dt: add helper to read 64-bit integers
Add a helper similar to of_property_read_u32() that handles 64-bit
integers.
v2/v3: constify device node and property name parameters.
Cc: Grant Likely <grant.likely@secretlab.ca>
Reviewed-by: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Jamie Iles <jamie@jamieiles.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
diff --git a/drivers/of/base.c b/drivers/of/base.c
index 8abde58..b970562 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -657,6 +657,35 @@
EXPORT_SYMBOL_GPL(of_property_read_u32_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.
+ * @out_value: pointer to return value, modified only if return value is 0.
+ *
+ * Search for a property in a device node and read a 64-bit value 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_value is modified only if a valid u64 value can be decoded.
+ */
+int of_property_read_u64(const struct device_node *np, const char *propname,
+ u64 *out_value)
+{
+ struct property *prop = of_find_property(np, propname, NULL);
+
+ if (!prop)
+ return -EINVAL;
+ if (!prop->value)
+ return -ENODATA;
+ if (sizeof(*out_value) > prop->length)
+ return -EOVERFLOW;
+ *out_value = of_read_number(prop->value, 2);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(of_property_read_u64);
+
+/**
* of_property_read_string - Find and read a string from a property
* @np: device node from which the property value is to be read.
* @propname: name of the property to be searched.