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
  12#include <drm/drm_crtc.h>
  13#include <drm/drm_modeset_helper_vtables.h>
  14#include <drm/drm_panel.h>
  15
  16#include "rcar_du_drv.h"
  17#include "rcar_du_encoder.h"
  18#include "rcar_du_kms.h"
  19#include "rcar_lvds.h"
  20
  21/* -----------------------------------------------------------------------------
  22 * Encoder
  23 */
  24
  25static const struct drm_encoder_helper_funcs encoder_helper_funcs = {
  26};
  27
  28static const struct drm_encoder_funcs encoder_funcs = {
  29        .destroy = drm_encoder_cleanup,
  30};
  31
  32static unsigned int rcar_du_encoder_count_ports(struct device_node *node)
  33{
  34        struct device_node *ports;
  35        struct device_node *port;
  36        unsigned int num_ports = 0;
  37
  38        ports = of_get_child_by_name(node, "ports");
  39        if (!ports)
  40                ports = of_node_get(node);
  41
  42        for_each_child_of_node(ports, port) {
  43                if (of_node_name_eq(port, "port"))
  44                        num_ports++;
  45        }
  46
  47        of_node_put(ports);
  48
  49        return num_ports;
  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_encoder *encoder;
  58        struct drm_bridge *bridge;
  59        int ret;
  60
  61        renc = devm_kzalloc(rcdu->dev, sizeof(*renc), GFP_KERNEL);
  62        if (renc == NULL)
  63                return -ENOMEM;
  64
  65        rcdu->encoders[output] = renc;
  66        renc->output = output;
  67        encoder = rcar_encoder_to_drm_encoder(renc);
  68
  69        dev_dbg(rcdu->dev, "initializing encoder %pOF for output %u\n",
  70                enc_node, output);
  71
  72        /*
  73         * Locate the DRM bridge from the DT node. For the DPAD outputs, if the
  74         * DT node has a single port, assume that it describes a panel and
  75         * create a panel bridge.
  76         */
  77        if ((output == RCAR_DU_OUTPUT_DPAD0 ||
  78             output == RCAR_DU_OUTPUT_DPAD1) &&
  79            rcar_du_encoder_count_ports(enc_node) == 1) {
  80                struct drm_panel *panel = of_drm_find_panel(enc_node);
  81
  82                if (IS_ERR(panel)) {
  83                        ret = PTR_ERR(panel);
  84                        goto done;
  85                }
  86
  87                bridge = devm_drm_panel_bridge_add(rcdu->dev, panel,
  88                                                   DRM_MODE_CONNECTOR_DPI);
  89                if (IS_ERR(bridge)) {
  90                        ret = PTR_ERR(bridge);
  91                        goto done;
  92                }
  93        } else {
  94                bridge = of_drm_find_bridge(enc_node);
  95                if (!bridge) {
  96                        ret = -EPROBE_DEFER;
  97                        goto done;
  98                }
  99        }
 100
 101        /*
 102         * On Gen3 skip the LVDS1 output if the LVDS1 encoder is used as a
 103         * companion for LVDS0 in dual-link mode.
 104         */
 105        if (rcdu->info->gen >= 3 && output == RCAR_DU_OUTPUT_LVDS1) {
 106                if (rcar_lvds_dual_link(bridge)) {
 107                        ret = -ENOLINK;
 108                        goto done;
 109                }
 110        }
 111
 112        ret = drm_encoder_init(rcdu->ddev, encoder, &encoder_funcs,
 113                               DRM_MODE_ENCODER_NONE, NULL);
 114        if (ret < 0)
 115                goto done;
 116
 117        drm_encoder_helper_add(encoder, &encoder_helper_funcs);
 118
 119        /*
 120         * Attach the bridge to the encoder. The bridge will create the
 121         * connector.
 122         */
 123        ret = drm_bridge_attach(encoder, bridge, NULL);
 124        if (ret) {
 125                drm_encoder_cleanup(encoder);
 126                return ret;
 127        }
 128
 129done:
 130        if (ret < 0) {
 131                if (encoder->name)
 132                        encoder->funcs->destroy(encoder);
 133                devm_kfree(rcdu->dev, renc);
 134        }
 135
 136        return ret;
 137}
 138