Commit 153cca9c authored by Hans de Goede's avatar Hans de Goede
Browse files

platform/x86: Add and use a dual_accel_detect() helper 

Various 360 degree hinges (yoga) style 2-in-1 devices use 2 accelerometers
to allow the OS to determine the angle between the display and the base of
the device.

On Windows these are read by a special HingeAngleService process which
calls undocumented ACPI methods, to let the firmware know if the 2-in-1 is
in tablet- or laptop-mode. The firmware may use this to disable the kbd and
touchpad to avoid spurious input in tablet-mode as well as to report
SW_TABLET_MODE info to the OS.

Since Linux does not call these undocumented methods, the SW_TABLET_MODE
info reported by various pdx86 drivers is incorrect on these devices.

Before this commit the intel-hid and thinkpad_acpi code already had 2
hardcoded checks for ACPI hardware-ids of dual-accel sensors to avoid
reporting broken info.

And now we also have a bug-report about the same problem in the intel-vbtn
code. Since there are at least 3 different ACPI hardware-ids in play, add
a new dual_accel_detect() helper which checks for all 3, rather then
adding different hardware-ids to the drivers as bug-reports trickle in.
Having shared code which checks all known hardware-ids is esp. important
for the intel-hid and intel-vbtn drivers as these are generic drivers
which are used on a lot of devices.

The BOSC0200 hardware-id requires special handling, because often it is
used for a single-accelerometer setup. Only in a few cases it refers to
a dual-accel setup, in which case there will be 2 I2cSerialBus resources
in the device's resource-list, so the helper checks for this.

BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=209011


Reported-and-tested-by: default avatarJulius Lehmann <julius@devpi.de>
Signed-off-by: default avatarHans de Goede <hdegoede@redhat.com>
Reviewed-by: default avatarAndy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20210729082134.6683-1-hdegoede@redhat.com
parent 2b2c66f6

drivers/platform/x86/Kconfig

+3 −0
Original line number Diff line number Diff line
@@ -508,6 +508,7 @@ config THINKPAD_ACPI 
	depends on RFKILL || RFKILL = n

	depends on ACPI_VIDEO || ACPI_VIDEO = n

	depends on BACKLIGHT_CLASS_DEVICE

	depends on I2C

	select ACPI_PLATFORM_PROFILE

	select HWMON

	select NVRAM
@@ -691,6 +692,7 @@ config INTEL_HID_EVENT 
	tristate "INTEL HID Event"

	depends on ACPI

	depends on INPUT

	depends on I2C

	select INPUT_SPARSEKMAP

	help

	  This driver provides support for the Intel HID Event hotkey interface.
@@ -742,6 +744,7 @@ config INTEL_VBTN 
	tristate "INTEL VIRTUAL BUTTON"

	depends on ACPI

	depends on INPUT

	depends on I2C

	select INPUT_SPARSEKMAP

	help

	  This driver provides support for the Intel Virtual Button interface.

drivers/platform/x86/dual_accel_detect.h

0 → 100644
+75 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0 */

/*

 * Helper code to detect 360 degree hinges (yoga) style 2-in-1 devices using 2 accelerometers

 * to allow the OS to determine the angle between the display and the base of the device.

 *

 * On Windows these are read by a special HingeAngleService process which calls undocumented

 * ACPI methods, to let the firmware know if the 2-in-1 is in tablet- or laptop-mode.

 * The firmware may use this to disable the kbd and touchpad to avoid spurious input in

 * tablet-mode as well as to report SW_TABLET_MODE info to the OS.

 *

 * Since Linux does not call these undocumented methods, the SW_TABLET_MODE info reported

 * by various drivers/platform/x86 drivers is incorrect. These drivers use the detection

 * code in this file to disable SW_TABLET_MODE reporting to avoid reporting broken info

 * (instead userspace can derive the status itself by directly reading the 2 accels).

