forked from mirrors/linux
58fe47d6ac
We already have of_graph_get_next_endpoint(), but it is not
intuitive to use in some case.
(X) node {
(Y) ports {
(P0) port@0 { endpoint { remote-endpoint = ...; };};
(P10) port@1 { endpoint { remote-endpoint = ...; };
(P11) endpoint { remote-endpoint = ...; };};
(P2) port@2 { endpoint { remote-endpoint = ...; };};
};
};
For example, if I want to handle port@1's 2 endpoints (= P10, P11),
I want to use like below
P10 = of_graph_get_next_endpoint(port1, NULL);
P11 = of_graph_get_next_endpoint(port1, P10);
But 1st one will be error, because of_graph_get_next_endpoint()
requested 1st parameter is "node" (X) or "ports" (Y), not but "port".
Below works well, but it will get P0
P0 = of_graph_get_next_endpoint(node, NULL);
P0 = of_graph_get_next_endpoint(ports, NULL);
In other words, we can't handle P10/P11 directly via
of_graph_get_next_endpoint().
There is another non intuitive behavior on of_graph_get_next_endpoint().
In case of if I could get P10 pointer for some way, and if I want to
handle port@1 things by loop, I would like use it like below
/*
* "ep" is now P10, and handle port1 things here,
* but we don't know how many endpoints port1 have.
*
* Because "ep" is non NULL now, we can use port1
* as of_graph_get_next_endpoint(port1, xxx)
*/
do {
/* do something for port1 specific things here */
} while (ep = of_graph_get_next_endpoint(port1, ep))
But it also not worked as I expected.
I expect it will be P10 -> P11 -> NULL,
but it will be P10 -> P11 -> P2, because
of_graph_get_next_endpoint() will fetch "endpoint" beyond the "port".
It is not useful for generic driver.
To handle endpoint more intuitive, create of_graph_get_next_port_endpoint()
of_graph_get_next_port_endpoint(port1, NULL); // P10
of_graph_get_next_port_endpoint(port1, P10); // P11
of_graph_get_next_port_endpoint(port1, P11); // NULL
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://lore.kernel.org/r/87jzdyb5t5.wl-kuninori.morimoto.gx@renesas.com
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
176 lines
5.4 KiB
C
176 lines
5.4 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/cleanup.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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/**
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* for_each_of_graph_port - iterate over every port in a device or ports node
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* @parent: parent device or ports node containing port
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* @child: loop variable pointing to the current port node
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*
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* When breaking out of the loop, and continue to use the @child, you need to
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* use return_ptr(@child) or no_free_ptr(@child) not to call __free() for it.
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*/
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#define for_each_of_graph_port(parent, child) \
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for (struct device_node *child __free(device_node) = of_graph_get_next_port(parent, NULL);\
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child != NULL; child = of_graph_get_next_port(parent, child))
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/**
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* for_each_of_graph_port_endpoint - iterate over every endpoint in a port node
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* @parent: parent port node
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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, and continue to use the @child, you need to
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* use return_ptr(@child) or no_free_ptr(@child) not to call __free() for it.
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*/
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#define for_each_of_graph_port_endpoint(parent, child) \
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for (struct device_node *child __free(device_node) = of_graph_get_next_port_endpoint(parent, NULL);\
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child != NULL; child = of_graph_get_next_port_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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unsigned int of_graph_get_endpoint_count(const struct device_node *np);
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unsigned int of_graph_get_port_count(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_next_port(const struct device_node *parent,
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struct device_node *port);
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struct device_node *of_graph_get_next_port_endpoint(const struct device_node *port,
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struct device_node *prev);
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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 unsigned 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 unsigned int of_graph_get_port_count(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_next_port(
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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_next_port_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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