1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * 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/of.h>
12 
13 #include <drm/drm_bridge.h>
14 #include <drm/drm_bridge_connector.h>
15 #include <drm/drm_panel.h>
16 
17 #include "rcar_du_drv.h"
18 #include "rcar_du_encoder.h"
19 #include "rcar_lvds.h"
20 
21 /* -----------------------------------------------------------------------------
22  * Encoder
23  */
24 
rcar_du_encoder_count_ports(struct device_node * node)25 static unsigned int rcar_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 rcar_du_encoder_funcs = {
46 };
47 
rcar_du_encoder_init(struct rcar_du_device * rcdu,enum rcar_du_output output,struct device_node * enc_node)48 int rcar_du_encoder_init(struct rcar_du_device *rcdu,
49 			 enum rcar_du_output output,
50 			 struct device_node *enc_node)
51 {
52 	struct rcar_du_encoder *renc;
53 	struct drm_connector *connector;
54 	struct drm_bridge *bridge;
55 	int ret;
56 
57 	/*
58 	 * Locate the DRM bridge from the DT node. For the DPAD outputs, if the
59 	 * DT node has a single port, assume that it describes a panel and
60 	 * create a panel bridge.
61 	 */
62 	if ((output == RCAR_DU_OUTPUT_DPAD0 ||
63 	     output == RCAR_DU_OUTPUT_DPAD1) &&
64 	    rcar_du_encoder_count_ports(enc_node) == 1) {
65 		struct drm_panel *panel = of_drm_find_panel(enc_node);
66 
67 		if (IS_ERR(panel))
68 			return PTR_ERR(panel);
69 
70 		bridge = devm_drm_panel_bridge_add_typed(rcdu->dev, panel,
71 							 DRM_MODE_CONNECTOR_DPI);
72 		if (IS_ERR(bridge))
73 			return PTR_ERR(bridge);
74 	} else {
75 		bridge = of_drm_find_bridge(enc_node);
76 		if (!bridge)
77 			return -EPROBE_DEFER;
78 
79 		if (output == RCAR_DU_OUTPUT_LVDS0 ||
80 		    output == RCAR_DU_OUTPUT_LVDS1)
81 			rcdu->lvds[output - RCAR_DU_OUTPUT_LVDS0] = bridge;
82 
83 		if (output == RCAR_DU_OUTPUT_DSI0 ||
84 		    output == RCAR_DU_OUTPUT_DSI1)
85 			rcdu->dsi[output - RCAR_DU_OUTPUT_DSI0] = bridge;
86 	}
87 
88 	/*
89 	 * Create and initialize the encoder. On Gen3, skip the LVDS1 output if
90 	 * the LVDS1 encoder is used as a companion for LVDS0 in dual-link
91 	 * mode, or any LVDS output if it isn't connected. The latter may happen
92 	 * on D3 or E3 as the LVDS encoders are needed to provide the pixel
93 	 * clock to the DU, even when the LVDS outputs are not used.
94 	 */
95 	if (rcdu->info->gen >= 3) {
96 		if (output == RCAR_DU_OUTPUT_LVDS1 &&
97 		    rcar_lvds_dual_link(bridge))
98 			return -ENOLINK;
99 
100 		if ((output == RCAR_DU_OUTPUT_LVDS0 ||
101 		     output == RCAR_DU_OUTPUT_LVDS1) &&
102 		    !rcar_lvds_is_connected(bridge))
103 			return -ENOLINK;
104 	}
105 
106 	dev_dbg(rcdu->dev, "initializing encoder %pOF for output %s\n",
107 		enc_node, rcar_du_output_name(output));
108 
109 	renc = drmm_encoder_alloc(&rcdu->ddev, struct rcar_du_encoder, base,
110 				  &rcar_du_encoder_funcs, DRM_MODE_ENCODER_NONE,
111 				  NULL);
112 	if (IS_ERR(renc))
113 		return PTR_ERR(renc);
114 
115 	renc->output = output;
116 
117 	/* Attach the bridge to the encoder. */
118 	ret = drm_bridge_attach(&renc->base, bridge, NULL,
119 				DRM_BRIDGE_ATTACH_NO_CONNECTOR);
120 	if (ret) {
121 		dev_err(rcdu->dev,
122 			"failed to attach bridge %pOF for output %s (%d)\n",
123 			bridge->of_node, rcar_du_output_name(output), ret);
124 		return ret;
125 	}
126 
127 	/* Create the connector for the chain of bridges. */
128 	connector = drm_bridge_connector_init(&rcdu->ddev, &renc->base);
129 	if (IS_ERR(connector)) {
130 		dev_err(rcdu->dev,
131 			"failed to created connector for output %s (%ld)\n",
132 			rcar_du_output_name(output), PTR_ERR(connector));
133 		return PTR_ERR(connector);
134 	}
135 
136 	return drm_connector_attach_encoder(connector, &renc->base);
137 }
138