// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2017-2020, The Linux Foundation. All rights reserved.
 */

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/debugfs.h>
#include <linux/component.h>
#include <linux/of_irq.h>
#include <linux/delay.h>
#include <drm/display/drm_dp_aux_bus.h>

#include "msm_drv.h"
#include "msm_kms.h"
#include "dp_parser.h"
#include "dp_power.h"
#include "dp_catalog.h"
#include "dp_aux.h"
#include "dp_reg.h"
#include "dp_link.h"
#include "dp_panel.h"
#include "dp_ctrl.h"
#include "dp_display.h"
#include "dp_drm.h"
#include "dp_audio.h"
#include "dp_debug.h"

static bool psr_enabled = false;
module_param(psr_enabled, bool, 0);
MODULE_PARM_DESC(psr_enabled, "enable PSR for eDP and DP displays");

#define HPD_STRING_SIZE 30

enum {
	ISR_DISCONNECTED,
	ISR_CONNECT_PENDING,
	ISR_CONNECTED,
	ISR_HPD_REPLUG_COUNT,
	ISR_IRQ_HPD_PULSE_COUNT,
	ISR_HPD_LO_GLITH_COUNT,
};

/* event thread connection state */
enum {
	ST_DISCONNECTED,
	ST_MAINLINK_READY,
	ST_CONNECTED,
	ST_DISCONNECT_PENDING,
	ST_DISPLAY_OFF,
	ST_SUSPENDED,
};

enum {
	EV_NO_EVENT,
	/* hpd events */
	EV_HPD_INIT_SETUP,
	EV_HPD_PLUG_INT,
	EV_IRQ_HPD_INT,
	EV_HPD_UNPLUG_INT,
	EV_USER_NOTIFICATION,
};

#define EVENT_TIMEOUT	(HZ/10)	/* 100ms */
#define DP_EVENT_Q_MAX	8

#define DP_TIMEOUT_NONE		0

#define WAIT_FOR_RESUME_TIMEOUT_JIFFIES (HZ / 2)

struct dp_event {
	u32 event_id;
	u32 data;
	u32 delay;
};

struct dp_display_private {
	char *name;
	int irq;

	unsigned int id;

	/* state variables */
	bool core_initialized;
	bool phy_initialized;
	bool hpd_irq_on;
	bool audio_supported;

	struct drm_device *drm_dev;
	struct platform_device *pdev;
	struct dentry *root;

	struct dp_parser  *parser;
	struct dp_power   *power;
	struct dp_catalog *catalog;
	struct drm_dp_aux *aux;
	struct dp_link    *link;
	struct dp_panel   *panel;
	struct dp_ctrl    *ctrl;
	struct dp_debug   *debug;

	struct dp_display_mode dp_mode;
	struct msm_dp dp_display;

	/* wait for audio signaling */
	struct completion audio_comp;

	/* event related only access by event thread */
	struct mutex event_mutex;
	wait_queue_head_t event_q;
	u32 hpd_state;
	u32 event_pndx;
	u32 event_gndx;
	struct task_struct *ev_tsk;
	struct dp_event event_list[DP_EVENT_Q_MAX];
	spinlock_t event_lock;

	bool wide_bus_en;

	struct dp_audio *audio;
};

struct msm_dp_desc {
	phys_addr_t io_start;
	unsigned int id;
	unsigned int connector_type;
	bool wide_bus_en;
};

static const struct msm_dp_desc sc7180_dp_descs[] = {
	{ .io_start = 0x0ae90000, .id = MSM_DP_CONTROLLER_0, .connector_type = DRM_MODE_CONNECTOR_DisplayPort },
	{}
};

static const struct msm_dp_desc sc7280_dp_descs[] = {
	{ .io_start = 0x0ae90000, .id = MSM_DP_CONTROLLER_0, .connector_type = DRM_MODE_CONNECTOR_DisplayPort, .wide_bus_en = true },
	{ .io_start = 0x0aea0000, .id = MSM_DP_CONTROLLER_1, .connector_type = DRM_MODE_CONNECTOR_eDP, .wide_bus_en = true },
	{}
};

static const struct msm_dp_desc sc8180x_dp_descs[] = {
	{ .io_start = 0x0ae90000, .id = MSM_DP_CONTROLLER_0, .connector_type = DRM_MODE_CONNECTOR_DisplayPort },
	{ .io_start = 0x0ae98000, .id = MSM_DP_CONTROLLER_1, .connector_type = DRM_MODE_CONNECTOR_DisplayPort },
	{ .io_start = 0x0ae9a000, .id = MSM_DP_CONTROLLER_2, .connector_type = DRM_MODE_CONNECTOR_eDP },
	{}
};

static const struct msm_dp_desc sc8280xp_dp_descs[] = {
	{ .io_start = 0x0ae90000, .id = MSM_DP_CONTROLLER_0, .connector_type = DRM_MODE_CONNECTOR_DisplayPort, .wide_bus_en = true },
	{ .io_start = 0x0ae98000, .id = MSM_DP_CONTROLLER_1, .connector_type = DRM_MODE_CONNECTOR_DisplayPort, .wide_bus_en = true },
	{ .io_start = 0x0ae9a000, .id = MSM_DP_CONTROLLER_2, .connector_type = DRM_MODE_CONNECTOR_DisplayPort, .wide_bus_en = true },
	{ .io_start = 0x0aea0000, .id = MSM_DP_CONTROLLER_3, .connector_type = DRM_MODE_CONNECTOR_DisplayPort, .wide_bus_en = true },
	{ .io_start = 0x22090000, .id = MSM_DP_CONTROLLER_0, .connector_type = DRM_MODE_CONNECTOR_DisplayPort, .wide_bus_en = true },
	{ .io_start = 0x22098000, .id = MSM_DP_CONTROLLER_1, .connector_type = DRM_MODE_CONNECTOR_DisplayPort, .wide_bus_en = true },
	{ .io_start = 0x2209a000, .id = MSM_DP_CONTROLLER_2, .connector_type = DRM_MODE_CONNECTOR_DisplayPort, .wide_bus_en = true },
	{ .io_start = 0x220a0000, .id = MSM_DP_CONTROLLER_3, .connector_type = DRM_MODE_CONNECTOR_DisplayPort, .wide_bus_en = true },
	{}
};

static const struct msm_dp_desc sc8280xp_edp_descs[] = {
	{ .io_start = 0x0ae9a000, .id = MSM_DP_CONTROLLER_2, .connector_type = DRM_MODE_CONNECTOR_eDP, .wide_bus_en = true },
	{ .io_start = 0x0aea0000, .id = MSM_DP_CONTROLLER_3, .connector_type = DRM_MODE_CONNECTOR_eDP, .wide_bus_en = true },
	{ .io_start = 0x2209a000, .id = MSM_DP_CONTROLLER_2, .connector_type = DRM_MODE_CONNECTOR_eDP, .wide_bus_en = true },
	{ .io_start = 0x220a0000, .id = MSM_DP_CONTROLLER_3, .connector_type = DRM_MODE_CONNECTOR_eDP, .wide_bus_en = true },
	{}
};

static const struct msm_dp_desc sm8350_dp_descs[] = {
	{ .io_start = 0x0ae90000, .id = MSM_DP_CONTROLLER_0, .connector_type = DRM_MODE_CONNECTOR_DisplayPort },
	{}
};

static const struct msm_dp_desc sm8650_dp_descs[] = {
	{ .io_start = 0x0af54000, .id = MSM_DP_CONTROLLER_0, .connector_type = DRM_MODE_CONNECTOR_DisplayPort },
	{}
};

