soc/amd/picasso/acpi: Add a wrapper method WAL1 for calling ALIB function 1

ALIB function 1 needs to be called every time there is a change in
AC/DC state of the system. This change adds a wrapper method that can
be called by PNOT (method to notify system power state change) to
report to ALIB that system power state has changed i.e. AC <-> DC.

Additionally, this change drops the call to ALIB from _INI method
since the PWRS object might not be initialized correctly at that
point. Instead EC makes a call to PNOT when PWRS is initialized.

This wrapper also fixes the value of power state being passed into
ALIB. ALIB expects 0 = AC and 1 = DC. On the other hand, PWRS reports
1 as AC and 0 as DC. WAL1() takes care of inverting the PWRS state
before passing into ALIB.

BUG=b:157752693
TEST=Verified that WAL1() gets called on AC connect/disconnect.

Steps followed:
$ echo 1 > /sys/module/acpi/parameters/aml_debug_output
$ dmesg -w | grep ACPI
[   76.306947] ACPI Debug:  "EC: AC DISCONNECTED"
[   76.307064] ACPI Debug:  "ALIB call: func 1 params 0x03 0x00 0x01"
[   82.264946] ACPI Debug:  "EC: GOT PD EVENT"
[   82.539833] ACPI Debug:  "EC: GOT PD EVENT"
[   82.753721] ACPI Debug:  "EC: GOT PD EVENT"
[   82.843676] ACPI Debug:  "EC: GOT PD EVENT"
[   82.970596] ACPI Debug:  "EC: AC CONNECTED"
[   82.970659] ACPI Debug:  "ALIB call: func 1 params 0x03 0x00 0x00"
[   83.047598] ACPI Debug:  "EC: GOT PD EVENT"
[   84.804733] ACPI Debug:  "EC: GOT PD EVENT"
[   86.317934] ACPI Debug:  "EC: GOT PD EVENT"
[   86.385920] ACPI Debug:  "EC: GOT PD EVENT"
[   86.515830] ACPI Debug:  "EC: AC DISCONNECTED"
[   86.515922] ACPI Debug:  "ALIB call: func 1 params 0x03 0x00 0x01"
[   90.089062] ACPI Debug:  "EC: GOT PD EVENT"
[   90.357914] ACPI Debug:  "EC: GOT PD EVENT"
[   90.573812] ACPI Debug:  "EC: GOT PD EVENT"
[   90.662744] ACPI Debug:  "EC: GOT PD EVENT"
[   90.788706] ACPI Debug:  "EC: AC CONNECTED"
[   90.788835] ACPI Debug:  "ALIB call: func 1 params 0x03 0x00 0x00"
[   90.865675] ACPI Debug:  "EC: GOT PD EVENT"
[   92.621793] ACPI Debug:  "EC: GOT PD EVENT"

Signed-off-by: Furquan Shaikh <furquan@google.com>
Change-Id: I1f2ade28ca35378ebf4647d8df3d2ea4d0b08096
Reviewed-on: https://review.coreboot.org/c/coreboot/+/42297
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Raul Rangel <rrangel@chromium.org>

2 files changed, 28 insertions, 12 deletions

diff --git a/src/soc/amd/picasso/acpi/cpu.asl b/src/soc/amd/picasso/acpi/cpu.asl
index 41d5bf5324..8b61b8f921 100644
--- a/src/soc/amd/picasso/acpi/cpu.asl
+++ b/src/soc/amd/picasso/acpi/cpu.asl
@@ -1,8 +1,35 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 
-/* Required function by EC, Notify OS to re-read CPU tables */
+/*
+ * Wrapper method that calls ALIB function 1 to report current AC/DC state.
+ */
+Method (WAL1)
+{
+	/* Send ALIB Function 1 the AC/DC state */
+	Local0 = Buffer (0x03) {}
+	CreateWordField (Local0, 0, F1SZ)
+	CreateByteField (Local0, 2, F1DA)
+
+	/* First argument is size i.e. 3 bytes */
+	F1SZ = 3
+
+	/*
+	 * Second argument is power state i.e. AC or DC.
+	 * ALIB expects AC = 0, DC = 1.
+	 * PWRS reports AC = 1, DC = 0.
+	 *
+	 * Hence, need to invert the state of PWRS.
+	 */
+	F1DA = \PWRS ^ 1
+
+	Printf ("ALIB call: func 1 params %o", Local0)
+	\_SB.ALIB (1, Local0)
+}
+
 Method (PNOT)
 {
+	/* Report AC/DC state to ALIB using WAL1() */
+	\WAL1 ()
 }
 
 /*
diff --git a/src/soc/amd/picasso/acpi/sb_pci0_fch.asl b/src/soc/amd/picasso/acpi/sb_pci0_fch.asl
index 751c178762..27c46611b3 100644
--- a/src/soc/amd/picasso/acpi/sb_pci0_fch.asl
+++ b/src/soc/amd/picasso/acpi/sb_pci0_fch.asl
@@ -128,17 +128,6 @@ Method(_INI, 0, Serialized) {
 
 	/* Determine the OS we're running on */
 	OSFL()
-
-	/* Send ALIB Function 1 the AC/DC state */
-	Name(F1BF, Buffer(0x03){})
-	CreateWordField(F1BF, 0, F1SZ)
-	CreateByteField(F1BF, 2, F1DA)
-
-	Store(3, F1SZ)
-	Store(\PWRS, F1DA)
-
-	\_SB.ALIB(1, F1BF)
-
 } /* End Method(_SB._INI) */
 
 Method(OSFL, 0){