 */



#include <linux/acpi.h>

#include <linux/i2c.h>



static int dual_accel_i2c_resource_count(struct acpi_resource *ares, void *data)

{

	struct acpi_resource_i2c_serialbus *sb;

	int *count = data;



	if (i2c_acpi_get_i2c_resource(ares, &sb))

		*count = *count + 1;



	return 1;

}



static int dual_accel_i2c_client_count(struct acpi_device *adev)

{

	int ret, count = 0;

	LIST_HEAD(r);



	ret = acpi_dev_get_resources(adev, &r, dual_accel_i2c_resource_count, &count);

	if (ret < 0)

		return ret;



	acpi_dev_free_resource_list(&r);

	return count;

}



static bool dual_accel_detect_bosc0200(void)

{

	struct acpi_device *adev;

	int count;



	adev = acpi_dev_get_first_match_dev("BOSC0200", NULL, -1);

	if (!adev)

		return false;



	count = dual_accel_i2c_client_count(adev);



	acpi_dev_put(adev);



	return count == 2;

}



static bool dual_accel_detect(void)

{

	/* Systems which use a pair of accels with KIOX010A / KIOX020A ACPI ids */

	if (acpi_dev_present("KIOX010A", NULL, -1))

		return true;



	/* Systems which use a single DUAL250E ACPI device to model 2 accels */

	if (acpi_dev_present("DUAL250E", NULL, -1))

		return true;



	/* Systems which use a single BOSC0200 ACPI device to model 2 accels */

	if (dual_accel_detect_bosc0200())

		return true;



	return false;

}

drivers/platform/x86/intel-hid.c

+6 −15
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ 
#include <linux/module.h>

#include <linux/platform_device.h>

#include <linux/suspend.h>

#include "dual_accel_detect.h"



/* When NOT in tablet mode, VGBS returns with the flag 0x40 */

#define TABLET_MODE_FLAG BIT(6)
@@ -122,6 +123,7 @@ struct intel_hid_priv { 
	struct input_dev *array;

	struct input_dev *switches;

	bool wakeup_mode;

	bool dual_accel;

};



#define HID_EVENT_FILTER_UUID	"eeec56b3-4442-408f-a792-4edd4d758054"
@@ -451,22 +453,9 @@ static void notify_handler(acpi_handle handle, u32 event, void *context) 
	 * SW_TABLET_MODE report, in these cases we enable support when receiving

	 * the first event instead of during driver setup.

	 *

	 * Some 360 degree hinges (yoga) style 2-in-1 devices use 2 accelerometers

	 * to allow the OS to determine the angle between the display and the base

	 * of the device. On Windows these are read by a special HingeAngleService

	 * process which calls an ACPI DSM (Device Specific Method) on the

	 * ACPI KIOX010A device node for the sensor in the display, to let the

	 * firmware know if the 2-in-1 is in tablet- or laptop-mode so that it can

	 * disable the kbd and touchpad to avoid spurious input in tablet-mode.

	 *

	 * The linux kxcjk1013 driver calls the DSM for this once at probe time

	 * to ensure that the builtin kbd and touchpad work. On some devices this

	 * causes a "spurious" 0xcd event on the intel-hid ACPI dev. In this case

	 * there is not a functional tablet-mode switch, so we should not register

	 * the tablet-mode switch device.

	 * See dual_accel_detect.h for more info on the dual_accel check.

	 */

	if (!priv->switches && (event == 0xcc || event == 0xcd) &&

	    !acpi_dev_present("KIOX010A", NULL, -1)) {

	if (!priv->switches && !priv->dual_accel && (event == 0xcc || event == 0xcd)) {

		dev_info(&device->dev, "switch event received, enable switches supports\n");

		err = intel_hid_switches_setup(device);

		if (err)
@@ -607,6 +596,8 @@ static int intel_hid_probe(struct platform_device *device) 
		return -ENOMEM;

	dev_set_drvdata(&device->dev, priv);



	priv->dual_accel = dual_accel_detect();



	err = intel_hid_input_setup(device);

	if (err) {

		pr_err("Failed to setup Intel HID hotkeys\n");

drivers/platform/x86/intel-vbtn.c

+15 −3
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ 
#include <linux/module.h>

