315 lines
8.4 KiB
C
315 lines
8.4 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Copyright (C) 2015-2016 Free Electrons
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* Copyright (C) 2015-2016 NextThing Co
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*
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* Maxime Ripard <maxime.ripard@free-electrons.com>
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*/
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#include <linux/gpio/consumer.h>
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#include <linux/module.h>
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#include <linux/of_device.h>
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#include <linux/of_graph.h>
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#include <linux/regulator/consumer.h>
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#include <drm/drm_atomic_helper.h>
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#include <drm/drm_bridge.h>
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#include <drm/drm_crtc.h>
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#include <drm/drm_edid.h>
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#include <drm/drm_print.h>
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#include <drm/drm_probe_helper.h>
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struct simple_bridge_info {
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const struct drm_bridge_timings *timings;
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unsigned int connector_type;
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};
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struct simple_bridge {
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struct drm_bridge bridge;
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struct drm_connector connector;
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const struct simple_bridge_info *info;
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struct drm_bridge *next_bridge;
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struct regulator *vdd;
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struct gpio_desc *enable;
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};
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static inline struct simple_bridge *
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drm_bridge_to_simple_bridge(struct drm_bridge *bridge)
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{
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return container_of(bridge, struct simple_bridge, bridge);
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}
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static inline struct simple_bridge *
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drm_connector_to_simple_bridge(struct drm_connector *connector)
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{
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return container_of(connector, struct simple_bridge, connector);
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}
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static int simple_bridge_get_modes(struct drm_connector *connector)
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{
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struct simple_bridge *sbridge = drm_connector_to_simple_bridge(connector);
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struct edid *edid;
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int ret;
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if (sbridge->next_bridge->ops & DRM_BRIDGE_OP_EDID) {
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edid = drm_bridge_get_edid(sbridge->next_bridge, connector);
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if (!edid)
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DRM_INFO("EDID read failed. Fallback to standard modes\n");
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} else {
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edid = NULL;
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}
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if (!edid) {
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/*
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* In case we cannot retrieve the EDIDs (missing or broken DDC
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* bus from the next bridge), fallback on the XGA standards and
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* prefer a mode pretty much anyone can handle.
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*/
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ret = drm_add_modes_noedid(connector, 1920, 1200);
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drm_set_preferred_mode(connector, 1024, 768);
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return ret;
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}
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drm_connector_update_edid_property(connector, edid);
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ret = drm_add_edid_modes(connector, edid);
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kfree(edid);
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return ret;
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}
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static const struct drm_connector_helper_funcs simple_bridge_con_helper_funcs = {
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.get_modes = simple_bridge_get_modes,
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};
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static enum drm_connector_status
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simple_bridge_connector_detect(struct drm_connector *connector, bool force)
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{
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struct simple_bridge *sbridge = drm_connector_to_simple_bridge(connector);
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return drm_bridge_detect(sbridge->next_bridge);
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}
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static const struct drm_connector_funcs simple_bridge_con_funcs = {
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.detect = simple_bridge_connector_detect,
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.fill_modes = drm_helper_probe_single_connector_modes,
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.destroy = drm_connector_cleanup,
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.reset = drm_atomic_helper_connector_reset,
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.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
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.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
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};
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static int simple_bridge_attach(struct drm_bridge *bridge,
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enum drm_bridge_attach_flags flags)
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{
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struct simple_bridge *sbridge = drm_bridge_to_simple_bridge(bridge);
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int ret;
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ret = drm_bridge_attach(bridge->encoder, sbridge->next_bridge, bridge,
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DRM_BRIDGE_ATTACH_NO_CONNECTOR);
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if (ret < 0)
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return ret;
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if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)
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return 0;
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if (!bridge->encoder) {
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DRM_ERROR("Missing encoder\n");
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return -ENODEV;
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}
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drm_connector_helper_add(&sbridge->connector,
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&simple_bridge_con_helper_funcs);
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ret = drm_connector_init_with_ddc(bridge->dev, &sbridge->connector,
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&simple_bridge_con_funcs,
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sbridge->info->connector_type,
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sbridge->next_bridge->ddc);
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if (ret) {
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DRM_ERROR("Failed to initialize connector\n");
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return ret;
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}
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drm_connector_attach_encoder(&sbridge->connector, bridge->encoder);
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return 0;
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}
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static void simple_bridge_enable(struct drm_bridge *bridge)
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{
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struct simple_bridge *sbridge = drm_bridge_to_simple_bridge(bridge);
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int ret;
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if (sbridge->vdd) {
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ret = regulator_enable(sbridge->vdd);
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if (ret)
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DRM_ERROR("Failed to enable vdd regulator: %d\n", ret);
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}
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gpiod_set_value_cansleep(sbridge->enable, 1);
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}
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static void simple_bridge_disable(struct drm_bridge *bridge)
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{
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struct simple_bridge *sbridge = drm_bridge_to_simple_bridge(bridge);
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gpiod_set_value_cansleep(sbridge->enable, 0);
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if (sbridge->vdd)
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regulator_disable(sbridge->vdd);
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}
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static const struct drm_bridge_funcs simple_bridge_bridge_funcs = {
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.attach = simple_bridge_attach,
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.enable = simple_bridge_enable,