static const struct of_device_id dp_dt_match[] = {
	{ .compatible = "qcom,sc7180-dp", .data = &sc7180_dp_descs },
	{ .compatible = "qcom,sc7280-dp", .data = &sc7280_dp_descs },
	{ .compatible = "qcom,sc7280-edp", .data = &sc7280_dp_descs },
	{ .compatible = "qcom,sc8180x-dp", .data = &sc8180x_dp_descs },
	{ .compatible = "qcom,sc8180x-edp", .data = &sc8180x_dp_descs },
	{ .compatible = "qcom,sc8280xp-dp", .data = &sc8280xp_dp_descs },
	{ .compatible = "qcom,sc8280xp-edp", .data = &sc8280xp_edp_descs },
	{ .compatible = "qcom,sdm845-dp", .data = &sc7180_dp_descs },
	{ .compatible = "qcom,sm8350-dp", .data = &sm8350_dp_descs },
	{ .compatible = "qcom,sm8650-dp", .data = &sm8650_dp_descs },
	{}
};

static struct dp_display_private *dev_get_dp_display_private(struct device *dev)
{
	struct msm_dp *dp = dev_get_drvdata(dev);

	return container_of(dp, struct dp_display_private, dp_display);
}

static int dp_add_event(struct dp_display_private *dp_priv, u32 event,
						u32 data, u32 delay)
{
	unsigned long flag;
	struct dp_event *todo;
	int pndx;

	spin_lock_irqsave(&dp_priv->event_lock, flag);
	pndx = dp_priv->event_pndx + 1;
	pndx %= DP_EVENT_Q_MAX;
	if (pndx == dp_priv->event_gndx) {
		pr_err("event_q is full: pndx=%d gndx=%d\n",
			dp_priv->event_pndx, dp_priv->event_gndx);
		spin_unlock_irqrestore(&dp_priv->event_lock, flag);
		return -EPERM;
	}
	todo = &dp_priv->event_list[dp_priv->event_pndx++];
	dp_priv->event_pndx %= DP_EVENT_Q_MAX;
	todo->event_id = event;
	todo->data = data;
	todo->delay = delay;
	wake_up(&dp_priv->event_q);
	spin_unlock_irqrestore(&dp_priv->event_lock, flag);

	return 0;
}

static int dp_del_event(struct dp_display_private *dp_priv, u32 event)
{
	unsigned long flag;
	struct dp_event *todo;
	u32	gndx;

	spin_lock_irqsave(&dp_priv->event_lock, flag);
	if (dp_priv->event_pndx == dp_priv->event_gndx) {
		spin_unlock_irqrestore(&dp_priv->event_lock, flag);
		return -ENOENT;
	}

	gndx = dp_priv->event_gndx;
	while (dp_priv->event_pndx != gndx) {
		todo = &dp_priv->event_list[gndx];
		if (todo->event_id == event) {
			todo->event_id = EV_NO_EVENT;	/* deleted */
			todo->delay = 0;
		}
		gndx++;
		gndx %= DP_EVENT_Q_MAX;
	}
	spin_unlock_irqrestore(&dp_priv->event_lock, flag);

	return 0;
}

void dp_display_signal_audio_start(struct msm_dp *dp_display)
{
	struct dp_display_private *dp;

	dp = container_of(dp_display, struct dp_display_private, dp_display);

	reinit_completion(&dp->audio_comp);
}

void dp_display_signal_audio_complete(struct msm_dp *dp_display)
{
	struct dp_display_private *dp;

	dp = container_of(dp_display, struct dp_display_private, dp_display);

	complete_all(&dp->audio_comp);
}

static int dp_hpd_event_thread_start(struct dp_display_private *dp_priv);

static int dp_display_bind(struct device *dev, struct device *master,
			   void *data)
{
	int rc = 0;
	struct dp_display_private *dp = dev_get_dp_display_private(dev);
	struct msm_drm_private *priv = dev_get_drvdata(master);
	struct drm_device *drm = priv->dev;

	dp->dp_display.drm_dev = drm;
	priv->dp[dp->id] = &dp->dp_display;

	rc = dp->parser->parse(dp->parser);
	if (rc) {
		DRM_ERROR("device tree parsing failed\n");
		goto end;
	}


	dp->drm_dev = drm;
	dp->aux->drm_dev = drm;
	rc = dp_aux_register(dp->aux);
	if (rc) {
		DRM_ERROR("DRM DP AUX register failed\n");
		goto end;
	}

	rc = dp_power_client_init(dp->power);
	if (rc) {
		DRM_ERROR("Power client create failed\n");
		goto end;
	}

	rc = dp_register_audio_driver(dev, dp->audio);
	if (rc) {
		DRM_ERROR("Audio registration Dp failed\n");
		goto end;
	}

	rc = dp_hpd_event_thread_start(dp);
	if (rc) {
		DRM_ERROR("Event thread create failed\n");
		goto end;
	}

	return 0;
end:
	return rc;
}

static void dp_display_unbind(struct device *dev, struct device *master,
			      void *data)
{
	struct dp_display_private *dp = dev_get_dp_display_private(dev);
	struct msm_drm_private *priv = dev_get_drvdata(master);

	/* disable all HPD interrupts */
	if (dp->core_initialized)
		dp_catalog_hpd_config_intr(dp->catalog, DP_DP_HPD_INT_MASK, false);

	kthread_stop(dp->ev_tsk);

	of_dp_aux_depopulate_bus(dp->aux);

	dp_power_client_deinit(dp->power);
	dp_unregister_audio_driver(dev, dp->audio);
	dp_aux_unregister(dp->aux);
	dp->drm_dev = NULL;
	dp->aux->drm_dev = NULL;
	priv->dp[dp->id] = NULL;
}

static const struct component_ops dp_display_comp_ops = {
	.bind = dp_display_bind,
	.unbind = dp_display_unbind,
};

static bool dp_display_is_ds_bridge(struct dp_panel *panel)
{
	return (panel->dpcd[DP_DOWNSTREAMPORT_PRESENT] &
		DP_DWN_STRM_PORT_PRESENT);
}

static bool dp_display_is_sink_count_zero(struct dp_display_private *dp)
{
	drm_dbg_dp(dp->drm_dev, "present=%#x sink_count=%d\n",
			dp->panel->dpcd[DP_DOWNSTREAMPORT_PRESENT],
		dp->link->sink_count);
	return dp_display_is_ds_bridge(dp->panel) &&
		(dp->link->sink_count == 0);
}

static void dp_display_send_hpd_event(struct msm_dp *dp_display)
{
	struct dp_display_private *dp;
	struct drm_connector *connector;

	dp = container_of(dp_display, struct dp_display_private, dp_display);

	connector = dp->dp_display.connector;
	drm_helper_hpd_irq_event(connector->dev);
}


static int dp_display_send_hpd_notification(struct dp_display_private *dp,
					    bool hpd)
{
	if ((hpd && dp->dp_display.is_connected) ||
			(!hpd && !dp->dp_display.is_connected)) {
		drm_dbg_dp(dp->drm_dev, "HPD already %s\n",
				(hpd ? "on" : "off"));
		return 0;
	}

