drivers/gpu/drm/bridge/lvds-encoder.c

   1 /*
   2  * Copyright (C) 2016 Laurent Pinchart <[email protected]>
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License as
   6  * published by the Free Software Foundation; either version 2 of
   7  * the License, or (at your option) any later version.
   8  */
   9
  10 #include <drm/drmP.h>
  11 #include <drm/drm_bridge.h>
  12 #include <drm/drm_panel.h>
  13
  14 #include <linux/of_graph.h>
  15
  16 static int lvds_encoder_probe(struct platform_device *pdev)
  17 {
  18         struct device_node *port;
  19         struct device_node *endpoint;
  20         struct device_node *panel_node;
  21         struct drm_panel *panel;
  22         struct drm_bridge *bridge;
  23
  24         /* Locate the panel DT node. */
  25         port = of_graph_get_port_by_id(pdev->dev.of_node, 1);
  26         if (!port) {
  27                 dev_dbg(&pdev->dev, "port 1 not found\n");
  28                 return -ENXIO;
  29         }
  30
  31         endpoint = of_get_child_by_name(port, "endpoint");
  32         of_node_put(port);
  33         if (!endpoint) {
  34                 dev_dbg(&pdev->dev, "no endpoint for port 1\n");
  35                 return -ENXIO;
  36         }
  37
  38         panel_node = of_graph_get_remote_port_parent(endpoint);
  39         of_node_put(endpoint);
  40         if (!panel_node) {
  41                 dev_dbg(&pdev->dev, "no remote endpoint for port 1\n");
  42                 return -ENXIO;
  43         }
  44
  45         panel = of_drm_find_panel(panel_node);
  46         of_node_put(panel_node);
  47         if (!panel) {
  48                 dev_dbg(&pdev->dev, "panel not found, deferring probe\n");
  49                 return -EPROBE_DEFER;
  50         }
  51
  52         bridge = drm_panel_bridge_add(panel, DRM_MODE_CONNECTOR_LVDS);
  53         if (IS_ERR(bridge))
  54                 return PTR_ERR(bridge);
  55
  56         platform_set_drvdata(pdev, bridge);
  57
  58         return 0;
  59 }
  60
  61 static int lvds_encoder_remove(struct platform_device *pdev)
  62 {
  63         struct drm_bridge *bridge = platform_get_drvdata(pdev);
  64
  65         drm_bridge_remove(bridge);
  66
  67         return 0;
  68 }
  69
  70 static const struct of_device_id lvds_encoder_match[] = {
  71         { .compatible = "lvds-encoder" },
  72         { .compatible = "thine,thc63lvdm83d" },
  73         {},
  74 };
  75 MODULE_DEVICE_TABLE(of, lvds_encoder_match);
  76
  77 static struct platform_driver lvds_encoder_driver = {
  78         .probe  = lvds_encoder_probe,
  79         .remove = lvds_encoder_remove,
  80         .driver         = {
  81                 .name           = "lvds-encoder",
  82                 .of_match_table = lvds_encoder_match,
  83         },
  84 };
  85 module_platform_driver(lvds_encoder_driver);
  86
  87 MODULE_AUTHOR("Laurent Pinchart <[email protected]>");
  88 MODULE_DESCRIPTION("Transparent parallel to LVDS encoder");
  89 MODULE_LICENSE("GPL");