LXR linux/drivers/platform/x86/surfacepro3

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * power/home/volume button support for
   4 * Microsoft Surface Pro 3/4 tablet.
   5 *
   6 * Copyright (c) 2015 Intel Corporation.
   7 * All rights reserved.
   8 */
   9
  10#include <linux/kernel.h>
  11#include <linux/module.h>
  12#include <linux/init.h>
  13#include <linux/types.h>
  14#include <linux/input.h>
  15#include <linux/acpi.h>
  16#include <acpi/button.h>
  17
  18#define SURFACE_PRO3_BUTTON_HID         "MSHW0028"
  19#define SURFACE_PRO4_BUTTON_HID         "MSHW0040"
  20#define SURFACE_BUTTON_OBJ_NAME         "VGBI"
  21#define SURFACE_BUTTON_DEVICE_NAME      "Surface Pro 3/4 Buttons"
  22
  23#define MSHW0040_DSM_REVISION           0x01
  24#define MSHW0040_DSM_GET_OMPR           0x02    // get OEM Platform Revision
  25static const guid_t MSHW0040_DSM_UUID =
  26        GUID_INIT(0x6fd05c69, 0xcde3, 0x49f4, 0x95, 0xed, 0xab, 0x16, 0x65,
  27                  0x49, 0x80, 0x35);
  28
  29#define SURFACE_BUTTON_NOTIFY_TABLET_MODE       0xc8
  30
  31#define SURFACE_BUTTON_NOTIFY_PRESS_POWER       0xc6
  32#define SURFACE_BUTTON_NOTIFY_RELEASE_POWER     0xc7
  33
  34#define SURFACE_BUTTON_NOTIFY_PRESS_HOME        0xc4
  35#define SURFACE_BUTTON_NOTIFY_RELEASE_HOME      0xc5
  36
  37#define SURFACE_BUTTON_NOTIFY_PRESS_VOLUME_UP   0xc0
  38#define SURFACE_BUTTON_NOTIFY_RELEASE_VOLUME_UP 0xc1
  39
  40#define SURFACE_BUTTON_NOTIFY_PRESS_VOLUME_DOWN         0xc2
  41#define SURFACE_BUTTON_NOTIFY_RELEASE_VOLUME_DOWN       0xc3
  42
  43ACPI_MODULE_NAME("surface pro 3 button");
  44
  45MODULE_AUTHOR("Chen Yu");
  46MODULE_DESCRIPTION("Surface Pro3 Button Driver");
  47MODULE_LICENSE("GPL v2");
  48
  49/*
  50 * Power button, Home button, Volume buttons support is supposed to
  51 * be covered by drivers/input/misc/soc_button_array.c, which is implemented
  52 * according to "Windows ACPI Design Guide for SoC Platforms".
  53 * However surface pro3 seems not to obey the specs, instead it uses
  54 * device VGBI(MSHW0028) for dispatching the events.
  55 * We choose acpi_driver rather than platform_driver/i2c_driver because
  56 * although VGBI has an i2c resource connected to i2c controller, it
  57 * is not embedded in any i2c controller's scope, thus neither platform_device
  58 * will be created, nor i2c_client will be enumerated, we have to use
  59 * acpi_driver.
  60 */
  61static const struct acpi_device_id surface_button_device_ids[] = {
  62        {SURFACE_PRO3_BUTTON_HID,    0},
  63        {SURFACE_PRO4_BUTTON_HID,    0},
  64        {"", 0},
  65};
  66MODULE_DEVICE_TABLE(acpi, surface_button_device_ids);
  67
  68struct surface_button {
  69        unsigned int type;
  70        struct input_dev *input;
  71        char phys[32];                  /* for input device */
  72        unsigned long pushed;
  73        bool suspended;
  74};
  75
  76static void surface_button_notify(struct acpi_device *device, u32 event)
  77{
  78        struct surface_button *button = acpi_driver_data(device);
  79        struct input_dev *input;
  80        int key_code = KEY_RESERVED;
  81        bool pressed = false;
  82
  83        switch (event) {
  84        /* Power button press,release handle */
  85        case SURFACE_BUTTON_NOTIFY_PRESS_POWER:
  86                pressed = true;
  87                fallthrough;
  88        case SURFACE_BUTTON_NOTIFY_RELEASE_POWER:
  89                key_code = KEY_POWER;
  90                break;
  91        /* Home button press,release handle */
  92        case SURFACE_BUTTON_NOTIFY_PRESS_HOME:
  93                pressed = true;
  94                fallthrough;
  95        case SURFACE_BUTTON_NOTIFY_RELEASE_HOME:
  96                key_code = KEY_LEFTMETA;
  97                break;
  98        /* Volume up button press,release handle */
  99        case SURFACE_BUTTON_NOTIFY_PRESS_VOLUME_UP:
 100                pressed = true;
 101                fallthrough;
 102        case SURFACE_BUTTON_NOTIFY_RELEASE_VOLUME_UP:
 103                key_code = KEY_VOLUMEUP;
 104                break;
 105        /* Volume down button press,release handle */
 106        case SURFACE_BUTTON_NOTIFY_PRESS_VOLUME_DOWN:
 107                pressed = true;
 108                fallthrough;
 109        case SURFACE_BUTTON_NOTIFY_RELEASE_VOLUME_DOWN:
 110                key_code = KEY_VOLUMEDOWN;
 111                break;
 112        case SURFACE_BUTTON_NOTIFY_TABLET_MODE:
 113                dev_warn_once(&device->dev, "Tablet mode is not supported\n");
 114                break;
 115        default:
 116                dev_info_ratelimited(&device->dev,
 117                                     "Unsupported event [0x%x]\n", event);
 118                break;
 119        }
 120        input = button->input;
 121        if (key_code == KEY_RESERVED)
 122                return;
 123        if (pressed)
 124                pm_wakeup_dev_event(&device->dev, 0, button->suspended);
 125        if (button->suspended)
 126                return;
 127        input_report_key(input, key_code, pressed?1:0);
 128        input_sync(input);
 129}
 130
 131#ifdef CONFIG_PM_SLEEP
 132static int surface_button_suspend(struct device *dev)
 133{
 134        struct acpi_device *device = to_acpi_device(dev);
 135        struct surface_button *button = acpi_driver_data(device);
 136
 137        button->suspended = true;
 138        return 0;
 139}
 140
 141static int surface_button_resume(struct device *dev)
 142{
 143        struct acpi_device *device = to_acpi_device(dev);
 144        struct surface_button *button = acpi_driver_data(device);
 145
 146        button->suspended = false;
 147        return 0;
 148}
 149#endif
 150
 151/*
 152 * Surface Pro 4 and Surface Book 2 / Surface Pro 2017 use the same device
 153 * ID (MSHW0040) for the power/volume buttons. Make sure this is the right
 154 * device by checking for the _DSM method and OEM Platform Revision.
