drivers/gpu/drm/rcar-du/rcar_du_encoder.c

   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_bridge.h>
  13 #include <drm/drm_crtc.h>
  14 #include <drm/drm_modeset_helper_vtables.h>
  15 #include <drm/drm_panel.h>
  16
  17 #include "rcar_du_drv.h"
  18 #include "rcar_du_encoder.h"
  19 #include "rcar_du_kms.h"
  20 #include "rcar_lvds.h"
  21
  22 /* -----------------------------------------------------------------------------
  23  * Encoder
  24  */
  25
  26 static const struct drm_encoder_helper_funcs encoder_helper_funcs = {
  27 };
  28
  29 static const struct drm_encoder_funcs encoder_funcs = {
  30         .destroy = drm_encoder_cleanup,
  31 };
  32
  33 static unsigned int rcar_du_encoder_count_ports(struct device_node *node)
  34 {
  35         struct device_node *ports;
  36         struct device_node *port;
  37         unsigned int num_ports = 0;
  38
  39         ports = of_get_child_by_name(node, "ports");
  40         if (!ports)
  41                 ports = of_node_get(node);
  42
  43         for_each_child_of_node(ports, port) {
  44                 if (of_node_name_eq(port, "port"))
  45                         num_ports++;
  46         }
  47
  48         of_node_put(ports);
  49
  50         return num_ports;
  51 }
  52
  53 int rcar_du_encoder_init(struct rcar_du_device *rcdu,
  54                          enum rcar_du_output output,
  55                          struct device_node *enc_node)
  56 {
  57         struct rcar_du_encoder *renc;
  58         struct drm_encoder *encoder;
  59         struct drm_bridge *bridge;
  60         int ret;
  61
  62         renc = devm_kzalloc(rcdu->dev, sizeof(*renc), GFP_KERNEL);
  63         if (renc == NULL)
  64                 return -ENOMEM;
  65
  66         rcdu->encoders[output] = renc;
  67         renc->output = output;
  68         encoder = rcar_encoder_to_drm_encoder(renc);
  69
  70         dev_dbg(rcdu->dev, "initializing encoder %pOF for output %u\n",
  71                 enc_node, output);
  72
  73         /*
  74          * Locate the DRM bridge from the DT node. For the DPAD outputs, if the
  75          * DT node has a single port, assume that it describes a panel and
  76          * create a panel bridge.
  77          */
  78         if ((output == RCAR_DU_OUTPUT_DPAD0 ||
  79              output == RCAR_DU_OUTPUT_DPAD1) &&
  80             rcar_du_encoder_count_ports(enc_node) == 1) {
  81                 struct drm_panel *panel = of_drm_find_panel(enc_node);
  82
  83                 if (IS_ERR(panel)) {
  84                         ret = PTR_ERR(panel);
  85                         goto done;
  86                 }
  87
  88                 bridge = devm_drm_panel_bridge_add(rcdu->dev, panel,
  89                                                    DRM_MODE_CONNECTOR_DPI);
  90                 if (IS_ERR(bridge)) {
  91                         ret = PTR_ERR(bridge);
  92                         goto done;
  93                 }
  94         } else {
  95                 bridge = of_drm_find_bridge(enc_node);
  96                 if (!bridge) {
  97                         ret = -EPROBE_DEFER;
  98                         goto done;
  99                 }
 100         }
 101
 102         /*
 103          * On Gen3 skip the LVDS1 output if the LVDS1 encoder is used as a
 104          * companion for LVDS0 in dual-link mode.
 105          */
 106         if (rcdu->info->gen >= 3 && output == RCAR_DU_OUTPUT_LVDS1) {
 107                 if (rcar_lvds_dual_link(bridge)) {
 108                         ret = -ENOLINK;
 109                         goto done;
 110                 }
 111         }
 112
 113         ret = drm_encoder_init(rcdu->ddev, encoder, &encoder_funcs,
 114                                DRM_MODE_ENCODER_NONE, NULL);
 115         if (ret < 0)
 116                 goto done;
 117
 118         drm_encoder_helper_add(encoder, &encoder_helper_funcs);
 119
 120         /*
 121          * Attach the bridge to the encoder. The bridge will create the
 122          * connector.
 123          */
 124         ret = drm_bridge_attach(encoder, bridge, NULL);
 125         if (ret) {
 126                 drm_encoder_cleanup(encoder);
 127                 return ret;
 128         }
 129
 130 done:
 131         if (ret < 0) {
 132                 if (encoder->name)
 133                         encoder->funcs->destroy(encoder);
 134                 devm_kfree(rcdu->dev, renc);
 135         }
 136
 137         return ret;
 138 }