of: Add of-graph helpers to loop over endpoints and find ports by id

This series converts of_graph_get_next_endpoint to decrement the refcount of
 the passed prev parameter. This allows to add a for_each_endpoint_of_node
 helper macro to loop over all endpoints in a device tree node.
 The of_graph_get_port_by_id function is added to retrieve a port by its known
 port id (contained in the reg property) from the device tree.
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Merge tag 'of-graph-for-4.0' of git://git.pengutronix.de/git/pza/linux into for-next

Pull of-graph helpers from Philipp Zabel:
of: Add of-graph helpers to loop over endpoints and find ports by id

This series converts of_graph_get_next_endpoint to decrement the refcount of
the passed prev parameter. This allows to add a for_each_endpoint_of_node
helper macro to loop over all endpoints in a device tree node.
The of_graph_get_port_by_id function is added to retrieve a port by its known
port id (contained in the reg property) from the device tree.
This commit is contained in:
Rob Herring 2015-03-25 00:41:08 -05:00
commit 8147e2e8f1
8 changed files with 61 additions and 48 deletions

View file

@ -2082,14 +2082,45 @@ int of_graph_parse_endpoint(const struct device_node *node,
}
EXPORT_SYMBOL(of_graph_parse_endpoint);
/**
* of_graph_get_port_by_id() - get the port matching a given id
* @parent: pointer to the parent device node
* @id: id of the port
*
* Return: A 'port' node pointer with refcount incremented. The caller
* has to use of_node_put() on it when done.
*/
struct device_node *of_graph_get_port_by_id(struct device_node *parent, u32 id)
{
struct device_node *node, *port;
node = of_get_child_by_name(parent, "ports");
if (node)
parent = node;
for_each_child_of_node(parent, port) {
u32 port_id = 0;
if (of_node_cmp(port->name, "port") != 0)
continue;
of_property_read_u32(port, "reg", &port_id);
if (id == port_id)
break;
}
of_node_put(node);
return port;
}
EXPORT_SYMBOL(of_graph_get_port_by_id);
/**
* of_graph_get_next_endpoint() - get next endpoint node
* @parent: pointer to the parent device node
* @prev: previous endpoint node, or NULL to get first
*
* Return: An 'endpoint' node pointer with refcount incremented. Refcount
* of the passed @prev node is not decremented, the caller have to use
* of_node_put() on it when done.
* of the passed @prev node is decremented.
*/
struct device_node *of_graph_get_next_endpoint(const struct device_node *parent,
struct device_node *prev)
@ -2125,12 +2156,6 @@ struct device_node *of_graph_get_next_endpoint(const struct device_node *parent,
if (WARN_ONCE(!port, "%s(): endpoint %s has no parent node\n",
__func__, prev->full_name))
return NULL;
/*
* Avoid dropping prev node refcount to 0 when getting the next
* child below.
*/
of_node_get(prev);
}
while (1) {