[PATCH v2 1/7] of: base: Add of_count_phandle_with_fixed_args()

Richard Fitzgerald
2020-10-16T17:36:08Z

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

The existing of_count_phandle_with_args() is modified to be a
private function that handles both cases and the public functions
are trivial wrappers round that.

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
---
drivers/of/base.c | 73 +++++++++++++++++++++++++++++++---------------
include/linux/of.h | 9 ++++++
2 files changed, 59 insertions(+), 23 deletions(-)

diff --git a/drivers/of/base.c b/drivers/of/base.c
index 161a23631472..c5ff2524bf40 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -1720,34 +1720,22 @@ int of_parse_phandle_with_fixed_args(const struct device_node *np,
}
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
- * @cells_name: property name that specifies phandles' arguments count
- *
- * 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. The number of arguments is encoded
- * by a property in the phandle-target node. For example, a gpios
- * property would contain a list of GPIO specifies consisting of a
- * phandle and 1 or more arguments. The number of arguments are
- * determined by the #gpio-cells property in the node pointed to by the
- * phandle.
- */
-int of_count_phandle_with_args(const struct device_node *np, const char *list_name,
- const char *cells_name)
+static int __of_count_phandle_with_args(const struct device_node *np,
+ const char *list_name,
+ const char *cells_name,
+ int cells_count)
{
struct of_phandle_iterator it;
int rc, cur_index = 0;

/*
- * If cells_name is NULL we assume a cell count of 0. This makes
- * counting the phandles trivial as each 32bit word in the list is a
- * phandle and no arguments are to consider. So we don't iterate through
- * the list but just use the length to determine the phandle count.
+ * If cells_count < 0 and cells_name is NULL we assume a cell count
+ * of 0. A zero cell count makes counting the phandles trivial as each
+ * 32bit word in the list is a phandle and no arguments are to consider.
+ * So we don't iterate through the list but just use the length to
+ * determine the phandle count.
*/
- if (!cells_name) {
+ if ((cells_count < 0 && !cells_name) || cells_count == 0) {
const __be32 *list;
int size;

@@ -1758,7 +1746,7 @@ int of_count_phandle_with_args(const struct device_node *np, const char *list_na
return size / sizeof(*list);
}

- rc = of_phandle_iterator_init(&it, np, list_name, cells_name, -1);
+ rc = of_phandle_iterator_init(&it, np, list_name, cells_name, cells_count);
if (rc)
return rc;

@@ -1770,8 +1758,47 @@ int of_count_phandle_with_args(const struct device_node *np, const char *list_na

return cur_index;
}
+
+/**
+ * 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
+ * @cells_name: property name that specifies phandles' arguments count
+ *
+ * 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. The number of arguments is encoded
+ * by a property in the phandle-target node. For example, a gpios
+ * property would contain a list of GPIO specifies consisting of a
+ * phandle and 1 or more arguments. The number of arguments are
+ * determined by the #gpio-cells property in the node pointed to by the
+ * phandle.
+ */
+int of_count_phandle_with_args(const struct device_node *np, const char *list_name,
+ const char *cells_name)
+{
+ return __of_count_phandle_with_args(np, list_name, cells_name, -1);
+}
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)
+{
+ return __of_count_phandle_with_args(np, list_name, NULL, cells_count);
+}
+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 481ec0467285..4382a8946310 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