 155 *
 156 * Returns true if the driver should bind to this device, i.e. the device is
 157 * either MSWH0028 (Pro 3) or MSHW0040 on a Pro 4 or Book 1.
 158 */
 159static bool surface_button_check_MSHW0040(struct acpi_device *dev)
 160{
 161        acpi_handle handle = dev->handle;
 162        union acpi_object *result;
 163        u64 oem_platform_rev = 0;       // valid revisions are nonzero
 164
 165        // get OEM platform revision
 166        result = acpi_evaluate_dsm_typed(handle, &MSHW0040_DSM_UUID,
 167                                         MSHW0040_DSM_REVISION,
 168                                         MSHW0040_DSM_GET_OMPR,
 169                                         NULL, ACPI_TYPE_INTEGER);
 170
 171        /*
 172         * If evaluating the _DSM fails, the method is not present. This means
 173         * that we have either MSHW0028 or MSHW0040 on Pro 4 or Book 1, so we
 174         * should use this driver. We use revision 0 indicating it is
 175         * unavailable.
 176         */
 177
 178        if (result) {
 179                oem_platform_rev = result->integer.value;
 180                ACPI_FREE(result);
 181        }
 182
 183        dev_dbg(&dev->dev, "OEM Platform Revision %llu\n", oem_platform_rev);
 184
 185        return oem_platform_rev == 0;
 186}
 187
 188
 189static int surface_button_add(struct acpi_device *device)
 190{
 191        struct surface_button *button;
 192        struct input_dev *input;
 193        const char *hid = acpi_device_hid(device);
 194        char *name;
 195        int error;
 196
 197        if (strncmp(acpi_device_bid(device), SURFACE_BUTTON_OBJ_NAME,
 198            strlen(SURFACE_BUTTON_OBJ_NAME)))
 199                return -ENODEV;
 200
 201        if (!surface_button_check_MSHW0040(device))
 202                return -ENODEV;
 203
 204        button = kzalloc(sizeof(struct surface_button), GFP_KERNEL);
 205        if (!button)
 206                return -ENOMEM;
 207
 208        device->driver_data = button;
 209        button->input = input = input_allocate_device();
 210        if (!input) {
 211                error = -ENOMEM;
 212                goto err_free_button;
 213        }
 214
 215        name = acpi_device_name(device);
 216        strcpy(name, SURFACE_BUTTON_DEVICE_NAME);
 217        snprintf(button->phys, sizeof(button->phys), "%s/buttons", hid);
 218
 219        input->name = name;
 220        input->phys = button->phys;
 221        input->id.bustype = BUS_HOST;
 222        input->dev.parent = &device->dev;
 223        input_set_capability(input, EV_KEY, KEY_POWER);
 224        input_set_capability(input, EV_KEY, KEY_LEFTMETA);
 225        input_set_capability(input, EV_KEY, KEY_VOLUMEUP);
 226        input_set_capability(input, EV_KEY, KEY_VOLUMEDOWN);
 227
 228        error = input_register_device(input);
 229        if (error)
 230                goto err_free_input;
 231
 232        device_init_wakeup(&device->dev, true);
 233        dev_info(&device->dev,
 234                        "%s [%s]\n", name, acpi_device_bid(device));
 235        return 0;
 236
 237 err_free_input:
 238        input_free_device(input);
 239 err_free_button:
 240        kfree(button);
 241        return error;
 242}
 243
 244static int surface_button_remove(struct acpi_device *device)
 245{
 246        struct surface_button *button = acpi_driver_data(device);
 247
 248        input_unregister_device(button->input);
 249        kfree(button);
 250        return 0;
 251}
 252
 253static SIMPLE_DEV_PM_OPS(surface_button_pm,
 254                surface_button_suspend, surface_button_resume);
 255
 256static struct acpi_driver surface_button_driver = {
 257        .name = "surface_pro3_button",
 258        .class = "SurfacePro3",
 259        .ids = surface_button_device_ids,
 260        .ops = {
 261                .add = surface_button_add,
 262                .remove = surface_button_remove,
 263                .notify = surface_button_notify,
 264        },
 265        .drv.pm = &surface_button_pm,
 266};
 267
 268module_acpi_driver(surface_button_driver);
 269