[PATCH 01/17] fdt: Add function to look up a phandle's register address
Simon Glass
sjg at chromium.org
Sun Jan 15 11:47:13 EST 2012
This is a commonly-used requirement, so add a function to support it
easily.
Signed-off-by: Simon Glass <sjg at chromium.org>
---
include/fdtdec.h | 13 +++++++++++++
lib/fdtdec.c | 11 +++++++++++
2 files changed, 24 insertions(+), 0 deletions(-)
diff --git a/include/fdtdec.h b/include/fdtdec.h
index e705124..81ce3f6 100644
--- a/include/fdtdec.h
+++ b/include/fdtdec.h
@@ -239,6 +239,19 @@ const char *fdtdec_get_compatible(enum fdt_compat_id id);
int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name);
/**
+ * Look up a phandle and follow it to its node. Then return the register
+ * address of that node as a pointer. This can be used to access the
+ * peripheral directly.
+ *
+ * @param blob FDT blob
+ * @param node node to examine
+ * @param prop_name name of property to find
+ * @return pointer to node's register address
+ */
+void *fdtdec_lookup_phandle_reg(const void *blob, int node,
+ const char *prop_name);
+
+/**
* Look up a property in a node and return its contents in an integer
* array of given length. The property must have at least enough data for
* the array (4*count bytes). It may have more, but this will be ignored.
diff --git a/lib/fdtdec.c b/lib/fdtdec.c
index 48abf02..bcb2343 100644
--- a/lib/fdtdec.c
+++ b/lib/fdtdec.c
@@ -311,6 +311,17 @@ int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name)
return lookup;
}
+void *fdtdec_lookup_phandle_reg(const void *blob, int node,
+ const char *prop_name)
+{
+ int lookup;
+
+ lookup = fdtdec_lookup_phandle(blob, node, prop_name);
+ if (lookup < 0)
+ return NULL;
+ return (void *)fdtdec_get_addr(blob, lookup, "reg");
+}
+
/**
* Look up a property in a node and check that it has a minimum length.
*
--
1.7.7.3
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