/*
 * Copyright 2012-15 Advanced Micro Devices, Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 *
 * Authors: AMD
 *
 */

#include "dm_services.h"
#include "atom.h"
#include "dm_helpers.h"
#include "dc.h"
#include "grph_object_id.h"
#include "gpio_service_interface.h"
#include "core_status.h"
#include "dc_link_dp.h"
#include "dc_link_ddc.h"
#include "link_hwss.h"
#include "opp.h"

#include "link_encoder.h"
#include "hw_sequencer.h"
#include "resource.h"
#include "abm.h"
#include "fixed31_32.h"
#include "dpcd_defs.h"
#include "dmcu.h"

#include "dce/dce_11_0_d.h"
#include "dce/dce_11_0_enum.h"
#include "dce/dce_11_0_sh_mask.h"

#define DC_LOGGER_INIT(logger)


#define LINK_INFO(...) \
        DC_LOG_HW_HOTPLUG(  \
                __VA_ARGS__)

#define RETIMER_REDRIVER_INFO(...) \
        DC_LOG_RETIMER_REDRIVER(  \
                __VA_ARGS__)
/*******************************************************************************
 * Private structures
 ******************************************************************************/

enum {
        LINK_RATE_REF_FREQ_IN_MHZ = 27,
        PEAK_FACTOR_X1000 = 1006,
        /*
        * Some receivers fail to train on first try and are good
        * on subsequent tries. 2 retries should be plenty. If we
        * don't have a successful training then we don't expect to
        * ever get one.
        */
        LINK_TRAINING_MAX_VERIFY_RETRY = 2
};

/*******************************************************************************
 * Private functions
 ******************************************************************************/
static void destruct(struct dc_link *link)
{
        int i;

        if (link->ddc)
                dal_ddc_service_destroy(&link->ddc);

        if(link->link_enc)
                link->link_enc->funcs->destroy(&link->link_enc);

        if (link->local_sink)
                dc_sink_release(link->local_sink);

        for (i = 0; i < link->sink_count; ++i)
                dc_sink_release(link->remote_sinks[i]);
}

struct gpio *get_hpd_gpio(struct dc_bios *dcb,
                struct graphics_object_id link_id,
                struct gpio_service *gpio_service)
{
        enum bp_result bp_result;
        struct graphics_object_hpd_info hpd_info;
        struct gpio_pin_info pin_info;

        if (dcb->funcs->get_hpd_info(dcb, link_id, &hpd_info) != BP_RESULT_OK)
                return NULL;

        bp_result = dcb->funcs->get_gpio_pin_info(dcb,
                hpd_info.hpd_int_gpio_uid, &pin_info);

        if (bp_result != BP_RESULT_OK) {
                ASSERT(bp_result == BP_RESULT_NORECORD);
                return NULL;
        }

        return dal_gpio_service_create_irq(
                gpio_service,
                pin_info.offset,
                pin_info.mask);
}

/*
 *  Function: program_hpd_filter
 *
 *  @brief
 *     Programs HPD filter on associated HPD line
 *
 *  @param [in] delay_on_connect_in_ms: Connect filter timeout
 *  @param [in] delay_on_disconnect_in_ms: Disconnect filter timeout
 *
 *  @return
 *     true on success, false otherwise
 */
static bool program_hpd_filter(
        const struct dc_link *link)
{
        bool result = false;

        struct gpio *hpd;

        int delay_on_connect_in_ms = 0;
        int delay_on_disconnect_in_ms = 0;

        if (link->is_hpd_filter_disabled)
                return false;
        /* Verify feature is supported */
        switch (link->connector_signal) {
        case SIGNAL_TYPE_DVI_SINGLE_LINK:
        case SIGNAL_TYPE_DVI_DUAL_LINK:
        case SIGNAL_TYPE_HDMI_TYPE_A:
                /* Program hpd filter */
                delay_on_connect_in_ms = 500;
                delay_on_disconnect_in_ms = 100;
                break;
        case SIGNAL_TYPE_DISPLAY_PORT:
        case SIGNAL_TYPE_DISPLAY_PORT_MST:
                /* Program hpd filter to allow DP signal to settle */
                /* 500: not able to detect MST <-> SST switch as HPD is low for
                 *      only 100ms on DELL U2413
                 * 0:   some passive dongle still show aux mode instead of i2c
                 * 20-50:not enough to hide bouncing HPD with passive dongle.
                 *      also see intermittent i2c read issues.
                 */
                delay_on_connect_in_ms = 80;
                delay_on_disconnect_in_ms = 0;
                break;
        case SIGNAL_TYPE_LVDS:
        case SIGNAL_TYPE_EDP:
        default:
                /* Don't program hpd filter */
                return false;
        }

        /* Obtain HPD handle */
        hpd = get_hpd_gpio(link->ctx->dc_bios, link->link_id, link->ctx->gpio_service);

        if (!hpd)
                return result;

        /* Setup HPD filtering */
        if (dal_gpio_open(hpd, GPIO_MODE_INTERRUPT) == GPIO_RESULT_OK) {
                struct gpio_hpd_config config;

                config.delay_on_connect = delay_on_connect_in_ms;
                config.delay_on_disconnect = delay_on_disconnect_in_ms;

                dal_irq_setup_hpd_filter(hpd, &config);

                dal_gpio_close(hpd);

                result = true;
        } else {
                ASSERT_CRITICAL(false);
        }

        /* Release HPD handle */
        dal_gpio_destroy_irq(&hpd);

        return result;
}

bool dc_link_detect_sink(struct dc_link *link, enum dc_connection_type *type)
{
        uint32_t is_hpd_high = 0;
        struct gpio *hpd_pin;

        if (link->connector_signal == SIGNAL_TYPE_LVDS) {
                *type = dc_connection_single;
                return true;
        }

        if (link->connector_signal == SIGNAL_TYPE_EDP)
                link->dc->hwss.edp_wait_for_hpd_ready(link, true);

        /* todo: may need to lock gpio access */
        hpd_pin = get_hpd_gpio(link->ctx->dc_bios, link->link_id, link->ctx->gpio_service);
        if (hpd_pin == NULL)
                goto hpd_gpio_failure;

        dal_gpio_open(hpd_pin, GPIO_MODE_INTERRUPT);
        dal_gpio_get_value(hpd_pin, &is_hpd_high);
        dal_gpio_close(hpd_pin);
        dal_gpio_destroy_irq(&hpd_pin);

        if (is_hpd_high) {
                *type = dc_connection_single;
                /* TODO: need to do the actual detection */
        } else {
                *type = dc_connection_none;
        }

        return true;

hpd_gpio_failure:
        return false;
}

static enum ddc_transaction_type get_ddc_transaction_type(
                enum signal_type sink_signal)
{
        enum ddc_transaction_type transaction_type = DDC_TRANSACTION_TYPE_NONE;

        switch (sink_signal) {
        case SIGNAL_TYPE_DVI_SINGLE_LINK:
        case SIGNAL_TYPE_DVI_DUAL_LINK:
        case SIGNAL_TYPE_HDMI_TYPE_A:
        case SIGNAL_TYPE_LVDS:
        case SIGNAL_TYPE_RGB:
                transaction_type = DDC_TRANSACTION_TYPE_I2C;
                break;

        case SIGNAL_TYPE_DISPLAY_PORT:
        case SIGNAL_TYPE_EDP:
                transaction_type = DDC_TRANSACTION_TYPE_I2C_OVER_AUX;
                break;

        case SIGNAL_TYPE_DISPLAY_PORT_MST:
                /* MST does not use I2COverAux, but there is the
                 * SPECIAL use case for "immediate dwnstrm device
                 * access" (EPR#370830). */
                transaction_type = DDC_TRANSACTION_TYPE_I2C_OVER_AUX;
                break;

        default:
                break;
        }

        return transaction_type;
}

static enum signal_type get_basic_signal_type(
        struct graphics_object_id encoder,
        struct graphics_object_id downstream)
{
        if (downstream.type == OBJECT_TYPE_CONNECTOR) {
                switch (downstream.id) {
                case CONNECTOR_ID_SINGLE_LINK_DVII:
                        switch (encoder.id) {
                        case ENCODER_ID_INTERNAL_DAC1:
                        case ENCODER_ID_INTERNAL_KLDSCP_DAC1:
                        case ENCODER_ID_INTERNAL_DAC2:
                        case ENCODER_ID_INTERNAL_KLDSCP_DAC2:
                                return SIGNAL_TYPE_RGB;
                        default:
                                return SIGNAL_TYPE_DVI_SINGLE_LINK;
                        }
                break;
                case CONNECTOR_ID_DUAL_LINK_DVII:
                {
                        switch (encoder.id) {
                        case ENCODER_ID_INTERNAL_DAC1:
                        case ENCODER_ID_INTERNAL_KLDSCP_DAC1:
                        case ENCODER_ID_INTERNAL_DAC2:
                        case ENCODER_ID_INTERNAL_KLDSCP_DAC2:
                                return SIGNAL_TYPE_RGB;
                        default:
                                return SIGNAL_TYPE_DVI_DUAL_LINK;
                        }
                }
                break;
                case CONNECTOR_ID_SINGLE_LINK_DVID:
                        return SIGNAL_TYPE_DVI_SINGLE_LINK;
                case CONNECTOR_ID_DUAL_LINK_DVID:
                        return SIGNAL_TYPE_DVI_DUAL_LINK;
                case CONNECTOR_ID_VGA:
                        return SIGNAL_TYPE_RGB;
                case CONNECTOR_ID_HDMI_TYPE_A:
                        return SIGNAL_TYPE_HDMI_TYPE_A;
                case CONNECTOR_ID_LVDS:
                        return SIGNAL_TYPE_LVDS;
                case CONNECTOR_ID_DISPLAY_PORT:
                        return SIGNAL_TYPE_DISPLAY_PORT;
                case CONNECTOR_ID_EDP:
                        return SIGNAL_TYPE_EDP;
                default:
                        return SIGNAL_TYPE_NONE;
                }
        } else if (downstream.type == OBJECT_TYPE_ENCODER) {
                switch (downstream.id) {
                case ENCODER_ID_EXTERNAL_NUTMEG:
                case ENCODER_ID_EXTERNAL_TRAVIS:
                        return SIGNAL_TYPE_DISPLAY_PORT;
                default:
                        return SIGNAL_TYPE_NONE;
                }
        }

        return SIGNAL_TYPE_NONE;
}

/*
 * @brief
 * Check whether there is a dongle on DP connector
 */
bool dc_link_is_dp_sink_present(struct dc_link *link)
{
        enum gpio_result gpio_result;
        uint32_t clock_pin = 0;
        uint8_t retry = 0;
        struct ddc *ddc;

        enum connector_id connector_id =
                dal_graphics_object_id_get_connector_id(link->link_id);

        bool present =
                ((connector_id == CONNECTOR_ID_DISPLAY_PORT) ||
                (connector_id == CONNECTOR_ID_EDP));

        ddc = dal_ddc_service_get_ddc_pin(link->ddc);

        if (!ddc) {
                BREAK_TO_DEBUGGER();
                return present;
        }

        /* Open GPIO and set it to I2C mode */
        /* Note: this GpioMode_Input will be converted
         * to GpioConfigType_I2cAuxDualMode in GPIO component,
         * which indicates we need additional delay */

        if (GPIO_RESULT_OK != dal_ddc_open(
                ddc, GPIO_MODE_INPUT, GPIO_DDC_CONFIG_TYPE_MODE_I2C)) {
                dal_gpio_destroy_ddc(&ddc);

                return present;
        }

        /*
         * Read GPIO: DP sink is present if both clock and data pins are zero
         *
         * [W/A] plug-unplug DP cable, sometimes customer board has
         * one short pulse on clk_pin(1V, < 1ms). DP will be config to HDMI/DVI
         * then monitor can't br light up. Add retry 3 times
         * But in real passive dongle, it need additional 3ms to detect
         */
        do {
                gpio_result = dal_gpio_get_value(ddc->pin_clock, &clock_pin);
                ASSERT(gpio_result == GPIO_RESULT_OK);
                if (clock_pin)
                        udelay(1000);
                else
                        break;
        } while (retry++ < 3);

        present = (gpio_result == GPIO_RESULT_OK) && !clock_pin;

        dal_ddc_close(ddc);

        return present;
}

/*
 * @brief
 * Detect output sink type
 */
static enum signal_type link_detect_sink(
        struct dc_link *link,
        enum dc_detect_reason reason)
{
        enum signal_type result = get_basic_signal_type(
                link->link_enc->id, link->link_id);