	/* reset video pattern flag on disconnect */
	if (!hpd)
		dp->panel->video_test = false;

	dp->dp_display.is_connected = hpd;

	drm_dbg_dp(dp->drm_dev, "type=%d hpd=%d\n",
			dp->dp_display.connector_type, hpd);
	dp_display_send_hpd_event(&dp->dp_display);

	return 0;
}

static int dp_display_process_hpd_high(struct dp_display_private *dp)
{
	int rc = 0;
	struct edid *edid;

	dp->panel->max_dp_lanes = dp->parser->max_dp_lanes;
	dp->panel->max_dp_link_rate = dp->parser->max_dp_link_rate;

	drm_dbg_dp(dp->drm_dev, "max_lanes=%d max_link_rate=%d\n",
		dp->panel->max_dp_lanes, dp->panel->max_dp_link_rate);

	rc = dp_panel_read_sink_caps(dp->panel, dp->dp_display.connector);
	if (rc)
		goto end;

	dp_link_process_request(dp->link);

	edid = dp->panel->edid;

	dp->dp_display.psr_supported = dp->panel->psr_cap.version && psr_enabled;

	dp->audio_supported = drm_detect_monitor_audio(edid);
	dp_panel_handle_sink_request(dp->panel);

	dp->dp_display.max_dp_lanes = dp->parser->max_dp_lanes;

	/*
	 * set sink to normal operation mode -- D0
	 * before dpcd read
	 */
	dp_link_psm_config(dp->link, &dp->panel->link_info, false);

	dp_link_reset_phy_params_vx_px(dp->link);
	rc = dp_ctrl_on_link(dp->ctrl);
	if (rc) {
		DRM_ERROR("failed to complete DP link training\n");
		goto end;
	}

	dp_add_event(dp, EV_USER_NOTIFICATION, true, 0);

end:
	return rc;
}

static void dp_display_host_phy_init(struct dp_display_private *dp)
{
	drm_dbg_dp(dp->drm_dev, "type=%d core_init=%d phy_init=%d\n",
		dp->dp_display.connector_type, dp->core_initialized,
		dp->phy_initialized);

	if (!dp->phy_initialized) {
		dp_ctrl_phy_init(dp->ctrl);
		dp->phy_initialized = true;
	}
}

static void dp_display_host_phy_exit(struct dp_display_private *dp)
{
	drm_dbg_dp(dp->drm_dev, "type=%d core_init=%d phy_init=%d\n",
		dp->dp_display.connector_type, dp->core_initialized,
		dp->phy_initialized);

	if (dp->phy_initialized) {
		dp_ctrl_phy_exit(dp->ctrl);
		dp->phy_initialized = false;
	}
}

static void dp_display_host_init(struct dp_display_private *dp)
{
	drm_dbg_dp(dp->drm_dev, "type=%d core_init=%d phy_init=%d\n",
		dp->dp_display.connector_type, dp->core_initialized,
		dp->phy_initialized);

	dp_power_init(dp->power);
	dp_ctrl_reset_irq_ctrl(dp->ctrl, true);
	dp_aux_init(dp->aux);
	dp->core_initialized = true;
}

static void dp_display_host_deinit(struct dp_display_private *dp)
{
	drm_dbg_dp(dp->drm_dev, "type=%d core_init=%d phy_init=%d\n",
		dp->dp_display.connector_type, dp->core_initialized,
		dp->phy_initialized);

	dp_ctrl_reset_irq_ctrl(dp->ctrl, false);
	dp_aux_deinit(dp->aux);
	dp_power_deinit(dp->power);
	dp->core_initialized = false;
}

static int dp_display_usbpd_configure_cb(struct device *dev)
{
	struct dp_display_private *dp = dev_get_dp_display_private(dev);

	dp_display_host_phy_init(dp);

	return dp_display_process_hpd_high(dp);
}

static int dp_display_notify_disconnect(struct device *dev)
{
	struct dp_display_private *dp = dev_get_dp_display_private(dev);

	dp_add_event(dp, EV_USER_NOTIFICATION, false, 0);

	return 0;
}

static void dp_display_handle_video_request(struct dp_display_private *dp)
{
	if (dp->link->sink_request & DP_TEST_LINK_VIDEO_PATTERN) {
		dp->panel->video_test = true;
		dp_link_send_test_response(dp->link);
	}
}

static int dp_display_handle_port_ststus_changed(struct dp_display_private *dp)
{
	int rc = 0;

	if (dp_display_is_sink_count_zero(dp)) {
		drm_dbg_dp(dp->drm_dev, "sink count is zero, nothing to do\n");
		if (dp->hpd_state != ST_DISCONNECTED) {
			dp->hpd_state = ST_DISCONNECT_PENDING;
			dp_add_event(dp, EV_USER_NOTIFICATION, false, 0);
		}
	} else {
		if (dp->hpd_state == ST_DISCONNECTED) {
			dp->hpd_state = ST_MAINLINK_READY;
			rc = dp_display_process_hpd_high(dp);
			if (rc)
				dp->hpd_state = ST_DISCONNECTED;
		}
	}

	return rc;
}

static int dp_display_handle_irq_hpd(struct dp_display_private *dp)
{
	u32 sink_request = dp->link->sink_request;

	drm_dbg_dp(dp->drm_dev, "%d\n", sink_request);
	if (dp->hpd_state == ST_DISCONNECTED) {
		if (sink_request & DP_LINK_STATUS_UPDATED) {
			drm_dbg_dp(dp->drm_dev, "Disconnected sink_request: %d\n",
							sink_request);
			DRM_ERROR("Disconnected, no DP_LINK_STATUS_UPDATED\n");
			return -EINVAL;
		}
	}

	dp_ctrl_handle_sink_request(dp->ctrl);

	if (sink_request & DP_TEST_LINK_VIDEO_PATTERN)
		dp_display_handle_video_request(dp);

	return 0;
}

static int dp_display_usbpd_attention_cb(struct device *dev)
{
	int rc = 0;
	u32 sink_request;
	struct dp_display_private *dp = dev_get_dp_display_private(dev);

	/* check for any test request issued by sink */
	rc = dp_link_process_request(dp->link);
	if (!rc) {
		sink_request = dp->link->sink_request;
		drm_dbg_dp(dp->drm_dev, "hpd_state=%d sink_request=%d\n",
					dp->hpd_state, sink_request);
		if (sink_request & DS_PORT_STATUS_CHANGED)
			rc = dp_display_handle_port_ststus_changed(dp);
		else
			rc = dp_display_handle_irq_hpd(dp);
	}

	return rc;
}

static int dp_hpd_plug_handle(struct dp_display_private *dp, u32 data)
{
	u32 state;
	int ret;

	mutex_lock(&dp->event_mutex);

	state =  dp->hpd_state;
	drm_dbg_dp(dp->drm_dev, "Before, type=%d hpd_state=%d\n",
			dp->dp_display.connector_type, state);

	if (state == ST_DISPLAY_OFF || state == ST_SUSPENDED) {
		mutex_unlock(&dp->event_mutex);
		return 0;
	}

	if (state == ST_MAINLINK_READY || state == ST_CONNECTED) {
		mutex_unlock(&dp->event_mutex);
		return 0;
	}

	if (state == ST_DISCONNECT_PENDING) {
		/* wait until ST_DISCONNECTED */
		dp_add_event(dp, EV_HPD_PLUG_INT, 0, 1); /* delay = 1 */
		mutex_unlock(&dp->event_mutex);
		return 0;
	}

	ret = dp_display_usbpd_configure_cb(&dp->pdev->dev);
	if (ret) {	/* link train failed */
		dp->hpd_state = ST_DISCONNECTED;
	} else {
		dp->hpd_state = ST_MAINLINK_READY;
	}

	drm_dbg_dp(dp->drm_dev, "After, type=%d hpd_state=%d\n",
			dp->dp_display.connector_type, state);
	mutex_unlock(&dp->event_mutex);

