ec/google/wilco: Add EC ACPI methods for privacy screen

Add ACPI methods to the Wilco EC for controlling a privacy screen
on the device.

BUG=b:142237145, b:142656363
TEST=none

Change-Id: Ic3c136f9d2de90eeb3c9e468e4c7430ccf6dcc42
Signed-off-by: Mathew King <mathewk@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/36044
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

3 files changed, 50 insertions, 0 deletions

diff --git a/src/ec/google/wilco/acpi/ec.asl b/src/ec/google/wilco/acpi/ec.asl
index 532f421780..8fcd0dd5c2 100644
--- a/src/ec/google/wilco/acpi/ec.asl
+++ b/src/ec/google/wilco/acpi/ec.asl
@@ -178,4 +178,7 @@ Device (EC0)
 #ifdef EC_ENABLE_DPTF
 	#include "dptf.asl"
 #endif
+#ifdef EC_ENABLE_PRIVACY
+	#include "privacy.asl"
+#endif
 }
diff --git a/src/ec/google/wilco/acpi/ec_ram.asl b/src/ec/google/wilco/acpi/ec_ram.asl
index 47e9072dcb..af8fc0effc 100644
--- a/src/ec/google/wilco/acpi/ec_ram.asl
+++ b/src/ec/google/wilco/acpi/ec_ram.asl
@@ -125,6 +125,9 @@ Name (BCCY, Package () { 0x3e, 0xffff, RD })	/* BCACHE: Cycle Count */
 
 Name (ESGN, Package () { 0x5c, 0xff, RD })	/* Indicate EC uses signed FW */
 
+Name (EPDT, Package () { 0x5d, 0xff, RD })	/* Privacy Screen Detection */
+Name (EPST, Package () { 0x5e, 0xff, RD })	/* Privacy Screen State */
+
 /*
  * EC RAM WRITE
  */
@@ -135,6 +138,7 @@ Name (SSEL, Package () { 0x04, 0xff, WR })	/* Battery String Select */
 Name (ERDY, Package () { 0x05, 0xff, WR })	/* EC Ready */
 Name (FWAK, Package () { 0x06, 0xff, WR })	/* EC _WAK */
 Name (PS2M, Package () { 0x20, 0xff, WR })	/* EC PS/2 Mouse Emulation */
+Name (EPCT, Package () { 0x25, 0xff, WR })	/* Privacy Screen Control */
 Name (DWST, Package () { 0x32, 0xff, WR })	/* DPTF: Write State */
 Name (DWTI, Package () { 0x33, 0xff, WR })	/* DPTF: Write Thermal Index */
 Name (DWTL, Package () { 0x35, 0xff, WR })	/* DPTF: Write Trip Low */
diff --git a/src/ec/google/wilco/acpi/privacy.asl b/src/ec/google/wilco/acpi/privacy.asl
new file mode 100644
index 0000000000..5c620b0fca
--- /dev/null
+++ b/src/ec/google/wilco/acpi/privacy.asl
@@ -0,0 +1,43 @@
+/*
+ * 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.
+ */
+
+/* Read Privacy Screen Present */
+Method (GPVD, 0, Serialized)
+{
+	Return (R (EPDT))
+}
+
+/* Read Privacy Screen Status */
+Method (GPVX, 0, Serialized)
+{
+	If (R (EPST) == Zero) {
+		Return (Zero)
+	}
+
+	Return (One)
+}
+
+/* Enable Privacy Screen */
+Method (EPVX, 0, Serialized)
+{
+	W (EPCT, One)
+}
+
+/* Disable Privacy Screen */
+Method (DPVX, 0, Serialized)
+{
+	W (EPCT, Zero)
+}