        /* Internal digital encoder will detect only dongles
         * that require digital signal */

        /* Detection mechanism is different
         * for different native connectors.
         * LVDS connector supports only LVDS signal;
         * PCIE is a bus slot, the actual connector needs to be detected first;
         * eDP connector supports only eDP signal;
         * HDMI should check straps for audio */

        /* PCIE detects the actual connector on add-on board */

        if (link->link_id.id == CONNECTOR_ID_PCIE) {
                /* ZAZTODO implement PCIE add-on card detection */
        }

        switch (link->link_id.id) {
        case CONNECTOR_ID_HDMI_TYPE_A: {
                /* check audio support:
                 * if native HDMI is not supported, switch to DVI */
                struct audio_support *aud_support = &link->dc->res_pool->audio_support;

                if (!aud_support->hdmi_audio_native)
                        if (link->link_id.id == CONNECTOR_ID_HDMI_TYPE_A)
                                result = SIGNAL_TYPE_DVI_SINGLE_LINK;
        }
        break;
        case CONNECTOR_ID_DISPLAY_PORT: {
                /* DP HPD short pulse. Passive DP dongle will not
                 * have short pulse
                 */
                if (reason != DETECT_REASON_HPDRX) {
                        /* Check whether DP signal detected: if not -
                         * we assume signal is DVI; it could be corrected
                         * to HDMI after dongle detection
                         */
                        if (!dm_helpers_is_dp_sink_present(link))
                                result = SIGNAL_TYPE_DVI_SINGLE_LINK;
                }
        }
        break;
        default:
        break;
        }

        return result;
}

static enum signal_type decide_signal_from_strap_and_dongle_type(
                enum display_dongle_type dongle_type,
                struct audio_support *audio_support)
{
        enum signal_type signal = SIGNAL_TYPE_NONE;

        switch (dongle_type) {
        case DISPLAY_DONGLE_DP_HDMI_DONGLE:
                if (audio_support->hdmi_audio_on_dongle)
                        signal =  SIGNAL_TYPE_HDMI_TYPE_A;
                else
                        signal = SIGNAL_TYPE_DVI_SINGLE_LINK;
                break;
        case DISPLAY_DONGLE_DP_DVI_DONGLE:
                signal = SIGNAL_TYPE_DVI_SINGLE_LINK;
                break;
        case DISPLAY_DONGLE_DP_HDMI_MISMATCHED_DONGLE:
                if (audio_support->hdmi_audio_native)
                        signal =  SIGNAL_TYPE_HDMI_TYPE_A;
                else
                        signal = SIGNAL_TYPE_DVI_SINGLE_LINK;
                break;
        default:
                signal = SIGNAL_TYPE_NONE;
                break;
        }

        return signal;
}

static enum signal_type dp_passive_dongle_detection(
                struct ddc_service *ddc,
                struct display_sink_capability *sink_cap,
                struct audio_support *audio_support)
{
        dal_ddc_service_i2c_query_dp_dual_mode_adaptor(
                                                ddc, sink_cap);
        return decide_signal_from_strap_and_dongle_type(
                        sink_cap->dongle_type,
                        audio_support);
}

static void link_disconnect_sink(struct dc_link *link)
{
        if (link->local_sink) {
                dc_sink_release(link->local_sink);
                link->local_sink = NULL;
        }

        link->dpcd_sink_count = 0;
}

static void link_disconnect_remap(struct dc_sink *prev_sink, struct dc_link *link)
{
        dc_sink_release(link->local_sink);
        link->local_sink = prev_sink;
}


static bool detect_dp(
        struct dc_link *link,
        struct display_sink_capability *sink_caps,
        bool *converter_disable_audio,
        struct audio_support *audio_support,
        enum dc_detect_reason reason)
{
        bool boot = false;
        sink_caps->signal = link_detect_sink(link, reason);
        sink_caps->transaction_type =
                get_ddc_transaction_type(sink_caps->signal);

        if (sink_caps->transaction_type == DDC_TRANSACTION_TYPE_I2C_OVER_AUX) {
                sink_caps->signal = SIGNAL_TYPE_DISPLAY_PORT;
                if (!detect_dp_sink_caps(link))
                        return false;

                if (is_mst_supported(link)) {
                        sink_caps->signal = SIGNAL_TYPE_DISPLAY_PORT_MST;
                        link->type = dc_connection_mst_branch;

                        dal_ddc_service_set_transaction_type(
                                                        link->ddc,
                                                        sink_caps->transaction_type);

                        /*
                         * This call will initiate MST topology discovery. Which
                         * will detect MST ports and add new DRM connector DRM
                         * framework. Then read EDID via remote i2c over aux. In
                         * the end, will notify DRM detect result and save EDID
                         * into DRM framework.
                         *
                         * .detect is called by .fill_modes.
                         * .fill_modes is called by user mode ioctl
                         * DRM_IOCTL_MODE_GETCONNECTOR.
                         *
                         * .get_modes is called by .fill_modes.
                         *
                         * call .get_modes, AMDGPU DM implementation will create
                         * new dc_sink and add to dc_link. For long HPD plug
                         * in/out, MST has its own handle.
                         *
                         * Therefore, just after dc_create, link->sink is not
                         * created for MST until user mode app calls
                         * DRM_IOCTL_MODE_GETCONNECTOR.
                         *
                         * Need check ->sink usages in case ->sink = NULL
                         * TODO: s3 resume check
                         */
                        if (reason == DETECT_REASON_BOOT)
                                boot = true;

                        dm_helpers_dp_update_branch_info(
                                link->ctx,
                                link);

                        if (!dm_helpers_dp_mst_start_top_mgr(
                                link->ctx,
                                link, boot)) {
                                /* MST not supported */
                                link->type = dc_connection_single;
                                sink_caps->signal = SIGNAL_TYPE_DISPLAY_PORT;
                        }
                }

                if (link->type != dc_connection_mst_branch &&
                        is_dp_active_dongle(link)) {
                        /* DP active dongles */
                        link->type = dc_connection_active_dongle;
                        if (!link->dpcd_caps.sink_count.bits.SINK_COUNT) {
                                /*
                                 * active dongle unplug processing for short irq
                                 */
                                link_disconnect_sink(link);
                                return true;
                        }

                        if (link->dpcd_caps.dongle_type != DISPLAY_DONGLE_DP_HDMI_CONVERTER)
                                *converter_disable_audio = true;
                }
        } else {
                /* DP passive dongles */
                sink_caps->signal = dp_passive_dongle_detection(link->ddc,
                                sink_caps,
                                audio_support);
        }

        return true;
}

static bool is_same_edid(struct dc_edid *old_edid, struct dc_edid *new_edid)
{
        if (old_edid->length != new_edid->length)
                return false;

        if (new_edid->length == 0)
                return false;

        return (memcmp(old_edid->raw_edid, new_edid->raw_edid, new_edid->length) == 0);
}

bool dc_link_detect(struct dc_link *link, enum dc_detect_reason reason)
{
        struct dc_sink_init_data sink_init_data = { 0 };
        struct display_sink_capability sink_caps = { 0 };
        uint8_t i;
        bool converter_disable_audio = false;
        struct audio_support *aud_support = &link->dc->res_pool->audio_support;
        bool same_edid = false;
        enum dc_edid_status edid_status;
        struct dc_context *dc_ctx = link->ctx;
        struct dc_sink *sink = NULL;
        struct dc_sink *prev_sink = NULL;
        struct dpcd_caps prev_dpcd_caps;
        bool same_dpcd = true;
        enum dc_connection_type new_connection_type = dc_connection_none;
        DC_LOGGER_INIT(link->ctx->logger);
        if (link->connector_signal == SIGNAL_TYPE_VIRTUAL)
                return false;

        if (false == dc_link_detect_sink(link, &new_connection_type)) {
                BREAK_TO_DEBUGGER();
                return false;
        }

        if (link->connector_signal == SIGNAL_TYPE_EDP &&
                        link->local_sink)
                return true;

        if (link->connector_signal == SIGNAL_TYPE_LVDS &&
                        link->local_sink)
                return true;

        prev_sink = link->local_sink;
        if (prev_sink != NULL) {
                dc_sink_retain(prev_sink);
                memcpy(&prev_dpcd_caps, &link->dpcd_caps, sizeof(struct dpcd_caps));
        }
        link_disconnect_sink(link);

        if (new_connection_type != dc_connection_none) {
                link->type = new_connection_type;

                /* From Disconnected-to-Connected. */
                switch (link->connector_signal) {
                case SIGNAL_TYPE_HDMI_TYPE_A: {
                        sink_caps.transaction_type = DDC_TRANSACTION_TYPE_I2C;
                        if (aud_support->hdmi_audio_native)
                                sink_caps.signal = SIGNAL_TYPE_HDMI_TYPE_A;
                        else
                                sink_caps.signal = SIGNAL_TYPE_DVI_SINGLE_LINK;
                        break;
                }

                case SIGNAL_TYPE_DVI_SINGLE_LINK: {
                        sink_caps.transaction_type = DDC_TRANSACTION_TYPE_I2C;
                        sink_caps.signal = SIGNAL_TYPE_DVI_SINGLE_LINK;
                        break;
                }

                case SIGNAL_TYPE_DVI_DUAL_LINK: {
                        sink_caps.transaction_type = DDC_TRANSACTION_TYPE_I2C;
                        sink_caps.signal = SIGNAL_TYPE_DVI_DUAL_LINK;
                        break;
                }

                case SIGNAL_TYPE_LVDS: {
                        sink_caps.transaction_type = DDC_TRANSACTION_TYPE_I2C;
                        sink_caps.signal = SIGNAL_TYPE_LVDS;
                        break;
                }

                case SIGNAL_TYPE_EDP: {
                        detect_edp_sink_caps(link);
                        sink_caps.transaction_type =
                                DDC_TRANSACTION_TYPE_I2C_OVER_AUX;
                        sink_caps.signal = SIGNAL_TYPE_EDP;
                        break;
                }

                case SIGNAL_TYPE_DISPLAY_PORT: {
                        if (!detect_dp(
                                link,
                                &sink_caps,
                                &converter_disable_audio,
                                aud_support, reason)) {
                                if (prev_sink != NULL)
                                        dc_sink_release(prev_sink);
                                return false;
                        }

                        // Check if dpcp block is the same
                        if (prev_sink != NULL) {
                                if (memcmp(&link->dpcd_caps, &prev_dpcd_caps, sizeof(struct dpcd_caps)))
                                        same_dpcd = false;
                        }
                        /* Active dongle downstream unplug */
                        if (link->type == dc_connection_active_dongle
                                        && link->dpcd_caps.sink_count.
                                        bits.SINK_COUNT == 0) {
                                if (prev_sink != NULL)
                                        dc_sink_release(prev_sink);
                                return true;
                        }

                        if (link->type == dc_connection_mst_branch) {
                                LINK_INFO("link=%d, mst branch is now Connected\n",
                                        link->link_index);
                                /* Need to setup mst link_cap struct here
                                 * otherwise dc_link_detect() will leave mst link_cap
                                 * empty which leads to allocate_mst_payload() has "0"
                                 * pbn_per_slot value leading to exception on dc_fixpt_div()
                                 */
                                link->verified_link_cap = link->reported_link_cap;
                                if (prev_sink != NULL)
                                        dc_sink_release(prev_sink);
                                return false;
                        }

