[PATCH 1/7] of: base: Add of_count_phandle_with_fixed_args()

From: Richard Fitzgerald
Date: Wed Oct 14 2020 - 10:54:56 EST


Add an equivalent of of_count_phandle_with_args() for fixed argument
sets, to pair with of_parse_phandle_with_fixed_args().

Signed-off-by: Richard Fitzgerald <rf@xxxxxxxxxxxxxxxxxxxxx>
---
drivers/of/base.c | 42 ++++++++++++++++++++++++++++++++++++++++++
include/linux/of.h | 9 +++++++++
2 files changed, 51 insertions(+)

diff --git a/drivers/of/base.c b/drivers/of/base.c
index ea44fea99813..45d8b0e65345 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -1772,6 +1772,48 @@ int of_count_phandle_with_args(const struct device_node *np, const char *list_na
}
EXPORT_SYMBOL(of_count_phandle_with_args);

+/**
+ * of_count_phandle_with_fixed_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
+ * @cell_count: number of argument cells following the phandle
+ *
+ * Returns the number of phandle + argument tuples within a property. It
+ * is a typical pattern to encode a list of phandle and variable
+ * arguments into a single property.
+ */
+int of_count_phandle_with_fixed_args(const struct device_node *np,
+ const char *list_name,
+ int cells_count)
+{
+ struct of_phandle_iterator it;
+ int rc, cur_index = 0;
+
+ if (!cells_count) {
+ const __be32 *list;
+ int size;
+
+ list = of_get_property(np, list_name, &size);
+ if (!list)
+ return -ENOENT;
+
+ return size / sizeof(*list);
+ }
+
+ rc = of_phandle_iterator_init(&it, np, list_name, NULL, cells_count);
+ if (rc)
+ return rc;
+
+ while ((rc = of_phandle_iterator_next(&it)) == 0)
+ cur_index += 1;
+
+ if (rc != -ENOENT)
+ return rc;
+
+ return cur_index;
+}
+EXPORT_SYMBOL(of_count_phandle_with_fixed_args);
+
/**
* __of_add_property - Add a property to a node without lock operations
*/
diff --git a/include/linux/of.h b/include/linux/of.h
index 5cf7ae0465d1..9f315da4e9da 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -377,6 +377,8 @@ extern int of_parse_phandle_with_fixed_args(const struct device_node *np,
struct of_phandle_args *out_args);
extern int of_count_phandle_with_args(const struct device_node *np,
const char *list_name, const char *cells_name);
+extern int of_count_phandle_with_fixed_args(const struct device_node *np,
+ const char *list_name, int cells_count);

/* phandle iterator functions */
extern int of_phandle_iterator_init(struct of_phandle_iterator *it,
@@ -886,6 +888,13 @@ static inline int of_count_phandle_with_args(struct device_node *np,
return -ENOSYS;
}

+static inline int of_count_phandle_with_fixed_args(const struct device_node *np,
+ const char *list_name,
+ int cells_count)
+{
+ return -ENOSYS;
+}
+
static inline int of_phandle_iterator_init(struct of_phandle_iterator *it,
const struct device_node *np,
const char *list_name,
--
2.20.1