LXR linux/drivers/gpu/drm/rcar-du/rcar_du

   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * rcar_du_encoder.c  --  R-Car Display Unit Encoder
   4 *
   5 * Copyright (C) 2013-2014 Renesas Electronics Corporation
   6 *
   7 * Contact: Laurent Pinchart (laurent.pinchart@ideasonboard.com)
   8 */
   9
  10#include <linux/export.h>
  11#include <linux/slab.h>
  12
  13#include <drm/drm_bridge.h>
  14#include <drm/drm_bridge_connector.h>
  15#include <drm/drm_crtc.h>
  16#include <drm/drm_managed.h>
  17#include <drm/drm_modeset_helper_vtables.h>
  18#include <drm/drm_panel.h>
  19
  20#include "rcar_du_drv.h"
  21#include "rcar_du_encoder.h"
  22#include "rcar_du_kms.h"
  23#include "rcar_lvds.h"
  24
  25/* -----------------------------------------------------------------------------
  26 * Encoder
  27 */
  28
  29static unsigned int rcar_du_encoder_count_ports(struct device_node *node)
  30{
  31        struct device_node *ports;
  32        struct device_node *port;
  33        unsigned int num_ports = 0;
  34
  35        ports = of_get_child_by_name(node, "ports");
  36        if (!ports)
  37                ports = of_node_get(node);
  38
  39        for_each_child_of_node(ports, port) {
  40                if (of_node_name_eq(port, "port"))
  41                        num_ports++;
  42        }
  43
  44        of_node_put(ports);
  45
  46        return num_ports;
  47}
  48
  49static const struct drm_encoder_funcs rcar_du_encoder_funcs = {
  50};
  51
  52int rcar_du_encoder_init(struct rcar_du_device *rcdu,
  53                         enum rcar_du_output output,
  54                         struct device_node *enc_node)
  55{
  56        struct rcar_du_encoder *renc;
  57        struct drm_connector *connector;
  58        struct drm_bridge *bridge;
  59        int ret;
  60
  61        /*
  62         * Locate the DRM bridge from the DT node. For the DPAD outputs, if the
  63         * DT node has a single port, assume that it describes a panel and
  64         * create a panel bridge.
  65         */
  66        if ((output == RCAR_DU_OUTPUT_DPAD0 ||
  67             output == RCAR_DU_OUTPUT_DPAD1) &&
  68            rcar_du_encoder_count_ports(enc_node) == 1) {
  69                struct drm_panel *panel = of_drm_find_panel(enc_node);
  70
  71                if (IS_ERR(panel))
  72                        return PTR_ERR(panel);
  73
  74                bridge = devm_drm_panel_bridge_add_typed(rcdu->dev, panel,
  75                                                         DRM_MODE_CONNECTOR_DPI);
  76                if (IS_ERR(bridge))
  77                        return PTR_ERR(bridge);
  78        } else {
  79                bridge = of_drm_find_bridge(enc_node);
  80                if (!bridge)
  81                        return -EPROBE_DEFER;
  82
  83                if (output == RCAR_DU_OUTPUT_LVDS0 ||
  84                    output == RCAR_DU_OUTPUT_LVDS1)
  85                        rcdu->lvds[output - RCAR_DU_OUTPUT_LVDS0] = bridge;
  86        }
  87
  88        /*
  89         * Create and initialize the encoder. On Gen3, skip the LVDS1 output if
  90         * the LVDS1 encoder is used as a companion for LVDS0 in dual-link
  91         * mode, or any LVDS output if it isn't connected. The latter may happen
  92         * on D3 or E3 as the LVDS encoders are needed to provide the pixel
  93         * clock to the DU, even when the LVDS outputs are not used.
  94         */
  95        if (rcdu->info->gen >= 3) {
  96                if (output == RCAR_DU_OUTPUT_LVDS1 &&
  97                    rcar_lvds_dual_link(bridge))
  98                        return -ENOLINK;
  99
 100                if ((output == RCAR_DU_OUTPUT_LVDS0 ||
 101                     output == RCAR_DU_OUTPUT_LVDS1) &&
 102                    !rcar_lvds_is_connected(bridge))
 103                        return -ENOLINK;
 104        }
 105
 106        dev_dbg(rcdu->dev, "initializing encoder %pOF for output %u\n",
 107                enc_node, output);
 108
 109        renc = drmm_encoder_alloc(&rcdu->ddev, struct rcar_du_encoder, base,
 110                                  &rcar_du_encoder_funcs, DRM_MODE_ENCODER_NONE,
 111                                  NULL);
 112        if (!renc)
 113                return -ENOMEM;
 114
 115        renc->output = output;
 116
 117        /* Attach the bridge to the encoder. */
 118        ret = drm_bridge_attach(&renc->base, bridge, NULL,
 119                                DRM_BRIDGE_ATTACH_NO_CONNECTOR);
 120        if (ret) {
 121                dev_err(rcdu->dev, "failed to attach bridge for output %u\n",
 122                        output);
 123                return ret;
 124        }
 125
 126        /* Create the connector for the chain of bridges. */
 127        connector = drm_bridge_connector_init(&rcdu->ddev, &renc->base);
 128        if (IS_ERR(connector)) {
 129                dev_err(rcdu->dev,
 130                        "failed to created connector for output %u\n", output);
 131                return PTR_ERR(connector);
 132        }
 133
 134        return drm_connector_attach_encoder(connector, &renc->base);
 135}
 136