[U-Boot] [PATCH 1/6] fdtdec: allow board to provide fdt for CONFIG_OF_SEPARATE

[Rob Clark]

Similar to CONFIG_OF_BOARD, but in this case the fdt is still built by
u-boot build.  This allows the board to patch the fdt, etc.

In the specific case of dragonboard 410c, we pass the u-boot generated
fdt to the previous stage of bootloader (by embedding it in the
u-boot.img that is loaded by lk/aboot), which patches the fdt and passes
it back to u-boot.

Signed-off-by: Rob Clark <robdclark at gmail.com>
---
 include/fdtdec.h |  3 ++-
 lib/fdtdec.c     | 45 ++++++++++++++++++++++++++-------------------
 2 files changed, 28 insertions(+), 20 deletions(-)

diff --git a/include/fdtdec.h b/include/fdtdec.h
index 4a0947c626..b9acec735a 100644
--- a/include/fdtdec.h
+++ b/include/fdtdec.h
@@ -986,7 +986,8 @@ int fdtdec_setup(void);
 
 /**
  * Board-specific FDT initialization. Returns the address to a device tree blob.
- * Called when CONFIG_OF_BOARD is defined.
+ * Called when CONFIG_OF_BOARD is defined, or if CONFIG_OF_SEPARATE is defined
+ * and the board implements it.
  */
 void *board_fdt_blob_setup(void);
 
diff --git a/lib/fdtdec.c b/lib/fdtdec.c
index d2dbd0f122..07c458673c 100644
--- a/lib/fdtdec.c
+++ b/lib/fdtdec.c
@@ -1203,34 +1203,41 @@ int fdtdec_setup_memory_banksize(void)
 }
 #endif
 
-int fdtdec_setup(void)
+#ifdef CONFIG_OF_SEPARATE
+/*
+ * For CONFIG_OF_SEPARATE, the board may optionally implement this to
+ * provide and/or fixup the fdt.
+ */
+__weak void *board_fdt_blob_setup(void)
 {
-#if CONFIG_IS_ENABLED(OF_CONTROL)
-# ifdef CONFIG_OF_EMBED
-	/* Get a pointer to the FDT */
-	gd->fdt_blob = __dtb_dt_begin;
-# elif defined CONFIG_OF_SEPARATE
-#  ifdef CONFIG_SPL_BUILD
+	void *fdt_blob = NULL;
+#ifdef CONFIG_SPL_BUILD
 	/* FDT is at end of BSS unless it is in a different memory region */
 	if (IS_ENABLED(CONFIG_SPL_SEPARATE_BSS))
-		gd->fdt_blob = (ulong *)&_image_binary_end;
+		fdt_blob = (ulong *)&_image_binary_end;
 	else
-		gd->fdt_blob = (ulong *)&__bss_end;
+		fdt_blob = (ulong *)&__bss_end;
 
-#  elif defined CONFIG_FIT_EMBED
-	gd->fdt_blob = locate_dtb_in_fit(&_end);
+#elif defined CONFIG_FIT_EMBED
+	fdt_blob = locate_dtb_in_fit(&_end);
 
-	if (gd->fdt_blob == NULL || gd->fdt_blob <= ((void *)&_end)) {
+	if (fdt_blob == NULL || fdt_blob <= ((void *)&_end))
 		puts("Failed to find proper dtb in embedded FIT Image\n");
-		return -1;
-	}
-
-#  else
+#else
 	/* FDT is at end of image */
-	gd->fdt_blob = (ulong *)&_end;
+	fdt_blob = (ulong *)&_end;
 #  endif
-# elif defined(CONFIG_OF_BOARD)
-	/* Allow the board to override the fdt address. */
+	return fdt_blob;
+}
+#endif
+
+int fdtdec_setup(void)
+{
+#if CONFIG_IS_ENABLED(OF_CONTROL)
+# ifdef CONFIG_OF_EMBED
+	/* Get a pointer to the FDT */
+	gd->fdt_blob = __dtb_dt_begin;
+# elif defined(CONFIG_OF_SEPARATE) || defined(CONFIG_OF_BOARD)
 	gd->fdt_blob = board_fdt_blob_setup();
 # elif defined(CONFIG_OF_HOSTFILE)
 	if (sandbox_read_fdt_from_file()) {
-- 
2.13.0