                        break;
                }

                default:
                        DC_ERROR("Invalid connector type! signal:%d\n",
                                link->connector_signal);
                        if (prev_sink != NULL)
                                dc_sink_release(prev_sink);
                        return false;
                } /* switch() */

                if (link->dpcd_caps.sink_count.bits.SINK_COUNT)
                        link->dpcd_sink_count = link->dpcd_caps.sink_count.
                                        bits.SINK_COUNT;
                else
                        link->dpcd_sink_count = 1;

                dal_ddc_service_set_transaction_type(
                                                link->ddc,
                                                sink_caps.transaction_type);

                link->aux_mode = dal_ddc_service_is_in_aux_transaction_mode(
                                link->ddc);

                sink_init_data.link = link;
                sink_init_data.sink_signal = sink_caps.signal;

                sink = dc_sink_create(&sink_init_data);
                if (!sink) {
                        DC_ERROR("Failed to create sink!\n");
                        if (prev_sink != NULL)
                                dc_sink_release(prev_sink);
                        return false;
                }

                sink->dongle_max_pix_clk = sink_caps.max_hdmi_pixel_clock;
                sink->converter_disable_audio = converter_disable_audio;

                link->local_sink = sink;

                edid_status = dm_helpers_read_local_edid(
                                link->ctx,
                                link,
                                sink);

                switch (edid_status) {
                case EDID_BAD_CHECKSUM:
                        DC_LOG_ERROR("EDID checksum invalid.\n");
                        break;
                case EDID_NO_RESPONSE:
                        DC_LOG_ERROR("No EDID read.\n");

                        /*
                         * Abort detection for non-DP connectors if we have
                         * no EDID
                         *
                         * DP needs to report as connected if HDP is high
                         * even if we have no EDID in order to go to
                         * fail-safe mode
                         */
                        if (dc_is_hdmi_signal(link->connector_signal) ||
                            dc_is_dvi_signal(link->connector_signal)) {
                                if (prev_sink != NULL)
                                        dc_sink_release(prev_sink);

                                return false;
                        }
                default:
                        break;
                }

                // Check if edid is the same
                if ((prev_sink != NULL) && ((edid_status == EDID_THE_SAME) || (edid_status == EDID_OK)))
                        same_edid = is_same_edid(&prev_sink->dc_edid, &sink->dc_edid);

                if (link->connector_signal == SIGNAL_TYPE_DISPLAY_PORT &&
                        sink_caps.transaction_type == DDC_TRANSACTION_TYPE_I2C_OVER_AUX &&
                        reason != DETECT_REASON_HPDRX) {
                        /*
                         * TODO debug why Dell 2413 doesn't like
                         *  two link trainings
                         */

                        /* deal with non-mst cases */
                        for (i = 0; i < LINK_TRAINING_MAX_VERIFY_RETRY; i++) {
                                int fail_count = 0;

                                dp_verify_link_cap(link,
                                                  &link->reported_link_cap,
                                                  &fail_count);

                                if (fail_count == 0)
                                        break;
                        }

                } else {
                        // If edid is the same, then discard new sink and revert back to original sink
                        if (same_edid) {
                                link_disconnect_remap(prev_sink, link);
                                sink = prev_sink;
                                prev_sink = NULL;

                        }
                }

                /* HDMI-DVI Dongle */
                if (sink->sink_signal == SIGNAL_TYPE_HDMI_TYPE_A &&
                                !sink->edid_caps.edid_hdmi)
                        sink->sink_signal = SIGNAL_TYPE_DVI_SINGLE_LINK;

                /* Connectivity log: detection */
                for (i = 0; i < sink->dc_edid.length / EDID_BLOCK_SIZE; i++) {
                        CONN_DATA_DETECT(link,
                                        &sink->dc_edid.raw_edid[i * EDID_BLOCK_SIZE],
                                        EDID_BLOCK_SIZE,
                                        "%s: [Block %d] ", sink->edid_caps.display_name, i);
                }

                DC_LOG_DETECTION_EDID_PARSER("%s: "
                        "manufacturer_id = %X, "
                        "product_id = %X, "
                        "serial_number = %X, "
                        "manufacture_week = %d, "
                        "manufacture_year = %d, "
                        "display_name = %s, "
                        "speaker_flag = %d, "
                        "audio_mode_count = %d\n",
                        __func__,
                        sink->edid_caps.manufacturer_id,
                        sink->edid_caps.product_id,
                        sink->edid_caps.serial_number,
                        sink->edid_caps.manufacture_week,
                        sink->edid_caps.manufacture_year,
                        sink->edid_caps.display_name,
                        sink->edid_caps.speaker_flags,
                        sink->edid_caps.audio_mode_count);

                for (i = 0; i < sink->edid_caps.audio_mode_count; i++) {
                        DC_LOG_DETECTION_EDID_PARSER("%s: mode number = %d, "
                                "format_code = %d, "
                                "channel_count = %d, "
                                "sample_rate = %d, "
                                "sample_size = %d\n",
                                __func__,
                                i,
                                sink->edid_caps.audio_modes[i].format_code,
                                sink->edid_caps.audio_modes[i].channel_count,
                                sink->edid_caps.audio_modes[i].sample_rate,
                                sink->edid_caps.audio_modes[i].sample_size);
                }

        } else {
                /* From Connected-to-Disconnected. */
                if (link->type == dc_connection_mst_branch) {
                        LINK_INFO("link=%d, mst branch is now Disconnected\n",
                                link->link_index);

                        dm_helpers_dp_mst_stop_top_mgr(link->ctx, link);

                        link->mst_stream_alloc_table.stream_count = 0;
                        memset(link->mst_stream_alloc_table.stream_allocations, 0, sizeof(link->mst_stream_alloc_table.stream_allocations));
                }

                link->type = dc_connection_none;
                sink_caps.signal = SIGNAL_TYPE_NONE;
        }

        LINK_INFO("link=%d, dc_sink_in=%p is now %s prev_sink=%p dpcd same=%d edid same=%d\n",
                link->link_index, sink,
                (sink_caps.signal == SIGNAL_TYPE_NONE ?
                        "Disconnected":"Connected"), prev_sink,
                        same_dpcd, same_edid);

        if (prev_sink != NULL)
                dc_sink_release(prev_sink);

        return true;
}

bool dc_link_get_hpd_state(struct dc_link *dc_link)
{
        struct gpio *hpd_pin;
        uint32_t state;

        hpd_pin = get_hpd_gpio(dc_link->ctx->dc_bios,
                                        dc_link->link_id, dc_link->ctx->gpio_service);
        if (hpd_pin == NULL)
                ASSERT(false);

        dal_gpio_open(hpd_pin, GPIO_MODE_INTERRUPT);
        dal_gpio_get_value(hpd_pin, &state);
        dal_gpio_close(hpd_pin);
        dal_gpio_destroy_irq(&hpd_pin);

        return state;
}

static enum hpd_source_id get_hpd_line(
                struct dc_link *link)
{
        struct gpio *hpd;
        enum hpd_source_id hpd_id = HPD_SOURCEID_UNKNOWN;

        hpd = get_hpd_gpio(link->ctx->dc_bios, link->link_id, link->ctx->gpio_service);

        if (hpd) {
                switch (dal_irq_get_source(hpd)) {
                case DC_IRQ_SOURCE_HPD1:
                        hpd_id = HPD_SOURCEID1;
                break;
                case DC_IRQ_SOURCE_HPD2:
                        hpd_id = HPD_SOURCEID2;
                break;
                case DC_IRQ_SOURCE_HPD3:
                        hpd_id = HPD_SOURCEID3;
                break;
                case DC_IRQ_SOURCE_HPD4:
                        hpd_id = HPD_SOURCEID4;
                break;
                case DC_IRQ_SOURCE_HPD5:
                        hpd_id = HPD_SOURCEID5;
                break;
                case DC_IRQ_SOURCE_HPD6:
                        hpd_id = HPD_SOURCEID6;
                break;
                default:
                        BREAK_TO_DEBUGGER();
                break;
                }

                dal_gpio_destroy_irq(&hpd);
        }

        return hpd_id;
}

static enum channel_id get_ddc_line(struct dc_link *link)
{
        struct ddc *ddc;
        enum channel_id channel = CHANNEL_ID_UNKNOWN;

        ddc = dal_ddc_service_get_ddc_pin(link->ddc);

        if (ddc) {
                switch (dal_ddc_get_line(ddc)) {
                case GPIO_DDC_LINE_DDC1:
                        channel = CHANNEL_ID_DDC1;
                        break;
                case GPIO_DDC_LINE_DDC2:
                        channel = CHANNEL_ID_DDC2;
                        break;
                case GPIO_DDC_LINE_DDC3:
                        channel = CHANNEL_ID_DDC3;
                        break;
                case GPIO_DDC_LINE_DDC4:
                        channel = CHANNEL_ID_DDC4;
                        break;
                case GPIO_DDC_LINE_DDC5:
                        channel = CHANNEL_ID_DDC5;
                        break;
                case GPIO_DDC_LINE_DDC6:
                        channel = CHANNEL_ID_DDC6;
                        break;
                case GPIO_DDC_LINE_DDC_VGA:
                        channel = CHANNEL_ID_DDC_VGA;
                        break;
                case GPIO_DDC_LINE_I2C_PAD:
                        channel = CHANNEL_ID_I2C_PAD;
                        break;
                default:
                        BREAK_TO_DEBUGGER();
                        break;
                }
        }

        return channel;
}

static enum transmitter translate_encoder_to_transmitter(
        struct graphics_object_id encoder)
{
        switch (encoder.id) {
        case ENCODER_ID_INTERNAL_UNIPHY:
                switch (encoder.enum_id) {
                case ENUM_ID_1:
                        return TRANSMITTER_UNIPHY_A;
                case ENUM_ID_2:
                        return TRANSMITTER_UNIPHY_B;
                default:
                        return TRANSMITTER_UNKNOWN;
                }
        break;
        case ENCODER_ID_INTERNAL_UNIPHY1:
                switch (encoder.enum_id) {
                case ENUM_ID_1:
                        return TRANSMITTER_UNIPHY_C;
                case ENUM_ID_2:
                        return TRANSMITTER_UNIPHY_D;
                default:
                        return TRANSMITTER_UNKNOWN;
                }
        break;
        case ENCODER_ID_INTERNAL_UNIPHY2:
                switch (encoder.enum_id) {
                case ENUM_ID_1:
                        return TRANSMITTER_UNIPHY_E;
                case ENUM_ID_2:
                        return TRANSMITTER_UNIPHY_F;
                default:
                        return TRANSMITTER_UNKNOWN;
                }
        break;
        case ENCODER_ID_INTERNAL_UNIPHY3:
                switch (encoder.enum_id) {
                case ENUM_ID_1:
                        return TRANSMITTER_UNIPHY_G;
                default:
                        return TRANSMITTER_UNKNOWN;
                }
        break;
        case ENCODER_ID_EXTERNAL_NUTMEG:
                switch (encoder.enum_id) {
                case ENUM_ID_1:
                        return TRANSMITTER_NUTMEG_CRT;
                default:
                        return TRANSMITTER_UNKNOWN;
                }
        break;
        case ENCODER_ID_EXTERNAL_TRAVIS:
                switch (encoder.enum_id) {
                case ENUM_ID_1:
                        return TRANSMITTER_TRAVIS_CRT;
                case ENUM_ID_2:
                        return TRANSMITTER_TRAVIS_LCD;
                default:
                        return TRANSMITTER_UNKNOWN;
                }
        break;
        default:
                return TRANSMITTER_UNKNOWN;
        }
}

static bool construct(
        struct dc_link *link,
        const struct link_init_data *init_params)
{
        uint8_t i;
        struct gpio *hpd_gpio = NULL;
        struct ddc_service_init_data ddc_service_init_data = { { 0 } };
        struct dc_context *dc_ctx = init_params->ctx;
        struct encoder_init_data enc_init_data = { 0 };
        struct integrated_info info = {{{ 0 }}};
        struct dc_bios *bios = init_params->dc->ctx->dc_bios;
        const struct dc_vbios_funcs *bp_funcs = bios->funcs;
        DC_LOGGER_INIT(dc_ctx->logger);

        link->irq_source_hpd = DC_IRQ_SOURCE_INVALID;
        link->irq_source_hpd_rx = DC_IRQ_SOURCE_INVALID;

        link->link_status.dpcd_caps = &link->dpcd_caps;

