rockchip: Use an external TPL binary on RK3568

Rockchip SoCs typically use U-Boot TPL to initialize DRAM, then jumps
back to BootRom to load next stage, U-Boot SPL, into DRAM. BootRom then
jumps to U-Boot SPL to continue the normal boot flow.

However, there is no support to initialize DRAM on RK35xx SoCs using
U-Boot TPL and instead an external TPL binary must be used to generate a
bootable u-boot-rockchip.bin image.

Add CONFIG_ROCKCHIP_EXTERNAL_TPL to indicate that an external TPL should
be used. Build U-Boot with ROCKCHIP_TPL=/path/to/ddr.bin to generate a
bootable u-boot-rockchip.bin image for RK3568.

Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
Tested-by: Eugen Hristev <eugen.hristev@collabora.com>

Makefile

@@ -1336,6 +1336,7 @@ cmd_binman = $(srctree)/tools/binman/binman $(if $(BINMAN_DEBUG),-D) \
 		-a opensbi-path=${OPENSBI} \
 		-a default-dt=$(default_dt) \
 		-a scp-path=$(SCP) \
+		-a rockchip-tpl-path=$(ROCKCHIP_TPL) \
 		-a spl-bss-pad=$(if $(CONFIG_SPL_SEPARATE_BSS),,1) \
 		-a tpl-bss-pad=$(if $(CONFIG_TPL_SEPARATE_BSS),,1) \
 		-a spl-dtb=$(CONFIG_SPL_OF_REAL) \

arch/arm/dts/rockchip-u-boot.dtsi

@@ -20,9 +20,12 @@
 		mkimage {
 			filename = "idbloader.img";
 			args = "-n", CONFIG_SYS_SOC, "-T", "rksd";
-#ifdef CONFIG_TPL
 			multiple-data-files;
 
+#ifdef CONFIG_ROCKCHIP_EXTERNAL_TPL
+			rockchip-tpl {
+			};
+#elif defined(CONFIG_TPL)
 			u-boot-tpl {
 			};
 #endif
@@ -134,9 +137,12 @@
 		mkimage {
 			filename = "idbloader-spi.img";
 			args = "-n", CONFIG_SYS_SOC, "-T", "rkspi";
-#ifdef CONFIG_TPL
 			multiple-data-files;
 
+#ifdef CONFIG_ROCKCHIP_EXTERNAL_TPL
+			rockchip-tpl {
+			};
+#elif defined(CONFIG_TPL)
 			u-boot-tpl {
 			};
 #endif

arch/arm/mach-rockchip/Kconfig

@@ -401,6 +401,14 @@ config TPL_ROCKCHIP_COMMON_BOARD
 	  common board is a basic TPL board init which can be shared for most
 	  of SoCs to avoid copy-paste for different SoCs.
 
+config ROCKCHIP_EXTERNAL_TPL
+	bool "Use external TPL binary"
+	default y if ROCKCHIP_RK3568
+	help
+	  Some Rockchip SoCs require an external TPL to initialize DRAM.
+	  Enable this option and build with ROCKCHIP_TPL=/path/to/ddr.bin to
+	  include the external TPL in the image built by binman.
+
 config ROCKCHIP_BOOT_MODE_REG
 	hex "Rockchip boot mode flag register address"
 	help

doc/board/rockchip/rockchip.rst

@@ -86,6 +86,8 @@ List of mainline supported Rockchip boards:
      - Radxa ROCK Pi 4 (rock-pi-4-rk3399)
      - Rockchip Evb-RK3399 (evb_rk3399)
      - Theobroma Systems RK3399-Q7 SoM - Puma (puma_rk3399)
+* rk3568
+     - Rockchip Evb-RK3568 (evb-rk3568)
 * rv1108
      - Rockchip Evb-rv1108 (evb-rv1108)
      - Elgin-R1 (elgin-rv1108)
@@ -167,6 +169,15 @@ To build rk3399 boards:
         make evb-rk3399_defconfig
         make CROSS_COMPILE=aarch64-linux-gnu-
 
+To build rk3568 boards:
+
+.. code-block:: bash
+
+        export BL31=../rkbin/bin/rk35/rk3568_bl31_v1.34.elf
+        export ROCKCHIP_TPL=../rkbin/bin/rk35/rk3568_ddr_1560MHz_v1.13.bin
+        make evb-rk3568_defconfig
+        make CROSS_COMPILE=aarch64-linux-gnu-
+
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