OpenRISC: Device tree

The OpenRISC architecture uses the device tree infrastructure for the
platform description.  This is currently limited to having a device tree
built into the kernel, but work is underway within the OpenRISC project
to define how this device tree blob should be passed into the kernel from
an external resource.

Patch contains a single example DTS file to go with the defconfig for
or1ksim.

Signed-off-by: Jonas Bonn <jonas@southpole.se>
Cc: devicetree-discuss@lists.ozlabs.org
Reviewed-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 108 insertions, 0 deletions

diff --git a/arch/openrisc/kernel/prom.c b/arch/openrisc/kernel/prom.c
new file mode 100644
index 000000000000..1bb58ba89afa
--- /dev/null
+++ b/arch/openrisc/kernel/prom.c
@@ -0,0 +1,108 @@
+/*
+ * OpenRISC prom.c
+ *
+ * Linux architectural port borrowing liberally from similar works of
+ * others.  All original copyrights apply as per the original source
+ * declaration.
+ *
+ * Modifications for the OpenRISC architecture:
+ * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
+ *
+ *      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.
+ *
+ * Architecture specific procedures for creating, accessing and
+ * interpreting the device tree.
+ *
+ */
+
+#include <stdarg.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/init.h>
+#include <linux/threads.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+#include <linux/pci.h>
+#include <linux/stringify.h>
+#include <linux/delay.h>
+#include <linux/initrd.h>
+#include <linux/bitops.h>
+#include <linux/module.h>
+#include <linux/kexec.h>
+#include <linux/debugfs.h>
+#include <linux/irq.h>
+#include <linux/memblock.h>
+#include <linux/of_fdt.h>
+
+#include <asm/prom.h>
+#include <asm/page.h>
+#include <asm/processor.h>
+#include <asm/irq.h>
+#include <linux/io.h>
+#include <asm/system.h>
+#include <asm/mmu.h>
+#include <asm/pgtable.h>
+#include <asm/sections.h>
+#include <asm/setup.h>
+
+extern char cmd_line[COMMAND_LINE_SIZE];
+
+void __init early_init_dt_add_memory_arch(u64 base, u64 size)
+{
+        size &= PAGE_MASK;
+        memblock_add(base, size);
+}
+
+void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
+{
+        return __va(memblock_alloc(size, align));
+}
+
+void __init early_init_devtree(void *params)
+{
+        void *alloc;
+
+        /* 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, TCE reserve, and more ...
+         */
+        of_scan_flat_dt(early_init_dt_scan_chosen, cmd_line);
+
+        /* Scan memory nodes and rebuild MEMBLOCKs */
+        memblock_init();
+        of_scan_flat_dt(early_init_dt_scan_root, NULL);
+        of_scan_flat_dt(early_init_dt_scan_memory, NULL);
+
+        /* Save command line for /proc/cmdline and then parse parameters */
+        strlcpy(boot_command_line, cmd_line, COMMAND_LINE_SIZE);
+
+        memblock_analyze();
+
+        /* We must copy the flattend device tree from init memory to regular
+         * memory because the device tree references the strings in it
+         * directly.
+         */
+
+        alloc = __va(memblock_alloc(initial_boot_params->totalsize, PAGE_SIZE));
+
+        memcpy(alloc, initial_boot_params, initial_boot_params->totalsize);
+
+        initial_boot_params = alloc;
+}
+
+#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