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		of_node_put(ports);
 65	}
 66
 67	return port;
 68}
 69EXPORT_SYMBOL_GPL(omapdss_of_get_next_port);
 70
 71struct device_node *
 72omapdss_of_get_next_endpoint(const struct device_node *parent,
 73			     struct device_node *prev)
 74{
 75	struct device_node *ep = NULL;
 76
 77	if (!parent)
 78		return NULL;
 79
 80	do {
 81		ep = of_get_next_child(parent, prev);
 82		if (!ep)
 83			return NULL;
 84		prev = ep;
 85	} while (of_node_cmp(ep->name, "endpoint") != 0);
 86
 87	return ep;
 88}
 89EXPORT_SYMBOL_GPL(omapdss_of_get_next_endpoint);
 90
 91struct device_node *dss_of_port_get_parent_device(struct device_node *port)
 92{
 93	struct device_node *np;
 94	int i;
 95
 96	if (!port)
 97		return NULL;
 98
 99	np = of_get_parent(port);
100
101	for (i = 0; i < 2 && np; ++i) {
102		struct property *prop;
103
104		prop = of_find_property(np, "compatible", NULL);
105
106		if (prop)
107			return np;
108
109		np = of_get_next_parent(np);
110	}
111
112	return NULL;
113}
114
115u32 dss_of_port_get_port_number(struct device_node *port)
116{
117	int r;
118	u32 reg;
119
120	r = of_property_read_u32(port, "reg", &reg);
121	if (r)
122		reg = 0;
123
124	return reg;
125}
126
127static struct device_node *omapdss_of_get_remote_port(const struct device_node *node)
128{
129	struct device_node *np;
130
131	np = of_parse_phandle(node, "remote-endpoint", 0);
132	if (!np)
133		return NULL;
134
135	np = of_get_next_parent(np);
136
137	return np;
138}
139
140struct device_node *
141omapdss_of_get_first_endpoint(const struct device_node *parent)
142{
143	struct device_node *port, *ep;
144
145	port = omapdss_of_get_next_port(parent, NULL);
146
147	if (!port)
148		return NULL;
149
150	ep = omapdss_of_get_next_endpoint(port, NULL);
151
152	of_node_put(port);
153
154	return ep;
155}
156EXPORT_SYMBOL_GPL(omapdss_of_get_first_endpoint);
157
158struct omap_dss_device *
159omapdss_of_find_source_for_first_ep(struct device_node *node)
160{
161	struct device_node *ep;
162	struct device_node *src_port;
163	struct omap_dss_device *src;
164
165	ep = omapdss_of_get_first_endpoint(node);
166	if (!ep)
167		return ERR_PTR(-EINVAL);
168
169	src_port = omapdss_of_get_remote_port(ep);
170	if (!src_port) {
171		of_node_put(ep);
172		return ERR_PTR(-EINVAL);
173	}
174
175	of_node_put(ep);
176
177	src = omap_dss_find_output_by_port_node(src_port);
178
179	of_node_put(src_port);
180
181	return src ? src : ERR_PTR(-EPROBE_DEFER);
182}
183EXPORT_SYMBOL_GPL(omapdss_of_find_source_for_first_ep);