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Subject: Re: [PATCH v6 5/6] drm/bridge: add support for MST in mhdp8546
 driver
To:     Damian Kos <dkos@cadence.com>, David Airlie <airlied@linux.ie>,
        Rob Herring <robh+dt@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Archit Taneja <architt@codeaurora.org>,
        Laurent Pinchart <Laurent.pinchart@ideasonboard.com>,
        Gustavo Padovan <gustavo@padovan.org>,
        Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
        Sean Paul <sean@poorly.run>, Sandy Huang <hjc@rock-chips.com>,
        =?UTF-8?Q?Heiko_St=c3=bcbner?= <heiko@sntech.de>,
        Quentin Schulz <quentin.schulz@free-electrons.com>,
        Piotr Sroka <piotrs@cadence.com>,
        dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-rockchip@lists.infradead.org
Cc:     rafalc@cadence.com, quentin.schulz@bootlin.com, jbergsagel@ti.com
From:   Andrzej Hajda <a.hajda@samsung.com>
Message-ID: <4745c0e4-0147-59fd-1dda-c5644dadd10a@samsung.com>
Date:   Wed, 7 Nov 2018 12:40:12 +0100
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On 08.10.2018 23:42, Damian Kos wrote:
> From: Piotr Sroka <piotrs@cadence.com>
>
> - add hot plug support to handle HDP IRQ interrupts in case sideband
>   message is ready to read.
> - there is only one connector created at initialization stage. It is
>   used as SST connector when controller works in SST mode. If controller
>   works in MST mode then the SST connector status is disconnected all the
>   time. MST connectors are created/destroyed in runtime depends on what
>   devices are connected to the DP controller.
> - add callbacks functions to be able to inform module managing encoders
>   objects to create or destroy an encoder in case new a MST connector is
>   created/destroyed


I am not familiar with MST so I will stick to bike-shedding :) Reviewer
with MST experience needed.


>
> Signed-off-by: Piotr Sroka <piotrs@cadence.com>
> Signed-off-by: Damian Kos <dkos@cadence.com>
> ---
>  drivers/gpu/drm/bridge/Makefile        |   2 +-
>  drivers/gpu/drm/bridge/cdns-mhdp-mst.c | 594 +++++++++++++++++++++++++
>  drivers/gpu/drm/bridge/cdns-mhdp.c     | 560 ++++++++++++-----------
>  drivers/gpu/drm/bridge/cdns-mhdp.h     | 209 +++++++++
>  drivers/gpu/drm/rockchip/cdn-dp-core.c |  18 +-
>  include/drm/bridge/cdns-mhdp-cbs.h     |  27 ++
>  include/drm/bridge/cdns-mhdp-common.h  |  48 +-
>  7 files changed, 1189 insertions(+), 269 deletions(-)
>  create mode 100644 drivers/gpu/drm/bridge/cdns-mhdp-mst.c
>  create mode 100644 drivers/gpu/drm/bridge/cdns-mhdp.h
>  create mode 100644 include/drm/bridge/cdns-mhdp-cbs.h
>
> diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
> index e802fdb85750..b80f3d6ed2a6 100644
> --- a/drivers/gpu/drm/bridge/Makefile
> +++ b/drivers/gpu/drm/bridge/Makefile
> @@ -19,4 +19,4 @@ obj-$(CONFIG_DRM_TI_TFP410) += ti-tfp410.o
>  obj-$(CONFIG_DRM_CDNS_MHDP) += mhdp8546.o
>  obj-y += synopsys/
>  
> -mhdp8546-objs := cdns-mhdp-common.o cdns-mhdp.o
> +mhdp8546-objs := cdns-mhdp-common.o cdns-mhdp.o cdns-mhdp-mst.o
> diff --git a/drivers/gpu/drm/bridge/cdns-mhdp-mst.c b/drivers/gpu/drm/bridge/cdns-mhdp-mst.c
> new file mode 100644
> index 000000000000..782d4bf9b667
> --- /dev/null
> +++ b/drivers/gpu/drm/bridge/cdns-mhdp-mst.c
> @@ -0,0 +1,594 @@
> +// SPDX-License-Identifier: GPL v2
> +/*
> + * Cadence MHDP DP MST bridge driver.
> + *
> + * Copyright: 2018 Cadence Design Systems, Inc.
> + *
> + * Author: Piotr Sroka <piotrs@cadence.com>
> + */
> +#include <drm/drm_print.h>
> +#include <drm/drm_crtc_helper.h>
> +#include <drm/drm_atomic_helper.h>
> +#include <drm/drm_fixed.h>
> +#include <drm/drm_connector.h>
> +#include <linux/iopoll.h>
> +
> +#include <drm/bridge/cdns-mhdp-common.h>


Alphabetic order.


