of/mips: Add device tree support to MIPS

Add the ability to enable CONFIG_OF on the MIPS architecture.
Signed-off-by: Dezhong Diao <dediao@cisco.com>
[grant.likely@secretlab.ca: cleared out obsolete hooks,
	removed ARCH_HAS_DEVTREE_MEM,
	remove __init tags from header file,
	removed debugfs support hunk]
[ddaney@linux-mips.org: backed out over aggressive trimming of hooks]
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Tested-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

arch/mips/Kconfig

@@ -2107,6 +2107,13 @@ config SECCOMP
 
 	  If unsure, say Y. Only embedded should say N here.
 
+config USE_OF
+	bool "Flattened Device Tree support"
+	select OF
+	select OF_FLATTREE
+	help
+	  Include support for flattened device tree machine descriptions.
+
 endmenu
 
 config LOCKDEP_SUPPORT

arch/mips/include/asm/irq.h

@@ -16,6 +16,11 @@
 
 #include <irq.h>
 
+static inline void irq_dispose_mapping(unsigned int virq)
+{
+	return;
+}
+
 #ifdef CONFIG_I8259
 static inline int irq_canonicalize(int irq)
 {

arch/mips/include/asm/prom.h

+/*
+ *  arch/mips/include/asm/prom.h
+ *
+ *  Copyright (C) 2010 Cisco Systems Inc. <dediao@cisco.com>
+ *
+ * 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.
+ *
+ */
+#ifndef __ASM_MIPS_PROM_H
+#define __ASM_MIPS_PROM_H
+
+#ifdef CONFIG_OF
+#include <linux/init.h>
+
+#include <asm/setup.h>
+#include <asm/irq.h>
+#include <asm/bootinfo.h>
+
+/* which is compatible with the flattened device tree (FDT) */
+#define cmd_line arcs_cmdline
+
+extern int early_init_dt_scan_memory_arch(unsigned long node,
+	const char *uname, int depth, void *data);
+
+extern int reserve_mem_mach(unsigned long addr, unsigned long size);
+extern void free_mem_mach(unsigned long addr, unsigned long size);
+
+extern void __init device_tree_init(void);
+#else /* CONFIG_OF */
+static inline void __init device_tree_init(void) { }
+#endif /* CONFIG_OF */
+
+#endif /* _ASM_MIPS_PROM_H */

arch/mips/kernel/Makefile

@@ -96,6 +96,8 @@ obj-$(CONFIG_KEXEC)		+= machine_kexec.o relocate_kernel.o
 obj-$(CONFIG_EARLY_PRINTK)	+= early_printk.o
 obj-$(CONFIG_SPINLOCK_TEST)	+= spinlock_test.o
 
+obj-$(CONFIG_OF)		+= prom.o
+
 CFLAGS_cpu-bugs64.o	= $(shell if $(CC) $(KBUILD_CFLAGS) -Wa,-mdaddi -c -o /dev/null -xc /dev/null >/dev/null 2>&1; then echo "-DHAVE_AS_SET_DADDI"; fi)
 
 obj-$(CONFIG_HAVE_STD_PC_SERIAL_PORT)	+= 8250-platform.o

arch/mips/kernel/prom.c

+/*
+ * MIPS support for CONFIG_OF device tree support
+ *
+ * Copyright (C) 2010 Cisco Systems Inc. <dediao@cisco.com>
+ *
+ * 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.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/bootmem.h>
+#include <linux/initrd.h>
+#include <linux/debugfs.h>
+#include <linux/of.h>
+#include <linux/of_fdt.h>
+#include <linux/of_irq.h>
+#include <linux/of_platform.h>
+
+#include <asm/page.h>
+#include <asm/prom.h>
+
+int __init early_init_dt_scan_memory_arch(unsigned long node,
+					  const char *uname, int depth,
+					  void *data)
+{
+	return early_init_dt_scan_memory(node, uname, depth, data);
+}
+
+void __init early_init_dt_add_memory_arch(u64 base, u64 size)
+{
+	return add_memory_region(base, size, BOOT_MEM_RAM);
+}
+
+int __init reserve_mem_mach(unsigned long addr, unsigned long size)
+{
+	return reserve_bootmem(addr, size, BOOTMEM_DEFAULT);
+}
+
+void __init free_mem_mach(unsigned long addr, unsigned long size)
+{
+	return free_bootmem(addr, size);
+}
+
+u64 __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
+{
+	return virt_to_phys(
+		__alloc_bootmem(size, align, __pa(MAX_DMA_ADDRESS))
+		);
+}
+
+#ifdef CONFIG_BLK_DEV_INITRD
+void __init early_init_dt_setup_initrd_arch(unsigned long start,
+					    unsigned long end)
+{
+	initrd_start = (unsigned long)__va(start);
+	initrd_end = (unsigned long)__va(end);
+	initrd_below_start_ok = 1;
+}
+#endif
+
+/*
+ * irq_create_of_mapping - Hook to resolve OF irq specifier into a Linux irq#
+ *
+ * Currently the mapping mechanism is trivial; simple flat hwirq numbers are
+ * mapped 1:1 onto Linux irq numbers.  Cascaded irq controllers are not
+ * supported.
+ */
+unsigned int irq_create_of_mapping(struct device_node *controller,
+				   const u32 *intspec, unsigned int intsize)
+{
+	return intspec[0];
+}
+EXPORT_SYMBOL_GPL(irq_create_of_mapping);
+
+void __init early_init_devtree(void *params)
+{
+	/* Setup flat device-tree pointer */
+	initial_boot_params = params;
+
+	/* Retrieve various informations from the /chosen node of the
+	 * device-tree, including the platform type, initrd location and
+	 * size, and more ...
+	 */
+	of_scan_flat_dt(early_init_dt_scan_chosen, NULL);
+
+	/* Scan memory nodes */
+	of_scan_flat_dt(early_init_dt_scan_root, NULL);
+	of_scan_flat_dt(early_init_dt_scan_memory_arch, NULL);
+}
+
+void __init device_tree_init(void)
+{
+	unsigned long base, size;
+
+	if (!initial_boot_params)
+		return;
+
+	base = virt_to_phys((void *)initial_boot_params);
+	size = initial_boot_params->totalsize;
+
+	/* Before we do anything, lets reserve the dt blob */
+	reserve_mem_mach(base, size);
+
+	unflatten_device_tree();
+
+	/* free the space reserved for the dt blob */
+	free_mem_mach(base, size);
+}

arch/mips/kernel/setup.c

@@ -31,6 +31,7 @@
 #include <asm/setup.h>
 #include <asm/smp-ops.h>
 #include <asm/system.h>
+#include <asm/prom.h>
 
 struct cpuinfo_mips cpu_data[NR_CPUS] __read_mostly;
 
@@ -487,6 +488,7 @@ static void __init arch_mem_init(char **cmdline_p)
 	}
 
 	bootmem_init();
+	device_tree_init();
 	sparse_init();
 	paging_init();
 }