mb/intel/mtlrvp: Add MTL-P RVP board ids

This adds MTL-P board id definition. Change include,
1. Add board_id.c implementation
2. Add board_id.h implementation
3. Add board_id config in variants.h
4. Makefile changes

BUG=b:224325352
TEST=Able to build with the patch and boot the mtlrvp platform with the
subsequent patches in the train

Signed-off-by: Jamie Ryu <jamie.m.ryu@intel.com>
Change-Id: I90b0543d5db208f696d2c2c2dc3d2581514a845b
Signed-off-by: Harsha B R <harsha.b.r@intel.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/66102
Reviewed-by: Eric Lai <eric_lai@quanta.corp-partner.google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Usha P <usha.p@intel.com>
Reviewed-by: Subrata Banik <subratabanik@google.com>

src/ec/intel/board_id.c

@@ -2,9 +2,32 @@
 
 #include <boardid.h>
 #include "board_id.h"
+#include <ec/acpi/ec.h>
+#include <ec/google/chromeec/ec.h>
+#include <types.h>
 
-/* Get RVP Board ID */
+static uint32_t get_board_id_via_ext_ec(void)
+{
+	uint32_t id = BOARD_ID_INIT;
+
+	if (google_chromeec_get_board_version(&id))
+		id = BOARD_ID_UNKNOWN;
+
+	return id;
+}
+
+/* Get Board ID via EC I/O port write/read */
 int get_rvp_board_id(void)
 {
-	return BOARD_ID_INIT;
+	MAYBE_STATIC_NONZERO int id = BOARD_ID_UNKNOWN;
+
+	if (CONFIG(EC_GOOGLE_CHROMEEC)) { /* CHROME_EC */
+		id = get_board_id_via_ext_ec();
+	} else { /* WINDOWS_EC */
+		if (send_ec_command(EC_FAB_ID_CMD) == 0) {
+			id = recv_ec_data() << 8;
+			id |= recv_ec_data();
+		}
+	}
+	return (id & BOARD_ID_MASK);
 }

src/ec/intel/board_id.h

@@ -3,7 +3,15 @@
 #ifndef _MAINBOARD_COMMON_BOARD_ID_H_
 #define _MAINBOARD_COMMON_BOARD_ID_H_
 
-/* Returns RVP board_id */
+/* Board/FAB ID Command */
+#define EC_FAB_ID_CMD	0x0d
+/* Bit 5:0 for Board ID */
+#define BOARD_ID_MASK	0x3f
+
+/*
+ * Returns board information (board id[15:8] and
+ * Fab info[7:0]) on success and < 0 on error
+ */
 int get_rvp_board_id(void);
 
 #endif /* _MAINBOARD_COMMON_BOARD_ID_H_ */

src/mainboard/intel/mtlrvp/Makefile.inc

@@ -6,4 +6,5 @@ BASEBOARD_DIR:=$(call strip_quotes,$(CONFIG_BASEBOARD_DIR))
 subdirs-y += variants/baseboard/$(BASEBOARD_DIR)
 subdirs-y += variants/$(VARIANT_DIR)
 
+CPPFLAGS_common += -I$(src)/mainboard/$(MAINBOARDDIR)/variants/baseboard/include
 CPPFLAGS_common += -I$(src)/mainboard/$(MAINBOARDDIR)/variants/baseboard/$(BASEBOARD_DIR)/include

src/mainboard/intel/mtlrvp/variants/baseboard/include/baseboard/variants.h

@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef __BASEBOARD_VARIANTS_H__
+#define __BASEBOARD_VARIANTS_H__
+
+#include <stdint.h>
+
+enum mtl_boardid {
+	MTLP_DDR5_RVP = 0x01,
+	MTLP_LP5_T3_RVP = 0x02,
+	MTLP_LP5_T4_RVP = 0x04,
+	MTLM_LP5_RVP = 0x06,
+};
+
+#endif /*__BASEBOARD_VARIANTS_H__ */