> +#include "cdns-mhdp.h"
> +
> +
> +static void cdns_mhdp_mst_stream_enable(struct cdns_mhdp_bridge *mhdp_bridge,
> +					bool enable)
> +{
> +	u32 reg;
> +	struct cdns_mhdp_device *mhdp = mhdp_bridge->mhdp;
> +	u8 stream_id = mhdp_bridge->stream_id;
> +
> +	cdns_mhdp_reg_read(mhdp, CDNS_DP_MST_STREAM_CONFIG(stream_id), &reg);
> +
> +	if (enable) {
> +		reg |= CDNS_DP_MST_STRM_CFG_STREAM_EN;
> +		reg &= ~CDNS_DP_MST_STRM_CFG_NO_VIDEO;
> +	} else {
> +		reg &= ~CDNS_DP_MST_STRM_CFG_STREAM_EN;
> +		reg |= CDNS_DP_MST_STRM_CFG_NO_VIDEO;
> +	}
> +
> +	cdns_mhdp_reg_write(mhdp, CDNS_DP_MST_STREAM_CONFIG(stream_id), reg);
> +}
> +
> +static inline s64 calc_fixed_avg_slots(u32 pbn, u32 pbn_div)
> +{
> +	s64 fixed_pbn, fixed_pbn_div, fixed_targ_avg_slots;
> +
> +	fixed_pbn = drm_int2fixp(pbn);
> +	fixed_pbn_div = drm_int2fixp(pbn_div);
> +	fixed_targ_avg_slots = drm_fixp_div(fixed_pbn, fixed_pbn_div);
> +
> +	return fixed_targ_avg_slots;
> +}
> +
> +static void cdns_mhdp_mst_set_threshold(struct cdns_mhdp_bridge *bridge)
> +{
> +	u32 threshold;
> +	u8 stream_id = bridge->stream_id;
> +	struct cdns_mhdp_device *mhdp = bridge->mhdp;
> +	s64 fixed_targ_avg_slots, fixed_thresh, fixed_targ_entries;
> +
> +	fixed_targ_avg_slots = calc_fixed_avg_slots(bridge->pbn,
> +						    mhdp->mst_mgr.pbn_div);
> +
> +	fixed_targ_entries = drm_fixp_div(fixed_targ_avg_slots,
> +					  drm_int2fixp(2));
> +	fixed_thresh = drm_fixp_mul(fixed_targ_entries, fixed_targ_entries);
> +	fixed_thresh = drm_fixp_div(fixed_thresh, drm_int2fixp(32));
> +	fixed_thresh = fixed_targ_entries - fixed_thresh;
> +	fixed_thresh = drm_fixp_mul(fixed_thresh,
> +				    drm_int2fixp(mhdp->link.num_lanes));
> +	fixed_thresh = drm_fixp_div(fixed_thresh, drm_int2fixp(4));
> +
> +	threshold = drm_fixp2int_ceil(fixed_thresh);
> +	if (threshold < 2)
> +		threshold = 2;
> +
> +	cdns_mhdp_reg_write(mhdp, CDNS_DP_LINE_THRESH(stream_id),
> +			    CDNS_DP_ACTIVE_LINE_THRESH(threshold));


All this magic makes me think I am not a right person to review this
code, or the code is overcomplicated. Lets try layman approach.

Formula is as below:

threshold = (pbn/pbn_div/2 - (pbn/pbn_div/2)^2 / 32)*num_lanes / 4

plus round_up, and cap by 2.

Please describe the formula in comment to increase readability and use
some temporary variables instead of overusing fixed_thresh.

Where this formula comes from? Document it.

Moreover if there is no difference between drm_fixp_div(x,
drm_int2fixp(const)) and div_s64(x, const) I guess the latter is better.


> +}
> +
> +static void cdns_mhdp_set_rate_governing(struct cdns_mhdp_bridge *bridge,
> +					 bool enable)
> +{
> +	struct cdns_mhdp_device *mhdp = bridge->mhdp;
> +	u8 stream_id = bridge->stream_id;
> +
> +	if (enable) {
> +		s64 fixed_targ_avg_slots, fixed_y;
> +		u32 x, y;
> +
> +		fixed_targ_avg_slots =
> +			calc_fixed_avg_slots(bridge->pbn,
> +					     mhdp->mst_mgr.pbn_div);
> +
> +		x = drm_fixp2int(fixed_targ_avg_slots);
> +
> +		fixed_y = (fixed_targ_avg_slots - drm_int2fixp(x));
> +		fixed_y = drm_fixp_mul(fixed_y, drm_int2fixp(16));

Again, maybe fixed_y *= 16;


> +		y = drm_fixp2int_ceil(fixed_y);

Ok, at this point x is integer part of fixed_targ_avg_slots and y is
fractional part of fixed_targ_avg_slots * 16.

Looking at calc_fixed_avg_slots it means, that:

x = bridge->pbn / mhdp->mst_mgr.pbn_div;

y = bridge->pbn % mhdp->mst_mgr.pbn_div * 16 / mhdp->mst_mgr.pbn_div;


Without using fixed arithmetic, more direct?


