MIPS: SEAD3: Implement OF support.

Activate USE_OF for SEAD-3 platform. Add basic DTS file and convert memory
detection and reservations to use OF.

[ralf@linux-mips.org: Remove unnecessary #ifdef wrapper in generic.h.  Make
<asm/mips-boards/generic.h> inclusion work even without prior
<linux/of_fdt.h> inclusion.]

Signed-off-by: Steven J. Hill <sjhill@mips.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/4809/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/mti-sead3/sead3-setup.c b/arch/mips/mti-sead3/sead3-setup.c
index 8ad46ad..f012fd1 100644
--- a/arch/mips/mti-sead3/sead3-setup.c
+++ b/arch/mips/mti-sead3/sead3-setup.c
@@ -6,6 +6,12 @@
  * Copyright (C) 2012 MIPS Technologies, Inc.  All rights reserved.
  */
 #include <linux/init.h>
+#include <linux/of_platform.h>
+#include <linux/of_fdt.h>
+#include <linux/bootmem.h>
+
+#include <asm/mips-boards/generic.h>
+#include <asm/prom.h>
 
 int coherentio;		/* 0 => no DMA cache coherency (may be set by user) */
 int hw_coherentio;	/* 0 => no HW DMA cache coherency (reflects real HW) */
@@ -17,4 +23,25 @@
 
 void __init plat_mem_setup(void)
 {
+	/*
+	 * Load the builtin devicetree. This causes the chosen node to be
+	 * parsed resulting in our memory appearing
+	 */
+	__dt_setup_arch(&__dtb_start);
+}
+
+void __init device_tree_init(void)
+{
+	unsigned long base, size;
+
+	if (!initial_boot_params)
+		return;
+
+	base = virt_to_phys((void *)initial_boot_params);
+	size = be32_to_cpu(initial_boot_params->totalsize);
+
+	/* Before we do anything, lets reserve the dt blob */
+	reserve_bootmem(base, size, BOOTMEM_DEFAULT);
+
+	unflatten_device_tree();
 }