[U-Boot,v5,6/6] fdt: add decode helper library

diff --git a/include/fdtdec.h b/include/fdtdec.h
new file mode 100644
index 0000000..ae36f9c
--- /dev/null
+++ b/include/fdtdec.h
@@ -0,0 +1,122 @@ 
+/*
+ * Copyright (c) 2011 The Chromium OS Authors.
+ * 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 as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+
+/*
+ * This file contains convenience functions for decoding useful and
+ * enlightening information from FDTs. It is intended to be used by device
+ * drivers and board-specific code within U-Boot. It aims to reduce the
+ * amount of FDT munging required within U-Boot itself, so that driver code
+ * changes to support FDT are minimized.
+ */
+
+#include <libfdt.h>
+
+/*
+ * A typedef for a physical address. Note that fdt data is always big
+ * endian even on a litle endian machine.
+ */
+#ifdef CONFIG_PHYS_64BIT
+typedef u64 fdt_addr_t;
+#define FDT_ADDR_T_NONE (-1ULL)
+#define fdt_addr_to_cpu(reg) be64_to_cpu(reg)
+#else
+typedef u32 fdt_addr_t;
+#define FDT_ADDR_T_NONE (-1U)
+#define fdt_addr_to_cpu(reg) be32_to_cpu(reg)
+#endif
+
+/* Information obtained about memory from the FDT */
+struct fdt_memory {
+	fdt_addr_t start;
+	fdt_addr_t end;
+};
+
+/**
+ * Compat types that we know about and for which we might have drivers.
+ * Each is named COMPAT_<dir>_<filename> where <dir> is the directory
+ * within drivers.
+ */
+enum fdt_compat_id {
+	COMPAT_UNKNOWN,
+
+	COMPAT_COUNT,
+};
+
+/**
+ * Find the next numbered alias for a peripheral. This is used to enumerate
+ * all the peripherals of a certain type.
+ *
+ * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then
+ * this function will return a pointer to the node the alias points to, and
+ * then update *upto to 1. Next time you call this function, the next node
+ * will be returned.
+ *
+ * All nodes returned will match the compatible ID, as it is assumed that
+ * all peripherals use the same driver.
+ *
+ * @param blob		FDT blob to use
+ * @param name		Root name of alias to search for
+ * @param id		Compatible ID to look for
+ * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
+ */
+int fdtdec_next_alias(const void *blob, const char *name,
+		enum fdt_compat_id id, int *upto);
+
+/**
+ * Look up an address property in a node and return it as an address.
+ * The property must hold either one address with no trailing data or
+ * one address with a length. This is only tested on 32-bit machines.
+ *
+ * @param blob	FDT blob
+ * @param node	node to examine
+ * @param prop_name	name of property to find
+ * @return address, if found, or FDT_ADDR_T_NONE if not
+ */
+fdt_addr_t fdtdec_get_addr(const void *blob, int node,
+		const char *prop_name);
+
+/**
+ * Look up a 32-bit integer property in a node and return it. The property
+ * must have at least 4 bytes of data. The value of the first cell is
+ * returned.
+ *
+ * @param blob	FDT blob
+ * @param node	node to examine
+ * @param prop_name	name of property to find
+ * @param default_val	default value to return if the property is not found
+ * @return integer value, if found, or default_val if not
+ */
+s32 fdtdec_get_int(const void *blob, int node, const char *prop_name,
+		s32 default_val);
+
+/**
+ * Checks whether a node is enabled.
+ * This looks for a 'status' property. If this exists, then returns 1 if
+ * the status is 'ok' and 0 otherwise. If there is no status property,
+ * it returns the default value.
+ *
+ * @param blob	FDT blob
+ * @param node	node to examine
+ * @param default_val	default value to return if no 'status' property exists
+ * @return integer value 0/1, if found, or default_val if not
+ */
+int fdtdec_get_is_enabled(const void *blob, int node, int default_val);
diff --git a/lib/Makefile b/lib/Makefile
index 884f64c..3b901c9 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -38,6 +38,7 @@  COBJS-y += crc16.o
 COBJS-y += crc32.o
 COBJS-y += display_options.o
 COBJS-y += errno.o
+COBJS-$(CONFIG_OF_CONTROL) += fdtdec.o
 COBJS-$(CONFIG_GZIP) += gunzip.o
 COBJS-y += hashtable.o
 COBJS-$(CONFIG_LMB) += lmb.o
diff --git a/lib/fdtdec.c b/lib/fdtdec.c
new file mode 100644
index 0000000..d0f2cb8
--- /dev/null
+++ b/lib/fdtdec.c
@@ -0,0 +1,131 @@ 
+/*
+ * Copyright (c) 2011 The Chromium OS Authors.