> +
> +		cdns_mhdp_reg_write(mhdp, CDNS_DP_RATE_GOVERNING(stream_id),
> +				    CDNS_DP_RG_TARG_AV_SLOTS_Y(y) |
> +				    CDNS_DP_RG_TARG_AV_SLOTS_X(x) |
> +				    CDNS_DP_RG_ENABLE);
> +	} else
> +		cdns_mhdp_reg_write(mhdp, CDNS_DP_RATE_GOVERNING(stream_id), 0);
> +}
> +
> +
> +static struct drm_dp_payload *
> +cdns_mhdp_get_payload(struct cdns_mhdp_bridge *bridge)
> +{
> +	int vcpi = bridge->connector->port->vcpi.vcpi, i;
> +	struct cdns_mhdp_device *mhdp = bridge->mhdp;
> +
> +	for (i = 0; i < mhdp->mst_mgr.max_payloads; i++) {
> +		struct drm_dp_payload *payload = &mhdp->mst_mgr.payloads[i];
> +
> +		if (payload->vcpi == vcpi)
> +			return payload;
> +	}
> +
> +	return NULL;
> +}
> +
> +
> +static int
> +cdns_mhdp_set_act_enable(struct cdns_mhdp_device *mhdp)
> +{
> +	u32 reg;
> +	int ret;
> +
> +	cdns_mhdp_reg_read(mhdp, CDNS_DP_MTPH_CONTROL, &reg);
> +	cdns_mhdp_reg_write(mhdp, CDNS_DP_MTPH_CONTROL,
> +			    reg | CDNS_DP_MTPH_ACT_EN);
> +
> +	ret = readl_poll_timeout(mhdp->regs + CDNS_DP_MTPH_STATUS, reg,
> +				 ((reg & CDNS_DP_MTPH_ACT_STATUS) == 0), 0,
> +				 30);
> +	if (ret) {
> +		dev_err(mhdp->dev,
> +			"ACT sequence cannot complete in 30us\n");
> +		return -EIO;
> +	}
> +
> +	return drm_dp_check_act_status(&mhdp->mst_mgr);
> +}
> +
> +
> +static int
> +cdns_mhdp_apply_slot_allocation(struct cdns_mhdp_bridge *mhdp_bridge)
> +{
> +	struct drm_dp_payload *payload;
> +	struct cdns_mhdp_device *mhdp = mhdp_bridge->mhdp;
> +	u8 stream_id = mhdp_bridge->stream_id;
> +
> +	payload = cdns_mhdp_get_payload(mhdp_bridge);
> +
> +	if (!payload) {
> +		DRM_ERROR("payload is not found\n");
> +		return -EIO;
> +	}
> +
> +	cdns_mhdp_reg_write(mhdp, CDNS_DP_MST_SLOT_ALLOCATE(stream_id),
> +			    CDNS_DP_S_ALLOC_START_SLOT(payload->start_slot) |
> +			    CDNS_DP_S_ALLOC_END_SLOT(payload->start_slot
> +						     + payload->num_slots - 1));
> +
> +	return 0;
> +}
> +
> +static void
> +cdns_mhdp_update_slot_allocation(struct cdns_mhdp_bridge *mhdp_bridge)
> +{
> +	struct drm_device *dev = mhdp_bridge->base.dev;
> +	struct drm_connector *connector;
> +
> +	list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
> +		struct cdns_mhdp_connector *mhdp_connector;
> +
> +		mhdp_connector = to_mhdp_connector(connector);
> +		if (!connector->encoder)
> +			continue;
> +		if (!mhdp_connector->is_mst_connector)
> +			continue;
> +
> +		if (mhdp_connector->bridge->stream_id != -1)
> +			cdns_mhdp_apply_slot_allocation(mhdp_connector->bridge);
> +	}
> +}
> +
> +static enum drm_connector_status
> +cdns_dp_mst_detect(struct drm_connector *connector, bool force)
> +{
> +	enum drm_connector_status stat;
> +	struct cdns_mhdp_connector *mhdp_connector;
> +	struct cdns_mhdp_device *mhdp;
> +
> +	mhdp_connector = to_mhdp_connector(connector);
> +	mhdp =  mhdp_connector->bridge->mhdp;
> +
> +	stat = drm_dp_mst_detect_port(connector, &mhdp->mst_mgr,
> +				      mhdp_connector->port);
> +	return stat;
> +}
> +
> +static void
> +cdns_dp_mst_connector_destroy(struct drm_connector *connector)
> +{
> +	struct cdns_mhdp_connector *mhdp_connector;
> +	struct cdns_mhdp_bridge *mhdp_bridge;
> +
> +	mhdp_connector = to_mhdp_connector(connector);
> +	mhdp_bridge = mhdp_connector->bridge;
> +
> +	drm_connector_cleanup(&mhdp_connector->base);
> +	drm_bridge_remove(&mhdp_bridge->base);
> +	kfree(mhdp_connector);
> +	kfree(mhdp_bridge);
> +}
> +
> +static const struct drm_connector_funcs cdns_mhdp_mst_connector_funcs = {
> +	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
> +	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
> +	.reset = drm_atomic_helper_connector_reset,
> +	.dpms = drm_helper_connector_dpms,
> +	.detect = cdns_dp_mst_detect,
> +	.fill_modes = drm_helper_probe_single_connector_modes,
> +	.destroy = cdns_dp_mst_connector_destroy,
> +};
> +
> +
> +static int cdns_mhdp_mst_get_ddc_modes(struct drm_connector *connector)
> +{
> +	struct cdns_mhdp_connector *mhdp_connector;
> +	struct cdns_mhdp_device *mhdp;
> +	struct edid *edid;
> +	int ret = 0;
> +
> +	mhdp_connector = to_mhdp_connector(connector);
> +	mhdp =  mhdp_connector->bridge->mhdp;
> +
> +	edid = drm_dp_mst_get_edid(connector, &mhdp->mst_mgr,
> +				   mhdp_connector->port);
> +
> +	DRM_DEBUG_KMS("edid retrieved %p\n", edid);
> +	if (edid) {
> +		drm_connector_update_edid_property(connector, edid);
> +		ret = drm_add_edid_modes(connector, edid);
> +		return ret;
> +	}
> +	drm_connector_update_edid_property(connector, NULL);
> +
> +	return ret;


I suspect edid should be freed, but looking at other users of
drm_dp_mst_get_edid it is not so obvious (only intel frees it) - memory
leaks?


