![Peter Rosin](/assets/img/avatar_default.png)
Optionally power down the LVDS-encoder when it is not in use. Signed-off-by: Peter Rosin <peda@axentia.se> Reviewed-by: Andrzej Hajda <a.hajda@samsung.com> Signed-off-by: Andrzej Hajda <a.hajda@samsung.com> Link: https://patchwork.freedesktop.org/patch/msgid/20190111151843.11114-6-peda@axentia.se
157 lines
4 KiB
C
157 lines
4 KiB
C
/*
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* Copyright (C) 2016 Laurent Pinchart <laurent.pinchart@ideasonboard.com>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 2 of
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* the License, or (at your option) any later version.
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*/
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#include <drm/drmP.h>
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#include <drm/drm_bridge.h>
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#include <drm/drm_panel.h>
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#include <linux/gpio/consumer.h>
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#include <linux/of_graph.h>
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struct lvds_encoder {
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struct drm_bridge bridge;
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struct drm_bridge *panel_bridge;
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struct gpio_desc *powerdown_gpio;
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};
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static int lvds_encoder_attach(struct drm_bridge *bridge)
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{
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struct lvds_encoder *lvds_encoder = container_of(bridge,
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struct lvds_encoder,
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bridge);
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return drm_bridge_attach(bridge->encoder, lvds_encoder->panel_bridge,
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bridge);
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}
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static void lvds_encoder_enable(struct drm_bridge *bridge)
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{
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struct lvds_encoder *lvds_encoder = container_of(bridge,
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struct lvds_encoder,
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bridge);
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if (lvds_encoder->powerdown_gpio)
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gpiod_set_value_cansleep(lvds_encoder->powerdown_gpio, 0);
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}
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static void lvds_encoder_disable(struct drm_bridge *bridge)
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{
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struct lvds_encoder *lvds_encoder = container_of(bridge,
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struct lvds_encoder,
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bridge);
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if (lvds_encoder->powerdown_gpio)
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gpiod_set_value_cansleep(lvds_encoder->powerdown_gpio, 1);
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}
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static struct drm_bridge_funcs funcs = {
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.attach = lvds_encoder_attach,
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.enable = lvds_encoder_enable,
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.disable = lvds_encoder_disable,
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};
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static int lvds_encoder_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct device_node *port;
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struct device_node *endpoint;
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struct device_node *panel_node;
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struct drm_panel *panel;
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struct lvds_encoder *lvds_encoder;
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lvds_encoder = devm_kzalloc(dev, sizeof(*lvds_encoder), GFP_KERNEL);
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if (!lvds_encoder)
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return -ENOMEM;
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lvds_encoder->powerdown_gpio = devm_gpiod_get_optional(dev, "powerdown",
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GPIOD_OUT_HIGH);
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if (IS_ERR(lvds_encoder->powerdown_gpio)) {
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int err = PTR_ERR(lvds_encoder->powerdown_gpio);
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if (err != -EPROBE_DEFER)
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dev_err(dev, "powerdown GPIO failure: %d\n", err);
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return err;
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}
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/* Locate the panel DT node. */
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port = of_graph_get_port_by_id(dev->of_node, 1);
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if (!port) {
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dev_dbg(dev, "port 1 not found\n");
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return -ENXIO;
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}
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endpoint = of_get_child_by_name(port, "endpoint");
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of_node_put(port);
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if (!endpoint) {
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dev_dbg(dev, "no endpoint for port 1\n");
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return -ENXIO;
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}
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panel_node = of_graph_get_remote_port_parent(endpoint);
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of_node_put(endpoint);
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if (!panel_node) {
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dev_dbg(dev, "no remote endpoint for port 1\n");
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return -ENXIO;
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}
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panel = of_drm_find_panel(panel_node);
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of_node_put(panel_node);
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if (IS_ERR(panel)) {
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dev_dbg(dev, "panel not found, deferring probe\n");
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return PTR_ERR(panel);
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}
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lvds_encoder->panel_bridge =
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devm_drm_panel_bridge_add(dev, panel, DRM_MODE_CONNECTOR_LVDS);
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if (IS_ERR(lvds_encoder->panel_bridge))
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return PTR_ERR(lvds_encoder->panel_bridge);
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/* The panel_bridge bridge is attached to the panel's of_node,
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* but we need a bridge attached to our of_node for our user
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* to look up.
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*/
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lvds_encoder->bridge.of_node = dev->of_node;
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lvds_encoder->bridge.funcs = &funcs;
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drm_bridge_add(&lvds_encoder->bridge);
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platform_set_drvdata(pdev, lvds_encoder);
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return 0;
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}
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static int lvds_encoder_remove(struct platform_device *pdev)
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{
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struct lvds_encoder *lvds_encoder = platform_get_drvdata(pdev);
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drm_bridge_remove(&lvds_encoder->bridge);
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return 0;
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}
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static const struct of_device_id lvds_encoder_match[] = {
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{ .compatible = "lvds-encoder" },
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{ .compatible = "thine,thc63lvdm83d" },
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{},
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};
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MODULE_DEVICE_TABLE(of, lvds_encoder_match);
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static struct platform_driver lvds_encoder_driver = {
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.probe = lvds_encoder_probe,
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.remove = lvds_encoder_remove,
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.driver = {
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.name = "lvds-encoder",
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.of_match_table = lvds_encoder_match,
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},
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};
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module_platform_driver(lvds_encoder_driver);
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MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
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MODULE_DESCRIPTION("Transparent parallel to LVDS encoder");
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MODULE_LICENSE("GPL");
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