diff options
Diffstat (limited to 'drivers/platform/surface/surfacepro3_button.c')
| -rw-r--r-- | drivers/platform/surface/surfacepro3_button.c | 266 |
1 files changed, 266 insertions, 0 deletions
diff --git a/drivers/platform/surface/surfacepro3_button.c b/drivers/platform/surface/surfacepro3_button.c new file mode 100644 index 000000000..242fb690d --- /dev/null +++ b/drivers/platform/surface/surfacepro3_button.c @@ -0,0 +1,266 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * power/home/volume button support for + * Microsoft Surface Pro 3/4 tablet. + * + * Copyright (c) 2015 Intel Corporation. + * All rights reserved. + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/types.h> +#include <linux/input.h> +#include <linux/acpi.h> +#include <acpi/button.h> + +#define SURFACE_PRO3_BUTTON_HID "MSHW0028" +#define SURFACE_PRO4_BUTTON_HID "MSHW0040" +#define SURFACE_BUTTON_OBJ_NAME "VGBI" +#define SURFACE_BUTTON_DEVICE_NAME "Surface Pro 3/4 Buttons" + +#define MSHW0040_DSM_REVISION 0x01 +#define MSHW0040_DSM_GET_OMPR 0x02 // get OEM Platform Revision +static const guid_t MSHW0040_DSM_UUID = + GUID_INIT(0x6fd05c69, 0xcde3, 0x49f4, 0x95, 0xed, 0xab, 0x16, 0x65, + 0x49, 0x80, 0x35); + +#define SURFACE_BUTTON_NOTIFY_TABLET_MODE 0xc8 + +#define SURFACE_BUTTON_NOTIFY_PRESS_POWER 0xc6 +#define SURFACE_BUTTON_NOTIFY_RELEASE_POWER 0xc7 + +#define SURFACE_BUTTON_NOTIFY_PRESS_HOME 0xc4 +#define SURFACE_BUTTON_NOTIFY_RELEASE_HOME 0xc5 + +#define SURFACE_BUTTON_NOTIFY_PRESS_VOLUME_UP 0xc0 +#define SURFACE_BUTTON_NOTIFY_RELEASE_VOLUME_UP 0xc1 + +#define SURFACE_BUTTON_NOTIFY_PRESS_VOLUME_DOWN 0xc2 +#define SURFACE_BUTTON_NOTIFY_RELEASE_VOLUME_DOWN 0xc3 + +MODULE_AUTHOR("Chen Yu"); +MODULE_DESCRIPTION("Surface Pro3 Button Driver"); +MODULE_LICENSE("GPL v2"); + +/* + * Power button, Home button, Volume buttons support is supposed to + * be covered by drivers/input/misc/soc_button_array.c, which is implemented + * according to "Windows ACPI Design Guide for SoC Platforms". + * However surface pro3 seems not to obey the specs, instead it uses + * device VGBI(MSHW0028) for dispatching the events. + * We choose acpi_driver rather than platform_driver/i2c_driver because + * although VGBI has an i2c resource connected to i2c controller, it + * is not embedded in any i2c controller's scope, thus neither platform_device + * will be created, nor i2c_client will be enumerated, we have to use + * acpi_driver. + */ +static const struct acpi_device_id surface_button_device_ids[] = { + {SURFACE_PRO3_BUTTON_HID, 0}, + {SURFACE_PRO4_BUTTON_HID, 0}, + {"", 0}, +}; +MODULE_DEVICE_TABLE(acpi, surface_button_device_ids); + +struct surface_button { + unsigned int type; + struct input_dev *input; + char phys[32]; /* for input device */ + unsigned long pushed; + bool suspended; +}; + +static void surface_button_notify(struct acpi_device *device, u32 event) +{ + struct surface_button *button = acpi_driver_data(device); + struct input_dev *input; + int key_code = KEY_RESERVED; + bool pressed = false; + + switch (event) { + /* Power button press,release handle */ + case SURFACE_BUTTON_NOTIFY_PRESS_POWER: + pressed = true; + fallthrough; + case SURFACE_BUTTON_NOTIFY_RELEASE_POWER: + key_code = KEY_POWER; + break; + /* Home button press,release handle */ + case SURFACE_BUTTON_NOTIFY_PRESS_HOME: + pressed = true; + fallthrough; + case SURFACE_BUTTON_NOTIFY_RELEASE_HOME: + key_code = KEY_LEFTMETA; + break; + /* Volume up button press,release handle */ + case SURFACE_BUTTON_NOTIFY_PRESS_VOLUME_UP: + pressed = true; + fallthrough; + case SURFACE_BUTTON_NOTIFY_RELEASE_VOLUME_UP: + key_code = KEY_VOLUMEUP; + break; + /* Volume down button press,release handle */ + case SURFACE_BUTTON_NOTIFY_PRESS_VOLUME_DOWN: + pressed = true; + fallthrough; + case SURFACE_BUTTON_NOTIFY_RELEASE_VOLUME_DOWN: + key_code = KEY_VOLUMEDOWN; + break; + case SURFACE_BUTTON_NOTIFY_TABLET_MODE: + dev_warn_once(&device->dev, "Tablet mode is not supported\n"); + break; + default: + dev_info_ratelimited(&device->dev, + "Unsupported