1 /*
2 * Copyright (C) 2016 Laurent Pinchart <laurent.pinchart@ideasonboard.com>
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License as
6 * published by the Free Software Foundation; either version 2 of
7 * the License, or (at your option) any later version.
8 */
9
10 #include <drm/drmP.h>
11 #include <drm/drm_bridge.h>
12 #include <drm/drm_panel.h>
13
14 #include <linux/of_graph.h>
15
16 struct lvds_encoder {
17 struct drm_bridge bridge;
18 struct drm_bridge *panel_bridge;
19 };
20
lvds_encoder_attach(struct drm_bridge * bridge)21 static int lvds_encoder_attach(struct drm_bridge *bridge)
22 {
23 struct lvds_encoder *lvds_encoder = container_of(bridge,
24 struct lvds_encoder,
25 bridge);
26
27 return drm_bridge_attach(bridge->encoder, lvds_encoder->panel_bridge,
28 bridge);
29 }
30
31 static struct drm_bridge_funcs funcs = {
32 .attach = lvds_encoder_attach,
33 };
34
lvds_encoder_probe(struct platform_device * pdev)35 static int lvds_encoder_probe(struct platform_device *pdev)
36 {
37 struct device_node *port;
38 struct device_node *endpoint;
39 struct device_node *panel_node;
40 struct drm_panel *panel;
41 struct lvds_encoder *lvds_encoder;
42
43 lvds_encoder = devm_kzalloc(&pdev->dev, sizeof(*lvds_encoder),
44 GFP_KERNEL);
45 if (!lvds_encoder)
46 return -ENOMEM;
47
48 /* Locate the panel DT node. */
49 port = of_graph_get_port_by_id(pdev->dev.of_node, 1);
50 if (!port) {
51 dev_dbg(&pdev->dev, "port 1 not found\n");
52 return -ENXIO;
53 }
54
55 endpoint = of_get_child_by_name(port, "endpoint");
56 of_node_put(port);
57 if (!endpoint) {
58 dev_dbg(&pdev->dev, "no endpoint for port 1\n");
59 return -ENXIO;
60 }
61
62 panel_node = of_graph_get_remote_port_parent(endpoint);
63 of_node_put(endpoint);
64 if (!panel_node) {
65 dev_dbg(&pdev->dev, "no remote endpoint for port 1\n");
66 return -ENXIO;
67 }
68
69 panel = of_drm_find_panel(panel_node);
70 of_node_put(panel_node);
71 if (IS_ERR(panel)) {
72 dev_dbg(&pdev->dev, "panel not found, deferring probe\n");
73 return PTR_ERR(panel);
74 }
75
76 lvds_encoder->panel_bridge =
77 devm_drm_panel_bridge_add(&pdev->dev,
78 panel, DRM_MODE_CONNECTOR_LVDS);
79 if (IS_ERR(lvds_encoder->panel_bridge))
80 return PTR_ERR(lvds_encoder->panel_bridge);
81
82 /* The panel_bridge bridge is attached to the panel's of_node,
83 * but we need a bridge attached to our of_node for our user
84 * to look up.
85 */
86 lvds_encoder->bridge.of_node = pdev->dev.of_node;
87 lvds_encoder->bridge.funcs = &funcs;
88 drm_bridge_add(&lvds_encoder->bridge);
89
90 platform_set_drvdata(pdev, lvds_encoder);
91
92 return 0;
93 }
94
lvds_encoder_remove(struct platform_device * pdev)95 static int lvds_encoder_remove(struct platform_device *pdev)
96 {
97 struct lvds_encoder *lvds_encoder = platform_get_drvdata(pdev);
98
99 drm_bridge_remove(&lvds_encoder->bridge);
100
101 return 0;
102 }
103
104 static const struct of_device_id lvds_encoder_match[] = {
105 { .compatible = "lvds-encoder" },
106 { .compatible = "thine,thc63lvdm83d" },
107 {},
108 };
109 MODULE_DEVICE_TABLE(of, lvds_encoder_match);
110
111 static struct platform_driver lvds_encoder_driver = {
112 .probe = lvds_encoder_probe,
113 .remove = lvds_encoder_remove,
114 .driver = {
115 .name = "lvds-encoder",
116 .of_match_table = lvds_encoder_match,
117 },
118 };
119 module_platform_driver(lvds_encoder_driver);
120
121 MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
122 MODULE_DESCRIPTION("Transparent parallel to LVDS encoder");
123 MODULE_LICENSE("GPL");
124