drivers/gpu/drm/omapdrm/dss/dss-of.c

   1 /*
   2  * Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com/
   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 "omapdss.h"
  23
  24 struct device_node *dss_of_port_get_parent_device(struct device_node *port)
  25 {
  26         struct device_node *np;
  27         int i;
  28
  29         if (!port)
  30                 return NULL;
  31
  32         np = of_get_parent(port);
  33
  34         for (i = 0; i < 2 && np; ++i) {
  35                 struct property *prop;
  36
  37                 prop = of_find_property(np, "compatible", NULL);
  38
  39                 if (prop)
  40                         return np;
  41
  42                 np = of_get_next_parent(np);
  43         }
  44
  45         return NULL;
  46 }
  47 EXPORT_SYMBOL_GPL(dss_of_port_get_parent_device);
  48
  49 u32 dss_of_port_get_port_number(struct device_node *port)
  50 {
  51         int r;
  52         u32 reg;
  53
  54         r = of_property_read_u32(port, "reg", &reg);
  55         if (r)
  56                 reg = 0;
  57
  58         return reg;
  59 }
  60 EXPORT_SYMBOL_GPL(dss_of_port_get_port_number);
  61
  62 struct omap_dss_device *
  63 omapdss_of_find_source_for_first_ep(struct device_node *node)
  64 {
  65         struct device_node *ep;
  66         struct device_node *src_port;
  67         struct omap_dss_device *src;
  68
  69         ep = of_graph_get_endpoint_by_regs(node, 0, 0);
  70         if (!ep)
  71                 return ERR_PTR(-EINVAL);
  72
  73         src_port = of_graph_get_remote_port(ep);
  74         if (!src_port) {
  75                 of_node_put(ep);
  76                 return ERR_PTR(-EINVAL);
  77         }
  78
  79         of_node_put(ep);
  80
  81         src = omap_dss_find_output_by_port_node(src_port);
  82
  83         of_node_put(src_port);
  84
  85         return src ? src : ERR_PTR(-EPROBE_DEFER);
  86 }
  87 EXPORT_SYMBOL_GPL(omapdss_of_find_source_for_first_ep);