1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (C) 2019 Renesas Electronics Corporation
4 * Copyright (C) 2016 Laurent Pinchart <laurent.pinchart@ideasonboard.com>
5 */
6
7 #include <linux/gpio/consumer.h>
8 #include <linux/module.h>
9 #include <linux/of.h>
10 #include <linux/of_device.h>
11 #include <linux/of_graph.h>
12 #include <linux/platform_device.h>
13 #include <linux/regulator/consumer.h>
14
15 #include <drm/drm_bridge.h>
16 #include <drm/drm_panel.h>
17
18 struct lvds_codec {
19 struct device *dev;
20 struct drm_bridge bridge;
21 struct drm_bridge *panel_bridge;
22 struct regulator *vcc;
23 struct gpio_desc *powerdown_gpio;
24 u32 connector_type;
25 };
26
to_lvds_codec(struct drm_bridge * bridge)27 static inline struct lvds_codec *to_lvds_codec(struct drm_bridge *bridge)
28 {
29 return container_of(bridge, struct lvds_codec, bridge);
30 }
31
lvds_codec_attach(struct drm_bridge * bridge,enum drm_bridge_attach_flags flags)32 static int lvds_codec_attach(struct drm_bridge *bridge,
33 enum drm_bridge_attach_flags flags)
34 {
35 struct lvds_codec *lvds_codec = to_lvds_codec(bridge);
36
37 return drm_bridge_attach(bridge->encoder, lvds_codec->panel_bridge,
38 bridge, flags);
39 }
40
lvds_codec_enable(struct drm_bridge * bridge)41 static void lvds_codec_enable(struct drm_bridge *bridge)
42 {
43 struct lvds_codec *lvds_codec = to_lvds_codec(bridge);
44 int ret;
45
46 ret = regulator_enable(lvds_codec->vcc);
47 if (ret) {
48 dev_err(lvds_codec->dev,
49 "Failed to enable regulator \"vcc\": %d\n", ret);
50 return;
51 }
52
53 if (lvds_codec->powerdown_gpio)
54 gpiod_set_value_cansleep(lvds_codec->powerdown_gpio, 0);
55 }
56
lvds_codec_disable(struct drm_bridge * bridge)57 static void lvds_codec_disable(struct drm_bridge *bridge)
58 {
59 struct lvds_codec *lvds_codec = to_lvds_codec(bridge);
60 int ret;
61
62 if (lvds_codec->powerdown_gpio)
63 gpiod_set_value_cansleep(lvds_codec->powerdown_gpio, 1);
64
65 ret = regulator_disable(lvds_codec->vcc);
66 if (ret)
67 dev_err(lvds_codec->dev,
68 "Failed to disable regulator \"vcc\": %d\n", ret);
69 }
70
71 static const struct drm_bridge_funcs funcs = {
72 .attach = lvds_codec_attach,
73 .enable = lvds_codec_enable,
74 .disable = lvds_codec_disable,
75 };
76
lvds_codec_probe(struct platform_device * pdev)77 static int lvds_codec_probe(struct platform_device *pdev)
78 {
79 struct device *dev = &pdev->dev;
80 struct device_node *panel_node;
81 struct drm_panel *panel;
82 struct lvds_codec *lvds_codec;
83
84 lvds_codec = devm_kzalloc(dev, sizeof(*lvds_codec), GFP_KERNEL);
85 if (!lvds_codec)
86 return -ENOMEM;
87
88 lvds_codec->dev = &pdev->dev;
89 lvds_codec->connector_type = (uintptr_t)of_device_get_match_data(dev);
90
91 lvds_codec->vcc = devm_regulator_get(lvds_codec->dev, "power");
92 if (IS_ERR(lvds_codec->vcc))
93 return dev_err_probe(dev, PTR_ERR(lvds_codec->vcc),
94 "Unable to get \"vcc\" supply\n");
95
96 lvds_codec->powerdown_gpio = devm_gpiod_get_optional(dev, "powerdown",
97 GPIOD_OUT_HIGH);
98 if (IS_ERR(lvds_codec->powerdown_gpio))
99 return dev_err_probe(dev, PTR_ERR(lvds_codec->powerdown_gpio),
100 "powerdown GPIO failure\n");
101
102 /* Locate the panel DT node. */
103 panel_node = of_graph_get_remote_node(dev->of_node, 1, 0);
104 if (!panel_node) {
105 dev_dbg(dev, "panel DT node not found\n");
106 return -ENXIO;
107 }
108
109 panel = of_drm_find_panel(panel_node);
110 of_node_put(panel_node);
111 if (IS_ERR(panel)) {
112 dev_dbg(dev, "panel not found, deferring probe\n");
113 return PTR_ERR(panel);
114 }
115
116 lvds_codec->panel_bridge =
117 devm_drm_panel_bridge_add_typed(dev, panel,
118 lvds_codec->connector_type);
119 if (IS_ERR(lvds_codec->panel_bridge))
120 return PTR_ERR(lvds_codec->panel_bridge);
121
122 /*
123 * The panel_bridge bridge is attached to the panel's of_node,
124 * but we need a bridge attached to our of_node for our user
125 * to look up.
126 */
127 lvds_codec->bridge.of_node = dev->of_node;
128 lvds_codec->bridge.funcs = &funcs;
129 drm_bridge_add(&lvds_codec->bridge);
130
131 platform_set_drvdata(pdev, lvds_codec);
132
133 return 0;
134 }
135
lvds_codec_remove(struct platform_device * pdev)136 static int lvds_codec_remove(struct platform_device *pdev)
137 {
138 struct lvds_codec *lvds_codec = platform_get_drvdata(pdev);
139
140 drm_bridge_remove(&lvds_codec->bridge);
141
142 return 0;
143 }
144
145 static const struct of_device_id lvds_codec_match[] = {
146 {
147 .compatible = "lvds-decoder",
148 .data = (void *)DRM_MODE_CONNECTOR_DPI,
149 },
150 {
151 .compatible = "lvds-encoder",
152 .data = (void *)DRM_MODE_CONNECTOR_LVDS,
153 },
154 {
155 .compatible = "thine,thc63lvdm83d",
156 .data = (void *)DRM_MODE_CONNECTOR_LVDS,
157 },
158 {},
159 };
160 MODULE_DEVICE_TABLE(of, lvds_codec_match);
161
162 static struct platform_driver lvds_codec_driver = {
163 .probe = lvds_codec_probe,
164 .remove = lvds_codec_remove,
165 .driver = {
166 .name = "lvds-codec",
167 .of_match_table = lvds_codec_match,
168 },
169 };
170 module_platform_driver(lvds_codec_driver);
171
172 MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
173 MODULE_DESCRIPTION("LVDS encoders and decoders");
174 MODULE_LICENSE("GPL");
175