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