Commit 64dd243d authored by Maximilian Luz's avatar Maximilian Luz Committed by Dmitry Torokhov
Browse files

platform/x86: surfacepro3_button: Fix device check 



Do not use the surfacepro3_button driver on newer Microsoft Surface
models, only use it on the Surface Pro 3 and 4. Newer models (5th, 6th
and possibly future generations) use the same device as the Surface Pro
4 to represent their volume and power buttons (MSHW0040), but their
actual implementation is significantly different. This patch ensures
that the surfacepro3_button driver is only used on the Pro 3 and 4
models, allowing a different driver to bind on other models.

Signed-off-by: default avatarMaximilian Luz <luzmaximilian@gmail.com>
Acked-by: default avatarAndy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: default avatarChen Yu <yu.c.chen@intel.com>
Signed-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
parent 3b51c44b

drivers/platform/x86/surfacepro3_button.c

+47 −0
Original line number Diff line number Diff line
@@ -20,6 +20,12 @@ 
#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
@@ -142,6 +148,44 @@ static int surface_button_resume(struct device *dev) 
}

#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;
@@ -154,6 +198,9 @@ static int surface_button_add(struct acpi_device *device) 
	    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;

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