	/* uevent will complete connection part */
	return 0;
};

static void dp_display_handle_plugged_change(struct msm_dp *dp_display,
		bool plugged)
{
	struct dp_display_private *dp;

	dp = container_of(dp_display,
			struct dp_display_private, dp_display);

	/* notify audio subsystem only if sink supports audio */
	if (dp_display->plugged_cb && dp_display->codec_dev &&
			dp->audio_supported)
		dp_display->plugged_cb(dp_display->codec_dev, plugged);
}

static int dp_hpd_unplug_handle(struct dp_display_private *dp, u32 data)
{
	u32 state;

	mutex_lock(&dp->event_mutex);

	state = dp->hpd_state;

	drm_dbg_dp(dp->drm_dev, "Before, type=%d hpd_state=%d\n",
			dp->dp_display.connector_type, state);

	/* unplugged, no more irq_hpd handle */
	dp_del_event(dp, EV_IRQ_HPD_INT);

	if (state == ST_DISCONNECTED) {
		/* triggered by irq_hdp with sink_count = 0 */
		if (dp->link->sink_count == 0) {
			dp_display_host_phy_exit(dp);
		}
		dp_display_notify_disconnect(&dp->pdev->dev);
		mutex_unlock(&dp->event_mutex);
		return 0;
	} else if (state == ST_DISCONNECT_PENDING) {
		mutex_unlock(&dp->event_mutex);
		return 0;
	} else if (state == ST_MAINLINK_READY) {
		dp_ctrl_off_link(dp->ctrl);
		dp_display_host_phy_exit(dp);
		dp->hpd_state = ST_DISCONNECTED;
		dp_display_notify_disconnect(&dp->pdev->dev);
		mutex_unlock(&dp->event_mutex);
		return 0;
	}

	/*
	 * We don't need separate work for disconnect as
	 * connect/attention interrupts are disabled
	 */
	dp_display_notify_disconnect(&dp->pdev->dev);

	if (state == ST_DISPLAY_OFF) {
		dp->hpd_state = ST_DISCONNECTED;
	} else {
		dp->hpd_state = ST_DISCONNECT_PENDING;
	}

	/* signal the disconnect event early to ensure proper teardown */
	dp_display_handle_plugged_change(&dp->dp_display, false);

	drm_dbg_dp(dp->drm_dev, "After, type=%d hpd_state=%d\n",
			dp->dp_display.connector_type, state);

	/* uevent will complete disconnection part */
	mutex_unlock(&dp->event_mutex);
	return 0;
}

static int dp_irq_hpd_handle(struct dp_display_private *dp, u32 data)
{
	u32 state;

	mutex_lock(&dp->event_mutex);

	/* irq_hpd can happen at either connected or disconnected state */
	state =  dp->hpd_state;
	drm_dbg_dp(dp->drm_dev, "Before, type=%d hpd_state=%d\n",
			dp->dp_display.connector_type, state);

	if (state == ST_DISPLAY_OFF || state == ST_SUSPENDED) {
		mutex_unlock(&dp->event_mutex);
		return 0;
	}

	if (state == ST_MAINLINK_READY || state == ST_DISCONNECT_PENDING) {
		/* wait until ST_CONNECTED */
		dp_add_event(dp, EV_IRQ_HPD_INT, 0, 1); /* delay = 1 */
		mutex_unlock(&dp->event_mutex);
		return 0;
	}

	dp_display_usbpd_attention_cb(&dp->pdev->dev);

	drm_dbg_dp(dp->drm_dev, "After, type=%d hpd_state=%d\n",
			dp->dp_display.connector_type, state);

	mutex_unlock(&dp->event_mutex);

	return 0;
}

static void dp_display_deinit_sub_modules(struct dp_display_private *dp)
{
	dp_debug_put(dp->debug);
	dp_audio_put(dp->audio);
	dp_panel_put(dp->panel);
	dp_aux_put(dp->aux);
}

static int dp_init_sub_modules(struct dp_display_private *dp)
{
	int rc = 0;
	struct device *dev = &dp->pdev->dev;
	struct dp_panel_in panel_in = {
		.dev = dev,
	};

	dp->parser = dp_parser_get(dp->pdev);
	if (IS_ERR(dp->parser)) {
		rc = PTR_ERR(dp->parser);
		DRM_ERROR("failed to initialize parser, rc = %d\n", rc);
		dp->parser = NULL;
		goto error;
	}

	dp->catalog = dp_catalog_get(dev, &dp->parser->io);
	if (IS_ERR(dp->catalog)) {
		rc = PTR_ERR(dp->catalog);
		DRM_ERROR("failed to initialize catalog, rc = %d\n", rc);
		dp->catalog = NULL;
		goto error;
	}

	dp->power = dp_power_get(dev, dp->parser);
	if (IS_ERR(dp->power)) {
		rc = PTR_ERR(dp->power);
		DRM_ERROR("failed to initialize power, rc = %d\n", rc);
		dp->power = NULL;
		goto error;
	}

	dp->aux = dp_aux_get(dev, dp->catalog, dp->dp_display.is_edp);
	if (IS_ERR(dp->aux)) {
		rc = PTR_ERR(dp->aux);
		DRM_ERROR("failed to initialize aux, rc = %d\n", rc);
		dp->aux = NULL;
		goto error;
	}

	dp->link = dp_link_get(dev, dp->aux);
	if (IS_ERR(dp->link)) {
		rc = PTR_ERR(dp->link);
		DRM_ERROR("failed to initialize link, rc = %d\n", rc);
		dp->link = NULL;
		goto error_link;
	}

	panel_in.aux = dp->aux;
	panel_in.catalog = dp->catalog;
	panel_in.link = dp->link;

	dp->panel = dp_panel_get(&panel_in);
	if (IS_ERR(dp->panel)) {
		rc = PTR_ERR(dp->panel);
		DRM_ERROR("failed to initialize panel, rc = %d\n", rc);
		dp->panel = NULL;
		goto error_link;
	}

	dp->ctrl = dp_ctrl_get(dev, dp->link, dp->panel, dp->aux,
			       dp->power, dp->catalog, dp->parser);
	if (IS_ERR(dp->ctrl)) {
		rc = PTR_ERR(dp->ctrl);
		DRM_ERROR("failed to initialize ctrl, rc = %d\n", rc);
		dp->ctrl = NULL;
		goto error_ctrl;
	}

	dp->audio = dp_audio_get(dp->pdev, dp->panel, dp->catalog);
	if (IS_ERR(dp->audio)) {
		rc = PTR_ERR(dp->audio);
		pr_err("failed to initialize audio, rc = %d\n", rc);
		dp->audio = NULL;
		goto error_ctrl;
	}

