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

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2013 Texas Instruments
   4  * Author: Tomi Valkeinen <tomi.valkeinen@ti.com>
   5  */
   6
   7 #include <linux/device.h>
   8 #include <linux/err.h>
   9 #include <linux/module.h>
  10 #include <linux/of.h>
  11 #include <linux/of_graph.h>
  12 #include <linux/seq_file.h>
  13
  14 #include <video/omapfb_dss.h>
  15
  16 #include "dss.h"
  17
  18 struct device_node *
  19 omapdss_of_get_next_port(const struct device_node *parent,
  20                          struct device_node *prev)
  21 {
  22         struct device_node *port = NULL;
  23
  24         if (!parent)
  25                 return NULL;
  26
  27         if (!prev) {
  28                 struct device_node *ports;
  29                 /*
  30                  * It's the first call, we have to find a port subnode
  31                  * within this node or within an optional 'ports' node.
  32                  */
  33                 ports = of_get_child_by_name(parent, "ports");
  34                 if (ports)
  35                         parent = ports;
  36
  37                 port = of_get_child_by_name(parent, "port");
  38
  39                 /* release the 'ports' node */
  40                 of_node_put(ports);
  41         } else {
  42                 struct device_node *ports;
  43
  44                 ports = of_get_parent(prev);
  45                 if (!ports)
  46                         return NULL;
  47
  48                 do {
  49                         port = of_get_next_child(ports, prev);
  50                         if (!port) {
  51                                 of_node_put(ports);
  52                                 return NULL;
  53                         }
  54                         prev = port;
  55                 } while (!of_node_name_eq(port, "port"));
  56
  57                 of_node_put(ports);
  58         }
  59
  60         return port;
  61 }
  62 EXPORT_SYMBOL_GPL(omapdss_of_get_next_port);
  63
  64 struct device_node *
  65 omapdss_of_get_next_endpoint(const struct device_node *parent,
  66                              struct device_node *prev)
  67 {
  68         struct device_node *ep = NULL;
  69
  70         if (!parent)
  71                 return NULL;
  72
  73         do {
  74                 ep = of_get_next_child(parent, prev);
  75                 if (!ep)
  76                         return NULL;
  77                 prev = ep;
  78         } while (!of_node_name_eq(ep, "endpoint"));
  79
  80         return ep;
  81 }
  82 EXPORT_SYMBOL_GPL(omapdss_of_get_next_endpoint);
  83
  84 struct device_node *dss_of_port_get_parent_device(struct device_node *port)
  85 {
  86         struct device_node *np;
  87         int i;
  88
  89         if (!port)
  90                 return NULL;
  91
  92         np = of_get_parent(port);
  93
  94         for (i = 0; i < 2 && np; ++i) {
  95                 struct property *prop;
  96
  97                 prop = of_find_property(np, "compatible", NULL);
  98
  99                 if (prop)
 100                         return np;
 101
 102                 np = of_get_next_parent(np);
 103         }
 104
 105         return NULL;
 106 }
 107
 108 u32 dss_of_port_get_port_number(struct device_node *port)
 109 {
 110         int r;
 111         u32 reg;
 112
 113         r = of_property_read_u32(port, "reg", &reg);
 114         if (r)
 115                 reg = 0;
 116
 117         return reg;
 118 }
 119
 120 static struct device_node *omapdss_of_get_remote_port(const struct device_node *node)
 121 {
 122         struct device_node *np;
 123
 124         np = of_graph_get_remote_endpoint(node);
 125         if (!np)
 126                 return NULL;
 127
 128         np = of_get_next_parent(np);
 129
 130         return np;
 131 }
 132
 133 struct device_node *
 134 omapdss_of_get_first_endpoint(const struct device_node *parent)
 135 {
 136         struct device_node *port, *ep;
 137
 138         port = omapdss_of_get_next_port(parent, NULL);
 139
 140         if (!port)
 141                 return NULL;
 142
 143         ep = omapdss_of_get_next_endpoint(port, NULL);
 144
 145         of_node_put(port);
 146
 147         return ep;
 148 }
 149 EXPORT_SYMBOL_GPL(omapdss_of_get_first_endpoint);
 150
 151 struct omap_dss_device *
 152 omapdss_of_find_source_for_first_ep(struct device_node *node)
 153 {
 154         struct device_node *ep;
 155         struct device_node *src_port;
 156         struct omap_dss_device *src;
 157
 158         ep = omapdss_of_get_first_endpoint(node);
 159         if (!ep)
 160                 return ERR_PTR(-EINVAL);
 161
 162         src_port = omapdss_of_get_remote_port(ep);
 163         if (!src_port) {
 164                 of_node_put(ep);
 165                 return ERR_PTR(-EINVAL);
 166         }
 167
 168         of_node_put(ep);
 169
 170         src = omap_dss_find_output_by_port_node(src_port);
 171
 172         of_node_put(src_port);
 173
 174         return src ? src : ERR_PTR(-EPROBE_DEFER);
 175 }
 176 EXPORT_SYMBOL_GPL(omapdss_of_find_source_for_first_ep);