rzg2l_du_encoder.c

  1// SPDX-License-Identifier: GPL-2.0+
  2/*
  3 * RZ/G2L Display Unit Encoder
  4 *
  5 * Copyright (C) 2023 Renesas Electronics Corporation
  6 *
  7 * Based on rcar_du_encoder.c
  8 */
  9
 10#include <linux/export.h>
 11#include <linux/of.h>
 12
 13#include <drm/drm_atomic_helper.h>
 14#include <drm/drm_bridge.h>
 15#include <drm/drm_bridge_connector.h>
 16#include <drm/drm_panel.h>
 17
 18#include "rzg2l_du_drv.h"
 19#include "rzg2l_du_encoder.h"
 20
 21/* -----------------------------------------------------------------------------
 22 * Encoder
 23 */
 24
 25static unsigned int rzg2l_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 rzg2l_du_encoder_funcs = {
 46};
 47
 48static enum drm_mode_status
 49rzg2l_du_encoder_mode_valid(struct drm_encoder *encoder,
 50			    const struct drm_display_mode *mode)
 51{
 52	struct rzg2l_du_encoder *renc = to_rzg2l_encoder(encoder);
 53
 54	if (renc->output == RZG2L_DU_OUTPUT_DPAD0 && mode->clock > 83500)
 55		return MODE_CLOCK_HIGH;
 56
 57	return MODE_OK;
 58}
 59
 60static const struct drm_encoder_helper_funcs rzg2l_du_encoder_helper_funcs = {
 61	.mode_valid = rzg2l_du_encoder_mode_valid,
 62};
 63
 64int rzg2l_du_encoder_init(struct rzg2l_du_device  *rcdu,
 65			  enum rzg2l_du_output output,
 66			  struct device_node *enc_node)
 67{
 68	struct rzg2l_du_encoder *renc;
 69	struct drm_connector *connector;
 70	struct drm_bridge *bridge;
 71	int ret;
 72
 73	/*
 74	 * Locate the DRM bridge from the DT node. For the DPAD outputs, if the
 75	 * DT node has a single port, assume that it describes a panel and
 76	 * create a panel bridge.
 77	 */
 78	if (output == RZG2L_DU_OUTPUT_DPAD0 && rzg2l_du_encoder_count_ports(enc_node) == 1) {
 79		struct drm_panel *panel = of_drm_find_panel(enc_node);
 80
 81		if (IS_ERR(panel))
 82			return PTR_ERR(panel);
 83
 84		bridge = devm_drm_panel_bridge_add_typed(rcdu->dev, panel,
 85							 DRM_MODE_CONNECTOR_DPI);
 86		if (IS_ERR(bridge))
 87			return PTR_ERR(bridge);
 88	} else {
 89		bridge = of_drm_find_bridge(enc_node);
 90		if (!bridge)
 91			return -EPROBE_DEFER;
 92	}
 93
 94	dev_dbg(rcdu->dev, "initializing encoder %pOF for output %s\n",
 95		enc_node, rzg2l_du_output_name(output));
 96
 97	renc = drmm_encoder_alloc(&rcdu->ddev, struct rzg2l_du_encoder, base,
 98				  &rzg2l_du_encoder_funcs, DRM_MODE_ENCODER_NONE,
 99				  NULL);
100	if (IS_ERR(renc))
101		return PTR_ERR(renc);
102
103	renc->output = output;
104	drm_encoder_helper_add(&renc->base, &rzg2l_du_encoder_helper_funcs);
105
106	/* Attach the bridge to the encoder. */
107	ret = drm_bridge_attach(&renc->base, bridge, NULL,
108				DRM_BRIDGE_ATTACH_NO_CONNECTOR);
109	if (ret) {
110		dev_err(rcdu->dev,
111			"failed to attach bridge %pOF for output %s (%d)\n",
112			bridge->of_node, rzg2l_du_output_name(output), ret);
113		return ret;
114	}
115
116	/* Create the connector for the chain of bridges. */
117	connector = drm_bridge_connector_init(&rcdu->ddev, &renc->base);
118	if (IS_ERR(connector)) {
119		dev_err(rcdu->dev,
120			"failed to created connector for output %s (%ld)\n",
121			rzg2l_du_output_name(output), PTR_ERR(connector));
122		return PTR_ERR(connector);
123	}
124
125	return drm_connector_attach_encoder(connector, &renc->base);
126}