	/* populate wide_bus_en to differernt layers */
	dp->ctrl->wide_bus_en = dp->wide_bus_en;
	dp->catalog->wide_bus_en = dp->wide_bus_en;

	return rc;

error_ctrl:
	dp_panel_put(dp->panel);
error_link:
	dp_aux_put(dp->aux);
error:
	return rc;
}

static int dp_display_set_mode(struct msm_dp *dp_display,
			       struct dp_display_mode *mode)
{
	struct dp_display_private *dp;

	dp = container_of(dp_display, struct dp_display_private, dp_display);

	drm_mode_copy(&dp->panel->dp_mode.drm_mode, &mode->drm_mode);
	dp->panel->dp_mode.bpp = mode->bpp;
	dp->panel->dp_mode.capabilities = mode->capabilities;
	dp_panel_init_panel_info(dp->panel);
	return 0;
}

static int dp_display_enable(struct dp_display_private *dp, bool force_link_train)
{
	int rc = 0;
	struct msm_dp *dp_display = &dp->dp_display;

	drm_dbg_dp(dp->drm_dev, "sink_count=%d\n", dp->link->sink_count);
	if (dp_display->power_on) {
		drm_dbg_dp(dp->drm_dev, "Link already setup, return\n");
		return 0;
	}

	rc = dp_ctrl_on_stream(dp->ctrl, force_link_train);
	if (!rc)
		dp_display->power_on = true;

	return rc;
}

static int dp_display_post_enable(struct msm_dp *dp_display)
{
	struct dp_display_private *dp;
	u32 rate;

	dp = container_of(dp_display, struct dp_display_private, dp_display);

	rate = dp->link->link_params.rate;

	if (dp->audio_supported) {
		dp->audio->bw_code = drm_dp_link_rate_to_bw_code(rate);
		dp->audio->lane_count = dp->link->link_params.num_lanes;
	}

	/* signal the connect event late to synchronize video and display */
	dp_display_handle_plugged_change(dp_display, true);

	if (dp_display->psr_supported)
		dp_ctrl_config_psr(dp->ctrl);

	return 0;
}

static int dp_display_disable(struct dp_display_private *dp)
{
	struct msm_dp *dp_display = &dp->dp_display;

	if (!dp_display->power_on)
		return 0;

	/* wait only if audio was enabled */
	if (dp_display->audio_enabled) {
		/* signal the disconnect event */
		dp_display_handle_plugged_change(dp_display, false);
		if (!wait_for_completion_timeout(&dp->audio_comp,
				HZ * 5))
			DRM_ERROR("audio comp timeout\n");
	}

	dp_display->audio_enabled = false;

	if (dp->link->sink_count == 0) {
		/*
		 * irq_hpd with sink_count = 0
		 * hdmi unplugged out of dongle
		 */
		dp_ctrl_off_link_stream(dp->ctrl);
	} else {
		/*
		 * unplugged interrupt
		 * dongle unplugged out of DUT
		 */
		dp_ctrl_off(dp->ctrl);
		dp_display_host_phy_exit(dp);
	}

	dp_display->power_on = false;

	drm_dbg_dp(dp->drm_dev, "sink count: %d\n", dp->link->sink_count);
	return 0;
}

int dp_display_set_plugged_cb(struct msm_dp *dp_display,
		hdmi_codec_plugged_cb fn, struct device *codec_dev)
{
	bool plugged;

	dp_display->plugged_cb = fn;
	dp_display->codec_dev = codec_dev;
	plugged = dp_display->is_connected;
	dp_display_handle_plugged_change(dp_display, plugged);

	return 0;
}

/**
 * dp_bridge_mode_valid - callback to determine if specified mode is valid
 * @bridge: Pointer to drm bridge structure
 * @info: display info
 * @mode: Pointer to drm mode structure
 * Returns: Validity status for specified mode
 */
enum drm_mode_status dp_bridge_mode_valid(struct drm_bridge *bridge,
					  const struct drm_display_info *info,
					  const struct drm_display_mode *mode)
{
	const u32 num_components = 3, default_bpp = 24;
	struct dp_display_private *dp_display;
	struct dp_link_info *link_info;
	u32 mode_rate_khz = 0, supported_rate_khz = 0, mode_bpp = 0;
	struct msm_dp *dp;
	int mode_pclk_khz = mode->clock;

	dp = to_dp_bridge(bridge)->dp_display;

	if (!dp || !mode_pclk_khz || !dp->connector) {
		DRM_ERROR("invalid params\n");
		return -EINVAL;
	}

	if (mode->clock > DP_MAX_PIXEL_CLK_KHZ)
		return MODE_CLOCK_HIGH;

	dp_display = container_of(dp, struct dp_display_private, dp_display);
	link_info = &dp_display->panel->link_info;

	mode_bpp = dp->connector->display_info.bpc * num_components;
	if (!mode_bpp)
		mode_bpp = default_bpp;

	mode_bpp = dp_panel_get_mode_bpp(dp_display->panel,
			mode_bpp, mode_pclk_khz);

	mode_rate_khz = mode_pclk_khz * mode_bpp;
	supported_rate_khz = link_info->num_lanes * link_info->rate * 8;

	if (mode_rate_khz > supported_rate_khz)
		return MODE_BAD;

	return MODE_OK;
}

int dp_display_get_modes(struct msm_dp *dp)
{
	struct dp_display_private *dp_display;

	if (!dp) {
		DRM_ERROR("invalid params\n");
		return 0;
	}

	dp_display = container_of(dp, struct dp_display_private, dp_display);

	return dp_panel_get_modes(dp_display->panel,
		dp->connector);
}

bool dp_display_check_video_test(struct msm_dp *dp)
{
	struct dp_display_private *dp_display;

	dp_display = container_of(dp, struct dp_display_private, dp_display);

	return dp_display->panel->video_test;
}

int dp_display_get_test_bpp(struct msm_dp *dp)
{
	struct dp_display_private *dp_display;

	if (!dp) {
		DRM_ERROR("invalid params\n");
		return 0;
	}

	dp_display = container_of(dp, struct dp_display_private, dp_display);

	return dp_link_bit_depth_to_bpp(
		dp_display->link->test_video.test_bit_depth);
}

void msm_dp_snapshot(struct msm_disp_state *disp_state, struct msm_dp *dp)
{
	struct dp_display_private *dp_display;

	dp_display = container_of(dp, struct dp_display_private, dp_display);

	/*
	 * if we are reading registers we need the link clocks to be on
	 * however till DP cable is connected this will not happen as we
	 * do not know the resolution to power up with. Hence check the
	 * power_on status before dumping DP registers to avoid crash due
	 * to unclocked access
	 */
	mutex_lock(&dp_display->event_mutex);

	if (!dp->power_on) {
		mutex_unlock(&dp_display->event_mutex);
		return;
	}

	dp_catalog_snapshot(dp_display->catalog, disp_state);

	mutex_unlock(&dp_display->event_mutex);
}

void dp_display_set_psr(struct msm_dp *dp_display, bool enter)
{
	struct dp_display_private *dp;

	if (!dp_display) {
		DRM_ERROR("invalid params\n");
		return;
	}

	dp = container_of(dp_display, struct dp_display_private, dp_display);
	dp_ctrl_set_psr(dp->ctrl, enter);
}

static int hpd_event_thread(void *data)
{
	struct dp_display_private *dp_priv;
	unsigned long flag;
	struct dp_event *todo;
	int timeout_mode = 0;

	dp_priv = (struct dp_display_private *)data;

	while (1) {
		if (timeout_mode) {
			wait_event_timeout(dp_priv->event_q,
				(dp_priv->event_pndx == dp_priv->event_gndx) ||
					kthread_should_stop(), EVENT_TIMEOUT);
		} else {
			wait_event_interruptible(dp_priv->event_q,
				(dp_priv->event_pndx != dp_priv->event_gndx) ||
					kthread_should_stop());
		}

		if (kthread_should_stop())
			break;

		spin_lock_irqsave(&dp_priv->event_lock, flag);
		todo = &dp_priv->event_list[dp_priv->event_gndx];
		if (todo->delay) {
			struct dp_event *todo_next;

			dp_priv->event_gndx++;
			dp_priv->event_gndx %= DP_EVENT_Q_MAX;

			/* re enter delay event into q */
			todo_next = &dp_priv->event_list[dp_priv->event_pndx++];
			dp_priv->event_pndx %= DP_EVENT_Q_MAX;
			todo_next->event_id = todo->event_id;
			todo_next->data = todo->data;
			todo_next->delay = todo->delay - 1;

