mb/intel/kblrvp: Add helper function to get Board Id

Add 2 helper function get_board_id() & get_spd_index()
to read board id & spd index from EC.
Rename the old get_board_id() function to get_ec_boardinfo().

BUG=None
TEST= Tested on KBL RVP11, able to read the Board id (0x44)
      and verified in serial logs. not verified on KBL RVP8.

Signed-off-by: Praveen hodagatta pranesh <praveenx.hodagatta.pranesh@intel.com>
Change-Id: Ie20bf0d45a3568c2c433e5b844bea86aac07c47d
Reviewed-on: https://review.coreboot.org/c/30306
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>

src/mainboard/intel/kblrvp/board_id.c

@@ -1,7 +1,7 @@
 /*
  * This file is part of the coreboot project.
  *
- * Copyright (C) 2016 Intel Corporation.
+ * Copyright (C) 2016-2018 Intel Corporation.
  *
  * 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
@@ -15,18 +15,42 @@
 #include "board_id.h"
 #include <ec/acpi/ec.h>
 #include <stdint.h>
+#include <stddef.h>
 
 /*
- * Get Board ID via EC I/O port write/read
+ * Get Board info via EC I/O port write/read
  */
-int get_board_id(void)
+int get_ec_boardinfo(void)
 {
+	MAYBE_STATIC int ec_info = -1;
+	if (ec_info < 0) {
 		uint8_t buffer[2];
 		uint8_t index;
 		if (send_ec_command(EC_FAB_ID_CMD) == 0) {
 			for (index = 0; index < sizeof(buffer); index++)
 				buffer[index] = recv_ec_data();
-		return (buffer[1] << 8) | buffer[0];
+			ec_info = (buffer[1] << 8) | buffer[0];
 		}
+	}
+	return ec_info;
+}
+
+/* Get spd index */
+int get_spd_index(void)
+{
+	int ec_info = get_ec_boardinfo();
+	if (ec_info >= 0)
+		return ((uint16_t)ec_info >> 5) & 0x7;
+
+	return -1;
+}
+
+/* Get Board Id */
+int get_board_id(void)
+{
+	int ec_info = get_ec_boardinfo();
+	if (ec_info >= 0)
+		return ((uint16_t)ec_info >> 8) & 0xff;
+
 	return -1;
 }

src/mainboard/intel/kblrvp/board_id.h

@@ -1,7 +1,7 @@
 /*
  * This file is part of the coreboot project.
  *
- * Copyright (C) 2016 Intel Corporation.
+ * Copyright (C) 2016-2018 Intel Corporation.
  *
  * 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
@@ -19,6 +19,7 @@
 /* Mobile Board Id 0x00 - 0xFF */
 #define BOARD_ID_SKL_A0_RVP3	0x04
 #define BOARD_ID_SKL_RVP7	0x0B
+#define BOARD_ID_KBL_RVP11	0x44
 
 /* 60-6F reserved for KBL RVPs */
 #define BOARD_ID_KBL_LPDDR3_RVP3	0x60
@@ -31,6 +32,12 @@
  * Returns board information (board id[15:8] and
  * Fab info[7:0]) on success and < 0 on error
  */
+int get_ec_boardinfo(void);
+
+/* Return spd index */
+int get_spd_index(void);
+
+/* Board id[15:8] */
 int get_board_id(void);
 
 #endif /* _MAINBOARD_BOARD_ID_H_ */

src/mainboard/intel/kblrvp/romstage.c

@@ -31,7 +31,9 @@ void mainboard_memory_init_params(FSPM_UPD *mupd)
 {
 	FSP_M_CONFIG *mem_cfg;
 	mem_cfg = &mupd->FspmConfig;
-	u8 spd_index = (get_board_id() >> 5) & 0x7;
+	u8 spd_index = get_spd_index();
+	if ((int)spd_index < 0)
+		return;
 
 	printk(BIOS_INFO, "SPD index %d\n", spd_index);