openrisc: add initial device tree support

Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Cc: Franck Jullien <franck.jullien@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

arch/openrisc/Kconfig

@@ -1,5 +1,6 @@
 config OPENRISC
 	bool
+	select OFTREE
 	select HAS_CACHE
 	select HAVE_CONFIGURABLE_MEMORY_LAYOUT
 	select HAVE_DEFAULT_ENVIRONMENT_NEW
@@ -11,6 +12,14 @@ config ARCH_TEXT_BASE
 	hex
 	default 0x00000000
 
+config BUILTIN_DTB
+	bool "link a DTB into the barebox image"
+	depends on OFTREE
+
+config BUILTIN_DTB_NAME
+	string "DTB to build into the barebox image"
+	depends on BUILTIN_DTB
+
 choice
 	prompt "Select your board"
 

arch/openrisc/Makefile

@@ -19,3 +19,10 @@ common-y += arch/openrisc/lib/
 common-y += arch/openrisc/cpu/
 
 lds-y += arch/openrisc/cpu/barebox.lds
+
+common-$(CONFIG_BUILTIN_DTB) += arch/openrisc/dts/
+
+dts := arch/openrisc/dts
+
+%.dtb: scripts
+	$(Q)$(MAKE) $(build)=$(dts) $(dts)/$@

arch/openrisc/cpu/barebox.lds.S

@@ -69,6 +69,8 @@ SECTIONS
 	__usymtab : { BAREBOX_SYMS } > ram
 	___usymtab_end = .;
 
+	.dtb : { BAREBOX_DTB() } > ram
+
 	__etext = .; /* End of text and rodata section */
 
 	. = ALIGN(4);

arch/openrisc/dts/Makefile

@@ -0,0 +1,5 @@
+
+BUILTIN_DTB := $(patsubst "%",%,$(CONFIG_BUILTIN_DTB_NAME))
+obj-$(CONFIG_BUILTIN_DTB) += $(BUILTIN_DTB).dtb.o
+
+clean-files := *.dtb *.dtb.S

arch/openrisc/lib/Makefile

@@ -5,3 +5,4 @@ obj-y                 += muldi3.o
 obj-y                 += lshrdi3.o
 obj-y                 += ashldi3.o
 obj-y                 += ashrdi3.o
+obj-$(CONFIG_BUILTIN_DTB) += dtb.o

arch/openrisc/lib/dtb.c

@@ -0,0 +1,44 @@
+/*
+ * Copyright (C) 2014 Antony Pavlov <antonynpavlov@gmail.com>
+ *
+ * Based on arch/arm/cpu/dtb.c:
+ * Copyright (C) 2013 Sascha Hauer <s.hauer@pengutronix.de>, Pengutronix
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+#include <common.h>
+#include <init.h>
+#include <of.h>
+
+extern char __dtb_start[];
+
+static int of_openrisc_init(void)
+{
+	struct device_node *root;
+
+	root = of_get_root_node();
+	if (root)
+		return 0;
+
+	root = of_unflatten_dtb(__dtb_start);
+	if (root) {
+		pr_debug("using internal DTB\n");
+		of_set_root_node(root);
+		if (IS_ENABLED(CONFIG_OFDEVICE))
+			of_probe();
+	}
+
+	return 0;
+}
+core_initcall(of_openrisc_init);

drivers/of/Kconfig

@@ -4,7 +4,7 @@ config OFTREE
 
 config OFTREE_MEM_GENERIC
 	depends on OFTREE
-	depends on PPC || ARM || ARCH_EFI
+	depends on PPC || ARM || ARCH_EFI || OPENRISC
 	def_bool y
 
 config DTC