rockchip: rk3188: use boot0 hook to load up SPL in 2 steps

For the RK3188, the BROM will attempt to load up the first stage
image (SPL for the RK3188) in two steps: first 1KB to offset 0x800
in the SRAM and then the remainder to offset 0xc00 in the SRAM.
It always enters at 0x804, though.

With this changeset, the RK3188 boot removes the TPL (stub) stage and
builds a single SPL binary that utilizes the early back-to-bootrom via
the boot0-hook.

Consequently, the passing of the saved boot params via pmu->os_reg[2]
is also removed.

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
diff --git a/arch/arm/mach-rockchip/Kconfig b/arch/arm/mach-rockchip/Kconfig
index d59a1d5..09f2c45 100644
--- a/arch/arm/mach-rockchip/Kconfig
+++ b/arch/arm/mach-rockchip/Kconfig
@@ -18,7 +18,7 @@
 	select SUPPORT_SPL
 	select SUPPORT_TPL
 	select SPL
-	select TPL
+	select SPL_ROCKCHIP_EARLYRETURN_TO_BROM
 	select BOARD_LATE_INIT
 	select ROCKCHIP_BROM_HELPER
 	help
diff --git a/arch/arm/mach-rockchip/Makefile b/arch/arm/mach-rockchip/Makefile
index b875dfc..c15e9bf 100644
--- a/arch/arm/mach-rockchip/Makefile
+++ b/arch/arm/mach-rockchip/Makefile
@@ -11,7 +11,6 @@
 obj-spl-$(CONFIG_ROCKCHIP_BROM_HELPER) += bootrom.o
 obj-tpl-$(CONFIG_ROCKCHIP_BROM_HELPER) += bootrom.o
 
-obj-tpl-$(CONFIG_ROCKCHIP_RK3188) += rk3188-board-tpl.o
 obj-tpl-$(CONFIG_ROCKCHIP_RK3288) += rk3288-board-tpl.o
 obj-tpl-$(CONFIG_ROCKCHIP_RK3368) += rk3368-board-tpl.o
 
diff --git a/arch/arm/mach-rockchip/rk3188-board-spl.c b/arch/arm/mach-rockchip/rk3188-board-spl.c
index 406207e..05d4ae6 100644
--- a/arch/arm/mach-rockchip/rk3188-board-spl.c
+++ b/arch/arm/mach-rockchip/rk3188-board-spl.c
@@ -101,7 +101,6 @@
 void board_init_f(ulong dummy)
 {
 	struct udevice *pinctrl, *dev;
-	struct rk3188_pmu *pmu;
 	int ret;
 
 	/* Example code showing how to enable the debug UART on RK3188 */
@@ -145,15 +144,6 @@
 		return;
 	}
 
-	/*
-	 * Recover the bootrom's stackpointer.
-	 * For whatever reason needs to run after rockchip_get_clk.
-	 */
-	pmu = syscon_get_first_range(ROCKCHIP_SYSCON_PMU);
-	if (IS_ERR(pmu))
-		pr_err("pmu syscon returned %ld\n", PTR_ERR(pmu));
-	SAVE_SP_ADDR = readl(&pmu->sys_reg[2]);
-
 	ret = uclass_get_device(UCLASS_PINCTRL, 0, &pinctrl);
 	if (ret) {
 		debug("Pinctrl init failed: %d\n", ret);
diff --git a/arch/arm/mach-rockchip/rk3188-board-tpl.c b/arch/arm/mach-rockchip/rk3188-board-tpl.c
deleted file mode 100644
index b458ef6..0000000
--- a/arch/arm/mach-rockchip/rk3188-board-tpl.c
+++ /dev/null
@@ -1,86 +0,0 @@
-/*
- * (C) Copyright 2015 Google, Inc
- *
- * SPDX-License-Identifier:     GPL-2.0+
- */
-
-#include <common.h>
-#include <debug_uart.h>
-#include <spl.h>
-#include <asm/io.h>
-#include <asm/arch/bootrom.h>
-#include <asm/arch/pmu_rk3188.h>
-
-DECLARE_GLOBAL_DATA_PTR;
-
-/* track how often we were entered */
-static int rk3188_num_entries __attribute__ ((section(".data")));
-
-#define PMU_BASE	0x20004000
-#define SPL_ENTRY	0x10080C00
-
-static void jump_to_spl(void)
-{
-	typedef void __noreturn (*image_entry_noargs_t)(void);
-
-	struct rk3188_pmu * const pmu = (void *)PMU_BASE;
-	image_entry_noargs_t tpl_entry =
-		(image_entry_noargs_t)(unsigned long)SPL_ENTRY;
-
-	/* Store the SAVE_SP_ADDR in a location shared with SPL. */
-	writel(SAVE_SP_ADDR, &pmu->sys_reg[2]);
-	tpl_entry();
-}
-
-void board_init_f(ulong dummy)
-{
-	/* Example code showing how to enable the debug UART on RK3188 */
-#ifdef EARLY_UART
-#include <asm/arch/grf_rk3188.h>
-	/* Enable early UART on the RK3188 */
-#define GRF_BASE	0x20008000
-	struct rk3188_grf * const grf = (void *)GRF_BASE;
-
-	rk_clrsetreg(&grf->gpio1b_iomux,
-		     GPIO1B1_MASK << GPIO1B1_SHIFT |
-		     GPIO1B0_MASK << GPIO1B0_SHIFT,
-		     GPIO1B1_UART2_SOUT << GPIO1B1_SHIFT |
-		     GPIO1B0_UART2_SIN << GPIO1B0_SHIFT);
-	/*
-	 * Debug UART can be used from here if required:
-	 *
-	 * debug_uart_init();
-	 * printch('a');
-	 * printhex8(0x1234);
-	 * printascii("string");
-	 */
-	debug_uart_init();
-
-	printch('t');
-	printch('p');
-	printch('l');
-	printch('-');
-	printch(rk3188_num_entries + 1 + '0');
-	printch('\n');
-#endif
-
-	rk3188_num_entries++;
-
-	if (rk3188_num_entries == 1) {
-		/*
-		 * The original loader did some very basic integrity
-		 * checking at this point, but the remaining few bytes
-		 * could be used for any improvement making sense
-		 * really early on.
-		 */
-
-		back_to_bootrom();
-	} else {
-		/*
-		 * TPL part of the loader should now wait for us
-		 * at offset 0xC00 in the sram. Should never return
-		 * from there.
-		 */
-		jump_to_spl();
-	}
-}
diff --git a/doc/README.rockchip b/doc/README.rockchip
index da99f30..597f068 100644
--- a/doc/README.rockchip
+++ b/doc/README.rockchip
@@ -176,17 +176,17 @@
 
