Commit 3dda3b37 authored by Benjamin Tissoires's avatar Benjamin Tissoires Committed by Andy Shevchenko
Browse files

platform/x86: Add custom surface3 platform device for controlling LID 



The LID state provided by ACPI on the Surface 3 is not accurate.
The ACPI node doesn't get notified on LID open, which means the
LID input switch stays close most of the time.

Fortunatelly, there is a WMI method which directly queries the
GPIO underneath the LID state, so it's far more reliable than ACPI.
To get the notifications that the LID was opened/closed, we can
rely on the ACPI notification of the touchscreen: the DSDT shows
that the touchscreen will get notified on close/open as it also
controls its _STA method.

Note that we need to set the tag "power-switch" to the LID
input node through a udev rule for logind to accept it:

SUBSYSTEM=="input", KERNEL=="event*", KERNELS=="surface3-wmi", \
	TAG+="power-switch"

Signed-off-by: default avatarBenjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
parent afc47159

drivers/platform/x86/Kconfig

+12 −0
Original line number Diff line number Diff line
@@ -363,6 +363,18 @@ config IDEAPAD_LAPTOP 
	  This is a driver for Lenovo IdeaPad netbooks contains drivers for

	  rfkill switch, hotkey, fan control and backlight control.



config SURFACE3_WMI

	tristate "Surface 3 WMI Driver"

	depends on ACPI_WMI

	depends on DMI

	depends on INPUT

	depends on SPI

	---help---

	  Say Y here if you have a Surface 3.



	  To compile this driver as a module, choose M here: the module will

	  be called surface3-wmi.



config THINKPAD_ACPI

	tristate "ThinkPad ACPI Laptop Extras"

	depends on ACPI

drivers/platform/x86/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -34,6 +34,7 @@ obj-$(CONFIG_PANASONIC_LAPTOP) += panasonic-laptop.o 
obj-$(CONFIG_INTEL_MENLOW)	+= intel_menlow.o

obj-$(CONFIG_ACPI_WMI)		+= wmi.o

obj-$(CONFIG_MSI_WMI)		+= msi-wmi.o

obj-$(CONFIG_SURFACE3_WMI)	+= surface3-wmi.o

obj-$(CONFIG_TOPSTAR_LAPTOP)	+= topstar-laptop.o



# toshiba_acpi must link after wmi to ensure that wmi devices are found

drivers/platform/x86/surface3-wmi.c

0 → 100644
+296 −0
Original line number Diff line number Diff line 
/*

 *  Driver for the LID cover switch of the Surface 3

 *

 *  Copyright (c) 2016 Red Hat Inc.

 */



/*

 * This program is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License as published by the Free

 * Software Foundation; version 2 of the License.

 */



#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/slab.h>



#include <linux/acpi.h>

#include <linux/dmi.h>

#include <linux/input.h>

#include <linux/mutex.h>

#include <linux/platform_device.h>

#include <linux/spi/spi.h>



MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@redhat.com>");

MODULE_DESCRIPTION("Surface 3 platform driver");

MODULE_LICENSE("GPL");



#define ACPI_BUTTON_HID_LID		"PNP0C0D"

#define SPI_CTL_OBJ_NAME		"SPI"

#define SPI_TS_OBJ_NAME			"NTRG"



#define SURFACE3_LID_GUID "F7CC25EC-D20B-404C-8903-0ED4359C18AE"



MODULE_ALIAS("wmi:" SURFACE3_LID_GUID);



static const struct dmi_system_id surface3_dmi_table[] = {

#if defined(CONFIG_X86)

	{

		.matches = {

			DMI_MATCH(DMI_SYS_VENDOR, "Microsoft Corporation"),

			DMI_MATCH(DMI_PRODUCT_NAME, "Surface 3"),

		},

	},

#endif

	{ }

};



struct surface3_wmi {

	struct acpi_device *touchscreen_adev;

	struct acpi_device *pnp0c0d_adev;

	struct acpi_hotplug_context hp;

	struct input_dev *input;

};



static struct platform_device *s3_wmi_pdev;



static struct surface3_wmi s3_wmi;



static DEFINE_MUTEX(s3_wmi_lock);



static int s3_wmi_query_block(const char *guid, int instance, int *ret)

{

	acpi_status status;

	union acpi_object *obj;



	struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };



	mutex_lock(&s3_wmi_lock);

	status = wmi_query_block(guid, instance, &output);



	obj = output.pointer;



	if (!obj || obj->type != ACPI_TYPE_INTEGER) {

		if (obj) {

			pr_err("query block returned object type: %d - buffer length:%d\n",

			       obj->type,

			       obj->type == ACPI_TYPE_BUFFER ?

						obj->buffer.length : 0);

		}

		kfree(obj);

		return -EINVAL;

	}

	*ret = obj->integer.value;

	kfree(obj);

	mutex_unlock(&s3_wmi_lock);

	return 0;

}



static inline int s3_wmi_query_lid(int *ret)

{

	return s3_wmi_query_block(SURFACE3_LID_GUID, 0, ret);

}



static int s3_wmi_send_lid_state(void)

{

	int ret, lid_sw;



	ret = s3_wmi_query_lid(&lid_sw);

	if (ret)

		return ret;



	input_report_switch(s3_wmi.input, SW_LID, lid_sw);

	input_sync(s3_wmi.input);



	return 0;