> +}
> +
> +static int cdns_mhdp_mst_get_modes(struct drm_connector *connector)
> +{
> +	return cdns_mhdp_mst_get_ddc_modes(connector);
> +}
> +
> +
> +static struct
> +drm_encoder *cdns_mhdp_mst_best_encoder(struct drm_connector *connector)
> +{
> +	struct cdns_mhdp_connector *mhdp_connector;
> +
> +	mhdp_connector = to_mhdp_connector(connector);
> +
> +	return mhdp_connector->bridge->base.encoder;
> +}+
> +static const struct drm_connector_helper_funcs cdns_mhdp_mst_conn_helper_fun = {
> +	.get_modes = cdns_mhdp_mst_get_modes,
> +	.best_encoder = cdns_mhdp_mst_best_encoder,
> +};
> +
> +void cdns_mhdp_mst_enable(struct drm_bridge *bridge)
> +{
> +	struct cdns_mhdp_bridge *mhdp_bridge = to_mhdp_bridge(bridge);
> +	struct cdns_mhdp_device *mhdp = mhdp_bridge->mhdp;
> +	struct drm_display_info *disp_info;
> +	struct drm_display_mode *mode;
> +	struct cdns_mhdp_connector *mhdp_connector;
> +	u32 bpp;
> +	enum pixel_format pxlfmt;
> +	int ret, slots, stream_id;
> +
> +	disp_info = &mhdp_bridge->connector->base.display_info;
> +
> +	pxlfmt = cdns_mhdp_get_pxlfmt(disp_info->color_formats);
> +	bpp = cdns_mhdp_get_bpp(disp_info->bpc, pxlfmt);
> +
> +	mhdp_connector = mhdp_bridge->connector;
> +	if (mhdp_bridge->stream_id > -1) {
> +		DRM_ERROR("ERROR stream id is attached before bridge is enabled\n");
> +		return;
> +	}
> +
> +	stream_id = bridge->encoder->crtc->index;
> +
> +	mode = &bridge->encoder->crtc->state->adjusted_mode;
> +	mhdp_bridge->pbn = drm_dp_calc_pbn_mode(mode->clock, bpp);
> +
> +	slots = drm_dp_find_vcpi_slots(&mhdp->mst_mgr, mhdp_bridge->pbn);
> +	ret = drm_dp_mst_allocate_vcpi(&mhdp->mst_mgr,
> +				       mhdp_connector->port,
> +				       mhdp_bridge->pbn, slots);
> +	if (ret == false) {
> +		DRM_ERROR("failed to allocate vcpi\n");
> +		return;
> +	}
> +	ret = drm_dp_update_payload_part1(&mhdp->mst_mgr);
> +	if (ret < 0)
> +		DRM_ERROR("failed update_payload_part1\n");
> +
> +	mhdp_bridge->stream_id = stream_id;
> +	mhdp_bridge->is_active = true;
> +
> +	cdns_mhdp_mst_stream_enable(mhdp_bridge, true);
> +	cdns_mhdp_configure_video(bridge);
> +
> +	ret = cdns_mhdp_apply_slot_allocation(mhdp_bridge);
> +	if (ret < 0) {
> +		cdns_mhdp_mst_stream_enable(mhdp_bridge, false);
> +		mhdp_bridge->stream_id = -1;
> +		mhdp_bridge->is_active = false;
> +		return;
> +	}
> +
> +	ret = cdns_mhdp_set_act_enable(mhdp);
> +	if (ret)
> +		DRM_ERROR("failed ACT sequence\n");
> +
> +	cdns_mhdp_set_rate_governing(mhdp_bridge, true);
> +
> +	cdns_mhdp_mst_set_threshold(mhdp_bridge);
> +
> +	drm_dp_update_payload_part2(&mhdp->mst_mgr);
> +}
> +
> +void cdns_mhdp_mst_disable(struct drm_bridge *bridge)
> +{
> +	struct cdns_mhdp_bridge *mhdp_bridge = to_mhdp_bridge(bridge);
> +	struct cdns_mhdp_device *mhdp = mhdp_bridge->mhdp;
> +	struct cdns_mhdp_connector *connector = mhdp_bridge->connector;
> +
> +	drm_dp_mst_reset_vcpi_slots(&mhdp->mst_mgr, connector->port);
> +	drm_dp_update_payload_part1(&mhdp->mst_mgr);
> +
> +	cdns_mhdp_update_slot_allocation(mhdp_bridge);
> +
> +	drm_dp_check_act_status(&mhdp->mst_mgr);
> +
> +	drm_dp_update_payload_part2(&mhdp->mst_mgr);
> +
> +	drm_dp_mst_deallocate_vcpi(&mhdp->mst_mgr, connector->port);
> +
> +	cdns_mhdp_set_rate_governing(mhdp_bridge, false);
> +	cdns_mhdp_mst_stream_enable(mhdp_bridge, false);
> +	mhdp_bridge->stream_id = -1;
> +	mhdp_bridge->is_active = false;
> +}
> +
> +static const struct drm_bridge_funcs cdns_mhdp_mst_bridge_funcs = {
> +	.enable = cdns_mhdp_enable,
> +	.disable = cdns_mhdp_mst_disable,
> +};
> +
> +
> +static struct cdns_mhdp_bridge*
