From 96875e7d3b9900d0e63f0b591ff5693b31c4d9c3 Mon Sep 17 00:00:00 2001
From: Simon Glass <sjg@chromium.org>
Date: Mon, 2 Apr 2012 13:18:41 +0000
Subject: [PATCH] fdt: Add function to locate an array in the device tree
fdtdec_locate_array() locates an integer array but does not copy it. This
saves the caller having to allocated wasted space.
Access to array elements should be through the fdt32_to_cpu() macro.
Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>
---
include/fdtdec.h | 19 +++++++++++++++++++
lib/fdtdec.c | 11 +++++++++++
2 files changed, 30 insertions(+)
diff --git a/include/fdtdec.h b/include/fdtdec.h
index 171c6284853..84f07685268 100644
--- a/include/fdtdec.h
+++ b/include/fdtdec.h
@@ -271,6 +271,25 @@ int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name);
int fdtdec_get_int_array(const void *blob, int node, const char *prop_name,
u32 *array, int count);
+/**
+ * Look up a property in a node and return a pointer to its contents as a
+ * unsigned int array of given length. The property must have at least enough
+ * data for the array ('count' cells). It may have more, but this will be
+ * ignored. The data is not copied.
+ *
+ * Note that you must access elements of the array with fdt32_to_cpu(),
+ * since the elements will be big endian even on a little endian machine.
+ *
+ * @param blob FDT blob
+ * @param node node to examine
+ * @param prop_name name of property to find
+ * @param count number of array elements
+ * @return pointer to array if found, or NULL if the property is not
+ * found or there is not enough data
+ */
+const u32 *fdtdec_locate_array(const void *blob, int node,
+ const char *prop_name, int count);
+
/**
* Look up a boolean property in a node and return it.
*
diff --git a/lib/fdtdec.c b/lib/fdtdec.c
index bdec1a0d962..4a5ab712b54 100644
--- a/lib/fdtdec.c
+++ b/lib/fdtdec.c
@@ -363,6 +363,17 @@ int fdtdec_get_int_array(const void *blob, int node, const char *prop_name,
return err;
}
+const u32 *fdtdec_locate_array(const void *blob, int node,
+ const char *prop_name, int count)
+{
+ const u32 *cell;
+ int err;
+
+ cell = get_prop_check_min_len(blob, node, prop_name,
+ sizeof(u32) * count, &err);
+ return err ? NULL : cell;
+}
+
int fdtdec_get_bool(const void *blob, int node, const char *prop_name)
{
const s32 *cell;
--
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