[PATCH 1/1] of: Add a function to read 64-bit arrays

[Sakari Ailus]

Implement of_property_read_u64_array() for reading 64-bit arrays.

This is needed for e.g. reading the valid link frequencies in the smiapp
driver.

Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxx>
---
Hi,

While the smiapp (found in drivers/media/i2c/smiapp/) OF support which needs
this isn't in yet, other drivers such as mt9v032 which would be reading the
valid link frequency control values will need reading arrays. This might
make it to v4l2-of.c in the end.

 drivers/of/base.c  |   44 ++++++++++++++++++++++++++++++++++++--------
 include/linux/of.h |    3 +++
 2 files changed, 39 insertions(+), 8 deletions(-)

diff --git a/drivers/of/base.c b/drivers/of/base.c
index d8574ad..35e24f4 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -1214,6 +1214,41 @@ int of_property_read_u32_array(const struct device_node *np,
 EXPORT_SYMBOL_GPL(of_property_read_u32_array);
 
 /**
+ * of_property_read_u64_array - Find and read an array of 64 bit integers
+ * from a property.
+ *
+ * @np:		device node from which the property value is to be read.
+ * @propname:	name of the property to be searched.
+ * @out_values:	pointer to return value, modified only if return value is 0.
+ * @sz:		number of array elements to read
+ *
+ * Search for a property in a device node and read 64-bit value(s) from
+ * it. Returns 0 on success, -EINVAL if the property does not exist,
+ * -ENODATA if property does not have a value, and -EOVERFLOW if the
+ * property data isn't large enough.
+ *
+ * The out_values is modified only if a valid u32 value can be decoded.
+ */
+int of_property_read_u64_array(const struct device_node *np,
+			       const char *propname, u64 *out_value, size_t sz)
+{
+	const __be32 *val = of_find_property_value_of_size(
+		np, propname, sz * sizeof(*out_value));
+
+	if (IS_ERR(val))
+		return PTR_ERR(val);
+
+	while (sz--) {
+		*out_value = of_read_number(val, 2);
+		out_value++;
+		val += 2;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_property_read_u64_array);
+
+/**
  * of_property_read_u64 - Find and read a 64 bit integer from a property
  * @np:		device node from which the property value is to be read.
  * @propname:	name of the property to be searched.
@@ -1229,14 +1264,7 @@ EXPORT_SYMBOL_GPL(of_property_read_u32_array);
 int of_property_read_u64(const struct device_node *np, const char *propname,
 			 u64 *out_value)
 {
-	const __be32 *val = of_find_property_value_of_size(np, propname,
-						sizeof(*out_value));
-
-	if (IS_ERR(val))
-		return PTR_ERR(val);
-
-	*out_value = of_read_number(val, 2);
-	return 0;
+	return of_property_read_u64_array(np, propname, out_value, 1);
 }
 EXPORT_SYMBOL_GPL(of_property_read_u64);
 
diff --git a/include/linux/of.h b/include/linux/of.h
index 6c4363b..e84533f 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -263,6 +263,9 @@ extern int of_property_read_u32_array(const struct device_node *np,
 				      size_t sz);
 extern int of_property_read_u64(const struct device_node *np,
 				const char *propname, u64 *out_value);
+extern int of_property_read_u64_array(const struct device_node *np,
+				      const char *propname, u64 *out_value,
+				      size_t sz);
 
 extern int of_property_read_string(struct device_node *np,
 				   const char *propname,
-- 
1.7.10.4

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