MIPS: Malta: Basic DT plumbing

Build a DT for the Malta platform into the kernel, load it & probe
devices from it. The DT is essentially empty at this point, devices
will be added in further patches.

[ralf@linux-mips.org: Fixed conflicts.]
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: devicetree@vger.kernel.org
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ian Campbell <ijc+devicetree@hellion.org.uk>
Cc: Kumar Gala <galak@codeaurora.org>
Cc: Andrew Bresticker <abrestic@chromium.org>
Cc: linux-kernel@vger.kernel.org
Cc: Markos Chandras <markos.chandras@imgtec.com>
Patchwork: http://patchwork.linux-mips.org/patch/10119/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/Kconfig

@@ -404,6 +404,7 @@ config MIPS_MALTA
 	select ARCH_MAY_HAVE_PC_FDC
 	select BOOT_ELF32
 	select BOOT_RAW
+	select BUILTIN_DTB
 	select CEVT_R4K
 	select CSRC_R4K
 	select CLKSRC_MIPS_GIC
@@ -443,6 +444,7 @@ config MIPS_MALTA
 	select SYS_SUPPORTS_MULTITHREADING
 	select SYS_SUPPORTS_SMARTMIPS
 	select SYS_SUPPORTS_ZBOOT
+	select USE_OF
 	select ZONE_DMA32 if 64BIT
 	help
 	  This enables support for the MIPS Technologies Malta evaluation

arch/mips/boot/dts/mti/Makefile

+dtb-$(CONFIG_MIPS_MALTA)	+= malta.dtb
 dtb-$(CONFIG_MIPS_SEAD3)	+= sead3.dtb
 
 obj-y				+= $(patsubst %.dtb, %.dtb.o, $(dtb-y))

arch/mips/boot/dts/mti/malta.dts

+/dts-v1/;
+
+/ {
+	#address-cells = <1>;
+	#size-cells = <1>;
+	compatible = "mti,malta";
+};

arch/mips/mti-malta/Makefile

@@ -5,7 +5,7 @@
 # Copyright (C) 2008 Wind River Systems, Inc.
 #   written by Ralf Baechle <ralf@linux-mips.org>
 #
-obj-y				:= malta-display.o malta-init.o \
+obj-y				:= malta-display.o malta-dt.o malta-init.o \
 				   malta-int.o malta-memory.o malta-platform.o \
 				   malta-reset.o malta-setup.o malta-time.o
 

arch/mips/mti-malta/malta-dt.c

+/*
+ * Copyright (C) 2015 Imagination Technologies
+ * Author: Paul Burton <paul.burton@imgtec.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/init.h>
+#include <linux/of_fdt.h>
+#include <linux/of_platform.h>
+
+void __init device_tree_init(void)
+{
+	unflatten_and_copy_device_tree();
+}
+
+static const struct of_device_id bus_ids[] __initconst = {
+	{ .compatible = "simple-bus", },
+	{ .compatible = "isa", },
+	{},
+};
+
+static int __init publish_devices(void)
+{
+	if (!of_have_populated_dt())
+		return 0;
+
+	return of_platform_bus_probe(NULL, bus_ids, NULL);
+}
+device_initcall(publish_devices);

arch/mips/mti-malta/malta-setup.c

@@ -21,6 +21,7 @@
 #include <linux/sched.h>
 #include <linux/ioport.h>
 #include <linux/irq.h>
+#include <linux/of_fdt.h>
 #include <linux/pci.h>
 #include <linux/screen_info.h>
 #include <linux/time.h>
@@ -31,6 +32,7 @@
 #include <asm/mips-boards/malta.h>
 #include <asm/mips-boards/maltaint.h>
 #include <asm/dma.h>
+#include <asm/prom.h>
 #include <asm/traps.h>
 #ifdef CONFIG_VT
 #include <linux/console.h>
@@ -249,6 +251,8 @@ void __init plat_mem_setup(void)
 {
 	unsigned int i;
 
+	__dt_setup_arch(__dtb_start);
+
 	if (config_enabled(CONFIG_EVA))
 		/* EVA has already been configured in mach-malta/kernel-init.h */
 		pr_info("Enhanced Virtual Addressing (EVA) activated\n");