xref: /linux/drivers/gpu/drm/renesas/rz-du/rzg2l_du_encoder.c (revision 6e9a12f85a7567bb9a41d5230468886bd6a27b20)
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 
25 static 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 
45 static const struct drm_encoder_funcs rzg2l_du_encoder_funcs = {
46 };
47 
48 static enum drm_mode_status
49 rzg2l_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 
60 static const struct drm_encoder_helper_funcs rzg2l_du_encoder_helper_funcs = {
61 	.mode_valid = rzg2l_du_encoder_mode_valid,
62 };
63 
64 int 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 }
127