LXR linux/drivers/gpu/drm/omapdrm/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/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);
 184