+ * 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 as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+#include <serial.h>
+#include <libfdt.h>
+#include <fdtdec.h>
+
+/*
+ * Here are the type we know about. One day we might allow drivers to
+ * register. For now we just put them here. The COMPAT macro allows us to
+ * turn this into a sparse list later, and keeps the ID with the name.
+ */
+#define COMPAT(id, name) name
+static const char * const compat_names[COMPAT_COUNT] = {
+};
+
+/**
+ * Look in the FDT for an alias with the given name and return its node.
+ *
+ * @param blob	FDT blob
+ * @param name	alias name to look up
+ * @return node offset if found, or an error code < 0 otherwise
+ */
+static int find_alias_node(const void *blob, const char *name)
+{
+	const char *path;
+	int alias_node;
+
+	debug("find_alias_node: %s\n", name);
+	alias_node = fdt_path_offset(blob, "/aliases");
+	if (alias_node < 0)
+		return alias_node;
+	path = fdt_getprop(blob, alias_node, name, NULL);
+	if (!path)
+		return -FDT_ERR_NOTFOUND;
+	return fdt_path_offset(blob, path);
+}
+
+fdt_addr_t fdtdec_get_addr(const void *blob, int node,
+		const char *prop_name)
+{
+	const fdt_addr_t *cell;
+	int len;
+
+	debug("get_addr: %s\n", prop_name);
+	cell = fdt_getprop(blob, node, prop_name, &len);
+	if (cell && (len == sizeof(fdt_addr_t) ||
+			len == sizeof(fdt_addr_t) * 2))
+		return fdt_addr_to_cpu(*cell);
+	return FDT_ADDR_T_NONE;
+}
+
+s32 fdtdec_get_int(const void *blob, int node, const char *prop_name,
+		s32 default_val)
+{
+	const s32 *cell;
+	int len;
+
+	debug("get_size: %s\n", prop_name);
+	cell = fdt_getprop(blob, node, prop_name, &len);
+	if (cell && len >= sizeof(s32))
+		return fdt32_to_cpu(cell[0]);
+	return default_val;
+}
+
+int fdtdec_get_is_enabled(const void *blob, int node, int default_val)
+{
+	const char *cell;
+
+	cell = fdt_getprop(blob, node, "status", NULL);
+	if (cell)
+		return 0 == strcmp(cell, "ok");
+	return default_val;
+}
+
+enum fdt_compat_id fd_dec_lookup(const void *blob, int node)
+{
+	enum fdt_compat_id id;
+
+	/* Search our drivers */
+	for (id = COMPAT_UNKNOWN; id < COMPAT_COUNT; id++)
+		if (0 == fdt_node_check_compatible(blob, node,
+				compat_names[id]))
+			return id;
+	return COMPAT_UNKNOWN;
+}
+
+int fdtdec_next_compatible(const void *blob, int node,
+		enum fdt_compat_id id)
+{
+	return fdt_node_offset_by_compatible(blob, node, compat_names[id]);
+}
+
+int fdtdec_next_alias(const void *blob, const char *name,
+		enum fdt_compat_id id, int *upto)
+{
+#define MAX_STR_LEN 20
+	char str[MAX_STR_LEN + 20];
+	int node, err;
+
+	/* snprintf() is not available */
+	assert(strlen(name) < MAX_STR_LEN);
+	sprintf(str, "%.*s%d", MAX_STR_LEN, name, *upto);
+	(*upto)++;
+	node = find_alias_node(blob, str);
+	if (node < 0)
+		return node;
+	err = fdt_node_check_compatible(blob, node, compat_names[id]);
+	if (err < 0)
+		return err;
+	return err ? -FDT_ERR_NOTFOUND : node;
+}