			/* clean up older event */
			todo->event_id = EV_NO_EVENT;
			todo->delay = 0;

			/* switch to timeout mode */
			timeout_mode = 1;
			spin_unlock_irqrestore(&dp_priv->event_lock, flag);
			continue;
		}

		/* timeout with no events in q */
		if (dp_priv->event_pndx == dp_priv->event_gndx) {
			spin_unlock_irqrestore(&dp_priv->event_lock, flag);
			continue;
		}

		dp_priv->event_gndx++;
		dp_priv->event_gndx %= DP_EVENT_Q_MAX;
		timeout_mode = 0;
		spin_unlock_irqrestore(&dp_priv->event_lock, flag);

		switch (todo->event_id) {
		case EV_HPD_INIT_SETUP:
			dp_display_host_init(dp_priv);
			break;
		case EV_HPD_PLUG_INT:
			dp_hpd_plug_handle(dp_priv, todo->data);
			break;
		case EV_HPD_UNPLUG_INT:
			dp_hpd_unplug_handle(dp_priv, todo->data);
			break;
		case EV_IRQ_HPD_INT:
			dp_irq_hpd_handle(dp_priv, todo->data);
			break;
		case EV_USER_NOTIFICATION:
			dp_display_send_hpd_notification(dp_priv,
						todo->data);
			break;
		default:
			break;
		}
	}

	return 0;
}

static int dp_hpd_event_thread_start(struct dp_display_private *dp_priv)
{
	/* set event q to empty */
	dp_priv->event_gndx = 0;
	dp_priv->event_pndx = 0;

	dp_priv->ev_tsk = kthread_run(hpd_event_thread, dp_priv, "dp_hpd_handler");
	if (IS_ERR(dp_priv->ev_tsk))
		return PTR_ERR(dp_priv->ev_tsk);

	return 0;
}

static irqreturn_t dp_display_irq_handler(int irq, void *dev_id)
{
	struct dp_display_private *dp = dev_id;
	irqreturn_t ret = IRQ_NONE;
	u32 hpd_isr_status;

	if (!dp) {
		DRM_ERROR("invalid data\n");
		return IRQ_NONE;
	}

	hpd_isr_status = dp_catalog_hpd_get_intr_status(dp->catalog);

	if (hpd_isr_status & 0x0F) {
		drm_dbg_dp(dp->drm_dev, "type=%d isr=0x%x\n",
			dp->dp_display.connector_type, hpd_isr_status);
		/* hpd related interrupts */
		if (hpd_isr_status & DP_DP_HPD_PLUG_INT_MASK)
			dp_add_event(dp, EV_HPD_PLUG_INT, 0, 0);

		if (hpd_isr_status & DP_DP_IRQ_HPD_INT_MASK) {
			dp_add_event(dp, EV_IRQ_HPD_INT, 0, 0);
		}

		if (hpd_isr_status & DP_DP_HPD_REPLUG_INT_MASK) {
			dp_add_event(dp, EV_HPD_UNPLUG_INT, 0, 0);
			dp_add_event(dp, EV_HPD_PLUG_INT, 0, 3);
		}

		if (hpd_isr_status & DP_DP_HPD_UNPLUG_INT_MASK)
			dp_add_event(dp, EV_HPD_UNPLUG_INT, 0, 0);

		ret = IRQ_HANDLED;
	}

	/* DP controller isr */
	ret |= dp_ctrl_isr(dp->ctrl);

	/* DP aux isr */
	ret |= dp_aux_isr(dp->aux);

	return ret;
}

int dp_display_request_irq(struct msm_dp *dp_display)
{
	int rc = 0;
	struct dp_display_private *dp;

	if (!dp_display) {
		DRM_ERROR("invalid input\n");
		return -EINVAL;
	}

	dp = container_of(dp_display, struct dp_display_private, dp_display);

	dp->irq = irq_of_parse_and_map(dp->pdev->dev.of_node, 0);
	if (!dp->irq) {
		DRM_ERROR("failed to get irq\n");
		return -EINVAL;
	}

	rc = devm_request_irq(dp_display->drm_dev->dev, dp->irq,
			dp_display_irq_handler,
			IRQF_TRIGGER_HIGH, "dp_display_isr", dp);
	if (rc < 0) {
		DRM_ERROR("failed to request IRQ%u: %d\n",
				dp->irq, rc);
		return rc;
	}

	return 0;
}

static const struct msm_dp_desc *dp_display_get_desc(struct platform_device *pdev)
{
	const struct msm_dp_desc *descs = of_device_get_match_data(&pdev->dev);
	struct resource *res;
	int i;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!res)
		return NULL;

	for (i = 0; i < descs[i].io_start; i++) {
		if (descs[i].io_start == res->start)
			return &descs[i];
	}

	dev_err(&pdev->dev, "unknown displayport instance\n");
	return NULL;
}

static int dp_display_probe(struct platform_device *pdev)
{
	int rc = 0;
	struct dp_display_private *dp;
	const struct msm_dp_desc *desc;

	if (!pdev || !pdev->dev.of_node) {
		DRM_ERROR("pdev not found\n");
		return -ENODEV;
	}

	dp = devm_kzalloc(&pdev->dev, sizeof(*dp), GFP_KERNEL);
	if (!dp)
		return -ENOMEM;

	desc = dp_display_get_desc(pdev);
	if (!desc)
		return -EINVAL;

	dp->pdev = pdev;
	dp->name = "drm_dp";
	dp->id = desc->id;
	dp->dp_display.connector_type = desc->connector_type;
	dp->wide_bus_en = desc->wide_bus_en;
	dp->dp_display.is_edp =
		(dp->dp_display.connector_type == DRM_MODE_CONNECTOR_eDP);

	rc = dp_init_sub_modules(dp);
	if (rc) {
		DRM_ERROR("init sub module failed\n");
		return -EPROBE_DEFER;
	}

	/* setup event q */
	mutex_init(&dp->event_mutex);
	init_waitqueue_head(&dp->event_q);
	spin_lock_init(&dp->event_lock);

	/* Store DP audio handle inside DP display */
	dp->dp_display.dp_audio = dp->audio;

	init_completion(&dp->audio_comp);

	platform_set_drvdata(pdev, &dp->dp_display);

	rc = component_add(&pdev->dev, &dp_display_comp_ops);
	if (rc) {
		DRM_ERROR("component add failed, rc=%d\n", rc);
		dp_display_deinit_sub_modules(dp);
	}

	return rc;
}

static int dp_display_remove(struct platform_device *pdev)
{
	struct dp_display_private *dp = dev_get_dp_display_private(&pdev->dev);

	component_del(&pdev->dev, &dp_display_comp_ops);
	dp_display_deinit_sub_modules(dp);

	platform_set_drvdata(pdev, NULL);

	return 0;
}

static int dp_pm_resume(struct device *dev)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct msm_dp *dp_display = platform_get_drvdata(pdev);
	struct dp_display_private *dp;
	int sink_count = 0;

	dp = container_of(dp_display, struct dp_display_private, dp_display);

	mutex_lock(&dp->event_mutex);

	drm_dbg_dp(dp->drm_dev,
		"Before, type=%d core_inited=%d phy_inited=%d power_on=%d\n",
		dp->dp_display.connector_type, dp->core_initialized,
		dp->phy_initialized, dp_display->power_on);

	/* start from disconnected state */
	dp->hpd_state = ST_DISCONNECTED;

