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#include <linux/slab.h>
 12
 13#include <drm/drm_bridge.h>
 14#include <drm/drm_crtc.h>
 15#include <drm/drm_managed.h>
 16#include <drm/drm_modeset_helper_vtables.h>
 17#include <drm/drm_panel.h>
 18
 19#include "rcar_du_drv.h"
 20#include "rcar_du_encoder.h"
 21#include "rcar_du_kms.h"
 22#include "rcar_lvds.h"
 23
 24/* -----------------------------------------------------------------------------
 25 * Encoder
 26 */
 27
 28static unsigned int rcar_du_encoder_count_ports(struct device_node *node)
 29{
 30	struct device_node *ports;
 31	struct device_node *port;
 32	unsigned int num_ports = 0;
 33
 34	ports = of_get_child_by_name(node, "ports");
 35	if (!ports)
 36		ports = of_node_get(node);
 37
 38	for_each_child_of_node(ports, port) {
 39		if (of_node_name_eq(port, "port"))
 40			num_ports++;
 41	}
 42
 43	of_node_put(ports);
 44
 45	return num_ports;
 46}
 47
 48static const struct drm_encoder_funcs rcar_du_encoder_funcs = {
 49};
 50
 51int rcar_du_encoder_init(struct rcar_du_device *rcdu,
 52			 enum rcar_du_output output,
 53			 struct device_node *enc_node)
 54{
 55	struct rcar_du_encoder *renc;
 56	struct drm_bridge *bridge;
 57
 58	/*
 59	 * Locate the DRM bridge from the DT node. For the DPAD outputs, if the
 60	 * DT node has a single port, assume that it describes a panel and
 61	 * create a panel bridge.
 62	 */
 63	if ((output == RCAR_DU_OUTPUT_DPAD0 ||
 64	     output == RCAR_DU_OUTPUT_DPAD1) &&
 65	    rcar_du_encoder_count_ports(enc_node) == 1) {
 66		struct drm_panel *panel = of_drm_find_panel(enc_node);
 67
 68		if (IS_ERR(panel))
 69			return PTR_ERR(panel);
 70
 71		bridge = devm_drm_panel_bridge_add_typed(rcdu->dev, panel,
 72							 DRM_MODE_CONNECTOR_DPI);
 73		if (IS_ERR(bridge))
 74			return PTR_ERR(bridge);
 75	} else {
 76		bridge = of_drm_find_bridge(enc_node);
 77		if (!bridge)
 78			return -EPROBE_DEFER;
 79
 80		if (output == RCAR_DU_OUTPUT_LVDS0 ||
 81		    output == RCAR_DU_OUTPUT_LVDS1)
 82			rcdu->lvds[output - RCAR_DU_OUTPUT_LVDS0] = bridge;
 83	}
 84
 85	/*
 86	 * Create and initialize the encoder. On Gen3 skip the LVDS1 output if
 87	 * the LVDS1 encoder is used as a companion for LVDS0 in dual-link
 88	 * mode.
 89	 */
 90	if (rcdu->info->gen >= 3 && output == RCAR_DU_OUTPUT_LVDS1) {
 91		if (rcar_lvds_dual_link(bridge))
 92			return -ENOLINK;
 93	}
 94
 95	dev_dbg(rcdu->dev, "initializing encoder %pOF for output %u\n",
 96		enc_node, output);
 97
 98	renc = drmm_encoder_alloc(&rcdu->ddev, struct rcar_du_encoder, base,
 99				  &rcar_du_encoder_funcs, DRM_MODE_ENCODER_NONE,
100				  NULL);
101	if (!renc)
102		return -ENOMEM;
103
104	renc->output = output;
105
106	/*
107	 * Attach the bridge to the encoder. The bridge will create the
108	 * connector.
109	 */
110	return drm_bridge_attach(&renc->base, bridge, NULL, 0);
111}