Change in coreboot[master]: ec/system76/ec: Preserve ECOS through suspend

[Patrick Georgi (Code Review)]

Patrick Georgi has submitted this change. ( https://review.coreboot.org/c/coreboot/+/50489 )

Change subject: ec/system76/ec: Preserve ECOS through suspend
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ec/system76/ec: Preserve ECOS through suspend

When the EC is reset on PLTRST this information will be lost, causing
system control interrupts to potentially stop functioning.

Change-Id: I137ef6c574a372601bc51f6e815158767acd0e1b
Signed-off-by: Jeremy Soller 
Signed-off-by: Tim Crawford 
Reviewed-on: https://review.coreboot.org/c/coreboot/+/50489
Reviewed-by: Paul Menzel 
Tested-by: build bot (Jenkins) 
---
M src/ec/system76/ec/acpi/ec.asl
1 file changed, 7 insertions(+), 0 deletions(-)

Approvals:
  build bot (Jenkins): Verified
  Paul Menzel: Looks good to me, but someone else must approve
  Jeremy Soller: Looks good to me, approved

diff --git a/src/ec/system76/ec/acpi/ec.asl b/src/ec/system76/ec/acpi/ec.asl
index 128bd56..612c358 100644
--- a/src/ec/system76/ec/acpi/ec.asl
+++ b/src/ec/system76/ec/acpi/ec.asl
@@ -62,9 +62,13 @@
    	}
    }

+	Name (S3OS, Zero)
    Method (PTS, 1, Serialized) {
    	Debug = Concatenate("EC: PTS: ", ToHexString(Arg0))
    	If (ECOK) {
+			// Save ECOS during sleep
+			S3OS = ECOS
+
    		// Clear wake cause
    		WFNO = Zero
    	}
@@ -73,6 +77,9 @@
    Method (WAK, 1, Serialized) {
    	Debug = Concatenate("EC: WAK: ", ToHexString(Arg0))
    	If (ECOK) {
+			// Restore ECOS after sleep
+			ECOS = S3OS
+
    		// Set current AC state
    		^^^^AC.ACFG = ADP