> +cdns_mhpd_create_fake_mst_bridge(struct cdns_mhdp_device *mhdp,
> +				struct cdns_mhdp_connector *mhdp_connector)
> +{
> +	struct cdns_mhdp_bridge *mhdp_bridge;
> +	struct drm_encoder *encoder = NULL;
> +	struct cdns_mhdp_mst_cbs *cbs = &mhdp->cbs;
> +
> +	mhdp_bridge = kzalloc(sizeof(*mhdp_bridge), GFP_KERNEL);
> +	if (!mhdp_bridge)
> +		return NULL;
> +
> +	mhdp_bridge->mhdp = mhdp;
> +	mhdp_bridge->stream_id = -1;
> +	mhdp_bridge->connector = mhdp_connector;
> +	mhdp_bridge->is_active = false;
> +
> +	mhdp_bridge->base.funcs = &cdns_mhdp_mst_bridge_funcs;
> +
> +	drm_bridge_add(&mhdp_bridge->base);
> +
> +	if (cbs->funcs.create_mst_encoder)
> +		encoder = cbs->funcs.create_mst_encoder(cbs->priv_data,
> +							&mhdp_bridge->base);
> +	if (encoder) {
> +		int ret;
> +		/* use the same drm device as is in the first encoder */
> +		encoder->dev = mhdp->bridge.base.encoder->dev;
> +		encoder->possible_crtcs &= ((1 << CDNS_MHDP_MAX_STREAMS) - 1);
> +		ret = drm_bridge_attach(encoder, &mhdp_bridge->base, NULL);
> +		if (ret) {
> +			dev_err(mhdp->dev, "bridge attaching error %d\n", ret);
> +			return NULL;
> +		}
> +
> +		ret = drm_connector_attach_encoder(&mhdp_connector->base,
> +							encoder);
> +		if (ret) {
> +			dev_err(mhdp->dev, "failed to attach connector to encoder\n");
> +			return NULL;
> +		}
> +	}
> +
> +	return mhdp_bridge;
> +}
> +
> +static struct drm_connector *
> +cdns_mhdp_mst_cbs_add_connector(struct drm_dp_mst_topology_mgr *mgr,
> +				struct drm_dp_mst_port *port,
> +				const char *pathprop)
> +{
> +	struct cdns_mhdp_device *mhdp = mgr_to_mhdp(mgr);
> +	struct drm_device *dev = mhdp->bridge.base.dev;
> +	struct cdns_mhdp_connector *mhdp_connector;
> +	struct drm_connector *connector;
> +	struct drm_connector_state  *conn_state;
> +	int ret;
> +
> +	mhdp_connector = kzalloc(sizeof(struct cdns_mhdp_connector),
> +				 GFP_KERNEL);
> +	if (!mhdp_connector)
> +		return NULL;
> +
> +	mhdp_connector->is_mst_connector = true;
> +	connector = &mhdp_connector->base;
> +	mhdp_connector->port = port;
> +	DRM_DEBUG_KMS("\n");
> +
> +	conn_state = kzalloc(sizeof(*conn_state), GFP_KERNEL);
> +	if (!conn_state)
> +		return NULL;
> +
> +	__drm_atomic_helper_connector_reset(connector,
> +					    conn_state);
> +
> +	drm_connector_init(dev, connector, &cdns_mhdp_mst_connector_funcs,
> +			   DRM_MODE_CONNECTOR_DisplayPort);
> +	drm_connector_helper_add(connector, &cdns_mhdp_mst_conn_helper_fun);
> +	mhdp_connector->bridge =
> +		cdns_mhpd_create_fake_mst_bridge(mhdp, mhdp_connector);
> +
> +	drm_object_attach_property(&connector->base,
> +				   dev->mode_config.path_property, 0);
> +	drm_object_attach_property(&connector->base,
> +				   dev->mode_config.tile_property, 0);
> +	ret = drm_connector_set_path_property(connector, pathprop);
> +
> +	if (ret)
> +		DRM_ERROR("ERROR set path propertty failed\n");
> +
> +	return connector;
> +}
> +
> +static void
> +cdns_mhdp_mst_cbs_destroy_connector(struct drm_dp_mst_topology_mgr *mgr,
> +				    struct drm_connector *connector)
> +{
> +	struct cdns_mhdp_connector *mhdp_connector;
> +	struct cdns_mhdp_device *mhdp;
> +	struct cdns_mhdp_bridge *mhdp_bridge;
> +
> +	mhdp_connector = to_mhdp_connector(connector);
> +	mhdp_bridge = mhdp_connector->bridge;
> +	mhdp = mhdp_bridge->mhdp;
> +
> +	drm_connector_unregister(&mhdp_connector->base);
> +
> +	if (mhdp->cbs.funcs.create_mst_encoder)
> +		mhdp->cbs.funcs.destroy_mst_encoder(mhdp->cbs.priv_data,
> +						    &mhdp_bridge->base);
> +	drm_connector_unreference(&mhdp_connector->base);
> +}
> +