        link->dc = init_params->dc;
        link->ctx = dc_ctx;
        link->link_index = init_params->link_index;

        link->link_id = bios->funcs->get_connector_id(bios, init_params->connector_index);

        if (link->link_id.type != OBJECT_TYPE_CONNECTOR) {
                dm_error("%s: Invalid Connector ObjectID from Adapter Service for connector index:%d! type %d expected %d\n",
                         __func__, init_params->connector_index,
                         link->link_id.type, OBJECT_TYPE_CONNECTOR);
                goto create_fail;
        }

        if (link->dc->res_pool->funcs->link_init)
                link->dc->res_pool->funcs->link_init(link);

        hpd_gpio = get_hpd_gpio(link->ctx->dc_bios, link->link_id, link->ctx->gpio_service);

        if (hpd_gpio != NULL)
                link->irq_source_hpd = dal_irq_get_source(hpd_gpio);

        switch (link->link_id.id) {
        case CONNECTOR_ID_HDMI_TYPE_A:
                link->connector_signal = SIGNAL_TYPE_HDMI_TYPE_A;

                break;
        case CONNECTOR_ID_SINGLE_LINK_DVID:
        case CONNECTOR_ID_SINGLE_LINK_DVII:
                link->connector_signal = SIGNAL_TYPE_DVI_SINGLE_LINK;
                break;
        case CONNECTOR_ID_DUAL_LINK_DVID:
        case CONNECTOR_ID_DUAL_LINK_DVII:
                link->connector_signal = SIGNAL_TYPE_DVI_DUAL_LINK;
                break;
        case CONNECTOR_ID_DISPLAY_PORT:
                link->connector_signal =        SIGNAL_TYPE_DISPLAY_PORT;

                if (hpd_gpio != NULL)
                        link->irq_source_hpd_rx =
                                        dal_irq_get_rx_source(hpd_gpio);

                break;
        case CONNECTOR_ID_EDP:
                link->connector_signal = SIGNAL_TYPE_EDP;

                if (hpd_gpio != NULL) {
                        link->irq_source_hpd = DC_IRQ_SOURCE_INVALID;
                        link->irq_source_hpd_rx =
                                        dal_irq_get_rx_source(hpd_gpio);
                }
                break;
        case CONNECTOR_ID_LVDS:
                link->connector_signal = SIGNAL_TYPE_LVDS;
                break;
        default:
                DC_LOG_WARNING("Unsupported Connector type:%d!\n", link->link_id.id);
                goto create_fail;
        }

        if (hpd_gpio != NULL) {
                dal_gpio_destroy_irq(&hpd_gpio);
                hpd_gpio = NULL;
        }

        /* TODO: #DAL3 Implement id to str function.*/
        LINK_INFO("Connector[%d] description:"
                        "signal %d\n",
                        init_params->connector_index,
                        link->connector_signal);

        ddc_service_init_data.ctx = link->ctx;
        ddc_service_init_data.id = link->link_id;
        ddc_service_init_data.link = link;
        link->ddc = dal_ddc_service_create(&ddc_service_init_data);

        if (link->ddc == NULL) {
                DC_ERROR("Failed to create ddc_service!\n");
                goto ddc_create_fail;
        }

        link->ddc_hw_inst =
                dal_ddc_get_line(
                        dal_ddc_service_get_ddc_pin(link->ddc));

        enc_init_data.ctx = dc_ctx;
        bp_funcs->get_src_obj(dc_ctx->dc_bios, link->link_id, 0, &enc_init_data.encoder);
        enc_init_data.connector = link->link_id;
        enc_init_data.channel = get_ddc_line(link);
        enc_init_data.hpd_source = get_hpd_line(link);

        link->hpd_src = enc_init_data.hpd_source;

        enc_init_data.transmitter =
                        translate_encoder_to_transmitter(enc_init_data.encoder);
        link->link_enc = link->dc->res_pool->funcs->link_enc_create(
                                                                &enc_init_data);

        if( link->link_enc == NULL) {
                DC_ERROR("Failed to create link encoder!\n");
                goto link_enc_create_fail;
        }

        link->link_enc_hw_inst = link->link_enc->transmitter;

        for (i = 0; i < 4; i++) {
                if (BP_RESULT_OK !=
                                bp_funcs->get_device_tag(dc_ctx->dc_bios, link->link_id, i, &link->device_tag)) {
                        DC_ERROR("Failed to find device tag!\n");
                        goto device_tag_fail;
                }

                /* Look for device tag that matches connector signal,
                 * CRT for rgb, LCD for other supported signal tyes
                 */
                if (!bp_funcs->is_device_id_supported(dc_ctx->dc_bios, link->device_tag.dev_id))
                        continue;
                if (link->device_tag.dev_id.device_type == DEVICE_TYPE_CRT
                        && link->connector_signal != SIGNAL_TYPE_RGB)
                        continue;
                if (link->device_tag.dev_id.device_type == DEVICE_TYPE_LCD
                        && link->connector_signal == SIGNAL_TYPE_RGB)
                        continue;
                break;
        }

        if (bios->integrated_info)
                info = *bios->integrated_info;

        /* Look for channel mapping corresponding to connector and device tag */
        for (i = 0; i < MAX_NUMBER_OF_EXT_DISPLAY_PATH; i++) {
                struct external_display_path *path =
                        &info.ext_disp_conn_info.path[i];
                if (path->device_connector_id.enum_id == link->link_id.enum_id
                        && path->device_connector_id.id == link->link_id.id
                        && path->device_connector_id.type == link->link_id.type) {

                        if (link->device_tag.acpi_device != 0
                                && path->device_acpi_enum == link->device_tag.acpi_device) {
                                link->ddi_channel_mapping = path->channel_mapping;
                                link->chip_caps = path->caps;
                        } else if (path->device_tag ==
                                        link->device_tag.dev_id.raw_device_tag) {
                                link->ddi_channel_mapping = path->channel_mapping;
                                link->chip_caps = path->caps;
                        }
                        break;
                }
        }

        /*
         * TODO check if GPIO programmed correctly
         *
         * If GPIO isn't programmed correctly HPD might not rise or drain
         * fast enough, leading to bounces.
         */
        program_hpd_filter(link);

        return true;
device_tag_fail:
        link->link_enc->funcs->destroy(&link->link_enc);
link_enc_create_fail:
        dal_ddc_service_destroy(&link->ddc);
ddc_create_fail:
create_fail:

        if (hpd_gpio != NULL) {
                dal_gpio_destroy_irq(&hpd_gpio);
        }

        return false;
}

/*******************************************************************************
 * Public functions
 ******************************************************************************/
struct dc_link *link_create(const struct link_init_data *init_params)
{
        struct dc_link *link =
                        kzalloc(sizeof(*link), GFP_KERNEL);

        if (NULL == link)
                goto alloc_fail;

        if (false == construct(link, init_params))
                goto construct_fail;

        return link;

construct_fail:
        kfree(link);

alloc_fail:
        return NULL;
}

void link_destroy(struct dc_link **link)
{
        destruct(*link);
        kfree(*link);
        *link = NULL;
}

static void dpcd_configure_panel_mode(
        struct dc_link *link,
        enum dp_panel_mode panel_mode)
{
        union dpcd_edp_config edp_config_set;
        bool panel_mode_edp = false;
        DC_LOGGER_INIT(link->ctx->logger);

        memset(&edp_config_set, '\0', sizeof(union dpcd_edp_config));

        if (DP_PANEL_MODE_DEFAULT != panel_mode) {

                switch (panel_mode) {
                case DP_PANEL_MODE_EDP:
                case DP_PANEL_MODE_SPECIAL:
                        panel_mode_edp = true;
                        break;

                default:
                        break;
                }

                /*set edp panel mode in receiver*/
                core_link_read_dpcd(
                        link,
                        DP_EDP_CONFIGURATION_SET,
                        &edp_config_set.raw,
                        sizeof(edp_config_set.raw));

                if (edp_config_set.bits.PANEL_MODE_EDP
                        != panel_mode_edp) {
                        enum ddc_result result = DDC_RESULT_UNKNOWN;

                        edp_config_set.bits.PANEL_MODE_EDP =
                        panel_mode_edp;
                        result = core_link_write_dpcd(
                                link,
                                DP_EDP_CONFIGURATION_SET,
                                &edp_config_set.raw,
                                sizeof(edp_config_set.raw));

                        ASSERT(result == DDC_RESULT_SUCESSFULL);
                }
        }
        DC_LOG_DETECTION_DP_CAPS("Link: %d eDP panel mode supported: %d "
                        "eDP panel mode enabled: %d \n",
                        link->link_index,
                        link->dpcd_caps.panel_mode_edp,
                        panel_mode_edp);
}

static void enable_stream_features(struct pipe_ctx *pipe_ctx)
{
        struct dc_stream_state *stream = pipe_ctx->stream;
        struct dc_link *link = stream->sink->link;
        union down_spread_ctrl old_downspread;
        union down_spread_ctrl new_downspread;

        core_link_read_dpcd(link, DP_DOWNSPREAD_CTRL,
                        &old_downspread.raw, sizeof(old_downspread));

        new_downspread.raw = old_downspread.raw;

        new_downspread.bits.IGNORE_MSA_TIMING_PARAM =
                        (stream->ignore_msa_timing_param) ? 1 : 0;

        if (new_downspread.raw != old_downspread.raw) {
                core_link_write_dpcd(link, DP_DOWNSPREAD_CTRL,
                        &new_downspread.raw, sizeof(new_downspread));
        }
}

static enum dc_status enable_link_dp(
                struct dc_state *state,
                struct pipe_ctx *pipe_ctx)
{
        struct dc_stream_state *stream = pipe_ctx->stream;
        enum dc_status status;
        bool skip_video_pattern;
        struct dc_link *link = stream->sink->link;
        struct dc_link_settings link_settings = {0};
        enum dp_panel_mode panel_mode;
        enum dc_link_rate max_link_rate = LINK_RATE_HIGH2;

        /* get link settings for video mode timing */
        decide_link_settings(stream, &link_settings);

        /* raise clock state for HBR3 if required. Confirmed with HW DCE/DPCS
         * logic for HBR3 still needs Nominal (0.8V) on VDDC rail
         */
        if (link->link_enc->features.flags.bits.IS_HBR3_CAPABLE)
                max_link_rate = LINK_RATE_HIGH3;

        if (link_settings.link_rate == max_link_rate) {
                struct dc_clocks clocks = state->bw.dcn.clk;

                /* dce/dcn compat, do not update dispclk */
                clocks.dispclk_khz = 0;
                /* 27mhz = 27000000hz= 27000khz */
                clocks.phyclk_khz = link_settings.link_rate * 27000;

                state->dis_clk->funcs->update_clocks(
                                state->dis_clk, &clocks, false);
        }

        dp_enable_link_phy(
                link,
                pipe_ctx->stream->signal,
                pipe_ctx->clock_source->id,
                &link_settings);

        if (stream->sink->edid_caps.panel_patch.dppowerup_delay > 0) {
                int delay_dp_power_up_in_ms = stream->sink->edid_caps.panel_patch.dppowerup_delay;

                msleep(delay_dp_power_up_in_ms);
        }

        panel_mode = dp_get_panel_mode(link);
        dpcd_configure_panel_mode(link, panel_mode);

        skip_video_pattern = true;

        if (link_settings.link_rate == LINK_RATE_LOW)
                        skip_video_pattern = false;

        if (perform_link_training_with_retries(
                        link,
                        &link_settings,
                        skip_video_pattern,
                        LINK_TRAINING_ATTEMPTS)) {
                link->cur_link_settings = link_settings;
                status = DC_OK;
        }
        else
                status = DC_FAIL_DP_LINK_TRAINING;

        enable_stream_features(pipe_ctx);

        return status;
}

static enum dc_status enable_link_edp(
                struct dc_state *state,
                struct pipe_ctx *pipe_ctx)
{
        enum dc_status status;
        struct dc_stream_state *stream = pipe_ctx->stream;
        struct dc_link *link = stream->sink->link;
        /*in case it is not on*/
        link->dc->hwss.edp_power_control(link, true);
        link->dc->hwss.edp_wait_for_hpd_ready(link, true);

        status = enable_link_dp(state, pipe_ctx);


        return status;
}

static enum dc_status enable_link_dp_mst(
                struct dc_state *state,
                struct pipe_ctx *pipe_ctx)
{
        struct dc_link *link = pipe_ctx->stream->sink->link;