	/* turn on dp ctrl/phy */
	dp_display_host_init(dp);

	if (dp_display->is_edp)
		dp_catalog_ctrl_hpd_enable(dp->catalog);

	if (dp_catalog_link_is_connected(dp->catalog)) {
		/*
		 * set sink to normal operation mode -- D0
		 * before dpcd read
		 */
		dp_display_host_phy_init(dp);
		dp_link_psm_config(dp->link, &dp->panel->link_info, false);
		sink_count = drm_dp_read_sink_count(dp->aux);
		if (sink_count < 0)
			sink_count = 0;

		dp_display_host_phy_exit(dp);
	}

	dp->link->sink_count = sink_count;
	/*
	 * can not declared display is connected unless
	 * HDMI cable is plugged in and sink_count of
	 * dongle become 1
	 * also only signal audio when disconnected
	 */
	if (dp->link->sink_count) {
		dp->dp_display.is_connected = true;
	} else {
		dp->dp_display.is_connected = false;
		dp_display_handle_plugged_change(dp_display, false);
	}

	drm_dbg_dp(dp->drm_dev,
		"After, type=%d sink=%d conn=%d core_init=%d phy_init=%d power=%d\n",
		dp->dp_display.connector_type, dp->link->sink_count,
		dp->dp_display.is_connected, dp->core_initialized,
		dp->phy_initialized, dp_display->power_on);

	mutex_unlock(&dp->event_mutex);

	return 0;
}

static int dp_pm_suspend(struct device *dev)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct msm_dp *dp_display = platform_get_drvdata(pdev);
	struct dp_display_private *dp;

	dp = container_of(dp_display, struct dp_display_private, dp_display);

	mutex_lock(&dp->event_mutex);

	drm_dbg_dp(dp->drm_dev,
		"Before, type=%d core_inited=%d  phy_inited=%d power_on=%d\n",
		dp->dp_display.connector_type, dp->core_initialized,
		dp->phy_initialized, dp_display->power_on);

	/* mainlink enabled */
	if (dp_power_clk_status(dp->power, DP_CTRL_PM))
		dp_ctrl_off_link_stream(dp->ctrl);

	dp_display_host_phy_exit(dp);

	/* host_init will be called at pm_resume */
	dp_display_host_deinit(dp);

	dp->hpd_state = ST_SUSPENDED;

	drm_dbg_dp(dp->drm_dev,
		"After, type=%d core_inited=%d phy_inited=%d power_on=%d\n",
		dp->dp_display.connector_type, dp->core_initialized,
		dp->phy_initialized, dp_display->power_on);

	mutex_unlock(&dp->event_mutex);

	return 0;
}

static const struct dev_pm_ops dp_pm_ops = {
	.suspend = dp_pm_suspend,
	.resume =  dp_pm_resume,
};

static struct platform_driver dp_display_driver = {
	.probe  = dp_display_probe,
	.remove = dp_display_remove,
	.driver = {
		.name = "msm-dp-display",
		.of_match_table = dp_dt_match,
		.suppress_bind_attrs = true,
		.pm = &dp_pm_ops,
	},
};

int __init msm_dp_register(void)
{
	int ret;

	ret = platform_driver_register(&dp_display_driver);
	if (ret)
		DRM_ERROR("Dp display driver register failed");

	return ret;
}

void __exit msm_dp_unregister(void)
{
	platform_driver_unregister(&dp_display_driver);
}

void msm_dp_irq_postinstall(struct msm_dp *dp_display)
{
	struct dp_display_private *dp;

	if (!dp_display)
		return;

	dp = container_of(dp_display, struct dp_display_private, dp_display);

	if (!dp_display->is_edp)
		dp_add_event(dp, EV_HPD_INIT_SETUP, 0, 0);
}

bool msm_dp_wide_bus_available(const struct msm_dp *dp_display)
{
	struct dp_display_private *dp;

	dp = container_of(dp_display, struct dp_display_private, dp_display);

	return dp->wide_bus_en;
}

void msm_dp_debugfs_init(struct msm_dp *dp_display, struct drm_minor *minor)
{
	struct dp_display_private *dp;
	struct device *dev;
	int rc;

	dp = container_of(dp_display, struct dp_display_private, dp_display);
	dev = &dp->pdev->dev;

	dp->debug = dp_debug_get(dev, dp->panel,
					dp->link, dp->dp_display.connector,
					minor);
	if (IS_ERR(dp->debug)) {
		rc = PTR_ERR(dp->debug);
		DRM_ERROR("failed to initialize debug, rc = %d\n", rc);
		dp->debug = NULL;
	}
}

static int dp_display_get_next_bridge(struct msm_dp *dp)
{
	int rc;
	struct dp_display_private *dp_priv;
	struct device_node *aux_bus;
	struct device *dev;

	dp_priv = container_of(dp, struct dp_display_private, dp_display);
	dev = &dp_priv->pdev->dev;
	aux_bus = of_get_child_by_name(dev->of_node, "aux-bus");

	if (aux_bus && dp->is_edp) {
		dp_display_host_init(dp_priv);
		dp_catalog_ctrl_hpd_enable(dp_priv->catalog);
		dp_display_host_phy_init(dp_priv);

		/*
		 * The code below assumes that the panel will finish probing
		 * by the time devm_of_dp_aux_populate_ep_devices() returns.
		 * This isn't a great assumption since it will fail if the
		 * panel driver is probed asynchronously but is the best we
		 * can do without a bigger driver reorganization.
		 */
		rc = of_dp_aux_populate_bus(dp_priv->aux, NULL);
		of_node_put(aux_bus);
		if (rc)
			goto error;
	} else if (dp->is_edp) {
		DRM_ERROR("eDP aux_bus not found\n");
		return -ENODEV;
	}

	/*
	 * External bridges are mandatory for eDP interfaces: one has to
	 * provide at least an eDP panel (which gets wrapped into panel-bridge).
	 *
	 * For DisplayPort interfaces external bridges are optional, so
	 * silently ignore an error if one is not present (-ENODEV).
	 */
	rc = devm_dp_parser_find_next_bridge(dp->drm_dev->dev, dp_priv->parser);
	if (!dp->is_edp && rc == -ENODEV)
		return 0;

	if (!rc) {
		dp->next_bridge = dp_priv->parser->next_bridge;
		return 0;
	}

error:
	if (dp->is_edp) {
		of_dp_aux_depopulate_bus(dp_priv->aux);
		dp_display_host_phy_exit(dp_priv);
		dp_display_host_deinit(dp_priv);
	}
	return rc;
}

int msm_dp_modeset_init(struct msm_dp *dp_display, struct drm_device *dev,
			struct drm_encoder *encoder)
{
	struct msm_drm_private *priv = dev->dev_private;
	struct dp_display_private *dp_priv;
	int ret;

	dp_display->drm_dev = dev;

	dp_priv = container_of(dp_display, struct dp_display_private, dp_display);

	ret = dp_display_request_irq(dp_display);
	if (ret) {
		DRM_ERROR("request_irq failed, ret=%d\n", ret);
		return ret;
	}

	ret = dp_display_get_next_bridge(dp_display);
	if (ret)
		return ret;

	dp_display->bridge = dp_bridge_init(dp_display, dev, encoder);
	if (IS_ERR(dp_display->bridge)) {
		ret = PTR_ERR(dp_display->bridge);
		DRM_DEV_ERROR(dev->dev,
			"failed to create dp bridge: %d\n", ret);
		dp_display->bridge = NULL;
		return ret;
	}

	priv->bridges[priv->num_bridges++] = dp_display->bridge;