> +static void cdns_mhdp_mst_cbs_hotplug(struct drm_dp_mst_topology_mgr *mgr)
> +{
> +	struct cdns_mhdp_device *mhdp = mgr_to_mhdp(mgr);
> +	struct drm_device *dev = mhdp->bridge.base.encoder->dev;
> +
> +	drm_kms_helper_hotplug_event(dev);
> +}
> +
> +static void
> +cdns_mhdp_mst_cbs_register_connector(struct drm_connector *connector)
> +{
> +	int ret;
> +
> +	ret = drm_connector_register(connector);
> +	if (ret)
> +		DRM_ERROR("Register connector failed\n");
> +
> +}
> +
> +static const struct drm_dp_mst_topology_cbs mst_cbs = {
> +	.add_connector = cdns_mhdp_mst_cbs_add_connector,
> +	.register_connector = cdns_mhdp_mst_cbs_register_connector,
> +	.destroy_connector = cdns_mhdp_mst_cbs_destroy_connector,
> +	.hotplug = cdns_mhdp_mst_cbs_hotplug,
> +};
> +
> +
> +static void cdns_mhdp_set_mst_enable(struct cdns_mhdp_device *mhdp, bool enable)
> +{
> +	u32 reg_val;
> +
> +	cdns_mhdp_reg_read(mhdp, CDNS_DP_FRAMER_GLOBAL_CONFIG, &reg_val);
> +
> +	if (enable)
> +		reg_val |= CDNS_DP_MST_EN;
> +	else
> +		reg_val &= ~CDNS_DP_MST_EN;
> +
> +	cdns_mhdp_reg_write(mhdp, CDNS_DP_FRAMER_GLOBAL_CONFIG, reg_val);
> +}
> +
> +bool cdns_mhdp_mst_probe(struct cdns_mhdp_device *mhdp)
> +{
> +	u8 mstm_cap;
> +	u8 dpcd_cap[DP_RECEIVER_CAP_SIZE];
> +
> +	bool is_mst;
> +
> +	if (!mhdp->can_mst)
> +		return false;
> +
> +	drm_dp_dpcd_read(&mhdp->aux, DP_DPCD_REV, dpcd_cap,
> +			 DP_RECEIVER_CAP_SIZE);
> +
> +	if (dpcd_cap[DP_DPCD_REV] < 0x12)
> +		return false;
> +
> +	if (drm_dp_dpcd_readb(&mhdp->aux, DP_MSTM_CAP, &mstm_cap) != 1)
> +		return false;
> +
> +	if (mstm_cap & DP_MST_CAP) {
> +		DRM_DEBUG_KMS("Sink is MST capable\n");
> +		is_mst = true;
> +	} else {
> +		DRM_DEBUG_KMS("Sink is not MST capable\n");
> +		is_mst = false;
> +	}
> +
> +	if (is_mst != mhdp->is_mst) {
> +		mhdp->is_mst = is_mst;
> +		cdns_mhdp_set_mst_enable(mhdp, mhdp->is_mst);
> +
> +		drm_dp_mst_topology_mgr_set_mst(&mhdp->mst_mgr,
> +						mhdp->is_mst);
> +	}
> +
> +	return mhdp->is_mst;
> +}
> +
> +int cdns_mhdp_mst_init(struct cdns_mhdp_device *mhdp)
> +{
> +	struct cdns_mhdp_bridge *bridge = &mhdp->bridge;
> +	struct drm_device *dev = bridge->base.dev;
> +	struct cdns_mhdp_connector *connector = bridge->connector;
> +	int ret;
> +
> +	mhdp->mst_mgr.cbs = &mst_cbs;
> +	ret = drm_dp_mst_topology_mgr_init(&mhdp->mst_mgr, dev,
> +					   &mhdp->aux, 16,
> +					   CDNS_MHDP_MAX_STREAMS,
> +					   connector->base.base.id);
> +	if (ret)
> +		mhdp->can_mst = false;
> +	else
> +		mhdp->can_mst = true;
> +
> +	mhdp->is_mst = false;
> +
> +	bridge->stream_id = -1;
> +
> +	return ret;
> +}
> +
> +void cdns_mhdp_mst_deinit(struct cdns_mhdp_device *mhdp)
> +{
> +	if (mhdp->is_mst) {
> +		mhdp->is_mst = false;
> +		drm_dp_mst_topology_mgr_set_mst(&mhdp->mst_mgr,
> +						mhdp->is_mst);
> +	}
> +
> +	if (mhdp->can_mst)
> +		drm_dp_mst_topology_mgr_destroy(&mhdp->mst_mgr);
> +}
> diff --git a/drivers/gpu/drm/bridge/cdns-mhdp.c b/drivers/gpu/drm/bridge/cdns-mhdp.c
> index a3bbc0e809a5..48ac5cf1e031 100644
> --- a/drivers/gpu/drm/bridge/cdns-mhdp.c
> +++ b/drivers/gpu/drm/bridge/cdns-mhdp.c
> @@ -27,146 +27,15 @@
>  #include <drm/bridge/cdns-mhdp-common.h>
>  
>  #include <sound/hdmi-codec.h>
> +#include <linux/irq.h>
> +#include <linux/of_irq.h>
>  
> +#include "cdns-mhdp.h"
>  
>  #define DEBUG_MSG
>  
>  #define FW_NAME					"cadence/mhdp8546.bin"
>  
> -#define CDNS_APB_CFG				0x00000
> -#define CDNS_APB_CTRL				(CDNS_APB_CFG + 0x00)
> -#define CDNS_MAILBOX_FULL			(CDNS_APB_CFG + 0x08)
> -#define CDNS_MAILBOX_EMPTY			(CDNS_APB_CFG + 0x0c)
