Commit 02ac5f9d authored by Kuninori Morimoto's avatar Kuninori Morimoto Committed by Rob Herring (Arm)
Browse files

of: property: add of_graph_get_next_port() 



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: default avatarKuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://lore.kernel.org/r/87ldyeb5t9.wl-kuninori.morimoto.gx@renesas.com


Signed-off-by: default avatarRob Herring (Arm) <robh@kernel.org>
parent 2e030910

drivers/of/property.c

+54 −0
Original line number Diff line number Diff line
@@ -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

include/linux/of_graph.h

+28 −0
Original line number Diff line number Diff line
@@ -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)

{