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/*
* Copyright (C) 2016 Laurent Pinchart <laurent.pinchart@ideasonboard.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*/
#include <linux/gpio/consumer.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_graph.h>
#include <linux/platform_device.h>
#include <drm/drm_bridge.h>
#include <drm/drm_panel.h>
struct lvds_encoder {
struct drm_bridge bridge;
struct drm_bridge *panel_bridge;
struct gpio_desc *powerdown_gpio;
};
static int lvds_encoder_attach(struct drm_bridge *bridge)
{
struct lvds_encoder *lvds_encoder = container_of(bridge,
struct lvds_encoder,
bridge);
return drm_bridge_attach(bridge->encoder, lvds_encoder->panel_bridge,
bridge);
}
static void lvds_encoder_enable(struct drm_bridge *bridge)
{
struct lvds_encoder *lvds_encoder = container_of(bridge,
struct lvds_encoder,
bridge);
if (lvds_encoder->powerdown_gpio)
gpiod_set_value_cansleep(lvds_encoder->powerdown_gpio, 0);
}
static void lvds_encoder_disable(struct drm_bridge *bridge)
{
struct lvds_encoder *lvds_encoder = container_of(bridge,
struct lvds_encoder,
bridge);
if (lvds_encoder->powerdown_gpio)
gpiod_set_value_cansleep(lvds_encoder->powerdown_gpio, 1);
}
static struct drm_bridge_funcs funcs = {
.attach = lvds_encoder_attach,
.enable = lvds_encoder_enable,
.disable = lvds_encoder_disable,
};
static int lvds_encoder_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct device_node *port;
struct device_node *endpoint;
struct device_node *panel_node;
struct drm_panel *panel;
struct lvds_encoder *lvds_encoder;
lvds_encoder = devm_kzalloc(dev, sizeof(*lvds_encoder), GFP_KERNEL);
if (!lvds_encoder)
return -ENOMEM;
lvds_encoder->powerdown_gpio = devm_gpiod_get_optional(dev, "powerdown",
GPIOD_OUT_HIGH);
if (IS_ERR(lvds_encoder->powerdown_gpio)) {
int err = PTR_ERR(lvds_encoder->powerdown_gpio);
if (err != -EPROBE_DEFER)
dev_err(dev, "powerdown GPIO failure: %d\n", err);
return err;
}
/* Locate the panel DT node. */
port = of_graph_get_port_by_id(dev->of_node, 1);
if (!port) {
dev_dbg(dev, "port 1 not found\n");
return -ENXIO;
}
endpoint = of_get_child_by_name(port, "endpoint");
of_node_put(port);
if (!endpoint) {
dev_dbg(dev, "no endpoint for port 1\n");
return -ENXIO;
}
panel_node = of_graph_get_remote_port_parent(endpoint);
of_node_put(endpoint);
if (!panel_node) {
dev_dbg(dev, "no remote endpoint for port 1\n");
return -ENXIO;
}
panel = of_drm_find_panel(panel_node);
of_node_put(panel_node);
if (IS_ERR(panel)) {
dev_dbg(dev, "panel not found, deferring probe\n");
return PTR_ERR(panel);
}
lvds_encoder->panel_bridge =
devm_drm_panel_bridge_add(dev, panel, DRM_MODE_CONNECTOR_LVDS);
if (IS_ERR(lvds_encoder->panel_bridge))
return PTR_ERR(lvds_encoder->panel_bridge);
/* The panel_bridge bridge is attached to the panel's of_node,
* but we need a bridge attached to our of_node for our user
* to look up.
*/
lvds_encoder->bridge.of_node = dev->of_node;
lvds_encoder->bridge.funcs = &funcs;
drm_bridge_add(&lvds_encoder->bridge);
platform_set_drvdata(pdev, lvds_encoder);
return 0;
}
static int lvds_encoder_remove(struct platform_device *pdev)
{
struct lvds_encoder *lvds_encoder = platform_get_drvdata(pdev);
drm_bridge_remove(&lvds_encoder->bridge);
return 0;
}
static const struct of_device_id lvds_encoder_match[] = {
{ .compatible = "lvds-encoder" },
{ .compatible = "thine,thc63lvdm83d" },
{},
};
MODULE_DEVICE_TABLE(of, lvds_encoder_match);
static struct platform_driver lvds_encoder_driver = {
.probe = lvds_encoder_probe,
.remove = lvds_encoder_remove,
.driver = {
.name = "lvds-encoder",
.of_match_table = lvds_encoder_match,
},
};
module_platform_driver(lvds_encoder_driver);
MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
MODULE_DESCRIPTION("Transparent parallel to LVDS encoder");
MODULE_LICENSE("GPL");
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