        /* sink signal type after MST branch is MST. Multiple MST sinks
         * share one link. Link DP PHY is enable or training only once.
         */
        if (link->cur_link_settings.lane_count != LANE_COUNT_UNKNOWN)
                return DC_OK;

        /* clear payload table */
        dm_helpers_dp_mst_clear_payload_allocation_table(link->ctx, link);

        /* set the sink to MST mode before enabling the link */
        dp_enable_mst_on_sink(link, true);

        return enable_link_dp(state, pipe_ctx);
}

static bool get_ext_hdmi_settings(struct pipe_ctx *pipe_ctx,
                enum engine_id eng_id,
                struct ext_hdmi_settings *settings)
{
        bool result = false;
        int i = 0;
        struct integrated_info *integrated_info =
                        pipe_ctx->stream->ctx->dc_bios->integrated_info;

        if (integrated_info == NULL)
                return false;

        /*
         * Get retimer settings from sbios for passing SI eye test for DCE11
         * The setting values are varied based on board revision and port id
         * Therefore the setting values of each ports is passed by sbios.
         */

        // Check if current bios contains ext Hdmi settings
        if (integrated_info->gpu_cap_info & 0x20) {
                switch (eng_id) {
                case ENGINE_ID_DIGA:
                        settings->slv_addr = integrated_info->dp0_ext_hdmi_slv_addr;
                        settings->reg_num = integrated_info->dp0_ext_hdmi_6g_reg_num;
                        settings->reg_num_6g = integrated_info->dp0_ext_hdmi_6g_reg_num;
                        memmove(settings->reg_settings,
                                        integrated_info->dp0_ext_hdmi_reg_settings,
                                        sizeof(integrated_info->dp0_ext_hdmi_reg_settings));
                        memmove(settings->reg_settings_6g,
                                        integrated_info->dp0_ext_hdmi_6g_reg_settings,
                                        sizeof(integrated_info->dp0_ext_hdmi_6g_reg_settings));
                        result = true;
                        break;
                case ENGINE_ID_DIGB:
                        settings->slv_addr = integrated_info->dp1_ext_hdmi_slv_addr;
                        settings->reg_num = integrated_info->dp1_ext_hdmi_6g_reg_num;
                        settings->reg_num_6g = integrated_info->dp1_ext_hdmi_6g_reg_num;
                        memmove(settings->reg_settings,
                                        integrated_info->dp1_ext_hdmi_reg_settings,
                                        sizeof(integrated_info->dp1_ext_hdmi_reg_settings));
                        memmove(settings->reg_settings_6g,
                                        integrated_info->dp1_ext_hdmi_6g_reg_settings,
                                        sizeof(integrated_info->dp1_ext_hdmi_6g_reg_settings));
                        result = true;
                        break;
                case ENGINE_ID_DIGC:
                        settings->slv_addr = integrated_info->dp2_ext_hdmi_slv_addr;
                        settings->reg_num = integrated_info->dp2_ext_hdmi_6g_reg_num;
                        settings->reg_num_6g = integrated_info->dp2_ext_hdmi_6g_reg_num;
                        memmove(settings->reg_settings,
                                        integrated_info->dp2_ext_hdmi_reg_settings,
                                        sizeof(integrated_info->dp2_ext_hdmi_reg_settings));
                        memmove(settings->reg_settings_6g,
                                        integrated_info->dp2_ext_hdmi_6g_reg_settings,
                                        sizeof(integrated_info->dp2_ext_hdmi_6g_reg_settings));
                        result = true;
                        break;
                case ENGINE_ID_DIGD:
                        settings->slv_addr = integrated_info->dp3_ext_hdmi_slv_addr;
                        settings->reg_num = integrated_info->dp3_ext_hdmi_6g_reg_num;
                        settings->reg_num_6g = integrated_info->dp3_ext_hdmi_6g_reg_num;
                        memmove(settings->reg_settings,
                                        integrated_info->dp3_ext_hdmi_reg_settings,
                                        sizeof(integrated_info->dp3_ext_hdmi_reg_settings));
                        memmove(settings->reg_settings_6g,
                                        integrated_info->dp3_ext_hdmi_6g_reg_settings,
                                        sizeof(integrated_info->dp3_ext_hdmi_6g_reg_settings));
                        result = true;
                        break;
                default:
                        break;
                }

                if (result == true) {
                        // Validate settings from bios integrated info table
                        if (settings->slv_addr == 0)
                                return false;
                        if (settings->reg_num > 9)
                                return false;
                        if (settings->reg_num_6g > 3)
                                return false;

                        for (i = 0; i < settings->reg_num; i++) {
                                if (settings->reg_settings[i].i2c_reg_index > 0x20)
                                        return false;
                        }

                        for (i = 0; i < settings->reg_num_6g; i++) {
                                if (settings->reg_settings_6g[i].i2c_reg_index > 0x20)
                                        return false;
                        }
                }
        }

        return result;
}

static bool i2c_write(struct pipe_ctx *pipe_ctx,
                uint8_t address, uint8_t *buffer, uint32_t length)
{
        struct i2c_command cmd = {0};
        struct i2c_payload payload = {0};

        memset(&payload, 0, sizeof(payload));
        memset(&cmd, 0, sizeof(cmd));

        cmd.number_of_payloads = 1;
        cmd.engine = I2C_COMMAND_ENGINE_DEFAULT;
        cmd.speed = pipe_ctx->stream->ctx->dc->caps.i2c_speed_in_khz;

        payload.address = address;
        payload.data = buffer;
        payload.length = length;
        payload.write = true;
        cmd.payloads = &payload;

        if (dm_helpers_submit_i2c(pipe_ctx->stream->ctx,
                        pipe_ctx->stream->sink->link, &cmd))
                return true;

        return false;
}

static void write_i2c_retimer_setting(
                struct pipe_ctx *pipe_ctx,
                bool is_vga_mode,
                bool is_over_340mhz,
                struct ext_hdmi_settings *settings)
{
        uint8_t slave_address = (settings->slv_addr >> 1);
        uint8_t buffer[2];
        const uint8_t apply_rx_tx_change = 0x4;
        uint8_t offset = 0xA;
        uint8_t value = 0;
        int i = 0;
        bool i2c_success = false;
        DC_LOGGER_INIT(pipe_ctx->stream->ctx->logger);

        memset(&buffer, 0, sizeof(buffer));

        /* Start Ext-Hdmi programming*/

        for (i = 0; i < settings->reg_num; i++) {
                /* Apply 3G settings */
                if (settings->reg_settings[i].i2c_reg_index <= 0x20) {

                        buffer[0] = settings->reg_settings[i].i2c_reg_index;
                        buffer[1] = settings->reg_settings[i].i2c_reg_val;
                        i2c_success = i2c_write(pipe_ctx, slave_address,
                                                buffer, sizeof(buffer));
                        RETIMER_REDRIVER_INFO("retimer write to slave_address = 0x%x,\
                                offset = 0x%x, reg_val= 0x%x, i2c_success = %d\n",
                                slave_address, buffer[0], buffer[1], i2c_success?1:0);

                        if (!i2c_success)
                                /* Write failure */
                                ASSERT(i2c_success);

                        /* Based on DP159 specs, APPLY_RX_TX_CHANGE bit in 0x0A
                         * needs to be set to 1 on every 0xA-0xC write.
                         */
                        if (settings->reg_settings[i].i2c_reg_index == 0xA ||
                                settings->reg_settings[i].i2c_reg_index == 0xB ||
                                settings->reg_settings[i].i2c_reg_index == 0xC) {

                                /* Query current value from offset 0xA */
                                if (settings->reg_settings[i].i2c_reg_index == 0xA)
                                        value = settings->reg_settings[i].i2c_reg_val;
                                else {
                                        i2c_success =
                                                dal_ddc_service_query_ddc_data(
                                                pipe_ctx->stream->sink->link->ddc,
                                                slave_address, &offset, 1, &value, 1);
                                        if (!i2c_success)
                                                /* Write failure */
                                                ASSERT(i2c_success);
                                }

                                buffer[0] = offset;
                                /* Set APPLY_RX_TX_CHANGE bit to 1 */
                                buffer[1] = value | apply_rx_tx_change;
                                i2c_success = i2c_write(pipe_ctx, slave_address,
                                                buffer, sizeof(buffer));
                                RETIMER_REDRIVER_INFO("retimer write to slave_address = 0x%x,\
                                        offset = 0x%x, reg_val = 0x%x, i2c_success = %d\n",
                                        slave_address, buffer[0], buffer[1], i2c_success?1:0);
                                if (!i2c_success)
                                        /* Write failure */
                                        ASSERT(i2c_success);
                        }
                }
        }

        /* Apply 3G settings */
        if (is_over_340mhz) {
                for (i = 0; i < settings->reg_num_6g; i++) {
                        /* Apply 3G settings */
                        if (settings->reg_settings[i].i2c_reg_index <= 0x20) {

                                buffer[0] = settings->reg_settings_6g[i].i2c_reg_index;
                                buffer[1] = settings->reg_settings_6g[i].i2c_reg_val;
                                i2c_success = i2c_write(pipe_ctx, slave_address,
                                                        buffer, sizeof(buffer));
                                RETIMER_REDRIVER_INFO("above 340Mhz: retimer write to slave_address = 0x%x,\
                                        offset = 0x%x, reg_val = 0x%x, i2c_success = %d\n",
                                        slave_address, buffer[0], buffer[1], i2c_success?1:0);

                                if (!i2c_success)
                                        /* Write failure */
                                        ASSERT(i2c_success);

                                /* Based on DP159 specs, APPLY_RX_TX_CHANGE bit in 0x0A
                                 * needs to be set to 1 on every 0xA-0xC write.
                                 */
                                if (settings->reg_settings_6g[i].i2c_reg_index == 0xA ||
                                        settings->reg_settings_6g[i].i2c_reg_index == 0xB ||
                                        settings->reg_settings_6g[i].i2c_reg_index == 0xC) {

                                        /* Query current value from offset 0xA */
                                        if (settings->reg_settings_6g[i].i2c_reg_index == 0xA)
                                                value = settings->reg_settings_6g[i].i2c_reg_val;
                                        else {
                                                i2c_success =
                                                                dal_ddc_service_query_ddc_data(
                                                                pipe_ctx->stream->sink->link->ddc,
                                                                slave_address, &offset, 1, &value, 1);
                                                if (!i2c_success)
                                                        /* Write failure */
                                                        ASSERT(i2c_success);
                                        }

                                        buffer[0] = offset;
                                        /* Set APPLY_RX_TX_CHANGE bit to 1 */
                                        buffer[1] = value | apply_rx_tx_change;
                                        i2c_success = i2c_write(pipe_ctx, slave_address,
                                                        buffer, sizeof(buffer));
                                        RETIMER_REDRIVER_INFO("retimer write to slave_address = 0x%x,\
                                                offset = 0x%x, reg_val = 0x%x, i2c_success = %d\n",
                                                slave_address, buffer[0], buffer[1], i2c_success?1:0);
                                        if (!i2c_success)
                                                /* Write failure */
                                                ASSERT(i2c_success);
                                }
                        }
                }
        }

        if (is_vga_mode) {
                /* Program additional settings if using 640x480 resolution */

                /* Write offset 0xFF to 0x01 */
                buffer[0] = 0xff;
                buffer[1] = 0x01;
                i2c_success = i2c_write(pipe_ctx, slave_address,
                                buffer, sizeof(buffer));
                RETIMER_REDRIVER_INFO("retimer write to slave_address = 0x%x,\
                                offset = 0x%x, reg_val = 0x%x, i2c_success = %d\n",
                                slave_address, buffer[0], buffer[1], i2c_success?1:0);
                if (!i2c_success)
                        /* Write failure */
                        ASSERT(i2c_success);

