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