linux-stable/include/linux/of_graph.h
Dmitry Osipenko 4ec0a44ba8 of_graph: add of_graph_is_present()
In some cases it's very useful to silently check whether port node exists
at all in a device-tree before proceeding with parsing the graph. The DRM
bridges code is one example of such case where absence of a graph in a
device-tree is a legit condition.

This patch adds of_graph_is_present() which returns true if given
device-tree node contains OF graph port.

Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200701074232.13632-2-digetx@gmail.com
2020-07-01 10:49:02 +02:00

127 lines
3.6 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* OF graph binding parsing helpers
*
* Copyright (C) 2012 - 2013 Samsung Electronics Co., Ltd.
* Author: Sylwester Nawrocki <s.nawrocki@samsung.com>
*
* Copyright (C) 2012 Renesas Electronics Corp.
* Author: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
*/
#ifndef __LINUX_OF_GRAPH_H
#define __LINUX_OF_GRAPH_H
#include <linux/types.h>
#include <linux/errno.h>
/**
* struct of_endpoint - the OF graph endpoint data structure
* @port: identifier (value of reg property) of a port this endpoint belongs to
* @id: identifier (value of reg property) of this endpoint
* @local_node: pointer to device_node of this endpoint
*/
struct of_endpoint {
unsigned int port;
unsigned int id;
const struct device_node *local_node;
};
/**
* for_each_endpoint_of_node - iterate over every endpoint in a device node
* @parent: parent device node containing ports and endpoints
* @child: loop variable pointing to the current endpoint node
*
* When breaking out of the loop, of_node_put(child) has to be called manually.
*/
#define for_each_endpoint_of_node(parent, child) \
for (child = of_graph_get_next_endpoint(parent, NULL); child != NULL; \
child = of_graph_get_next_endpoint(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);
int of_graph_get_endpoint_count(const 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_endpoint_by_regs(
const struct device_node *parent, int port_reg, int reg);
struct device_node *of_graph_get_remote_endpoint(
const struct device_node *node);
struct device_node *of_graph_get_port_parent(struct device_node *node);
struct device_node *of_graph_get_remote_port_parent(
const struct device_node *node);
struct device_node *of_graph_get_remote_port(const struct device_node *node);
struct device_node *of_graph_get_remote_node(const struct device_node *node,
u32 port, u32 endpoint);
#else
static inline bool of_graph_is_present(const struct device_node *node)
{
return false;
}
static inline int of_graph_parse_endpoint(const struct device_node *node,
struct of_endpoint *endpoint)
{
return -ENOSYS;
}
static inline int of_graph_get_endpoint_count(const struct device_node *np)
{
return 0;
}
static inline struct device_node *of_graph_get_port_by_id(
struct device_node *node, u32 id)
{
return NULL;
}
static inline struct device_node *of_graph_get_next_endpoint(
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)
{
return NULL;
}
static inline struct device_node *of_graph_get_remote_endpoint(
const struct device_node *node)
{
return NULL;
}
static inline struct device_node *of_graph_get_port_parent(
struct device_node *node)
{
return NULL;
}
static inline struct device_node *of_graph_get_remote_port_parent(
const struct device_node *node)
{
return NULL;
}
static inline struct device_node *of_graph_get_remote_port(
const struct device_node *node)
{
return NULL;
}
static inline struct device_node *of_graph_get_remote_node(
const struct device_node *node,
u32 port, u32 endpoint)
{
return NULL;
}
#endif /* CONFIG_OF */
#endif /* __LINUX_OF_GRAPH_H */