	dp_display->connector = dp_drm_connector_init(dp_display, encoder);
	if (IS_ERR(dp_display->connector)) {
		ret = PTR_ERR(dp_display->connector);
		DRM_DEV_ERROR(dev->dev,
			"failed to create dp connector: %d\n", ret);
		dp_display->connector = NULL;
		return ret;
	}

	dp_priv->panel->connector = dp_display->connector;

	return 0;
}

void dp_bridge_atomic_enable(struct drm_bridge *drm_bridge,
			     struct drm_bridge_state *old_bridge_state)
{
	struct msm_dp_bridge *dp_bridge = to_dp_bridge(drm_bridge);
	struct msm_dp *dp = dp_bridge->dp_display;
	int rc = 0;
	struct dp_display_private *dp_display;
	u32 state;
	bool force_link_train = false;

	dp_display = container_of(dp, struct dp_display_private, dp_display);
	if (!dp_display->dp_mode.drm_mode.clock) {
		DRM_ERROR("invalid params\n");
		return;
	}

	if (dp->is_edp)
		dp_hpd_plug_handle(dp_display, 0);

	mutex_lock(&dp_display->event_mutex);

	state = dp_display->hpd_state;
	if (state != ST_DISPLAY_OFF && state != ST_MAINLINK_READY) {
		mutex_unlock(&dp_display->event_mutex);
		return;
	}

	rc = dp_display_set_mode(dp, &dp_display->dp_mode);
	if (rc) {
		DRM_ERROR("Failed to perform a mode set, rc=%d\n", rc);
		mutex_unlock(&dp_display->event_mutex);
		return;
	}

	state =  dp_display->hpd_state;

	if (state == ST_DISPLAY_OFF) {
		dp_display_host_phy_init(dp_display);
		force_link_train = true;
	}

	dp_display_enable(dp_display, force_link_train);

	rc = dp_display_post_enable(dp);
	if (rc) {
		DRM_ERROR("DP display post enable failed, rc=%d\n", rc);
		dp_display_disable(dp_display);
	}

	/* completed connection */
	dp_display->hpd_state = ST_CONNECTED;

	drm_dbg_dp(dp->drm_dev, "type=%d Done\n", dp->connector_type);
	mutex_unlock(&dp_display->event_mutex);
}

void dp_bridge_atomic_disable(struct drm_bridge *drm_bridge,
			      struct drm_bridge_state *old_bridge_state)
{
	struct msm_dp_bridge *dp_bridge = to_dp_bridge(drm_bridge);
	struct msm_dp *dp = dp_bridge->dp_display;
	struct dp_display_private *dp_display;

	dp_display = container_of(dp, struct dp_display_private, dp_display);

	dp_ctrl_push_idle(dp_display->ctrl);
}

void dp_bridge_atomic_post_disable(struct drm_bridge *drm_bridge,
				   struct drm_bridge_state *old_bridge_state)
{
	struct msm_dp_bridge *dp_bridge = to_dp_bridge(drm_bridge);
	struct msm_dp *dp = dp_bridge->dp_display;
	u32 state;
	struct dp_display_private *dp_display;

	dp_display = container_of(dp, struct dp_display_private, dp_display);

	if (dp->is_edp)
		dp_hpd_unplug_handle(dp_display, 0);

	mutex_lock(&dp_display->event_mutex);

	state = dp_display->hpd_state;
	if (state != ST_DISCONNECT_PENDING && state != ST_CONNECTED) {
		mutex_unlock(&dp_display->event_mutex);
		return;
	}

	dp_display_disable(dp_display);

	state =  dp_display->hpd_state;
	if (state == ST_DISCONNECT_PENDING) {
		/* completed disconnection */
		dp_display->hpd_state = ST_DISCONNECTED;
	} else {
		dp_display->hpd_state = ST_DISPLAY_OFF;
	}

	drm_dbg_dp(dp->drm_dev, "type=%d Done\n", dp->connector_type);
	mutex_unlock(&dp_display->event_mutex);
}

void dp_bridge_mode_set(struct drm_bridge *drm_bridge,
			const struct drm_display_mode *mode,
			const struct drm_display_mode *adjusted_mode)
{
	struct msm_dp_bridge *dp_bridge = to_dp_bridge(drm_bridge);
	struct msm_dp *dp = dp_bridge->dp_display;
	struct dp_display_private *dp_display;

	dp_display = container_of(dp, struct dp_display_private, dp_display);

	memset(&dp_display->dp_mode, 0x0, sizeof(struct dp_display_mode));

	if (dp_display_check_video_test(dp))
		dp_display->dp_mode.bpp = dp_display_get_test_bpp(dp);
	else /* Default num_components per pixel = 3 */
		dp_display->dp_mode.bpp = dp->connector->display_info.bpc * 3;

	if (!dp_display->dp_mode.bpp)
		dp_display->dp_mode.bpp = 24; /* Default bpp */

	drm_mode_copy(&dp_display->dp_mode.drm_mode, adjusted_mode);

	dp_display->dp_mode.v_active_low =
		!!(dp_display->dp_mode.drm_mode.flags & DRM_MODE_FLAG_NVSYNC);

	dp_display->dp_mode.h_active_low =
		!!(dp_display->dp_mode.drm_mode.flags & DRM_MODE_FLAG_NHSYNC);
}

void dp_bridge_hpd_enable(struct drm_bridge *bridge)
{
	struct msm_dp_bridge *dp_bridge = to_dp_bridge(bridge);
	struct msm_dp *dp_display = dp_bridge->dp_display;
	struct dp_display_private *dp = container_of(dp_display, struct dp_display_private, dp_display);

	mutex_lock(&dp->event_mutex);
	dp_catalog_ctrl_hpd_enable(dp->catalog);

	/* enable HDP interrupts */
	dp_catalog_hpd_config_intr(dp->catalog, DP_DP_HPD_INT_MASK, true);

	dp_display->internal_hpd = true;
	mutex_unlock(&dp->event_mutex);
}

void dp_bridge_hpd_disable(struct drm_bridge *bridge)
{
	struct msm_dp_bridge *dp_bridge = to_dp_bridge(bridge);
	struct msm_dp *dp_display = dp_bridge->dp_display;
	struct dp_display_private *dp = container_of(dp_display, struct dp_display_private, dp_display);

	mutex_lock(&dp->event_mutex);
	/* disable HDP interrupts */
	dp_catalog_hpd_config_intr(dp->catalog, DP_DP_HPD_INT_MASK, false);
	dp_catalog_ctrl_hpd_disable(dp->catalog);

	dp_display->internal_hpd = false;
	mutex_unlock(&dp->event_mutex);
}

void dp_bridge_hpd_notify(struct drm_bridge *bridge,
			  enum drm_connector_status status)
{
	struct msm_dp_bridge *dp_bridge = to_dp_bridge(bridge);
	struct msm_dp *dp_display = dp_bridge->dp_display;
	struct dp_display_private *dp = container_of(dp_display, struct dp_display_private, dp_display);

	/* Without next_bridge interrupts are handled by the DP core directly */
	if (dp_display->internal_hpd)
		return;

	if (!dp->core_initialized) {
		drm_dbg_dp(dp->drm_dev, "not initialized\n");
		return;
	}

	if (!dp_display->is_connected && status == connector_status_connected)
		dp_add_event(dp, EV_HPD_PLUG_INT, 0, 0);
	else if (dp_display->is_connected && status == connector_status_disconnected)
		dp_add_event(dp, EV_HPD_UNPLUG_INT, 0, 0);
}