                /* Write offset 0x00 to 0x23 */
                buffer[0] = 0x00;
                buffer[1] = 0x23;
                i2c_success = i2c_write(pipe_ctx, slave_address,
                                buffer, sizeof(buffer));
                RETIMER_REDRIVER_INFO("retimer write to slave_address = 0x%x,\
                        offset = 0x%x, reg_val = 0x%x, i2c_success = %d\n",
                        slave_address, buffer[0], buffer[1], i2c_success?1:0);
                if (!i2c_success)
                        /* Write failure */
                        ASSERT(i2c_success);

                /* Write offset 0xff to 0x00 */
                buffer[0] = 0xff;
                buffer[1] = 0x00;
                i2c_success = i2c_write(pipe_ctx, slave_address,
                                buffer, sizeof(buffer));
                RETIMER_REDRIVER_INFO("retimer write to slave_address = 0x%x,\
                        offset = 0x%x, reg_val = 0x%x, i2c_success = %d\n",
                        slave_address, buffer[0], buffer[1], i2c_success?1:0);
                if (!i2c_success)
                        /* Write failure */
                        ASSERT(i2c_success);

        }
}

static void write_i2c_default_retimer_setting(
                struct pipe_ctx *pipe_ctx,
                bool is_vga_mode,
                bool is_over_340mhz)
{
        uint8_t slave_address = (0xBA >> 1);
        uint8_t buffer[2];
        bool i2c_success = false;
        DC_LOGGER_INIT(pipe_ctx->stream->ctx->logger);

        memset(&buffer, 0, sizeof(buffer));

        /* Program Slave Address for tuning single integrity */
        /* Write offset 0x0A to 0x13 */
        buffer[0] = 0x0A;
        buffer[1] = 0x13;
        i2c_success = i2c_write(pipe_ctx, slave_address,
                        buffer, sizeof(buffer));
        RETIMER_REDRIVER_INFO("retimer writes default setting to slave_address = 0x%x,\
                offset = 0x%x, reg_val = 0x%x, i2c_success = %d\n",
                slave_address, buffer[0], buffer[1], i2c_success?1:0);
        if (!i2c_success)
                /* Write failure */
                ASSERT(i2c_success);

        /* Write offset 0x0A to 0x17 */
        buffer[0] = 0x0A;
        buffer[1] = 0x17;
        i2c_success = i2c_write(pipe_ctx, slave_address,
                        buffer, sizeof(buffer));
        RETIMER_REDRIVER_INFO("retimer write to slave_addr = 0x%x,\
                offset = 0x%x, reg_val = 0x%x, i2c_success = %d\n",
                slave_address, buffer[0], buffer[1], i2c_success?1:0);
        if (!i2c_success)
                /* Write failure */
                ASSERT(i2c_success);

        /* Write offset 0x0B to 0xDA or 0xD8 */
        buffer[0] = 0x0B;
        buffer[1] = is_over_340mhz ? 0xDA : 0xD8;
        i2c_success = i2c_write(pipe_ctx, slave_address,
                        buffer, sizeof(buffer));
        RETIMER_REDRIVER_INFO("retimer write to slave_addr = 0x%x,\
                offset = 0x%x, reg_val = 0x%x, i2c_success = %d\n",
                slave_address, buffer[0], buffer[1], i2c_success?1:0);
        if (!i2c_success)
                /* Write failure */
                ASSERT(i2c_success);

        /* Write offset 0x0A to 0x17 */
        buffer[0] = 0x0A;
        buffer[1] = 0x17;
        i2c_success = i2c_write(pipe_ctx, slave_address,
                        buffer, sizeof(buffer));
        RETIMER_REDRIVER_INFO("retimer write to slave_addr = 0x%x,\
                offset = 0x%x, reg_val= 0x%x, i2c_success = %d\n",
                slave_address, buffer[0], buffer[1], i2c_success?1:0);
        if (!i2c_success)
                /* Write failure */
                ASSERT(i2c_success);

        /* Write offset 0x0C to 0x1D or 0x91 */
        buffer[0] = 0x0C;
        buffer[1] = is_over_340mhz ? 0x1D : 0x91;
        i2c_success = i2c_write(pipe_ctx, slave_address,
                        buffer, sizeof(buffer));
        RETIMER_REDRIVER_INFO("retimer write to slave_addr = 0x%x,\
                offset = 0x%x, reg_val = 0x%x, i2c_success = %d\n",
                slave_address, buffer[0], buffer[1], i2c_success?1:0);
        if (!i2c_success)
                /* Write failure */
                ASSERT(i2c_success);

        /* Write offset 0x0A to 0x17 */
        buffer[0] = 0x0A;
        buffer[1] = 0x17;
        i2c_success = i2c_write(pipe_ctx, slave_address,
                        buffer, sizeof(buffer));
        RETIMER_REDRIVER_INFO("retimer write to slave_addr = 0x%x,\
                offset = 0x%x, reg_val = 0x%x, i2c_success = %d\n",
                slave_address, buffer[0], buffer[1], i2c_success?1:0);
        if (!i2c_success)
                /* Write failure */
                ASSERT(i2c_success);


        if (is_vga_mode) {
                /* Program additional settings if using 640x480 resolution */

                /* Write offset 0xFF to 0x01 */
                buffer[0] = 0xff;
                buffer[1] = 0x01;
                i2c_success = i2c_write(pipe_ctx, slave_address,
                                buffer, sizeof(buffer));
                RETIMER_REDRIVER_INFO("retimer write to slave_addr = 0x%x,\
                        offset = 0x%x, reg_val = 0x%x, i2c_success = %d\n",
                        slave_address, buffer[0], buffer[1], i2c_success?1:0);
                if (!i2c_success)
                        /* Write failure */
                        ASSERT(i2c_success);

                /* Write offset 0x00 to 0x23 */
                buffer[0] = 0x00;
                buffer[1] = 0x23;
                i2c_success = i2c_write(pipe_ctx, slave_address,
                                buffer, sizeof(buffer));
                RETIMER_REDRIVER_INFO("retimer write to slave_addr = 0x%x,\
                        offset = 0x%x, reg_val= 0x%x, i2c_success = %d\n",
                        slave_address, buffer[0], buffer[1], i2c_success?1:0);
                if (!i2c_success)
                        /* Write failure */
                        ASSERT(i2c_success);

                /* Write offset 0xff to 0x00 */
                buffer[0] = 0xff;
                buffer[1] = 0x00;
                i2c_success = i2c_write(pipe_ctx, slave_address,
                                buffer, sizeof(buffer));
                RETIMER_REDRIVER_INFO("retimer write default setting to slave_addr = 0x%x,\
                        offset = 0x%x, reg_val= 0x%x, i2c_success = %d end here\n",
                        slave_address, buffer[0], buffer[1], i2c_success?1:0);
                if (!i2c_success)
                        /* Write failure */
                        ASSERT(i2c_success);
        }
}

static void write_i2c_redriver_setting(
                struct pipe_ctx *pipe_ctx,
                bool is_over_340mhz)
{
        uint8_t slave_address = (0xF0 >> 1);
        uint8_t buffer[16];
        bool i2c_success = false;
        DC_LOGGER_INIT(pipe_ctx->stream->ctx->logger);

        memset(&buffer, 0, sizeof(buffer));

        // Program Slave Address for tuning single integrity
        buffer[3] = 0x4E;
        buffer[4] = 0x4E;
        buffer[5] = 0x4E;
        buffer[6] = is_over_340mhz ? 0x4E : 0x4A;

        i2c_success = i2c_write(pipe_ctx, slave_address,
                                        buffer, sizeof(buffer));
        RETIMER_REDRIVER_INFO("redriver write 0 to all 16 reg offset expect following:\n\
                \t slave_addr = 0x%x, offset[3] = 0x%x, offset[4] = 0x%x,\
                offset[5] = 0x%x,offset[6] is_over_340mhz = 0x%x,\
                i2c_success = %d\n",
                slave_address, buffer[3], buffer[4], buffer[5], buffer[6], i2c_success?1:0);

        if (!i2c_success)
                /* Write failure */
                ASSERT(i2c_success);
}

static void enable_link_hdmi(struct pipe_ctx *pipe_ctx)
{
        struct dc_stream_state *stream = pipe_ctx->stream;
        struct dc_link *link = stream->sink->link;
        enum dc_color_depth display_color_depth;
        enum engine_id eng_id;
        struct ext_hdmi_settings settings = {0};
        bool is_over_340mhz = false;
        bool is_vga_mode = (stream->timing.h_addressable == 640)
                        && (stream->timing.v_addressable == 480);

        if (stream->phy_pix_clk == 0)
                stream->phy_pix_clk = stream->timing.pix_clk_khz;
        if (stream->phy_pix_clk > 340000)
                is_over_340mhz = true;

        if (dc_is_hdmi_signal(pipe_ctx->stream->signal)) {
                unsigned short masked_chip_caps = pipe_ctx->stream->sink->link->chip_caps &
                                EXT_DISPLAY_PATH_CAPS__EXT_CHIP_MASK;
                if (masked_chip_caps == EXT_DISPLAY_PATH_CAPS__HDMI20_TISN65DP159RSBT) {
                        /* DP159, Retimer settings */
                        eng_id = pipe_ctx->stream_res.stream_enc->id;

                        if (get_ext_hdmi_settings(pipe_ctx, eng_id, &settings)) {
                                write_i2c_retimer_setting(pipe_ctx,
                                                is_vga_mode, is_over_340mhz, &settings);
                        } else {
                                write_i2c_default_retimer_setting(pipe_ctx,
                                                is_vga_mode, is_over_340mhz);
                        }
                } else if (masked_chip_caps == EXT_DISPLAY_PATH_CAPS__HDMI20_PI3EQX1204) {
                        /* PI3EQX1204, Redriver settings */
                        write_i2c_redriver_setting(pipe_ctx, is_over_340mhz);
                }
        }

        if (dc_is_hdmi_signal(pipe_ctx->stream->signal))
                dal_ddc_service_write_scdc_data(
                        stream->sink->link->ddc,
                        stream->phy_pix_clk,
                        stream->timing.flags.LTE_340MCSC_SCRAMBLE);

        memset(&stream->sink->link->cur_link_settings, 0,
                        sizeof(struct dc_link_settings));

        display_color_depth = stream->timing.display_color_depth;
        if (stream->timing.pixel_encoding == PIXEL_ENCODING_YCBCR422)
                display_color_depth = COLOR_DEPTH_888;

        link->link_enc->funcs->enable_tmds_output(
                        link->link_enc,
                        pipe_ctx->clock_source->id,
                        display_color_depth,
                        pipe_ctx->stream->signal,
                        stream->phy_pix_clk);

        if (pipe_ctx->stream->signal == SIGNAL_TYPE_HDMI_TYPE_A)
                dal_ddc_service_read_scdc_data(link->ddc);
}

static void enable_link_lvds(struct pipe_ctx *pipe_ctx)
{
        struct dc_stream_state *stream = pipe_ctx->stream;
        struct dc_link *link = stream->sink->link;

        if (stream->phy_pix_clk == 0)
                stream->phy_pix_clk = stream->timing.pix_clk_khz;

        memset(&stream->sink->link->cur_link_settings, 0,
                        sizeof(struct dc_link_settings));

        link->link_enc->funcs->enable_lvds_output(
                        link->link_enc,
                        pipe_ctx->clock_source->id,
                        stream->phy_pix_clk);

