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