1// SPDX-License-Identifier: GPL-2.0+
  2/*
  3 * 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#include <linux/of.h>
 12
 13#include <drm/drm_bridge.h>
 14#include <drm/drm_bridge_connector.h>
 15#include <drm/drm_panel.h>
 16
 17#include "rcar_du_drv.h"
 18#include "rcar_du_encoder.h"
 19#include "rcar_lvds.h"
 20
 21/* -----------------------------------------------------------------------------
 22 * Encoder
 23 */
 24
 25static unsigned int rcar_du_encoder_count_ports(struct device_node *node)
 26{
 27	struct device_node *ports;
 28	struct device_node *port;
 29	unsigned int num_ports = 0;
 30
 31	ports = of_get_child_by_name(node, "ports");
 32	if (!ports)
 33		ports = of_node_get(node);
 34
 35	for_each_child_of_node(ports, port) {
 36		if (of_node_name_eq(port, "port"))
 37			num_ports++;
 38	}
 39
 40	of_node_put(ports);
 41
 42	return num_ports;
 43}
 44
 45static const struct drm_encoder_funcs rcar_du_encoder_funcs = {
 46};
 47
 48int rcar_du_encoder_init(struct rcar_du_device *rcdu,
 49			 enum rcar_du_output output,
 50			 struct device_node *enc_node)
 51{
 52	struct rcar_du_encoder *renc;
 53	struct drm_connector *connector;
 54	struct drm_bridge *bridge;
 55	int ret;
 56
 57	/*
 58	 * Locate the DRM bridge from the DT node. For the DPAD outputs, if the
 59	 * DT node has a single port, assume that it describes a panel and
 60	 * create a panel bridge.
 61	 */
 62	if ((output == RCAR_DU_OUTPUT_DPAD0 ||
 63	     output == RCAR_DU_OUTPUT_DPAD1) &&
 64	    rcar_du_encoder_count_ports(enc_node) == 1) {
 65		struct drm_panel *panel = of_drm_find_panel(enc_node);
 66
 67		if (IS_ERR(panel))
 68			return PTR_ERR(panel);
 69
 70		bridge = devm_drm_panel_bridge_add_typed(rcdu->dev, panel,
 71							 DRM_MODE_CONNECTOR_DPI);
 72		if (IS_ERR(bridge))
 73			return PTR_ERR(bridge);
 74	} else {
 75		bridge = of_drm_find_bridge(enc_node);
 76		if (!bridge)
 77			return -EPROBE_DEFER;
 78
 79		if (output == RCAR_DU_OUTPUT_LVDS0 ||
 80		    output == RCAR_DU_OUTPUT_LVDS1)
 81			rcdu->lvds[output - RCAR_DU_OUTPUT_LVDS0] = bridge;
 82
 83		if (output == RCAR_DU_OUTPUT_DSI0 ||
 84		    output == RCAR_DU_OUTPUT_DSI1)
 85			rcdu->dsi[output - RCAR_DU_OUTPUT_DSI0] = bridge;
 86	}
 87
 88	/*
 89	 * Create and initialize the encoder. On Gen3, skip the LVDS1 output if
 90	 * the LVDS1 encoder is used as a companion for LVDS0 in dual-link
 91	 * mode, or any LVDS output if it isn't connected. The latter may happen
 92	 * on D3 or E3 as the LVDS encoders are needed to provide the pixel
 93	 * clock to the DU, even when the LVDS outputs are not used.
 94	 */
 95	if (rcdu->info->gen >= 3) {
 96		if (output == RCAR_DU_OUTPUT_LVDS1 &&
 97		    rcar_lvds_dual_link(bridge))
 98			return -ENOLINK;
 99
100		if ((output == RCAR_DU_OUTPUT_LVDS0 ||
101		     output == RCAR_DU_OUTPUT_LVDS1) &&
102		    !rcar_lvds_is_connected(bridge))
103			return -ENOLINK;
104	}
105
106	dev_dbg(rcdu->dev, "initializing encoder %pOF for output %s\n",
107		enc_node, rcar_du_output_name(output));
108
109	renc = drmm_encoder_alloc(&rcdu->ddev, struct rcar_du_encoder, base,
110				  &rcar_du_encoder_funcs, DRM_MODE_ENCODER_NONE,
111				  NULL);
112	if (IS_ERR(renc))
113		return PTR_ERR(renc);
114
115	renc->output = output;
116
117	/* Attach the bridge to the encoder. */
118	ret = drm_bridge_attach(&renc->base, bridge, NULL,
119				DRM_BRIDGE_ATTACH_NO_CONNECTOR);
120	if (ret) {
121		dev_err(rcdu->dev,
122			"failed to attach bridge %pOF for output %s (%d)\n",
123			bridge->of_node, rcar_du_output_name(output), ret);
124		return ret;
125	}
126
127	/* Create the connector for the chain of bridges. */
128	connector = drm_bridge_connector_init(&rcdu->ddev, &renc->base);
129	if (IS_ERR(connector)) {
130		dev_err(rcdu->dev,
131			"failed to created connector for output %s (%ld)\n",
132			rcar_du_output_name(output), PTR_ERR(connector));
133		return PTR_ERR(connector);
134	}
135
136	return drm_connector_attach_encoder(connector, &renc->base);
137}