 The bootrom of rk3188 expects to find a small 1kb loader which returns
 control to the bootrom, after which it will load the real loader, which
-can then be up to 29kb in size and does the regular ddr init.
+can then be up to 29kb in size and does the regular ddr init.  This is
+handled by a single image (built as the SPL stage) that tests whether
+it is handled for the first or second time via code executed from the
+boot0-hook.
 
 Additionally the rk3188 requires everything the bootrom loads to be
 rc4-encrypted. Except for the very first stage the bootrom always reads
 and decodes 2kb pages, so files should be sized accordingly.
 
 # copy tpl, pad to 1020 bytes and append spl
-cat tpl/u-boot-tpl.bin > tplspl.bin
-truncate -s 1020 tplspl.bin
-cat spl/u-boot-spl.bin >> tplspl.bin
-tools/mkimage -n rk3188 -T rksd -d tplspl.bin out
+tools/mkimage -n rk3188 -T rksd -d spl/u-boot-spl.bin out
 
 # truncate, encode and append u-boot.bin
 truncate -s %2048 u-boot.bin
diff --git a/include/configs/rk3188_common.h b/include/configs/rk3188_common.h
index cfa5364..68a42a9 100644
--- a/include/configs/rk3188_common.h
+++ b/include/configs/rk3188_common.h
@@ -36,14 +36,9 @@
 #define CONFIG_ROCKCHIP_MAX_INIT_SIZE	(0x8000 - 0x800)
 #define CONFIG_ROCKCHIP_CHIP_TAG	"RK31"
 
-#ifdef CONFIG_TPL_BUILD
-#define CONFIG_SPL_TEXT_BASE		0x10080804
-/* tpl size 1kb - 4byte RK31 header */
-#define CONFIG_SPL_MAX_SIZE		(0x400 - 0x4)
-#elif defined(CONFIG_SPL_BUILD)
-/* spl size 32kb sram - 2kb bootrom - 1kb spl */
-#define CONFIG_SPL_MAX_SIZE		(0x8000 - 0xC00)
-#define CONFIG_SPL_TEXT_BASE		0x10080C00
+#define CONFIG_SPL_TEXT_BASE		0x10080800
+/* spl size 32kb sram - 2kb bootrom */
+#define CONFIG_SPL_MAX_SIZE		(0x8000 - 0x800)
 #define CONFIG_SPL_FRAMEWORK		1
 #define CONFIG_SPL_CLK			1
 #define CONFIG_SPL_PINCTRL		1
@@ -52,7 +47,6 @@
 #define CONFIG_SPL_RAM			1
 #define CONFIG_SPL_DRIVERS_MISC_SUPPORT	1
 #define CONFIG_ROCKCHIP_SERIAL		1
-#endif
 
 #define CONFIG_SPL_STACK		0x10087fff