rockchip: add support to load and use kernel dtb

We are going to use a tiny dtb(with 'u-boot,dm-pre-reloc') in pre-relocate,
and then read kernel dtb and use it after relocate.
This feature only works with CONFIG_OF_LIVE enabled now.

Change-Id: I429ccd90ef562a96f2f7916255e7e427ce8f451d
Signed-off-by: Kever Yang <kever.yang@rock-chips.com>

arch/arm/mach-rockchip/Kconfig

@@ -349,6 +349,15 @@ config ROCKCHIP_VENDOR_PARTITION
 	  This enable support to read/write vendor configuration data from/to
 	  this partition.
 
+config USING_KERNEL_DTB
+	bool "Using dtb from Kernel/resource for U-Boot"
+	depends on RKIMG_BOOTLOADER && OF_LIVE
+	default y
+	help
+	  This enable support to read dtb from resource and use it for U-Boot,
+	  the uart and emmc will still using U-Boot dtb, but other devices like
+	  regulator/pmic, display, usb will use dts node from kernel.
+
 config ROCKCHIP_CRC
 	bool "Rockchip CRC verify images"
 	help

common/board_r.c

@@ -103,6 +103,41 @@ static int initr_reloc(void)
 
 	return 0;
 }
+#ifdef CONFIG_USING_KERNEL_DTB
+#include <asm/arch/resource_img.h>
+#define DTB_FILE                        "rk-kernel.dtb"
+int get_fdt_from_resource(void)
+{
+	int ret = 0;
+	struct mmc *mmc;
+	ulong fdt_addr = 0;
+
+	mmc_initialize(gd->bd);
+	mmc = find_mmc_device(0);
+	if (!mmc) {
+		printf("no mmc device at slot 0\n");
+		return -1;
+	}
+	ret = mmc_init(mmc);
+	if (ret)
+		printf("%s mmc init fail %d\n", __func__, ret);
+
+	fdt_addr = env_get_ulong("fdt_addr_r", 16, 0);
+	if (!fdt_addr) {
+		printf("No Found FDT Load Address.\n");
+		return -1;
+	}
+
+	ret = rockchip_read_resource_file((void *)fdt_addr, DTB_FILE, 0, 0);
+	if (ret < 0) {
+		printf("%s dtb in resource read fail\n", __func__);
+		return 0;
+	}
+	gd->kernel_fdt = (void *)fdt_addr;
+
+	return 0;
+}
+#endif
 
 #ifdef CONFIG_ARM
 /*
@@ -698,6 +733,9 @@ static init_fnc_t init_sequence_r[] = {
 	initr_noncached,
 #endif
 	bootstage_relocate,
+#ifdef CONFIG_USING_KERNEL_DTB
+	get_fdt_from_resource,
+#endif
 #ifdef CONFIG_OF_LIVE
 	initr_of_live,
 #endif

drivers/core/root.c

@@ -306,8 +306,20 @@ int dm_scan_fdt(const void *blob, bool pre_reloc_only)
 {
 #if CONFIG_IS_ENABLED(OF_LIVE)
 	if (of_live_active())
+#ifndef CONFIG_USING_KERNEL_DTB
 		return dm_scan_fdt_live(gd->dm_root, gd->of_root,
 					pre_reloc_only);
+#else
+	{
+		dm_scan_fdt_live(gd->dm_root, gd->of_root,
+					pre_reloc_only);
+		if (!gd->kernel_of_root)
+			return 0;
+
+		return dm_scan_fdt_live(gd->dm_root, gd->kernel_of_root,
+					pre_reloc_only);
+	}
+#endif
 	else
 #endif
 	return dm_scan_fdt_node(gd->dm_root, blob, 0, pre_reloc_only);

include/asm-generic/global_data.h

@@ -81,6 +81,10 @@ typedef struct global_data {
 	unsigned long fdt_size;		/* Space reserved for relocated FDT */
 #ifdef CONFIG_OF_LIVE
 	struct device_node *of_root;
+#ifdef CONFIG_USING_KERNEL_DTB
+	void *kernel_fdt;		/* Kernel FDT */
+	struct device_node *kernel_of_root;
+#endif
 #endif
 	struct jt_funcs *jt;		/* jump table */
 	char env_buf[32];		/* buffer for env_get() before reloc. */

lib/of_live.c

@@ -332,6 +332,15 @@ int of_live_build(const void *fdt_blob, struct device_node **rootp)
 		debug("Failed to scan live tree aliases: err=%d\n", ret);
 		return ret;
 	}
+#ifdef CONFIG_USING_KERNEL_DTB
+	ret = unflatten_device_tree(gd->kernel_fdt,
+				    (struct device_node **)&gd->kernel_of_root);
+	if (ret) {
+		printf("%s fail to build live dt from kernel dtb.\n", __func__);
+		return 0;
+	}
+	gd->fdt_blob = gd->kernel_fdt;
+#endif
 	debug("%s: stop\n", __func__);
 
 	return ret;