xref: /linux/drivers/gpu/drm/renesas/rcar-du/rcar_du_encoder.c (revision 3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d)
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 
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 
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 __free(drm_bridge_put) = NULL;
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 		drm_panel_put(panel);
73 		if (IS_ERR(bridge))
74 			return PTR_ERR(no_free_ptr(bridge));
75 
76 		/*
77 		 * The reference taken by devm_drm_panel_bridge_add_typed() is
78 		 * released automatically. Take a second one for the __free()
79 		 * when this function will return.
80 		 */
81 		drm_bridge_get(bridge);
82 	} else {
83 		bridge = of_drm_find_and_get_bridge(enc_node);
84 		if (!bridge)
85 			return -EPROBE_DEFER;
86 
87 		if (output == RCAR_DU_OUTPUT_LVDS0 ||
88 		    output == RCAR_DU_OUTPUT_LVDS1)
89 			rcdu->lvds[output - RCAR_DU_OUTPUT_LVDS0] =
90 				drm_bridge_get(bridge);
91 
92 		if (output == RCAR_DU_OUTPUT_DSI0 ||
93 		    output == RCAR_DU_OUTPUT_DSI1)
94 			rcdu->dsi[output - RCAR_DU_OUTPUT_DSI0] =
95 				drm_bridge_get(bridge);
96 	}
97 
98 	/*
99 	 * Create and initialize the encoder. On Gen3, skip the LVDS1 output if
100 	 * the LVDS1 encoder is used as a companion for LVDS0 in dual-link
101 	 * mode, or any LVDS output if it isn't connected. The latter may happen
102 	 * on D3 or E3 as the LVDS encoders are needed to provide the pixel
103 	 * clock to the DU, even when the LVDS outputs are not used.
104 	 */
105 	if (rcdu->info->gen >= 3) {
106 		if (output == RCAR_DU_OUTPUT_LVDS1 &&
107 		    rcar_lvds_dual_link(bridge))
108 			return -ENOLINK;
109 
110 		if ((output == RCAR_DU_OUTPUT_LVDS0 ||
111 		     output == RCAR_DU_OUTPUT_LVDS1) &&
112 		    !rcar_lvds_is_connected(bridge))
113 			return -ENOLINK;
114 	}
115 
116 	dev_dbg(rcdu->dev, "initializing encoder %pOF for output %s\n",
117 		enc_node, rcar_du_output_name(output));
118 
119 	renc = drmm_encoder_alloc(&rcdu->ddev, struct rcar_du_encoder, base,
120 				  &rcar_du_encoder_funcs, DRM_MODE_ENCODER_NONE,
121 				  NULL);
122 	if (IS_ERR(renc))
123 		return PTR_ERR(renc);
124 
125 	renc->output = output;
126 
127 	/* Attach the bridge to the encoder. */
128 	ret = drm_bridge_attach(&renc->base, bridge, NULL,
129 				DRM_BRIDGE_ATTACH_NO_CONNECTOR);
130 	if (ret) {
131 		dev_err(rcdu->dev,
132 			"failed to attach bridge %pOF for output %s (%d)\n",
133 			bridge->of_node, rcar_du_output_name(output), ret);
134 		return ret;
135 	}
136 
137 	/* Create the connector for the chain of bridges. */
138 	connector = drm_bridge_connector_init(&rcdu->ddev, &renc->base);
139 	if (IS_ERR(connector)) {
140 		dev_err(rcdu->dev,
141 			"failed to created connector for output %s (%ld)\n",
142 			rcar_du_output_name(output), PTR_ERR(connector));
143 		return PTR_ERR(connector);
144 	}
145 
146 	return 0;
147 }
148 
149 void rcar_du_encoder_cleanup(struct rcar_du_device *rcdu)
150 {
151 	unsigned int i;
152 
153 	for (i = 0; i < ARRAY_SIZE(rcdu->lvds); i++)
154 		drm_bridge_put(rcdu->lvds[i]);
155 	for (i = 0; i < ARRAY_SIZE(rcdu->dsi); i++)
156 		drm_bridge_put(rcdu->dsi[i]);
157 }
158