of: introduce of_parse_phandle_with_fixed_args
This is identical to of_parse_phandle_with_args(), except that the
number of argument cells is fixed, rather than being parsed out of the
node referenced by each phandle.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Grant Likely <grant.likely@linaro.org>
diff --git a/drivers/of/base.c b/drivers/of/base.c
index ef2f1d0..1f80acf 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -1082,7 +1082,8 @@
static int __of_parse_phandle_with_args(const struct device_node *np,
const char *list_name,
- const char *cells_name, int index,
+ const char *cells_name,
+ int cell_count, int index,
struct of_phandle_args *out_args)
{
const __be32 *list, *list_end;
@@ -1118,11 +1119,17 @@
np->full_name);
goto err;
}
- if (of_property_read_u32(node, cells_name, &count)) {
- pr_err("%s: could not get %s for %s\n",
- np->full_name, cells_name,
- node->full_name);
- goto err;
+
+ if (cells_name) {
+ if (of_property_read_u32(node, cells_name,
+ &count)) {
+ pr_err("%s: could not get %s for %s\n",
+ np->full_name, cells_name,
+ node->full_name);
+ goto err;
+ }
+ } else {
+ count = cell_count;
}
/*
@@ -1244,11 +1251,53 @@
{
if (index < 0)
return -EINVAL;
- return __of_parse_phandle_with_args(np, list_name, cells_name, index, out_args);
+ return __of_parse_phandle_with_args(np, list_name, cells_name, 0,
+ index, out_args);
}
EXPORT_SYMBOL(of_parse_phandle_with_args);
/**
+ * of_parse_phandle_with_fixed_args() - Find a node pointed by phandle in a list
+ * @np: pointer to a device tree node containing a list
+ * @list_name: property name that contains a list
+ * @cell_count: number of argument cells following the phandle
+ * @index: index of a phandle to parse out
+ * @out_args: optional pointer to output arguments structure (will be filled)
+ *
+ * This function is useful to parse lists of phandles and their arguments.
+ * Returns 0 on success and fills out_args, on error returns appropriate
+ * errno value.
+ *
+ * Caller is responsible to call of_node_put() on the returned out_args->node
+ * pointer.
+ *
+ * Example:
+ *
+ * phandle1: node1 {
+ * }
+ *
+ * phandle2: node2 {
+ * }
+ *
+ * node3 {
+ * list = <&phandle1 0 2 &phandle2 2 3>;
+ * }
+ *
+ * To get a device_node of the `node2' node you may call this:
+ * of_parse_phandle_with_fixed_args(node3, "list", 2, 1, &args);
+ */
+int of_parse_phandle_with_fixed_args(const struct device_node *np,
+ const char *list_name, int cell_count,
+ int index, struct of_phandle_args *out_args)
+{
+ if (index < 0)
+ return -EINVAL;
+ return __of_parse_phandle_with_args(np, list_name, NULL, cell_count,
+ index, out_args);
+}
+EXPORT_SYMBOL(of_parse_phandle_with_fixed_args);
+
+/**
* of_count_phandle_with_args() - Find the number of phandles references in a property
* @np: pointer to a device tree node containing a list
* @list_name: property name that contains a list
@@ -1266,7 +1315,8 @@
int of_count_phandle_with_args(const struct device_node *np, const char *list_name,
const char *cells_name)
{
- return __of_parse_phandle_with_args(np, list_name, cells_name, -1, NULL);
+ return __of_parse_phandle_with_args(np, list_name, cells_name, 0, -1,
+ NULL);
}
EXPORT_SYMBOL(of_count_phandle_with_args);