event [0x%x]\n", event); + break; + } + input = button->input; + if (key_code == KEY_RESERVED) + return; + if (pressed) + pm_wakeup_dev_event(&device->dev, 0, button->suspended); + if (button->suspended) + return; + input_report_key(input, key_code, pressed?1:0); + input_sync(input); +} + +#ifdef CONFIG_PM_SLEEP +static int surface_button_suspend(struct device *dev) +{ + struct acpi_device *device = to_acpi_device(dev); + struct surface_button *button = acpi_driver_data(device); + + button->suspended = true; + return 0; +} + +static int surface_button_resume(struct device *dev) +{ + struct acpi_device *device = to_acpi_device(dev); + struct surface_button *button = acpi_driver_data(device); + + button->suspended = false; + return 0; +} +#endif + +/* + * Surface Pro 4 and Surface Book 2 / Surface Pro 2017 use the same device + * ID (MSHW0040) for the power/volume buttons. Make sure this is the right + * device by checking for the _DSM method and OEM Platform Revision. + * + * Returns true if the driver should bind to this device, i.e. the device is + * either MSWH0028 (Pro 3) or MSHW0040 on a Pro 4 or Book 1. + */ +static bool surface_button_check_MSHW0040(struct acpi_device *dev) +{ + acpi_handle handle = dev->handle; + union acpi_object *result; + u64 oem_platform_rev = 0; // valid revisions are nonzero + + // get OEM platform revision + result = acpi_evaluate_dsm_typed(handle, &MSHW0040_DSM_UUID, + MSHW0040_DSM_REVISION, + MSHW0040_DSM_GET_OMPR, + NULL, ACPI_TYPE_INTEGER); + + /* + * If evaluating the _DSM fails, the method is not present. This means + * that we have either MSHW0028 or MSHW0040 on Pro 4 or Book 1, so we + * should use this driver. We use revision 0 indicating it is + * unavailable. + */ + + if (result) { + oem_platform_rev = result->integer.value; + ACPI_FREE(result); + } + + dev_dbg(&dev->dev, "OEM Platform Revision %llu\n", oem_platform_rev); + + return oem_platform_rev == 0; +} + + +static int surface_button_add(struct acpi_device *device) +{ + struct surface_button *button; + struct input_dev *input; + const char *hid = acpi_device_hid(device); + char *name; + int error; + + if (strncmp(acpi_device_bid(device), SURFACE_BUTTON_OBJ_NAME, + strlen(SURFACE_BUTTON_OBJ_NAME))) + return -ENODEV; + + if (!surface_button_check_MSHW0040(device)) + return -ENODEV; + + button = kzalloc(sizeof(struct surface_button), GFP_KERNEL); + if (!button) + return -ENOMEM; + + device->driver_data = button; + button->input = input = input_allocate_device(); + if (!input) { + error = -ENOMEM; + goto err_free_button; + } + + name = acpi_device_name(device); + strcpy(name, SURFACE_BUTTON_DEVICE_NAME); + snprintf(button->phys, sizeof(button->phys), "%s/buttons", hid); + + input->name = name; + input->phys = button->phys; + input->id.bustype = BUS_HOST; + input->dev.parent = &device->dev; + input_set_capability(input, EV_KEY, KEY_POWER); + input_set_capability(input, EV_KEY, KEY_LEFTMETA); + input_set_capability(input, EV_KEY, KEY_VOLUMEUP); + input_set_capability(input, EV_KEY, KEY_VOLUMEDOWN); + + error = input_register_device(input); + if (error) + goto err_free_input; + + device_init_wakeup(&device->dev, true); + dev_info(&device->dev, + "%s [%s]\n", name, acpi_device_bid(device)); + return 0; + + err_free_input: + input_free_device(input); + err_free_button: + kfree(button); + return error; +} + +static int surface_button_remove(struct acpi_device *device) +{ + struct surface_button *button = acpi_driver_data(device); + + input_unregister_device(button->input); + kfree(button); + return 0; +} + +static SIMPLE_DEV_PM_OPS(surface_button_pm, + surface_button_suspend, surface_button_resume); + +static struct acpi_driver surface_button_driver = { + .name = "surface_pro3_button", + .class = "SurfacePro3", + .ids = surface_button_device_ids, + .ops = { + .add = surface_button_add, + .remove = surface_button_remove, + .notify = surface_button_notify, + }, + .drv.pm = &surface_button_pm, +}; + +module_acpi_driver(surface_button_driver); |