> -#define CDNS_MAILBOX_TX_DATA			(CDNS_APB_CFG + 0x10)
> -#define CDNS_MAILBOX_RX_DATA			(CDNS_APB_CFG + 0x14)
> -#define CDNS_KEEP_ALIVE				(CDNS_APB_CFG + 0x18)
> -#define CDNS_KEEP_ALIVE_MASK			GENMASK(7, 0)
> -
> -#define CDNS_SW_CLK_L				(CDNS_APB_CFG + 0x3c)
> -#define CDNS_SW_CLK_H				(CDNS_APB_CFG + 0x40)
> -#define CDNS_SW_EVENT0				(CDNS_APB_CFG + 0x44)
> -#define CDNS_DPTX_HPD				BIT(0)
> -
> -#define CDNS_SW_EVENT1				(CDNS_APB_CFG + 0x48)
> -#define CDNS_SW_EVENT2				(CDNS_APB_CFG + 0x4c)
> -#define CDNS_SW_EVENT3				(CDNS_APB_CFG + 0x50)
> -
> -#define CDNS_DPTX_CAR				(CDNS_APB_CFG + 0x904)
> -#define CDNS_VIF_CLK_EN				BIT(0)
> -#define CDNS_VIF_CLK_RSTN			BIT(1)
> -
> -#define CDNS_SOURCE_VIDEO_INTERFACE		0x00b00
> -#define CDNS_BND_HSYNC2VSYNC			(CDNS_SOURCE_VIDEO_INTERFACE + \
> -						 0x00)
> -#define CDNS_IP_DTCT_WIN			GENMASK(11, 0)
> -#define CDNS_IP_DET_INTERLACE_FORMAT		BIT(12)
> -#define CDNS_IP_BYPASS_V_INTERFACE		BIT(13)
> -
> -#define CDNS_HSYNC2VSYNC_POL_CTRL		(CDNS_SOURCE_VIDEO_INTERFACE + \
> -						 0x10)
> -#define CDNS_H2V_HSYNC_POL_ACTIVE_LOW		BIT(1)
> -#define CDNS_H2V_VSYNC_POL_ACTIVE_LOW		BIT(2)
> -
> -#define CDNS_DPTX_PHY_CONFIG			0x02000
> -#define CDNS_PHY_TRAINING_EN			BIT(0)
> -#define CDNS_PHY_TRAINING_TYPE(x)		(((x) & GENMASK(3, 0)) << 1)
> -#define CDNS_PHY_SCRAMBLER_BYPASS		BIT(5)
> -#define CDNS_PHY_ENCODER_BYPASS			BIT(6)
> -#define CDNS_PHY_SKEW_BYPASS			BIT(7)
> -#define CDNS_PHY_TRAINING_AUTO			BIT(8)
> -#define CDNS_PHY_LANE0_SKEW(x)			(((x) & GENMASK(2, 0)) << 9)
> -#define CDNS_PHY_LANE1_SKEW(x)			(((x) & GENMASK(2, 0)) << 12)
> -#define CDNS_PHY_LANE2_SKEW(x)			(((x) & GENMASK(2, 0)) << 15)
> -#define CDNS_PHY_LANE3_SKEW(x)			(((x) & GENMASK(2, 0)) << 18)
> -#define CDNS_PHY_COMMON_CONFIG			(CDNS_PHY_LANE1_SKEW(1) | \
> -						CDNS_PHY_LANE2_SKEW(2) |  \
> -						CDNS_PHY_LANE3_SKEW(3))
> -#define CDNS_PHY_10BIT_EN			BIT(21)
> -
> -#define CDNS_DPTX_FRAMER			0x02200
> -#define CDNS_DP_FRAMER_GLOBAL_CONFIG		(CDNS_DPTX_FRAMER + 0x00)
> -#define CDNS_DP_NUM_LANES(x)			(x - 1)
> -#define CDNS_DP_FRAMER_EN			BIT(3)
> -#define CDNS_DP_RATE_GOVERNOR_EN		BIT(4)
> -#define CDNS_DP_NO_VIDEO_MODE			BIT(5)
> -#define CDNS_DP_DISABLE_PHY_RST			BIT(6)
> -#define CDNS_DP_WR_FAILING_EDGE_VSYNC		BIT(7)
> -
> -#define CDNS_DP_SW_RESET			(CDNS_DPTX_FRAMER + 0x04)
> -#define CDNS_DP_FRAMER_TU			(CDNS_DPTX_FRAMER + 0x08)
> -#define CDNS_DP_FRAMER_TU_SIZE(x)		(((x) & GENMASK(6, 0)) << 8)
> -#define CDNS_DP_FRAMER_TU_VS(x)			((x) & GENMASK(5, 0))
> -#define CDNS_DP_FRAMER_TU_CNT_RST_EN		BIT(15)
> -
> -#define CDNS_DPTX_STREAM			0x03000
> -#define CDNS_DP_MSA_HORIZONTAL_0		(CDNS_DPTX_STREAM + 0x00)
> -#define CDNS_DP_MSAH0_H_TOTAL(x)		(x)
> -#define CDNS_DP_MSAH0_HSYNC_START(x)		((x) << 16)
> -
> -#define CDNS_DP_MSA_HORIZONTAL_1		(CDNS_DPTX_STREAM + 0x04)
> -#define CDNS_DP_MSAH1_HSYNC_WIDTH(x)		(x)
> -#define CDNS_DP_MSAH1_HSYNC_POL_LOW		BIT(15)
> -#define CDNS_DP_MSAH1_HDISP_WIDTH(x)		((x) << 16)
> -
> -#define CDNS_DP_MSA_VERTICAL_0			(CDNS_DPTX_STREAM + 0x08)
> -#define CDNS_DP_MSAV0_V_TOTAL(x)		(x)
> -#define CDNS_DP_MSAV0_VSYNC_START(x)		((x) << 16)
> -
> -#define CDNS_DP_MSA_VERTICAL_1			(CDNS_DPTX_STREAM + 0x0c)
> -#define CDNS_DP_MSAV1_VSYNC_WIDTH(x)		(x)
> -#define CDNS_DP_MSAV1_VSYNC_POL_LOW		BIT(15)
> -#define CDNS_DP_MSAV1_VDISP_WIDTH(x)		((x) << 16)
> -
> -#define CDNS_DP_MSA_MISC			(CDNS_DPTX_STREAM + 0x10)
> -#define CDNS_DP_STREAM_CONFIG			(CDNS_DPTX_STREAM + 0x14)
> -#define CDNS_DP_RATE_GOVERNOR_STATUS		(CDNS_DPTX_STREAM + 0x2c)
> -#define CDNS_DP_RG_TU_VS_DIFF(x)		((x) << 8)
