fdtdec: allow board to provide fdt for CONFIG_OF_SEPARATE

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@gmail.com>
[trini: Update board_fdt_blob_setup #if check]
Signed-off-by: Tom Rini <trini@konsulko.com>

include/fdtdec.h

@@ -990,7 +990,8 @@ 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);
 

lib/fdtdec.c

@@ -1272,6 +1272,28 @@ static int uncompress_blob(const void *src, ulong sz_src, void **dstp)
 # endif
 #endif
 
+#if defined(CONFIG_OF_BOARD) || defined(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)
+{
+	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))
+		fdt_blob = (ulong *)&_image_binary_end;
+	else
+		fdt_blob = (ulong *)&__bss_end;
+#else
+	/* FDT is at end of image */
+	fdt_blob = (ulong *)&_end;
+#endif
+	return fdt_blob;
+}
+#endif
+
 int fdtdec_setup(void)
 {
 #if CONFIG_IS_ENABLED(OF_CONTROL)
@@ -1285,18 +1307,7 @@ int fdtdec_setup(void)
 #  else
 	gd->fdt_blob = __dtb_dt_begin;
 #  endif
-# elif defined CONFIG_OF_SEPARATE
-#  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;
-	else
-		gd->fdt_blob = (ulong *)&__bss_end;
-#  else
-	/* FDT is at end of image */
-	gd->fdt_blob = (ulong *)&_end;
-#  endif
-# elif defined(CONFIG_OF_BOARD)
+# elif defined(CONFIG_OF_BOARD) || defined(CONFIG_OF_SEPARATE)
 	/* Allow the board to override the fdt address. */
 	gd->fdt_blob = board_fdt_blob_setup();
 # elif defined(CONFIG_OF_HOSTFILE)