From: Maxime Ripard <maxime.rip...@free-electrons.com>
Add a function to retrieve the highest phandle in a given device tree.
Acked-by: Simon Glass <s...@chromium.org>
Reviewed-by: Stefan Agner <ste...@agner.ch>
Reviewed-by: David Gibson <da...@gibson.dropbear.id.au>
Signed-off-by: Maxime Ripard <maxime.rip...@free-electrons.com>
Signed-off-by: David Gibson <da...@gibson.dropbear.id.au>
---
cpukit/dtc/libfdt/fdt_ro.c | 26 ++++++++++++++++++++++++++
cpukit/include/libfdt.h | 15 +++++++++++++++
2 files changed, 41 insertions(+)
diff --git a/cpukit/dtc/libfdt/fdt_ro.c b/cpukit/dtc/libfdt/fdt_ro.c
index 50cce86428..04590984bd 100644
--- a/cpukit/dtc/libfdt/fdt_ro.c
+++ b/cpukit/dtc/libfdt/fdt_ro.c
@@ -88,6 +88,32 @@ static int _fdt_string_eq(const void *fdt, int stroffset,
return (strlen(p) == len) && (memcmp(p, s, len) == 0);
}
+uint32_t fdt_get_max_phandle(const void *fdt)
+{
+ uint32_t max_phandle = 0;
+ int offset;
+
+ for (offset = fdt_next_node(fdt, -1, NULL);;
+ offset = fdt_next_node(fdt, offset, NULL)) {
+ uint32_t phandle;
+
+ if (offset == -FDT_ERR_NOTFOUND)
+ return max_phandle;
+
+ if (offset < 0)
+ return (uint32_t)-1;
+
+ phandle = fdt_get_phandle(fdt, offset);
+ if (phandle == (uint32_t)-1)
+ continue;
+
+ if (phandle > max_phandle)
+ max_phandle = phandle;
+ }
+
+ return 0;
+}
+
int fdt_get_mem_rsv(const void *fdt, int n, uint64_t *address, uint64_t *size)
{
FDT_CHECK_HEADER(fdt);
diff --git a/cpukit/include/libfdt.h b/cpukit/include/libfdt.h
index be109a8aac..06b84cc16b 100644
--- a/cpukit/include/libfdt.h
+++ b/cpukit/include/libfdt.h
@@ -287,6 +287,21 @@ int fdt_move(const void *fdt, void *buf, int bufsize);
const char *fdt_string(const void *fdt, int stroffset);
/**
+ * fdt_get_max_phandle - retrieves the highest phandle in a tree
+ * @fdt: pointer to the device tree blob
+ *
+ * fdt_get_max_phandle retrieves the highest phandle in the given
+ * device tree. This will ignore badly formatted phandles, or phandles
+ * with a value of 0 or -1.
+ *
+ * returns:
+ * the highest phandle on success
+ * 0, if no phandle was found in the device tree
+ * -1, if an error occurred
+ */
+uint32_t fdt_get_max_phandle(const void *fdt);
+
+/**
* fdt_num_mem_rsv - retrieve the number of memory reserve map entries
* @fdt: pointer to the device tree blob
*
--
2.13.7
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