ec/google/wilco: Support board_id with EC provided ID

The EC can return a board ID value similar to the Chrome EC.
In order to use this for the board version returned by SMBIOS
this commit implements the board_id() function for mainboards
that use this EC.

BUG=b:123261132
TEST=Check /sys/class/dmi/id/board_version to see that it
is reflecting the value that the EC provides.

Change-Id: I3fbe0dc886701f37d2424fe7a2867fd860fa1ec0
Signed-off-by: Duncan Laurie <dlaurie@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/32276
Reviewed-by: Lijian Zhao <lijian.zhao@intel.com>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/ec/google/wilco/Makefile.inc

@@ -1,8 +1,8 @@
 ifeq ($(CONFIG_EC_GOOGLE_WILCO),y)
 
 bootblock-y += bootblock.c
-romstage-y += commands.c mailbox.c romstage.c
-ramstage-y += chip.c commands.c mailbox.c
-smm-y += commands.c mailbox.c smihandler.c
+romstage-y += commands.c mailbox.c romstage.c boardid.c
+ramstage-y += chip.c commands.c mailbox.c boardid.c
+smm-y += commands.c mailbox.c smihandler.c boardid.c
 
 endif

src/ec/google/wilco/boardid.c

@@ -0,0 +1,32 @@
+/*
+ * 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.
+ */
+
+#include <boardid.h>
+#include "commands.h"
+
+uint32_t board_id(void)
+{
+	MAYBE_STATIC uint32_t id = BOARD_ID_INIT;
+
+	if (id == BOARD_ID_INIT) {
+		uint8_t ec_id;
+		if (wilco_ec_get_board_id(&ec_id) <= 0)
+			id = BOARD_ID_UNKNOWN;
+		else
+			id = ec_id;
+	}
+
+	return id;
+}

src/ec/google/wilco/commands.c

@@ -135,6 +135,12 @@ int wilco_ec_get_lid_state(void)
 	return !!(pm.state[0] & EC_PM1_LID_OPEN);
 }
 
+int wilco_ec_get_board_id(uint8_t *id)
+{
+	return wilco_ec_mailbox(WILCO_EC_MSG_RAW, KB_BOARD_ID,
+				NULL, 0, id, sizeof(*id));
+}
+
 void wilco_ec_slp_en(void)
 {
 	/* EC does not respond to this command */

src/ec/google/wilco/commands.h

@@ -38,6 +38,8 @@ enum {
 	KB_EC_INFO = 0x38,
 	/* Set ACPI mode on or off */
 	KB_ACPI = 0x3a,
+	/* Board ID */
+	KB_BOARD_ID = 0x3d,
 	/* Change ACPI wake up source */
 	KB_ACPI_WAKEUP_CHANGE = 0x4a,
 	/* Manage the EC power button passthru to the host */
@@ -267,6 +269,17 @@ int wilco_ec_get_pm(struct ec_pm_event_state *pm, bool clear);
  */
 int wilco_ec_get_lid_state(void);
 
+/**
+ * wilco_ec_get_board_id
+ *
+ * Retrieve the board ID value from the EC.
+ * @id:		Pointer to variable to store the ID read from the EC.
+ *
+ * Returns number of bytes transferred from the EC
+ * Returns -1 if the EC command failed
+ */
+int wilco_ec_get_board_id(uint8_t *id);
+
 enum ec_wake_change {
 	WAKE_OFF = 0,
 	WAKE_ON