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
18struct 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
27static inline struct lvds_codec *to_lvds_codec(struct drm_bridge *bridge)
28{
29	return container_of(bridge, struct lvds_codec, bridge);
30}
31
32static 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
41static 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
57static 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
71static const struct drm_bridge_funcs funcs = {
72	.attach = lvds_codec_attach,
73	.enable = lvds_codec_enable,
74	.disable = lvds_codec_disable,
75};
76
77static 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	int ret;
84
85	lvds_codec = devm_kzalloc(dev, sizeof(*lvds_codec), GFP_KERNEL);
86	if (!lvds_codec)
87		return -ENOMEM;
88
89	lvds_codec->dev = &pdev->dev;
90	lvds_codec->connector_type = (uintptr_t)of_device_get_match_data(dev);
91
92	lvds_codec->vcc = devm_regulator_get(lvds_codec->dev, "power");
93	if (IS_ERR(lvds_codec->vcc)) {
94		ret = PTR_ERR(lvds_codec->vcc);
95		if (ret != -EPROBE_DEFER)
96			dev_err(lvds_codec->dev,
97				"Unable to get \"vcc\" supply: %d\n", ret);
98		return ret;
99	}
100
101	lvds_codec->powerdown_gpio = devm_gpiod_get_optional(dev, "powerdown",
102							     GPIOD_OUT_HIGH);
103	if (IS_ERR(lvds_codec->powerdown_gpio))
104		return dev_err_probe(dev, PTR_ERR(lvds_codec->powerdown_gpio),
105				     "powerdown GPIO failure\n");
106
107	/* Locate the panel DT node. */
108	panel_node = of_graph_get_remote_node(dev->of_node, 1, 0);
109	if (!panel_node) {
110		dev_dbg(dev, "panel DT node not found\n");
111		return -ENXIO;
112	}
113
114	panel = of_drm_find_panel(panel_node);
115	of_node_put(panel_node);
116	if (IS_ERR(panel)) {
117		dev_dbg(dev, "panel not found, deferring probe\n");
118		return PTR_ERR(panel);
119	}
120
121	lvds_codec->panel_bridge =
122		devm_drm_panel_bridge_add_typed(dev, panel,
123						lvds_codec->connector_type);
124	if (IS_ERR(lvds_codec->panel_bridge))
125		return PTR_ERR(lvds_codec->panel_bridge);
126
127	/*
128	 * The panel_bridge bridge is attached to the panel's of_node,
129	 * but we need a bridge attached to our of_node for our user
130	 * to look up.
131	 */
132	lvds_codec->bridge.of_node = dev->of_node;
133	lvds_codec->bridge.funcs = &funcs;
134	drm_bridge_add(&lvds_codec->bridge);
135
136	platform_set_drvdata(pdev, lvds_codec);
137
138	return 0;
139}
140
141static int lvds_codec_remove(struct platform_device *pdev)
142{
143	struct lvds_codec *lvds_codec = platform_get_drvdata(pdev);
144
145	drm_bridge_remove(&lvds_codec->bridge);
146
147	return 0;
148}
149
150static const struct of_device_id lvds_codec_match[] = {
151	{
152		.compatible = "lvds-decoder",
153		.data = (void *)DRM_MODE_CONNECTOR_DPI,
154	},
155	{
156		.compatible = "lvds-encoder",
157		.data = (void *)DRM_MODE_CONNECTOR_LVDS,
158	},
159	{
160		.compatible = "thine,thc63lvdm83d",
161		.data = (void *)DRM_MODE_CONNECTOR_LVDS,
162	},
163	{},
164};
165MODULE_DEVICE_TABLE(of, lvds_codec_match);
166
167static struct platform_driver lvds_codec_driver = {
168	.probe	= lvds_codec_probe,
169	.remove	= lvds_codec_remove,
170	.driver		= {
171		.name		= "lvds-codec",
172		.of_match_table	= lvds_codec_match,
173	},
174};
175module_platform_driver(lvds_codec_driver);
176
177MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
178MODULE_DESCRIPTION("LVDS encoders and decoders");
179MODULE_LICENSE("GPL");
180