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 #include <linux/slab.h>
12
13 #include <drm/drm_bridge.h>
14 #include <drm/drm_bridge_connector.h>
15 #include <drm/drm_crtc.h>
16 #include <drm/drm_managed.h>
17 #include <drm/drm_modeset_helper_vtables.h>
18 #include <drm/drm_panel.h>
19
20 #include "rcar_du_drv.h"
21 #include "rcar_du_encoder.h"
22 #include "rcar_du_kms.h"
23 #include "rcar_lvds.h"
24
25 /* -----------------------------------------------------------------------------
26 * Encoder
27 */
28
rcar_du_encoder_count_ports(struct device_node * node)29 static unsigned int rcar_du_encoder_count_ports(struct device_node *node)
30 {
31 struct device_node *ports;
32 struct device_node *port;
33 unsigned int num_ports = 0;
34
35 ports = of_get_child_by_name(node, "ports");
36 if (!ports)
37 ports = of_node_get(node);
38
39 for_each_child_of_node(ports, port) {
40 if (of_node_name_eq(port, "port"))
41 num_ports++;
42 }
43
44 of_node_put(ports);
45
46 return num_ports;
47 }
48
49 static const struct drm_encoder_funcs rcar_du_encoder_funcs = {
50 };
51
rcar_du_encoder_init(struct rcar_du_device * rcdu,enum rcar_du_output output,struct device_node * enc_node)52 int rcar_du_encoder_init(struct rcar_du_device *rcdu,
53 enum rcar_du_output output,
54 struct device_node *enc_node)
55 {
56 struct rcar_du_encoder *renc;
57 struct drm_connector *connector;
58 struct drm_bridge *bridge;
59 int ret;
60
61 /*
62 * Locate the DRM bridge from the DT node. For the DPAD outputs, if the
63 * DT node has a single port, assume that it describes a panel and
64 * create a panel bridge.
65 */
66 if ((output == RCAR_DU_OUTPUT_DPAD0 ||
67 output == RCAR_DU_OUTPUT_DPAD1) &&
68 rcar_du_encoder_count_ports(enc_node) == 1) {
69 struct drm_panel *panel = of_drm_find_panel(enc_node);
70
71 if (IS_ERR(panel))
72 return PTR_ERR(panel);
73
74 bridge = devm_drm_panel_bridge_add_typed(rcdu->dev, panel,
75 DRM_MODE_CONNECTOR_DPI);
76 if (IS_ERR(bridge))
77 return PTR_ERR(bridge);
78 } else {
79 bridge = of_drm_find_bridge(enc_node);
80 if (!bridge)
81 return -EPROBE_DEFER;
82
83 if (output == RCAR_DU_OUTPUT_LVDS0 ||
84 output == RCAR_DU_OUTPUT_LVDS1)
85 rcdu->lvds[output - RCAR_DU_OUTPUT_LVDS0] = 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 (!renc)
113 return -ENOMEM;
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