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

   1/*
   2 * Copyright (C) 2016 Laurent Pinchart <laurent.pinchart@ideasonboard.com>
   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
  16struct lvds_encoder {
  17        struct drm_bridge bridge;
  18        struct drm_bridge *panel_bridge;
  19};
  20
  21static int lvds_encoder_attach(struct drm_bridge *bridge)
  22{
  23        struct lvds_encoder *lvds_encoder = container_of(bridge,
  24                                                         struct lvds_encoder,
  25                                                         bridge);
  26
  27        return drm_bridge_attach(bridge->encoder, lvds_encoder->panel_bridge,
  28                                 bridge);
  29}
  30
  31static struct drm_bridge_funcs funcs = {
  32        .attach = lvds_encoder_attach,
  33};
  34
  35static int lvds_encoder_probe(struct platform_device *pdev)
  36{
  37        struct device_node *port;
  38        struct device_node *endpoint;
  39        struct device_node *panel_node;
  40        struct drm_panel *panel;
  41        struct lvds_encoder *lvds_encoder;
  42
  43        lvds_encoder = devm_kzalloc(&pdev->dev, sizeof(*lvds_encoder),
  44                                    GFP_KERNEL);
  45        if (!lvds_encoder)
  46                return -ENOMEM;
  47
  48        /* Locate the panel DT node. */
  49        port = of_graph_get_port_by_id(pdev->dev.of_node, 1);
  50        if (!port) {
  51                dev_dbg(&pdev->dev, "port 1 not found\n");
  52                return -ENXIO;
  53        }
  54
  55        endpoint = of_get_child_by_name(port, "endpoint");
  56        of_node_put(port);
  57        if (!endpoint) {
  58                dev_dbg(&pdev->dev, "no endpoint for port 1\n");
  59                return -ENXIO;
  60        }
  61
  62        panel_node = of_graph_get_remote_port_parent(endpoint);
  63        of_node_put(endpoint);
  64        if (!panel_node) {
  65                dev_dbg(&pdev->dev, "no remote endpoint for port 1\n");
  66                return -ENXIO;
  67        }
  68
  69        panel = of_drm_find_panel(panel_node);
  70        of_node_put(panel_node);
  71        if (!panel) {
  72                dev_dbg(&pdev->dev, "panel not found, deferring probe\n");
  73                return -EPROBE_DEFER;
  74        }
  75
  76        lvds_encoder->panel_bridge =
  77                devm_drm_panel_bridge_add(&pdev->dev,
  78                                          panel, DRM_MODE_CONNECTOR_LVDS);
  79        if (IS_ERR(lvds_encoder->panel_bridge))
  80                return PTR_ERR(lvds_encoder->panel_bridge);
  81
  82        /* The panel_bridge bridge is attached to the panel's of_node,
  83         * but we need a bridge attached to our of_node for our user
  84         * to look up.
  85         */
  86        lvds_encoder->bridge.of_node = pdev->dev.of_node;
  87        lvds_encoder->bridge.funcs = &funcs;
  88        drm_bridge_add(&lvds_encoder->bridge);
  89
  90        platform_set_drvdata(pdev, lvds_encoder);
  91
  92        return 0;
  93}
  94
  95static int lvds_encoder_remove(struct platform_device *pdev)
  96{
  97        struct lvds_encoder *lvds_encoder = platform_get_drvdata(pdev);
  98
  99        drm_bridge_remove(&lvds_encoder->bridge);
 100
 101        return 0;
 102}
 103
 104static const struct of_device_id lvds_encoder_match[] = {
 105        { .compatible = "lvds-encoder" },
 106        { .compatible = "thine,thc63lvdm83d" },
 107        {},
 108};
 109MODULE_DEVICE_TABLE(of, lvds_encoder_match);
 110
 111static struct platform_driver lvds_encoder_driver = {
 112        .probe  = lvds_encoder_probe,
 113        .remove = lvds_encoder_remove,
 114        .driver         = {
 115                .name           = "lvds-encoder",
 116                .of_match_table = lvds_encoder_match,
 117        },
 118};
 119module_platform_driver(lvds_encoder_driver);
 120
 121MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
 122MODULE_DESCRIPTION("Transparent parallel to LVDS encoder");
 123MODULE_LICENSE("GPL");
 124