1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2013 Texas Instruments
4 * Author: Tomi Valkeinen <tomi.valkeinen@ti.com>
5 */
6
7#include <linux/device.h>
8#include <linux/err.h>
9#include <linux/module.h>
10#include <linux/of.h>
11#include <linux/of_graph.h>
12#include <linux/seq_file.h>
13
14#include <video/omapfb_dss.h>
15
16#include "dss.h"
17
18struct device_node *
19omapdss_of_get_next_port(const struct device_node *parent,
20			 struct device_node *prev)
21{
22	struct device_node *port = NULL;
23
24	if (!parent)
25		return NULL;
26
27	if (!prev) {
28		struct device_node *ports;
29		/*
30		 * It's the first call, we have to find a port subnode
31		 * within this node or within an optional 'ports' node.
32		 */
33		ports = of_get_child_by_name(parent, "ports");
34		if (ports)
35			parent = ports;
36
37		port = of_get_child_by_name(parent, "port");
38
39		/* release the 'ports' node */
40		of_node_put(ports);
41	} else {
42		struct device_node *ports;
43
44		ports = of_get_parent(prev);
45		if (!ports)
46			return NULL;
47
48		do {
49			port = of_get_next_child(ports, prev);
50			if (!port) {
51				of_node_put(ports);
52				return NULL;
53			}
54			prev = port;
55		} while (!of_node_name_eq(port, "port"));
56
57		of_node_put(ports);
58	}
59
60	return port;
61}
62EXPORT_SYMBOL_GPL(omapdss_of_get_next_port);
63
64struct device_node *
65omapdss_of_get_next_endpoint(const struct device_node *parent,
66			     struct device_node *prev)
67{
68	struct device_node *ep = NULL;
69
70	if (!parent)
71		return NULL;
72
73	do {
74		ep = of_get_next_child(parent, prev);
75		if (!ep)
76			return NULL;
77		prev = ep;
78	} while (!of_node_name_eq(ep, "endpoint"));
79
80	return ep;
81}
82EXPORT_SYMBOL_GPL(omapdss_of_get_next_endpoint);
83
84struct device_node *dss_of_port_get_parent_device(struct device_node *port)
85{
86	struct device_node *np;
87	int i;
88
89	if (!port)
90		return NULL;
91
92	np = of_get_parent(port);
93
94	for (i = 0; i < 2 && np; ++i) {
95		struct property *prop;
96
97		prop = of_find_property(np, "compatible", NULL);
98
99		if (prop)
100			return np;
101
102		np = of_get_next_parent(np);
103	}
104
105	return NULL;
106}
107
108u32 dss_of_port_get_port_number(struct device_node *port)
109{
110	int r;
111	u32 reg;
112
113	r = of_property_read_u32(port, "reg", &reg);
114	if (r)
115		reg = 0;
116
117	return reg;
118}
119
120static struct device_node *omapdss_of_get_remote_port(const struct device_node *node)
121{
122	struct device_node *np;
123
124	np = of_graph_get_remote_endpoint(node);
125	if (!np)
126		return NULL;
127
128	np = of_get_next_parent(np);
129
130	return np;
131}
132
133struct device_node *
134omapdss_of_get_first_endpoint(const struct device_node *parent)
135{
136	struct device_node *port, *ep;
137
138	port = omapdss_of_get_next_port(parent, NULL);
139
140	if (!port)
141		return NULL;
142
143	ep = omapdss_of_get_next_endpoint(port, NULL);
144
145	of_node_put(port);
146
147	return ep;
148}
149EXPORT_SYMBOL_GPL(omapdss_of_get_first_endpoint);
150
151struct omap_dss_device *
152omapdss_of_find_source_for_first_ep(struct device_node *node)
153{
154	struct device_node *ep;
155	struct device_node *src_port;
156	struct omap_dss_device *src;
157
158	ep = omapdss_of_get_first_endpoint(node);
159	if (!ep)
160		return ERR_PTR(-EINVAL);
161
162	src_port = omapdss_of_get_remote_port(ep);
163	if (!src_port) {
164		of_node_put(ep);
165		return ERR_PTR(-EINVAL);
166	}
167
168	of_node_put(ep);
169
170	src = omap_dss_find_output_by_port_node(src_port);
171
172	of_node_put(src_port);
173
174	return src ? src : ERR_PTR(-EPROBE_DEFER);
175}
176EXPORT_SYMBOL_GPL(omapdss_of_find_source_for_first_ep);
177