK;
 226
 227         if (acpi_match_device_ids(dev, ids) == 0)
 228                 if (acpi_create_platform_device(dev, NULL))
 229                         dev_info(&dev->dev,
 230                                  "intel-vbtn: created platform device\n");
 231
 232         return AE_OK;
 233 }
 234
 235 static int __init intel_vbtn_init(void)
 236 {
 237         acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 238                             ACPI_UINT32_MAX, check_acpi_dev, NULL,
 239                             (void *)intel_vbtn_ids, NULL);
 240
 241         return platform_driver_register(&intel_vbtn_pl_driver);
 242 }
 243 module_init(intel_vbtn_init);
 244
 245 static void __exit intel_vbtn_exit(void)
 246 {
 247         platform_driver_unregister(&intel_vbtn_pl_driver);
 248 }
 249 module_exit(intel_vbtn_exit);