ec/google/wilco: Add virtual button support

Add an ACPI device that is compatible with the Intel Virtual
Button kernel driver for reporting tablet mode state and various
virtual button events that may come from the EC.

This driver is used in Windows and in the Linux kernel at
drivers/platform/x86/intel-vbtn.c

Because of a check in the kernel driver it expects the board to
define the SMBIOS enclosure type as convertible for the check at
driver load time for tablet/laptop and dock/undock to work.

The virtual tablet mode button will proxy the tablet mode state
sent from the Sensor Hub to a SW_TABLET_MODE event in the kernel.

The virtual power button is used during S0ix for the EC to wake
the system with an SCI.  There are separate press and release
events which are sent for completeness, although the kernel driver
will ignore the release event.

BUG=b:73137291
TEST=Test that the power button can wake the system from S0ix.
Also verify that the device is reported as laptop mode at boot.

Change-Id: I0d5dc985a3cfb1d01ff164c4e67f17e6b1cdd619
Signed-off-by: Duncan Laurie <dlaurie@google.com>
Reviewed-on: https://review.coreboot.org/c/31208
Reviewed-by: Furquan Shaikh <furquan@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

4 files changed, 116 insertions, 0 deletions

diff --git a/src/ec/google/wilco/acpi/ec.asl b/src/ec/google/wilco/acpi/ec.asl
index be80b2d69e..5aca1878d6 100644
--- a/src/ec/google/wilco/acpi/ec.asl
+++ b/src/ec/google/wilco/acpi/ec.asl
@@ -164,6 +164,7 @@ Device (EC0)
 	#include "event.asl"
 	#include "lid.asl"
 	#include "platform.asl"
+	#include "vbtn.asl"
 #ifdef EC_ENABLE_DPTF
 	#include "dptf.asl"
 #endif
diff --git a/src/ec/google/wilco/acpi/ec_ram.asl b/src/ec/google/wilco/acpi/ec_ram.asl
index 1e5d7cb1fc..1c030af06f 100644
--- a/src/ec/google/wilco/acpi/ec_ram.asl
+++ b/src/ec/google/wilco/acpi/ec_ram.asl
@@ -115,6 +115,7 @@ Name (DRHY, Package () { 0x37, 0xff, RD })	/* DPTF: Read Hysteresis */
 Name (DRTQ, Package () { 0x38, 0xff, RD })	/* DPTF: Read Trip Query */
 
 Name (ORST, Package () { 0x39, 0xff, RD })	/* Orientation State */
+Name (OTBL, Package () { 0x39, 0x02, RD })	/* Orientation: Tablet mode */
 Name (OREV, Package () { 0x3a, 0xff, RD })	/* Orientation Events */
 Name (OECH, Package () { 0x3a, 0x01, RD })	/* Event: Orientation */
 Name (OERL, Package () { 0x3a, 0x02, RD })	/* Event: Rotation Lock */
diff --git a/src/ec/google/wilco/acpi/event.asl b/src/ec/google/wilco/acpi/event.asl
index d818d22ca2..24cf268636 100644
--- a/src/ec/google/wilco/acpi/event.asl
+++ b/src/ec/google/wilco/acpi/event.asl
@@ -81,6 +81,16 @@ Method (ECQ2, 1, Serialized)
 		Printf ("QS EVENT")
 		Notify (^WEVT, 0x90)
 	}
+
+	If (EBIT (E2OR, Arg0)) {
+		If (R (OTBL)) {
+			Printf ("EC event indicates tablet mode")
+			Notify (^VBTN, ^VTBL)
+		} Else {
+			Printf ("EC event indicates laptop mode")
+			Notify (^VBTN, ^VLAP)
+		}
+	}
 }
 
 /* Handle events in PmEv3 */
@@ -88,6 +98,16 @@ Method (ECQ3, 1, Serialized)
 {
 	Printf ("EVT3: %o", Arg0)
 
+	If (EBIT (E3CP, Arg0)) {
+		If (R (P2PB)) {
+			Printf ("Power button pressed")
+			Notify (^VBTN, ^VPPB)
+		} Else {
+			Printf ("Power button released")
+			Notify (^VBTN, ^VRPB)
+		}
+	}
+
 #ifdef EC_ENABLE_DPTF
 	/* Theraml Events */
 	If (EBIT (E3TH, Arg0)) {
diff --git a/src/ec/google/wilco/acpi/vbtn.asl b/src/ec/google/wilco/acpi/vbtn.asl
new file mode 100644
index 0000000000..201ab51002
--- /dev/null
+++ b/src/ec/google/wilco/acpi/vbtn.asl
@@ -0,0 +1,94 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2019 Google LLC
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+/*
+ * Intel Virtual Button driver compatible with the driver found in
+ * the Linux kernel at drivers/platform/x86/intel-vbtn.c
+ *
+ * For tablet/laptop and dock/undock events to work the board must
+ * select SYSTEM_TYPE_CONVERTIBLE for the SMBIOS enclosure type to
+ * indicate the device is a convertible.
+ */
+
+Name (FLAP, 0x40) /* Flag indicating device is in laptop mode */
+
+/* Virtual events */
+Name (VPPB, 0xc0) /* Power Button press */
+Name (VRPB, 0xc1) /* Power Button release */
+Name (VPSP, 0xc2) /* Special key press (LEFTMETA in Linux) */
+Name (VRSP, 0xc3) /* Special key release (LEFTMETA in Linux) */
+Name (VPVU, 0xc4) /* Volume Up press */
+Name (VRVU, 0xc5) /* Volume Up release */
+Name (VPVD, 0xc6) /* Volume Down press */
+Name (VRVD, 0xc7) /* Volume Down release */
+Name (VPRL, 0xc8) /* Rotate Lock press */
+Name (VRRL, 0xc9) /* Rotate Lock release */
+Name (VDOC, 0xca) /* Docked */
+Name (VUND, 0xcb) /* Undocked */
+Name (VTBL, 0xcc) /* Tablet Mode */
+Name (VLAP, 0xcd) /* Laptop Mode */
+
+Device (VBTN)
+{
+	Name (_HID, "INT33D6")
+	Name (_UID, One)
+	Name (_DDN, "Intel Virtual Button Driver")
+
+	/*
+	 * This method is called at driver probe time and must exist or
+	 * the driver will not load.
+	 */
+	Method (VBDL)
+	{
+	}
+
+	/*
+	 * This method returns flags indicating tablet and dock modes.
+	 * It is called at driver probe time so the OS knows what the
+	 * state of the device is at boot.
+	 */
+	Method (VGBS)
+	{
+		Local0 = Zero
+
+		/* Check EC orientation for tablet mode flag */
+		If (R (OTBL)) {
+			Printf ("EC reports tablet mode at boot")
+		} Else {
+			Printf ("EC reports laptop mode at boot")
+			Local0 |= ^^FLAP
+		}
+		Return (Local0)
+	}
+
+	Method(_STA, 0)
+	{
+		Return (0xF)
+	}
+}
+
+Device (VBTO)
+{
+	Name (_HID, "INT33D3")
+	Name (_CID, "PNP0C60")
+	Name (_UID, One)
+	Name (_DDN, "Laptop/tablet mode indicator driver")
+
+	Method (_STA, 0)
+	{
+		Return (0xF)
+	}
+}