}



static int s3_wmi_hp_notify(struct acpi_device *adev, u32 value)

{

	return s3_wmi_send_lid_state();

}



static acpi_status s3_wmi_attach_spi_device(acpi_handle handle,

					    u32 level,

					    void *data,

					    void **return_value)

{

	struct acpi_device *adev, **ts_adev;



	if (acpi_bus_get_device(handle, &adev))

		return AE_OK;



	ts_adev = data;



	if (strncmp(acpi_device_bid(adev), SPI_TS_OBJ_NAME,

	    strlen(SPI_TS_OBJ_NAME)))

		return AE_OK;



	if (*ts_adev) {

		pr_err("duplicate entry %s\n", SPI_TS_OBJ_NAME);

		return AE_OK;

	}



	*ts_adev = adev;



	return AE_OK;

}



static int s3_wmi_check_platform_device(struct device *dev, void *data)

{

	struct acpi_device *adev, *ts_adev;

	acpi_handle handle;

	acpi_status status;



	/* ignore non ACPI devices */

	handle = ACPI_HANDLE(dev);

	if (!handle || acpi_bus_get_device(handle, &adev))

		return 0;



	/* check for LID ACPI switch */

	if (!strcmp(ACPI_BUTTON_HID_LID, acpi_device_hid(adev))) {

		s3_wmi.pnp0c0d_adev = adev;

		return 0;

	}



	/* ignore non SPI controllers */

	if (strncmp(acpi_device_bid(adev), SPI_CTL_OBJ_NAME,

	    strlen(SPI_CTL_OBJ_NAME)))

		return 0;



	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,

				     s3_wmi_attach_spi_device, NULL,

				     &ts_adev, NULL);

	if (ACPI_FAILURE(status))

		dev_warn(dev, "failed to enumerate SPI slaves\n");



	if (!ts_adev)

		return 0;



	s3_wmi.touchscreen_adev = ts_adev;



	return 0;

}



static int s3_wmi_create_and_register_input(struct platform_device *pdev)

{

	struct input_dev *input;

	int error;



	input = devm_input_allocate_device(&pdev->dev);

	if (!input)

		return -ENOMEM;



	input->name = "Lid Switch";

	input->phys = "button/input0";

	input->id.bustype = BUS_HOST;

	input->id.product = 0x0005;



	input_set_capability(input, EV_SW, SW_LID);



	error = input_register_device(input);

	if (error)

		goto out_err;



	s3_wmi.input = input;



	return 0;

 out_err:

	input_free_device(s3_wmi.input);

	return error;

}



static int __init s3_wmi_probe(struct platform_device *pdev)

{

	int error;



	if (!dmi_check_system(surface3_dmi_table))

		return -ENODEV;



	memset(&s3_wmi, 0, sizeof(s3_wmi));



	bus_for_each_dev(&platform_bus_type, NULL, NULL,

			 s3_wmi_check_platform_device);



	if (!s3_wmi.touchscreen_adev)

		return -ENODEV;



	acpi_bus_trim(s3_wmi.pnp0c0d_adev);



	error = s3_wmi_create_and_register_input(pdev);

	if (error)

		goto restore_acpi_lid;



	acpi_initialize_hp_context(s3_wmi.touchscreen_adev, &s3_wmi.hp,

				   s3_wmi_hp_notify, NULL);



	s3_wmi_send_lid_state();



	return 0;



 restore_acpi_lid:

	acpi_bus_scan(s3_wmi.pnp0c0d_adev->handle);

	return error;

}



static int s3_wmi_remove(struct platform_device *device)

{

	/* remove the hotplug context from the acpi device */

	s3_wmi.touchscreen_adev->hp = NULL;



	/* reinstall the actual PNPC0C0D LID default handle */

	acpi_bus_scan(s3_wmi.pnp0c0d_adev->handle);

	return 0;

}



#ifdef CONFIG_PM

static int s3_wmi_resume(struct device *dev)

{

	s3_wmi_send_lid_state();

	return 0;

}

#endif

static SIMPLE_DEV_PM_OPS(s3_wmi_pm, NULL, s3_wmi_resume);



static struct platform_driver s3_wmi_driver = {

	.driver = {

		.name = "surface3-wmi",

		.pm = &s3_wmi_pm,

	},

	.remove = s3_wmi_remove,

};



static int __init s3_wmi_init(void)

{

	int error;



	s3_wmi_pdev = platform_device_alloc("surface3-wmi", -1);

	if (!s3_wmi_pdev)

		return -ENOMEM;



	error = platform_device_add(s3_wmi_pdev);

	if (error)

		goto err_device_put;



	error = platform_driver_probe(&s3_wmi_driver, s3_wmi_probe);

	if (error)

		goto err_device_del;



	pr_info("Surface 3 WMI Extras loaded\n");

	return 0;



 err_device_del:

	platform_device_del(s3_wmi_pdev);

 err_device_put:

	platform_device_put(s3_wmi_pdev);

	return error;

}



static void __exit s3_wmi_exit(void)

{

	platform_device_unregister(s3_wmi_pdev);

	platform_driver_unregister(&s3_wmi_driver);

}



module_init(s3_wmi_init);

module_exit(s3_wmi_exit);

CRA Git | Maintained and supported by SUSTech CRA and CCSE