#include <linux/platform_device.h>

#include <linux/suspend.h>

#include "dual_accel_detect.h"



/* Returned when NOT in tablet mode on some HP Stream x360 11 models */

#define VGBS_TABLET_MODE_FLAG_ALT	0x10
@@ -66,6 +67,7 @@ static const struct key_entry intel_vbtn_switchmap[] = { 
struct intel_vbtn_priv {

	struct input_dev *buttons_dev;

	struct input_dev *switches_dev;

	bool dual_accel;

	bool has_buttons;

	bool has_switches;

	bool wakeup_mode;
@@ -160,6 +162,10 @@ static void notify_handler(acpi_handle handle, u32 event, void *context) 
		input_dev = priv->buttons_dev;

	} else if ((ke = sparse_keymap_entry_from_scancode(priv->switches_dev, event))) {

		if (!priv->has_switches) {

			/* See dual_accel_detect.h for more info */

			if (priv->dual_accel)

				return;



			dev_info(&device->dev, "Registering Intel Virtual Switches input-dev after receiving a switch event\n");

			ret = input_register_device(priv->switches_dev);

			if (ret)
@@ -248,11 +254,15 @@ static const struct dmi_system_id dmi_switches_allow_list[] = { 
	{} /* Array terminator */

};



static bool intel_vbtn_has_switches(acpi_handle handle)

static bool intel_vbtn_has_switches(acpi_handle handle, bool dual_accel)

{

	unsigned long long vgbs;

	acpi_status status;



	/* See dual_accel_detect.h for more info */

	if (dual_accel)

		return false;



	if (!dmi_check_system(dmi_switches_allow_list))

		return false;
@@ -263,13 +273,14 @@ static bool intel_vbtn_has_switches(acpi_handle handle) 
static int intel_vbtn_probe(struct platform_device *device)

{

	acpi_handle handle = ACPI_HANDLE(&device->dev);

	bool has_buttons, has_switches;

	bool dual_accel, has_buttons, has_switches;

	struct intel_vbtn_priv *priv;

	acpi_status status;

	int err;



	dual_accel = dual_accel_detect();

	has_buttons = acpi_has_method(handle, "VBDL");

	has_switches = intel_vbtn_has_switches(handle);

	has_switches = intel_vbtn_has_switches(handle, dual_accel);



	if (!has_buttons && !has_switches) {

		dev_warn(&device->dev, "failed to read Intel Virtual Button driver\n");
@@ -281,6 +292,7 @@ static int intel_vbtn_probe(struct platform_device *device) 
		return -ENOMEM;

	dev_set_drvdata(&device->dev, priv);



	priv->dual_accel = dual_accel;

	priv->has_buttons = has_buttons;

	priv->has_switches = has_switches;

drivers/platform/x86/thinkpad_acpi.c

+2 −1
Original line number Diff line number Diff line
@@ -73,6 +73,7 @@ 
#include <linux/uaccess.h>

#include <acpi/battery.h>

#include <acpi/video.h>

#include "dual_accel_detect.h"



/* ThinkPad CMOS commands */

#define TP_CMOS_VOLUME_DOWN	0
@@ -3232,7 +3233,7 @@ static int hotkey_init_tablet_mode(void) 
		 * the laptop/tent/tablet mode to the EC. The bmc150 iio driver

		 * does not support this, so skip the hotkey on these models.

		 */

		if (has_tablet_mode && !acpi_dev_present("BOSC0200", "1", -1))

		if (has_tablet_mode && !dual_accel_detect())

			tp_features.hotkey_tablet = TP_HOTKEY_TABLET_USES_GMMS;

		type = "GMMS";

	} else if (acpi_evalf(hkey_handle, &res, "MHKG", "qd")) {