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.disable = simple_bridge_disable,
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};
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static int simple_bridge_probe(struct platform_device *pdev)
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{
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struct simple_bridge *sbridge;
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struct device_node *remote;
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sbridge = devm_kzalloc(&pdev->dev, sizeof(*sbridge), GFP_KERNEL);
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if (!sbridge)
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return -ENOMEM;
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platform_set_drvdata(pdev, sbridge);
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sbridge->info = of_device_get_match_data(&pdev->dev);
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/* Get the next bridge in the pipeline. */
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remote = of_graph_get_remote_node(pdev->dev.of_node, 1, -1);
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if (!remote)
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return -EINVAL;
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sbridge->next_bridge = of_drm_find_bridge(remote);
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of_node_put(remote);
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if (!sbridge->next_bridge) {
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dev_dbg(&pdev->dev, "Next bridge not found, deferring probe\n");
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return -EPROBE_DEFER;
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}
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/* Get the regulator and GPIO resources. */
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sbridge->vdd = devm_regulator_get_optional(&pdev->dev, "vdd");
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if (IS_ERR(sbridge->vdd)) {
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int ret = PTR_ERR(sbridge->vdd);
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if (ret == -EPROBE_DEFER)
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return -EPROBE_DEFER;
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sbridge->vdd = NULL;
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dev_dbg(&pdev->dev, "No vdd regulator found: %d\n", ret);
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}
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sbridge->enable = devm_gpiod_get_optional(&pdev->dev, "enable",
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GPIOD_OUT_LOW);
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if (IS_ERR(sbridge->enable)) {
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if (PTR_ERR(sbridge->enable) != -EPROBE_DEFER)
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dev_err(&pdev->dev, "Unable to retrieve enable GPIO\n");
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return PTR_ERR(sbridge->enable);
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}
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/* Register the bridge. */
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sbridge->bridge.funcs = &simple_bridge_bridge_funcs;
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sbridge->bridge.of_node = pdev->dev.of_node;
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sbridge->bridge.timings = sbridge->info->timings;
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drm_bridge_add(&sbridge->bridge);
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return 0;
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}
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static int simple_bridge_remove(struct platform_device *pdev)
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{
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struct simple_bridge *sbridge = platform_get_drvdata(pdev);
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drm_bridge_remove(&sbridge->bridge);
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return 0;
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}
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/*
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* We assume the ADV7123 DAC is the "default" for historical reasons
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* Information taken from the ADV7123 datasheet, revision D.
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* NOTE: the ADV7123EP seems to have other timings and need a new timings
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* set if used.
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*/
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static const struct drm_bridge_timings default_bridge_timings = {
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/* Timing specifications, datasheet page 7 */
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.input_bus_flags = DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE,
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.setup_time_ps = 500,
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.hold_time_ps = 1500,
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};
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/*
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* Information taken from the THS8134, THS8134A, THS8134B datasheet named
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* "SLVS205D", dated May 1990, revised March 2000.
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*/
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static const struct drm_bridge_timings ti_ths8134_bridge_timings = {
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/* From timing diagram, datasheet page 9 */
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.input_bus_flags = DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE,
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/* From datasheet, page 12 */
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.setup_time_ps = 3000,
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/* I guess this means latched input */
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.hold_time_ps = 0,
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};
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/*
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* Information taken from the THS8135 datasheet named "SLAS343B", dated
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* May 2001, revised April 2013.
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*/
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static const struct drm_bridge_timings ti_ths8135_bridge_timings = {
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/* From timing diagram, datasheet page 14 */
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.input_bus_flags = DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE,
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/* From datasheet, page 16 */
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.setup_time_ps = 2000,
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.hold_time_ps = 500,
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};
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static const struct of_device_id simple_bridge_match[] = {
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{
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.compatible = "dumb-vga-dac",
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.data = &(const struct simple_bridge_info) {
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.connector_type = DRM_MODE_CONNECTOR_VGA,
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},
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}, {
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.compatible = "adi,adv7123",
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.data = &(const struct simple_bridge_info) {
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.timings = &default_bridge_timings,
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.connector_type = DRM_MODE_CONNECTOR_VGA,
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},
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}, {
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.compatible = "ti,opa362",
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.data = &(const struct simple_bridge_info) {
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.connector_type = DRM_MODE_CONNECTOR_Composite,
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},
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}, {
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.compatible = "ti,ths8135",
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.data = &(const struct simple_bridge_info) {
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.timings = &ti_ths8135_bridge_timings,
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.connector_type = DRM_MODE_CONNECTOR_VGA,
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},
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}, {
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.compatible = "ti,ths8134",
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.data = &(const struct simple_bridge_info) {
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.timings = &ti_ths8134_bridge_timings,
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.connector_type = DRM_MODE_CONNECTOR_VGA,
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},
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},
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{},
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};
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MODULE_DEVICE_TABLE(of, simple_bridge_match);
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static struct platform_driver simple_bridge_driver = {
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.probe = simple_bridge_probe,
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.remove = simple_bridge_remove,
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.driver = {
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.name = "simple-bridge",
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.of_match_table = simple_bridge_match,
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},
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};
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module_platform_driver(simple_bridge_driver);
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MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
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MODULE_DESCRIPTION("Simple DRM bridge driver");
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MODULE_LICENSE("GPL");
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