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_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
  27static 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
  47int 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
 122done:
 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}
 131