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authorPhilipp Zabel <p.zabel@pengutronix.de>2014-02-10 22:01:48 +0100
committerPhilipp Zabel <p.zabel@pengutronix.de>2014-03-06 17:41:22 +0100
commitfd9fdb78a9bf85b94fb2190c82ff280c8f8375cc (patch)
tree49ad197ab19b401edbc4957b5ce2ed53af643b09 /drivers/of/base.c
parent0414855fdc4a40da05221fc6062cccbc0c30f169 (diff)
[media] of: move graph helpers from drivers/media/v4l2-core to drivers/of
This patch moves the parsing helpers used to parse connected graphs in the device tree, like the video interface bindings documented in Documentation/devicetree/bindings/media/video-interfaces.txt, from drivers/media/v4l2-core/v4l2-of.c into drivers/of/base.c. This allows to reuse the same parser code from outside the V4L2 framework, most importantly from display drivers. The functions v4l2_of_get_next_endpoint, v4l2_of_get_remote_port, and v4l2_of_get_remote_port_parent are moved. They are renamed to of_graph_get_next_endpoint, of_graph_get_remote_port, and of_graph_get_remote_port_parent, respectively. Since there are not that many current users yet, switch all of them to the new functions right away. Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de> Acked-by: Tomi Valkeinen <tomi.valkeinen@ti.com> Acked-by: Mauro Carvalho Chehab <m.chehab@samsung.com> Acked-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Diffstat (limited to 'drivers/of/base.c')
-rw-r--r--drivers/of/base.c118
1 files changed, 118 insertions, 0 deletions
diff --git a/drivers/of/base.c b/drivers/of/base.c
index 89e888a78899..b2f223fa47e9 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -21,6 +21,7 @@
#include <linux/cpu.h>
#include <linux/module.h>
#include <linux/of.h>
+#include <linux/of_graph.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <linux/proc_fs.h>
@@ -1982,3 +1983,120 @@ struct device_node *of_find_next_cache_node(const struct device_node *np)
return NULL;
}
+
+/**
+ * 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.
+ */
+struct device_node *of_graph_get_next_endpoint(const struct device_node *parent,
+ struct device_node *prev)
+{
+ struct device_node *endpoint;
+ struct device_node *port = NULL;
+
+ if (!parent)
+ return NULL;
+
+ if (!prev) {
+ struct device_node *node;
+ /*
+ * It's the first call, we have to find a port subnode
+ * within this node or within an optional 'ports' node.
+ */
+ node = of_get_child_by_name(parent, "ports");
+ if (node)
+ parent = node;
+
+ port = of_get_child_by_name(parent, "port");
+
+ if (port) {
+ /* Found a port, get an endpoint. */
+ endpoint = of_get_next_child(port, NULL);
+ of_node_put(port);
+ } else {
+ endpoint = NULL;
+ }
+
+ if (!endpoint)
+ pr_err("%s(): no endpoint nodes specified for %s\n",
+ __func__, parent->full_name);
+ of_node_put(node);
+ } else {
+ port = of_get_parent(prev);
+ if (!port)
+ /* Hm, has someone given us the root node ?... */
+ return NULL;
+
+ /* Avoid dropping prev node refcount to 0. */
+ of_node_get(prev);
+ endpoint = of_get_next_child(port, prev);
+ if (endpoint) {
+ of_node_put(port);
+ return endpoint;
+ }
+
+ /* No more endpoints under this port, try the next one. */
+ do {
+ port = of_get_next_child(parent, port);
+ if (!port)
+ return NULL;
+ } while (of_node_cmp(port->name, "port"));
+
+ /* Pick up the first endpoint in this port. */
+ endpoint = of_get_next_child(port, NULL);
+ of_node_put(port);
+ }
+
+ return endpoint;
+}
+EXPORT_SYMBOL(of_graph_get_next_endpoint);
+
+/**
+ * of_graph_get_remote_port_parent() - get remote port's parent node
+ * @node: pointer to a local endpoint device_node
+ *
+ * Return: Remote device node associated with remote endpoint node linked
+ * to @node. Use of_node_put() on it when done.
+ */
+struct device_node *of_graph_get_remote_port_parent(
+ const struct device_node *node)
+{
+ struct device_node *np;
+ unsigned int depth;
+
+ /* Get remote endpoint node. */
+ np = of_parse_phandle(node, "remote-endpoint", 0);
+
+ /* Walk 3 levels up only if there is 'ports' node. */
+ for (depth = 3; depth && np; depth--) {
+ np = of_get_next_parent(np);
+ if (depth == 2 && of_node_cmp(np->name, "ports"))
+ break;
+ }
+ return np;
+}
+EXPORT_SYMBOL(of_graph_get_remote_port_parent);
+
+/**
+ * of_graph_get_remote_port() - get remote port node
+ * @node: pointer to a local endpoint device_node
+ *
+ * Return: Remote port node associated with remote endpoint node linked
+ * to @node. Use of_node_put() on it when done.
+ */
+struct device_node *of_graph_get_remote_port(const struct device_node *node)
+{
+ struct device_node *np;
+
+ /* Get remote endpoint node. */
+ np = of_parse_phandle(node, "remote-endpoint", 0);
+ if (!np)
+ return NULL;
+ return of_get_next_parent(np);
+}
+EXPORT_SYMBOL(of_graph_get_remote_port);