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}