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}