1/*
2 * Copyright (C) 2013 Texas Instruments
3 * Author: Tomi Valkeinen <tomi.valkeinen@ti.com>
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 as published by
7 * the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
12 * more details.
13 */
14
15#include <linux/device.h>
16#include <linux/err.h>
17#include <linux/module.h>
18#include <linux/of.h>
19#include <linux/seq_file.h>
20
21#include <video/omapdss.h>
22
23#include "dss.h"
24
25struct device_node *
26omapdss_of_get_next_port(const struct device_node *parent,
27			 struct device_node *prev)
28{
29	struct device_node *port = NULL;
30
31	if (!parent)
32		return NULL;
33
34	if (!prev) {
35		struct device_node *ports;
36		/*
37		 * It's the first call, we have to find a port subnode
38		 * within this node or within an optional 'ports' node.
39		 */
40		ports = of_get_child_by_name(parent, "ports");
41		if (ports)
42			parent = ports;
43
44		port = of_get_child_by_name(parent, "port");
45
46		/* release the 'ports' node */
47		of_node_put(ports);
48	} else {
49		struct device_node *ports;
50
51		ports = of_get_parent(prev);
52		if (!ports)
53			return NULL;
54
55		do {
56			port = of_get_next_child(ports, prev);
57			if (!port) {
58				of_node_put(ports);
59				return NULL;
60			}
61			prev = port;
62		} while (of_node_cmp(port->name, "port") != 0);
63	}
64
65	return port;
66}
67EXPORT_SYMBOL_GPL(omapdss_of_get_next_port);
68
69struct device_node *
70omapdss_of_get_next_endpoint(const struct device_node *parent,
71			     struct device_node *prev)
72{
73	struct device_node *ep = NULL;
74
75	if (!parent)
76		return NULL;
77
78	do {
79		ep = of_get_next_child(parent, prev);
80		if (!ep)
81			return NULL;
82		prev = ep;
83	} while (of_node_cmp(ep->name, "endpoint") != 0);
84
85	return ep;
86}
87EXPORT_SYMBOL_GPL(omapdss_of_get_next_endpoint);
88
89struct device_node *dss_of_port_get_parent_device(struct device_node *port)
90{
91	struct device_node *np;
92	int i;
93
94	if (!port)
95		return NULL;
96
97	np = of_get_next_parent(port);
98
99	for (i = 0; i < 2 && np; ++i) {
100		struct property *prop;
101
102		prop = of_find_property(np, "compatible", NULL);
103
104		if (prop)
105			return np;
106
107		np = of_get_next_parent(np);
108	}
109
110	return NULL;
111}
112
113u32 dss_of_port_get_port_number(struct device_node *port)
114{
115	int r;
116	u32 reg;
117
118	r = of_property_read_u32(port, "reg", &reg);
119	if (r)
120		reg = 0;
121
122	return reg;
123}
124
125static struct device_node *omapdss_of_get_remote_port(const struct device_node *node)
126{
127	struct device_node *np;
128
129	np = of_parse_phandle(node, "remote-endpoint", 0);
130	if (!np)
131		return NULL;
132
133	np = of_get_next_parent(np);
134
135	return np;
136}
137
138struct device_node *
139omapdss_of_get_first_endpoint(const struct device_node *parent)
140{
141	struct device_node *port, *ep;
142
143	port = omapdss_of_get_next_port(parent, NULL);
144
145	if (!port)
146		return NULL;
147
148	ep = omapdss_of_get_next_endpoint(port, NULL);
149
150	of_node_put(port);
151
152	return ep;
153}
154EXPORT_SYMBOL_GPL(omapdss_of_get_first_endpoint);
155
156struct omap_dss_device *
157omapdss_of_find_source_for_first_ep(struct device_node *node)
158{
159	struct device_node *ep;
160	struct device_node *src_port;
161	struct omap_dss_device *src;
162
163	ep = omapdss_of_get_first_endpoint(node);
164	if (!ep)
165		return ERR_PTR(-EINVAL);
166
167	src_port = omapdss_of_get_remote_port(ep);
168	if (!src_port) {
169		of_node_put(ep);
170		return ERR_PTR(-EINVAL);
171	}
172
173	of_node_put(ep);
174
175	src = omap_dss_find_output_by_port_node(src_port);
176
177	of_node_put(src_port);
178
179	return src ? src : ERR_PTR(-EPROBE_DEFER);
180}
181EXPORT_SYMBOL_GPL(omapdss_of_find_source_for_first_ep);
182