}

/****************************enable_link***********************************/
static enum dc_status enable_link(
                struct dc_state *state,
                struct pipe_ctx *pipe_ctx)
{
        enum dc_status status = DC_ERROR_UNEXPECTED;
        switch (pipe_ctx->stream->signal) {
        case SIGNAL_TYPE_DISPLAY_PORT:
                status = enable_link_dp(state, pipe_ctx);
                break;
        case SIGNAL_TYPE_EDP:
                status = enable_link_edp(state, pipe_ctx);
                break;
        case SIGNAL_TYPE_DISPLAY_PORT_MST:
                status = enable_link_dp_mst(state, pipe_ctx);
                msleep(200);
                break;
        case SIGNAL_TYPE_DVI_SINGLE_LINK:
        case SIGNAL_TYPE_DVI_DUAL_LINK:
        case SIGNAL_TYPE_HDMI_TYPE_A:
                enable_link_hdmi(pipe_ctx);
                status = DC_OK;
                break;
        case SIGNAL_TYPE_LVDS:
                enable_link_lvds(pipe_ctx);
                status = DC_OK;
                break;
        case SIGNAL_TYPE_VIRTUAL:
                status = DC_OK;
                break;
        default:
                break;
        }

        return status;
}

static void disable_link(struct dc_link *link, enum signal_type signal)
{
        /*
         * TODO: implement call for dp_set_hw_test_pattern
         * it is needed for compliance testing
         */

        /* here we need to specify that encoder output settings
         * need to be calculated as for the set mode,
         * it will lead to querying dynamic link capabilities
         * which should be done before enable output */

        if (dc_is_dp_signal(signal)) {
                /* SST DP, eDP */
                if (dc_is_dp_sst_signal(signal))
                        dp_disable_link_phy(link, signal);
                else
                        dp_disable_link_phy_mst(link, signal);
        } else
                link->link_enc->funcs->disable_output(link->link_enc, signal);
}

static bool dp_active_dongle_validate_timing(
                const struct dc_crtc_timing *timing,
                const struct dpcd_caps *dpcd_caps)
{
        unsigned int required_pix_clk = timing->pix_clk_khz;
        const struct dc_dongle_caps *dongle_caps = &dpcd_caps->dongle_caps;

        switch (dpcd_caps->dongle_type) {
        case DISPLAY_DONGLE_DP_VGA_CONVERTER:
        case DISPLAY_DONGLE_DP_DVI_CONVERTER:
        case DISPLAY_DONGLE_DP_DVI_DONGLE:
                if (timing->pixel_encoding == PIXEL_ENCODING_RGB)
                        return true;
                else
                        return false;
        default:
                break;
        }

        if (dongle_caps->dongle_type != DISPLAY_DONGLE_DP_HDMI_CONVERTER ||
                dongle_caps->extendedCapValid == false)
                return true;

        /* Check Pixel Encoding */
        switch (timing->pixel_encoding) {
        case PIXEL_ENCODING_RGB:
        case PIXEL_ENCODING_YCBCR444:
                break;
        case PIXEL_ENCODING_YCBCR422:
                if (!dongle_caps->is_dp_hdmi_ycbcr422_pass_through)
                        return false;
                break;
        case PIXEL_ENCODING_YCBCR420:
                if (!dongle_caps->is_dp_hdmi_ycbcr420_pass_through)
                        return false;
                break;
        default:
                /* Invalid Pixel Encoding*/
                return false;
        }


        /* Check Color Depth and Pixel Clock */
        if (timing->pixel_encoding == PIXEL_ENCODING_YCBCR420)
                required_pix_clk /= 2;
        else if (timing->pixel_encoding == PIXEL_ENCODING_YCBCR422)
                required_pix_clk = required_pix_clk * 2 / 3;

        switch (timing->display_color_depth) {
        case COLOR_DEPTH_666:
        case COLOR_DEPTH_888:
                /*888 and 666 should always be supported*/
                break;
        case COLOR_DEPTH_101010:
                if (dongle_caps->dp_hdmi_max_bpc < 10)
                        return false;
                required_pix_clk = required_pix_clk * 10 / 8;
                break;
        case COLOR_DEPTH_121212:
                if (dongle_caps->dp_hdmi_max_bpc < 12)
                        return false;
                required_pix_clk = required_pix_clk * 12 / 8;
                break;

        case COLOR_DEPTH_141414:
        case COLOR_DEPTH_161616:
        default:
                /* These color depths are currently not supported */
                return false;
        }

        if (required_pix_clk > dongle_caps->dp_hdmi_max_pixel_clk)
                return false;

        return true;
}

enum dc_status dc_link_validate_mode_timing(
                const struct dc_stream_state *stream,
                struct dc_link *link,
                const struct dc_crtc_timing *timing)
{
        uint32_t max_pix_clk = stream->sink->dongle_max_pix_clk;
        struct dpcd_caps *dpcd_caps = &link->dpcd_caps;

        /* A hack to avoid failing any modes for EDID override feature on
         * topology change such as lower quality cable for DP or different dongle
         */
        if (link->remote_sinks[0])
                return DC_OK;

        /* Passive Dongle */
        if (0 != max_pix_clk && timing->pix_clk_khz > max_pix_clk)
                return DC_EXCEED_DONGLE_CAP;

        /* Active Dongle*/
        if (!dp_active_dongle_validate_timing(timing, dpcd_caps))
                return DC_EXCEED_DONGLE_CAP;

        switch (stream->signal) {
        case SIGNAL_TYPE_EDP:
        case SIGNAL_TYPE_DISPLAY_PORT:
                if (!dp_validate_mode_timing(
                                link,
                                timing))
                        return DC_NO_DP_LINK_BANDWIDTH;
                break;

        default:
                break;
        }

        return DC_OK;
}

int dc_link_get_backlight_level(const struct dc_link *link)
{
        struct abm *abm = link->ctx->dc->res_pool->abm;

        if (abm == NULL || abm->funcs->get_current_backlight_8_bit == NULL)
                return DC_ERROR_UNEXPECTED;

        return (int) abm->funcs->get_current_backlight_8_bit(abm);
}

bool dc_link_set_backlight_level(const struct dc_link *link, uint32_t level,
                uint32_t frame_ramp, const struct dc_stream_state *stream)
{
        struct dc  *core_dc = link->ctx->dc;
        struct abm *abm = core_dc->res_pool->abm;
        struct dmcu *dmcu = core_dc->res_pool->dmcu;
        unsigned int controller_id = 0;
        bool use_smooth_brightness = true;
        int i;
        DC_LOGGER_INIT(link->ctx->logger);

        if ((dmcu == NULL) ||
                (abm == NULL) ||
                (abm->funcs->set_backlight_level == NULL))
                return false;

        if (stream) {
                if (stream->bl_pwm_level == EDP_BACKLIGHT_RAMP_DISABLE_LEVEL)
                        frame_ramp = 0;

                ((struct dc_stream_state *)stream)->bl_pwm_level = level;
        }

        use_smooth_brightness = dmcu->funcs->is_dmcu_initialized(dmcu);

        DC_LOG_BACKLIGHT("New Backlight level: %d (0x%X)\n", level, level);

        if (dc_is_embedded_signal(link->connector_signal)) {
                if (stream != NULL) {
                        for (i = 0; i < MAX_PIPES; i++) {
                                if (core_dc->current_state->res_ctx.
                                                pipe_ctx[i].stream
                                                == stream)
                                        /* DMCU -1 for all controller id values,
                                         * therefore +1 here
                                         */
                                        controller_id =
                                                core_dc->current_state->
                                                res_ctx.pipe_ctx[i].stream_res.tg->inst +
                                                1;
                        }
                }
                abm->funcs->set_backlight_level(
                                abm,
                                level,
                                frame_ramp,
                                controller_id,
                                use_smooth_brightness);
        }

        return true;
}

bool dc_link_set_abm_disable(const struct dc_link *link)
{
        struct dc  *core_dc = link->ctx->dc;
        struct abm *abm = core_dc->res_pool->abm;

        if ((abm == NULL) || (abm->funcs->set_backlight_level == NULL))
                return false;

        abm->funcs->set_abm_immediate_disable(abm);

        return true;
}

bool dc_link_set_psr_enable(const struct dc_link *link, bool enable, bool wait)
{
        struct dc  *core_dc = link->ctx->dc;
        struct dmcu *dmcu = core_dc->res_pool->dmcu;

        if (dmcu != NULL && link->psr_enabled)
                dmcu->funcs->set_psr_enable(dmcu, enable, wait);

        return true;
}

const struct dc_link_status *dc_link_get_status(const struct dc_link *link)
{
        return &link->link_status;
}

void core_link_resume(struct dc_link *link)
{
        if (link->connector_signal != SIGNAL_TYPE_VIRTUAL)
                program_hpd_filter(link);
}

static struct fixed31_32 get_pbn_per_slot(struct dc_stream_state *stream)
{
        struct dc_link_settings *link_settings =
                        &stream->sink->link->cur_link_settings;
        uint32_t link_rate_in_mbps =
                        link_settings->link_rate * LINK_RATE_REF_FREQ_IN_MHZ;
        struct fixed31_32 mbps = dc_fixpt_from_int(
                        link_rate_in_mbps * link_settings->lane_count);

        return dc_fixpt_div_int(mbps, 54);
}

static int get_color_depth(enum dc_color_depth color_depth)
{
        switch (color_depth) {
        case COLOR_DEPTH_666: return 6;
        case COLOR_DEPTH_888: return 8;
        case COLOR_DEPTH_101010: return 10;
        case COLOR_DEPTH_121212: return 12;
        case COLOR_DEPTH_141414: return 14;
        case COLOR_DEPTH_161616: return 16;
        default: return 0;
        }
}

static struct fixed31_32 get_pbn_from_timing(struct pipe_ctx *pipe_ctx)
{
        uint32_t bpc;
        uint64_t kbps;
        struct fixed31_32 peak_kbps;
        uint32_t numerator;
        uint32_t denominator;

        bpc = get_color_depth(pipe_ctx->stream_res.pix_clk_params.color_depth);
        kbps = pipe_ctx->stream_res.pix_clk_params.requested_pix_clk * bpc * 3;

        /*
         * margin 5300ppm + 300ppm ~ 0.6% as per spec, factor is 1.006
         * The unit of 54/64Mbytes/sec is an arbitrary unit chosen based on
         * common multiplier to render an integer PBN for all link rate/lane
         * counts combinations
         * calculate
         * peak_kbps *= (1006/1000)
         * peak_kbps *= (64/54)
         * peak_kbps *= 8    convert to bytes
         */

        numerator = 64 * PEAK_FACTOR_X1000;
        denominator = 54 * 8 * 1000 * 1000;
        kbps *= numerator;
        peak_kbps = dc_fixpt_from_fraction(kbps, denominator);

        return peak_kbps;
}

static void update_mst_stream_alloc_table(
        struct dc_link *link,
        struct stream_encoder *stream_enc,
        const struct dp_mst_stream_allocation_table *proposed_table)
{
        struct link_mst_stream_allocation work_table[MAX_CONTROLLER_NUM] = {
                        { 0 } };
        struct link_mst_stream_allocation *dc_alloc;

        int i;
        int j;

        /* if DRM proposed_table has more than one new payload */
        ASSERT(proposed_table->stream_count -
                        link->mst_stream_alloc_table.stream_count < 2);

        /* copy proposed_table to link, add stream encoder */
        for (i = 0; i < proposed_table->stream_count; i++) {

                for (j = 0; j < link->mst_stream_alloc_table.stream_count; j++) {
                        dc_alloc =
                        &link->mst_stream_alloc_table.stream_allocations[j];

                        if (dc_alloc->vcp_id ==
                                proposed_table->stream_allocations[i].vcp_id) {

                                work_table[i] = *dc_alloc;
                                break; /* exit j loop */
                        }
                }

                /* new vcp_id */
                if (j == link->mst_stream_alloc_table.stream_count) {
                        work_table[i].vcp_id =
                                proposed_table->stream_allocations[i].vcp_id;
                        work_table[i].slot_count =
                                proposed_table->stream_allocations[i].slot_count;
                        work_table[i].stream_enc = stream_enc;
                }
        }

        /* update link->mst_stream_alloc_table with work_table */
        link->mst_stream_alloc_table.stream_count =
                        proposed_table->stream_count;
        for (i = 0; i < MAX_CONTROLLER_NUM; i++)
                link->mst_stream_alloc_table.stream_allocations[i] =
                                work_table[i];
}

