We have endpoint base functions
- of_graph_get_next_endpoint()
- of_graph_get_endpoint_count()
- for_each_endpoint_of_node()
Here, for_each_endpoint_of_node() loop finds each endpoints
ports {
port@0 {
(1) endpoint {...};
};
port@1 {
(2) endpoint {...};
};
...
};
In above case, it finds endpoint as (1) -> (2) -> ...
Basically, user/driver knows which port is used for what, but not in
all cases. For example on flexible/generic driver case, how many ports
are used is not fixed.
For example Sound Generic Card driver which is very flexible/generic and
used from many venders can't know how many ports are used, and used for
what, because it depends on each vender SoC and/or its used board.
And more, the port can have multi endpoints. For example Generic Sound
Card case, it supports many type of connection between CPU / Codec, and
some of them uses multi endpoint in one port. see below.
ports {
(A) port@0 {
(1) endpoint@0 {...};
(2) endpoint@1 {...};
};
(B) port@1 {
(3) endpoint {...};
};
...
};
Generic Sound Card want to handle each connection via "port" base instead
of "endpoint" base. But, it is very difficult to handle each "port" via
existing for_each_endpoint_of_node(). Because getting each "port" via
of_get_parent() from each "endpoint" doesn't work. For example in above
case, both (1) (2) endpoint has same "port" (= A).
Add "port" base functions.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@xxxxxxxxxxx>
---
drivers/of/property.c | 54 ++++++++++++++++++++++++++++++++++++++++
include/linux/of_graph.h | 28 +++++++++++++++++++++
2 files changed, 82 insertions(+)
diff --git a/drivers/of/property.c b/drivers/of/property.c
index 11b922fde7af..6a5d27dd0c64 100644
--- a/drivers/of/property.c
+++ b/drivers/of/property.c
@@ -630,6 +630,43 @@ struct device_node *of_graph_get_port_by_id(struct device_node *parent, u32 id)
}
EXPORT_SYMBOL(of_graph_get_port_by_id);
+/**
+ * of_graph_get_next_port() - get next port node.
+ * @parent: pointer to the parent device node, or parent ports node
+ * @prev: previous port node, or NULL to get first
+ *
+ * Parent device node can be used as @parent whether device node has ports node or not.
+ * It will work same as ports@0 node.
+ *
+ * Return: A 'port' node pointer with refcount incremented. Refcount
+ * of the passed @prev node is decremented.
+ */
+struct device_node *of_graph_get_next_port(const struct device_node *parent,
+ struct device_node *prev)
+{
+ if (!parent)
+ return NULL;
+
+ if (!prev) {
+ struct device_node *node __free(device_node) =
+ of_get_child_by_name(parent, "ports");
+
+ if (node)
+ parent = node;
+
+ return of_get_child_by_name(parent, "port");
+ }
+
+ do {
+ prev = of_get_next_child(parent, prev);
+ if (!prev)
+ break;
+ } while (!of_node_name_eq(prev, "port"));
+
+ return prev;
+}
+EXPORT_SYMBOL(of_graph_get_next_port);
+
/**
* of_graph_get_next_endpoint() - get next endpoint node
* @parent: pointer to the parent device node
@@ -823,6 +860,23 @@ unsigned int of_graph_get_endpoint_count(const struct device_node *np)
}
EXPORT_SYMBOL(of_graph_get_endpoint_count);
+/**
+ * of_graph_get_port_count() - get the number of port in a device or ports node
+ * @np: pointer to the device or ports node
+ *
+ * Return: count of port of this device or ports node
+ */
+unsigned int of_graph_get_port_count(struct device_node *np)
+{
+ unsigned int num = 0;
+
+ for_each_of_graph_port(np, port)
+ num++;
+
+ return num;
+}
+EXPORT_SYMBOL(of_graph_get_port_count);
+
/**
* of_graph_get_remote_node() - get remote parent device_node for given port/endpoint
* @node: pointer to parent device_node containing graph port/endpoint
diff --git a/include/linux/of_graph.h b/include/linux/of_graph.h
index a4bea62bfa29..44518f3583a4 100644
--- a/include/linux/of_graph.h
+++ b/include/linux/of_graph.h
@@ -11,6 +11,7 @@
#ifndef __LINUX_OF_GRAPH_H
#define __LINUX_OF_GRAPH_H
+#include <linux/cleanup.h>
#include <linux/types.h>
#include <linux/errno.h>
@@ -37,14 +38,29 @@ struct of_endpoint {
for (child = of_graph_get_next_endpoint(parent, NULL); child != NULL; \
child = of_graph_get_next_endpoint(parent, child))
+/**
+ * for_each_of_graph_port - iterate over every port in a device or ports node
+ * @parent: parent device or ports node containing port
+ * @child: loop variable pointing to the current port node
+ *
+ * When breaking out of the loop, and continue to use the @child, you need to
+ * use return_ptr(@child) or no_free_ptr(@child) not to call __free() for it.
+ */
+#define for_each_of_graph_port(parent, child) \
+ for (struct device_node *child __free(device_node) = of_graph_get_next_port(parent, NULL);\
+ child != NULL; child = of_graph_get_next_port(parent, child))
+
#ifdef CONFIG_OF
bool of_graph_is_present(const struct device_node *node);
int of_graph_parse_endpoint(const struct device_node *node,
struct of_endpoint *endpoint);
unsigned int of_graph_get_endpoint_count(const struct device_node *np);
+unsigned int of_graph_get_port_count(struct device_node *np);
struct device_node *of_graph_get_port_by_id(struct device_node *node, u32 id);
struct device_node *of_graph_get_next_endpoint(const struct device_node *parent,
struct device_node *previous);
+struct device_node *of_graph_get_next_port(const struct device_node *parent,
+ struct device_node *port);
struct device_node *of_graph_get_endpoint_by_regs(
const struct device_node *parent, int port_reg, int reg);
struct device_node *of_graph_get_remote_endpoint(
@@ -73,6 +89,11 @@ static inline unsigned int of_graph_get_endpoint_count(const struct device_node
return 0;
}
+static inline unsigned int of_graph_get_port_count(struct device_node *np)
+{
+ return 0;
+}
+
static inline struct device_node *of_graph_get_port_by_id(
struct device_node *node, u32 id)
{
@@ -86,6 +107,13 @@ static inline struct device_node *of_graph_get_next_endpoint(
return NULL;
}
+static inline struct device_node *of_graph_get_next_port(
+ const struct device_node *parent,
+ struct device_node *previous)
+{
+ return NULL;
+}
+
static inline struct device_node *of_graph_get_endpoint_by_regs(
const struct device_node *parent, int port_reg, int reg)
{
--
2.43.0
