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	renc->output = output;
61	encoder = rcar_encoder_to_drm_encoder(renc);
62
63	dev_dbg(rcdu->dev, "initializing encoder %pOF for output %u\n",
64		enc_node, output);
65
66	/*
67	 * Locate the DRM bridge from the DT node. For the DPAD outputs, if the
68	 * DT node has a single port, assume that it describes a panel and
69	 * create a panel bridge.
70	 */
71	if ((output == RCAR_DU_OUTPUT_DPAD0 ||
72	     output == RCAR_DU_OUTPUT_DPAD1) &&
73	    rcar_du_encoder_count_ports(enc_node) == 1) {
74		struct drm_panel *panel = of_drm_find_panel(enc_node);
75
76		if (IS_ERR(panel)) {
77			ret = PTR_ERR(panel);
78			goto done;
79		}
80
81		bridge = devm_drm_panel_bridge_add_typed(rcdu->dev, panel,
82							 DRM_MODE_CONNECTOR_DPI);
83		if (IS_ERR(bridge)) {
84			ret = PTR_ERR(bridge);
85			goto done;
86		}
87	} else {
88		bridge = of_drm_find_bridge(enc_node);
89		if (!bridge) {
90			ret = -EPROBE_DEFER;
91			goto done;
92		}
93
94		if (output == RCAR_DU_OUTPUT_LVDS0 ||
95		    output == RCAR_DU_OUTPUT_LVDS1)
96			rcdu->lvds[output - RCAR_DU_OUTPUT_LVDS0] = bridge;
97	}
98
99	/*
100	 * On Gen3 skip the LVDS1 output if the LVDS1 encoder is used as a
101	 * companion for LVDS0 in dual-link mode.
102	 */
103	if (rcdu->info->gen >= 3 && output == RCAR_DU_OUTPUT_LVDS1) {
104		if (rcar_lvds_dual_link(bridge)) {
105			ret = -ENOLINK;
106			goto done;
107		}
108	}
109
110	ret = drm_simple_encoder_init(rcdu->ddev, encoder,
111				      DRM_MODE_ENCODER_NONE);
112	if (ret < 0)
113		goto done;
114
115	/*
116	 * Attach the bridge to the encoder. The bridge will create the
117	 * connector.
118	 */
119	ret = drm_bridge_attach(encoder, bridge, NULL, 0);
120	if (ret) {
121		drm_encoder_cleanup(encoder);
122		return ret;
123	}
124
125done:
126	if (ret < 0) {
127		if (encoder->name)
128			encoder->funcs->destroy(encoder);
129		devm_kfree(rcdu->dev, renc);
130	}
131
132	return ret;
133}
134