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 "omapdss.h"
  22 #include "dss.h"
  23
  24 struct device_node *
  25 omapdss_of_get_next_port(const struct device_node *parent,
  26                          struct device_node *prev)
  27 {
  28         struct device_node *port = NULL;
  29
  30         if (!parent)
  31                 return NULL;
  32
  33         if (!prev) {
  34                 struct device_node *ports;
  35                 /*
  36                  * It's the first call, we have to find a port subnode
  37                  * within this node or within an optional 'ports' node.
  38                  */
  39                 ports = of_get_child_by_name(parent, "ports");
  40                 if (ports)
  41                         parent = ports;
  42
  43                 port = of_get_child_by_name(parent, "port");
  44
  45                 /* release the 'ports' node */
  46                 of_node_put(ports);
  47         } else {
  48                 struct device_node *ports;
  49
  50                 ports = of_get_parent(prev);
  51                 if (!ports)
  52                         return NULL;
  53
  54                 do {
  55                         port = of_get_next_child(ports, prev);
  56                         if (!port) {
  57                                 of_node_put(ports);
  58                                 return NULL;
  59                         }
  60                         prev = port;
  61                 } while (of_node_cmp(port->name, "port") != 0);
  62
  63                 of_node_put(ports);
  64         }
  65
  66         return port;
  67 }
  68 EXPORT_SYMBOL_GPL(omapdss_of_get_next_port);
  69
  70 struct device_node *
  71 omapdss_of_get_next_endpoint(const struct device_node *parent,
  72                              struct device_node *prev)
  73 {
  74         struct device_node *ep = NULL;
  75
  76         if (!parent)
  77                 return NULL;
  78
  79         do {
  80                 ep = of_get_next_child(parent, prev);
  81                 if (!ep)
  82                         return NULL;
  83                 prev = ep;
  84         } while (of_node_cmp(ep->name, "endpoint") != 0);
  85
  86         return ep;
  87 }
  88 EXPORT_SYMBOL_GPL(omapdss_of_get_next_endpoint);
  89
  90 struct device_node *dss_of_port_get_parent_device(struct device_node *port)
  91 {
  92         struct device_node *np;
  93         int i;
  94
  95         if (!port)
  96                 return NULL;
  97
  98         np = of_get_parent(port);
  99
 100         for (i = 0; i < 2 && np; ++i) {
 101                 struct property *prop;
 102
 103                 prop = of_find_property(np, "compatible", NULL);
 104
 105                 if (prop)
 106                         return np;
 107
 108                 np = of_get_next_parent(np);
 109         }
 110
 111         return NULL;
 112 }
 113
 114 u32 dss_of_port_get_port_number(struct device_node *port)
 115 {
 116         int r;
 117         u32 reg;
 118
 119         r = of_property_read_u32(port, "reg", &reg);
 120         if (r)
 121                 reg = 0;
 122
 123         return reg;
 124 }
 125
 126 static struct device_node *omapdss_of_get_remote_port(const struct device_node *node)
 127 {
 128         struct device_node *np, *np_parent;
 129
 130         np = of_parse_phandle(node, "remote-endpoint", 0);
 131         if (!np)
 132                 return NULL;
 133
 134         np_parent = of_get_next_parent(np);
 135         of_node_put(np);
 136
 137         return np_parent;
 138 }
 139
 140 struct device_node *
 141 omapdss_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 }
 156 EXPORT_SYMBOL_GPL(omapdss_of_get_first_endpoint);
 157
 158 struct omap_dss_device *
 159 omapdss_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 }
 183 EXPORT_SYMBOL_GPL(omapdss_of_find_source_for_first_ep);