gru: include ram_code in coreboot table

This is needed to ensure that the ram-code node is included in the
device tree by depthcharge.

BRANCH=none
BUG=chrome-os-partner:54566
TEST=built updated firmware, booted on kevin into Linux shell, checked
     the device tree contents:

  localhost ~ # od -tx1 /proc/device-tree/firmware/coreboot/ram-code
  0000000 00 00 00 01
  0000004
  localhost #

Change-Id: Ibe96e3bc8fc0106013241738f5726783d74bd78b
Signed-off-by: Martin Roth <martinroth@chromium.org>
Original-Commit-Id: 53c002114f7044b88728c9e17150cd3a2cf1f80f
Original-Change-Id: Iba573fba9f9b88b87867c6963e48215e254319ed
Original-Signed-off-by: Vadim Bendebury <vbendeb@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/354705
Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://review.coreboot.org/15566
Tested-by: build bot (Jenkins)
Reviewed-by: Furquan Shaikh <furquan@google.com>

src/mainboard/google/gru/Kconfig

@@ -30,6 +30,7 @@ config BOARD_SPECIFIC_OPTIONS
 	select MAINBOARD_DO_NATIVE_VGA_INIT
 	select MAINBOARD_HAS_CHROMEOS
 	select MAINBOARD_HAS_NATIVE_VGA_INIT
+	select RAM_CODE_SUPPORT
 	select RTC
 	select SOC_ROCKCHIP_RK3399
 	select SPI_FLASH

src/mainboard/google/gru/Makefile.inc

@@ -33,3 +33,4 @@ ramstage-y += chromeos.c
 ramstage-y += mainboard.c
 ramstage-y += memlayout.ld
 ramstage-y += reset.c
+ramstage-y += sdram_configs.c  # Needed for ram_code()

src/mainboard/google/gru/boardid.c

@@ -59,8 +59,3 @@ uint8_t board_id(void)
 	       adc_reading);
 	return 0;
 }
-
-uint32_t ram_code(void)
-{
-	return 0;
-}

src/mainboard/google/gru/sdram_configs.c

@@ -38,19 +38,29 @@ enum dram_speeds {
 /*	dram_928MHz = 4, */
 };
 
+static enum dram_speeds get_sdram_index(void)
+{
+	if (IS_ENABLED(CONFIG_BOARD_GOOGLE_KEVIN))
+		return dram_300MHz;
+	else if (IS_ENABLED(CONFIG_BOARD_GOOGLE_GRU))
+		return dram_800MHz;
+	else
+		return dram_200MHz;
+}
+
 const struct rk3399_sdram_params *get_sdram_config()
 {
-	enum dram_speeds speed;
 
-	if (IS_ENABLED(CONFIG_BOARD_GOOGLE_KEVIN))
-		speed = dram_300MHz;
-	else if (IS_ENABLED(CONFIG_BOARD_GOOGLE_GRU))
-		speed = dram_800MHz;
-	else
-		speed = dram_200MHz;
+	enum dram_speeds speed = get_sdram_index();
 
 	printk(BIOS_INFO, "Using SDRAM configuration for %d MHz\n",
 	       sdram_configs[speed].ddr_freq / (1000 * 1000));
 
 	return &sdram_configs[speed];
 }
+
+
+uint32_t ram_code(void)
+{
+	return get_sdram_index();
+}