/* convert link_mst_stream_alloc_table to dm dp_mst_stream_alloc_table
 * because stream_encoder is not exposed to dm
 */
static enum dc_status allocate_mst_payload(struct pipe_ctx *pipe_ctx)
{
        struct dc_stream_state *stream = pipe_ctx->stream;
        struct dc_link *link = stream->sink->link;
        struct link_encoder *link_encoder = link->link_enc;
        struct stream_encoder *stream_encoder = pipe_ctx->stream_res.stream_enc;
        struct dp_mst_stream_allocation_table proposed_table = {0};
        struct fixed31_32 avg_time_slots_per_mtp;
        struct fixed31_32 pbn;
        struct fixed31_32 pbn_per_slot;
        uint8_t i;
        DC_LOGGER_INIT(link->ctx->logger);

        /* enable_link_dp_mst already check link->enabled_stream_count
         * and stream is in link->stream[]. This is called during set mode,
         * stream_enc is available.
         */

        /* get calculate VC payload for stream: stream_alloc */
        if (dm_helpers_dp_mst_write_payload_allocation_table(
                stream->ctx,
                stream,
                &proposed_table,
                true)) {
                update_mst_stream_alloc_table(
                                        link, pipe_ctx->stream_res.stream_enc, &proposed_table);
        }
        else
                DC_LOG_WARNING("Failed to update"
                                "MST allocation table for"
                                "pipe idx:%d\n",
                                pipe_ctx->pipe_idx);

        DC_LOG_MST("%s  "
                        "stream_count: %d: \n ",
                        __func__,
                        link->mst_stream_alloc_table.stream_count);

        for (i = 0; i < MAX_CONTROLLER_NUM; i++) {
                DC_LOG_MST("stream_enc[%d]: %p      "
                "stream[%d].vcp_id: %d      "
                "stream[%d].slot_count: %d\n",
                i,
                (void *) link->mst_stream_alloc_table.stream_allocations[i].stream_enc,
                i,
                link->mst_stream_alloc_table.stream_allocations[i].vcp_id,
                i,
                link->mst_stream_alloc_table.stream_allocations[i].slot_count);
        }

        ASSERT(proposed_table.stream_count > 0);

        /* program DP source TX for payload */
        link_encoder->funcs->update_mst_stream_allocation_table(
                link_encoder,
                &link->mst_stream_alloc_table);

        /* send down message */
        dm_helpers_dp_mst_poll_for_allocation_change_trigger(
                        stream->ctx,
                        stream);

        dm_helpers_dp_mst_send_payload_allocation(
                        stream->ctx,
                        stream,
                        true);

        /* slot X.Y for only current stream */
        pbn_per_slot = get_pbn_per_slot(stream);
        pbn = get_pbn_from_timing(pipe_ctx);
        avg_time_slots_per_mtp = dc_fixpt_div(pbn, pbn_per_slot);

        stream_encoder->funcs->set_mst_bandwidth(
                stream_encoder,
                avg_time_slots_per_mtp);

        return DC_OK;

}

static enum dc_status deallocate_mst_payload(struct pipe_ctx *pipe_ctx)
{
        struct dc_stream_state *stream = pipe_ctx->stream;
        struct dc_link *link = stream->sink->link;
        struct link_encoder *link_encoder = link->link_enc;
        struct stream_encoder *stream_encoder = pipe_ctx->stream_res.stream_enc;
        struct dp_mst_stream_allocation_table proposed_table = {0};
        struct fixed31_32 avg_time_slots_per_mtp = dc_fixpt_from_int(0);
        uint8_t i;
        bool mst_mode = (link->type == dc_connection_mst_branch);
        DC_LOGGER_INIT(link->ctx->logger);

        /* deallocate_mst_payload is called before disable link. When mode or
         * disable/enable monitor, new stream is created which is not in link
         * stream[] yet. For this, payload is not allocated yet, so de-alloc
         * should not done. For new mode set, map_resources will get engine
         * for new stream, so stream_enc->id should be validated until here.
         */

        /* slot X.Y */
        stream_encoder->funcs->set_mst_bandwidth(
                stream_encoder,
                avg_time_slots_per_mtp);

        /* TODO: which component is responsible for remove payload table? */
        if (mst_mode) {
                if (dm_helpers_dp_mst_write_payload_allocation_table(
                                stream->ctx,
                                stream,
                                &proposed_table,
                                false)) {

                        update_mst_stream_alloc_table(
                                link, pipe_ctx->stream_res.stream_enc, &proposed_table);
                }
                else {
                                DC_LOG_WARNING("Failed to update"
                                                "MST allocation table for"
                                                "pipe idx:%d\n",
                                                pipe_ctx->pipe_idx);
                }
        }

        DC_LOG_MST("%s"
                        "stream_count: %d: ",
                        __func__,
                        link->mst_stream_alloc_table.stream_count);

        for (i = 0; i < MAX_CONTROLLER_NUM; i++) {
                DC_LOG_MST("stream_enc[%d]: %p      "
                "stream[%d].vcp_id: %d      "
                "stream[%d].slot_count: %d\n",
                i,
                (void *) link->mst_stream_alloc_table.stream_allocations[i].stream_enc,
                i,
                link->mst_stream_alloc_table.stream_allocations[i].vcp_id,
                i,
                link->mst_stream_alloc_table.stream_allocations[i].slot_count);
        }

        link_encoder->funcs->update_mst_stream_allocation_table(
                link_encoder,
                &link->mst_stream_alloc_table);

        if (mst_mode) {
                dm_helpers_dp_mst_poll_for_allocation_change_trigger(
                        stream->ctx,
                        stream);

                dm_helpers_dp_mst_send_payload_allocation(
                        stream->ctx,
                        stream,
                        false);
        }

        return DC_OK;
}

void core_link_enable_stream(
                struct dc_state *state,
                struct pipe_ctx *pipe_ctx)
{
        struct dc  *core_dc = pipe_ctx->stream->ctx->dc;
        struct dc_stream_state *stream = pipe_ctx->stream;
        enum dc_status status;
        DC_LOGGER_INIT(pipe_ctx->stream->ctx->logger);

        if (pipe_ctx->stream->signal != SIGNAL_TYPE_VIRTUAL) {
                stream->sink->link->link_enc->funcs->setup(
                        stream->sink->link->link_enc,
                        pipe_ctx->stream->signal);
                pipe_ctx->stream_res.stream_enc->funcs->setup_stereo_sync(
                        pipe_ctx->stream_res.stream_enc,
                        pipe_ctx->stream_res.tg->inst,
                        stream->timing.timing_3d_format != TIMING_3D_FORMAT_NONE);
        }

        if (dc_is_dp_signal(pipe_ctx->stream->signal))
                pipe_ctx->stream_res.stream_enc->funcs->dp_set_stream_attribute(
                        pipe_ctx->stream_res.stream_enc,
                        &stream->timing,
                        stream->output_color_space);

        if (dc_is_hdmi_signal(pipe_ctx->stream->signal))
                pipe_ctx->stream_res.stream_enc->funcs->hdmi_set_stream_attribute(
                        pipe_ctx->stream_res.stream_enc,
                        &stream->timing,
                        stream->phy_pix_clk,
                        pipe_ctx->stream_res.audio != NULL);

        if (dc_is_dvi_signal(pipe_ctx->stream->signal))
                pipe_ctx->stream_res.stream_enc->funcs->dvi_set_stream_attribute(
                        pipe_ctx->stream_res.stream_enc,
                        &stream->timing,
                        (pipe_ctx->stream->signal == SIGNAL_TYPE_DVI_DUAL_LINK) ?
                        true : false);

        if (dc_is_lvds_signal(pipe_ctx->stream->signal))
                pipe_ctx->stream_res.stream_enc->funcs->lvds_set_stream_attribute(
                        pipe_ctx->stream_res.stream_enc,
                        &stream->timing);

        if (!IS_FPGA_MAXIMUS_DC(core_dc->ctx->dce_environment)) {
                resource_build_info_frame(pipe_ctx);
                core_dc->hwss.update_info_frame(pipe_ctx);

                /* eDP lit up by bios already, no need to enable again. */
                if (pipe_ctx->stream->signal == SIGNAL_TYPE_EDP &&
                                pipe_ctx->stream->apply_edp_fast_boot_optimization) {
                        pipe_ctx->stream->apply_edp_fast_boot_optimization = false;
                        pipe_ctx->stream->dpms_off = false;
                        return;
                }

                if (pipe_ctx->stream->dpms_off)
                        return;

                status = enable_link(state, pipe_ctx);

                if (status != DC_OK) {
                        DC_LOG_WARNING("enabling link %u failed: %d\n",
                        pipe_ctx->stream->sink->link->link_index,
                        status);

                        /* Abort stream enable *unless* the failure was due to
                         * DP link training - some DP monitors will recover and
                         * show the stream anyway. But MST displays can't proceed
                         * without link training.
                         */
                        if (status != DC_FAIL_DP_LINK_TRAINING ||
                                        pipe_ctx->stream->signal == SIGNAL_TYPE_DISPLAY_PORT_MST) {
                                BREAK_TO_DEBUGGER();
                                return;
                        }
                }

                core_dc->hwss.enable_audio_stream(pipe_ctx);

                /* turn off otg test pattern if enable */
                if (pipe_ctx->stream_res.tg->funcs->set_test_pattern)
                        pipe_ctx->stream_res.tg->funcs->set_test_pattern(pipe_ctx->stream_res.tg,
                                        CONTROLLER_DP_TEST_PATTERN_VIDEOMODE,
                                        COLOR_DEPTH_UNDEFINED);

                core_dc->hwss.enable_stream(pipe_ctx);

                if (pipe_ctx->stream->signal == SIGNAL_TYPE_DISPLAY_PORT_MST)
                        allocate_mst_payload(pipe_ctx);

                core_dc->hwss.unblank_stream(pipe_ctx,
                        &pipe_ctx->stream->sink->link->cur_link_settings);

        }

}

void core_link_disable_stream(struct pipe_ctx *pipe_ctx, int option)
{
        struct dc  *core_dc = pipe_ctx->stream->ctx->dc;

        core_dc->hwss.blank_stream(pipe_ctx);

        if (pipe_ctx->stream->signal == SIGNAL_TYPE_DISPLAY_PORT_MST)
                deallocate_mst_payload(pipe_ctx);

        core_dc->hwss.disable_stream(pipe_ctx, option);

        disable_link(pipe_ctx->stream->sink->link, pipe_ctx->stream->signal);
}

void core_link_set_avmute(struct pipe_ctx *pipe_ctx, bool enable)
{
        struct dc  *core_dc = pipe_ctx->stream->ctx->dc;

        if (pipe_ctx->stream->signal != SIGNAL_TYPE_HDMI_TYPE_A)
                return;

        core_dc->hwss.set_avmute(pipe_ctx, enable);
}

/**
 *****************************************************************************
 *  Function: dc_link_enable_hpd_filter
 *
 *  @brief
 *     If enable is true, programs HPD filter on associated HPD line using
 *     delay_on_disconnect/delay_on_connect values dependent on
 *     link->connector_signal
 *
 *     If enable is false, programs HPD filter on associated HPD line with no
 *     delays on connect or disconnect
 *
 *  @param [in] link: pointer to the dc link
 *  @param [in] enable: boolean specifying whether to enable hbd
 *****************************************************************************
 */
void dc_link_enable_hpd_filter(struct dc_link *link, bool enable)
{
        struct gpio *hpd;

        if (enable) {
                link->is_hpd_filter_disabled = false;
                program_hpd_filter(link);
        } else {
                link->is_hpd_filter_disabled = true;
                /* Obtain HPD handle */
                hpd = get_hpd_gpio(link->ctx->dc_bios, link->link_id, link->ctx->gpio_service);

                if (!hpd)
                        return;

                /* Setup HPD filtering */
                if (dal_gpio_open(hpd, GPIO_MODE_INTERRUPT) == GPIO_RESULT_OK) {
                        struct gpio_hpd_config config;

                        config.delay_on_connect = 0;
                        config.delay_on_disconnect = 0;

                        dal_irq_setup_hpd_filter(hpd, &config);

                        dal_gpio_close(hpd);
                } else {
                        ASSERT_CRITICAL(false);
                }
                /* Release HPD handle */
                dal_gpio_destroy_irq(&hpd);
        }
}