LXR linux/drivers/video/fbdev/omap2/omapfb/dss/dss-of.c

   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/of_graph.h>
  20#include <linux/seq_file.h>
  21
  22#include <video/omapfb_dss.h>
  23
  24#include "dss.h"
  25
  26struct device_node *
  27omapdss_of_get_next_port(const struct device_node *parent,
  28                         struct device_node *prev)
  29{
  30        struct device_node *port = NULL;
  31
  32        if (!parent)
  33                return NULL;
  34
  35        if (!prev) {
  36                struct device_node *ports;
  37                /*
  38                 * It's the first call, we have to find a port subnode
  39                 * within this node or within an optional 'ports' node.
  40                 */
  41                ports = of_get_child_by_name(parent, "ports");
  42                if (ports)
  43                        parent = ports;
  44
  45                port = of_get_child_by_name(parent, "port");
  46
  47                /* release the 'ports' node */
  48                of_node_put(ports);
  49        } else {
  50                struct device_node *ports;
  51
  52                ports = of_get_parent(prev);
  53                if (!ports)
  54                        return NULL;
  55
  56                do {
  57                        port = of_get_next_child(ports, prev);
  58                        if (!port) {
  59                                of_node_put(ports);
  60                                return NULL;
  61                        }
  62                        prev = port;
  63                } while (of_node_cmp(port->name, "port") != 0);
  64
  65                of_node_put(ports);
  66        }
  67
  68        return port;
  69}
  70EXPORT_SYMBOL_GPL(omapdss_of_get_next_port);
  71
  72struct device_node *
  73omapdss_of_get_next_endpoint(const struct device_node *parent,
  74                             struct device_node *prev)
  75{
  76        struct device_node *ep = NULL;
  77
  78        if (!parent)
  79                return NULL;
  80
  81        do {
  82                ep = of_get_next_child(parent, prev);
  83                if (!ep)
  84                        return NULL;
  85                prev = ep;
  86        } while (of_node_cmp(ep->name, "endpoint") != 0);
  87
  88        return ep;
  89}
  90EXPORT_SYMBOL_GPL(omapdss_of_get_next_endpoint);
  91
  92struct device_node *dss_of_port_get_parent_device(struct device_node *port)
  93{
  94        struct device_node *np;
  95        int i;
  96
  97        if (!port)
  98                return NULL;
  99
 100        np = of_get_parent(port);
 101
 102        for (i = 0; i < 2 && np; ++i) {
 103                struct property *prop;
 104
 105                prop = of_find_property(np, "compatible", NULL);
 106
 107                if (prop)
 108                        return np;
 109
 110                np = of_get_next_parent(np);
 111        }
 112
 113        return NULL;
 114}
 115
 116u32 dss_of_port_get_port_number(struct device_node *port)
 117{
 118        int r;
 119        u32 reg;
 120
 121        r = of_property_read_u32(port, "reg", &reg);
 122        if (r)
 123                reg = 0;
 124
 125        return reg;
 126}
 127
 128static struct device_node *omapdss_of_get_remote_port(const struct device_node *node)
 129{
 130        struct device_node *np;
 131
 132        np = of_graph_get_remote_endpoint(node);
 133        if (!np)
 134                return NULL;
 135
 136        np = of_get_next_parent(np);
 137
 138        return np;
 139}
 140
 141struct device_node *
 142omapdss_of_get_first_endpoint(const struct device_node *parent)
 143{
 144        struct device_node *port, *ep;
 145
 146        port = omapdss_of_get_next_port(parent, NULL);
 147
 148        if (!port)
 149                return NULL;
 150
 151        ep = omapdss_of_get_next_endpoint(port, NULL);
 152
 153        of_node_put(port);
 154
 155        return ep;
 156}
 157EXPORT_SYMBOL_GPL(omapdss_of_get_first_endpoint);
 158
 159struct omap_dss_device *
 160omapdss_of_find_source_for_first_ep(struct device_node *node)
 161{
 162        struct device_node *ep;
 163        struct device_node *src_port;
 164        struct omap_dss_device *src;
 165
 166        ep = omapdss_of_get_first_endpoint(node);
 167        if (!ep)
 168                return ERR_PTR(-EINVAL);
 169
 170        src_port = omapdss_of_get_remote_port(ep);
 171        if (!src_port) {
 172                of_node_put(ep);
 173                return ERR_PTR(-EINVAL);
 174        }
 175
 176        of_node_put(ep);
 177
 178        src = omap_dss_find_output_by_port_node(src_port);
 179
 180        of_node_put(src_port);
 181
 182        return src ? src : ERR_PTR(-EPROBE_DEFER);
 183}
 184EXPORT_SYMBOL_GPL(omapdss_of_find_source_for_first_ep);
 185