> -
> -#define CDNS_DP_HORIZONTAL			(CDNS_DPTX_STREAM + 0x30)
> -#define CDNS_DP_H_HSYNC_WIDTH(x)		(x)
> -#define CDNS_DP_H_H_TOTAL(x)			((x) << 16)
> -
> -#define CDNS_DP_VERTICAL_0			(CDNS_DPTX_STREAM + 0x34)
> -#define CDNS_DP_V0_VHEIGHT(x)			(x)
> -#define CDNS_DP_V0_VSTART(x)			((x) << 16)
> -
> -#define CDNS_DP_VERTICAL_1			(CDNS_DPTX_STREAM + 0x38)
> -#define CDNS_DP_V1_VTOTAL(x)			(x)
> -#define CDNS_DP_V1_VTOTAL_EVEN			BIT(16)
> -
> -#define CDNS_DP_FRAMER_PXL_REPR			(CDNS_DPTX_STREAM + 0x4c)
> -#define CDNS_DP_FRAMER_6_BPC			BIT(0)
> -#define CDNS_DP_FRAMER_8_BPC			BIT(1)
> -#define CDNS_DP_FRAMER_10_BPC			BIT(2)
> -#define CDNS_DP_FRAMER_12_BPC			BIT(3)
> -#define CDNS_DP_FRAMER_16_BPC			BIT(4)
> -#define CDNS_DP_FRAMER_PXL_FORMAT		0x8
> -#define CDNS_DP_FRAMER_RGB			BIT(0)
> -#define CDNS_DP_FRAMER_YCBCR444			BIT(1)
> -#define CDNS_DP_FRAMER_YCBCR422			BIT(2)
> -#define CDNS_DP_FRAMER_YCBCR420			BIT(3)
> -#define CDNS_DP_FRAMER_Y_ONLY			BIT(4)
> -
> -#define CDNS_DP_FRAMER_SP			(CDNS_DPTX_STREAM + 0x10)
> -#define CDNS_DP_FRAMER_VSYNC_POL_LOW		BIT(0)
> -#define CDNS_DP_FRAMER_HSYNC_POL_LOW		BIT(1)
> -#define CDNS_DP_FRAMER_INTERLACE		BIT(2)
> -
> -#define CDNS_DP_LINE_THRESH			(CDNS_DPTX_STREAM + 0x64)
> -#define CDNS_DP_VB_ID				(CDNS_DPTX_STREAM + 0x68)
> -#define CDNS_DP_VB_ID_INTERLACED		BIT(2)
> -
> -#define CDNS_DP_FRONT_BACK_PORCH		(CDNS_DPTX_STREAM + 0x78)
> -#define CDNS_DP_BACK_PORCH(x)			(x)
> -#define CDNS_DP_FRONT_PORCH(x)			((x) << 16)
> -
> -#define CDNS_DP_BYTE_COUNT			(CDNS_DPTX_STREAM + 0x7c)
> -
> -#define CDNS_DPTX_GLOBAL			0x02300
> -#define CDNS_DP_LANE_EN				(CDNS_DPTX_GLOBAL + 0x00)
> -#define CDNS_DP_LANE_EN_LANES(x)		GENMASK(x - 1, 0)
> -#define CDNS_DP_ENHNCD				(CDNS_DPTX_GLOBAL + 0x04)
> -
>  #define CDNS_MHDP_IMEM				0x10000
>  #define CDNS_MHDP_DMEM				0x20000
>  
> @@ -216,13 +85,17 @@ MODULE_DEVICE_TABLE(of, mhdp_ids);
>  static inline struct cdns_mhdp_device *connector_to_mhdp(
>  	struct drm_connector *conn)
>  {
> -	return container_of(conn, struct cdns_mhdp_device, connector);
> +	struct cdns_mhdp_connector *mhdp_connector = to_mhdp_connector(conn);
> +
> +	return mhdp_connector->bridge->mhdp;
>  }
>  
>  static inline struct cdns_mhdp_device *bridge_to_mhdp(
>  	struct drm_bridge *bridge)
>  {
> -	return container_of(bridge, struct cdns_mhdp_device, bridge);
> +	struct cdns_mhdp_bridge *mhdp_bridge = to_mhdp_bridge(bridge);
> +
> +	return mhdp_bridge->mhdp;
>  }
>  
>  static unsigned int max_link_rate(struct cdns_mhdp_host host,
> @@ -237,6 +110,62 @@ static u8 eq_training_pattern_supported(struct cdns_mhdp_host host,
>  	return fls(host.pattern_supp & sink.pattern_supp);
>  }
>  
> +static void mhdp_hotplug_work_func(struct work_struct *work)
> +{
> +	struct cdns_mhdp_device *mhdp;
> +	int dret, retry;
> +	u8 esi[16] = { 0 };
> +	bool new_irq_handled;
> +	struct drm_connector *connector;
> +	bool old_plugged;
> +
> +
> +	mhdp = container_of(work, struct cdns_mhdp_device,
> +			    hotplug_work.work);
> +	connector = &mhdp->connector.base;
> +
> +	old_plugged = mhdp->plugged;
> +	connector->status = connector->funcs->detect(connector, false);
> +	if (old_plugged != mhdp->plugged) {
> +		drm_kms_helper_hotplug_event(mhdp->bridge.base.dev);
> +		return;
> +	}
> +
> +	if (mhdp->plugged) {
> +		dret = drm_dp_dpcd_read(&mhdp->aux,
> +					DP_SINK_COUNT_ESI, esi, 8);
> +
> +		if (dret == 8) {
> +			drm_dp_mst_hpd_irq(&mhdp->mst_mgr,
> +					   esi,
> +					   &new_irq_handled);
> +		}
> +
> +		if (new_irq_handled) {
> +			for (retry = 0; retry < 3; retry++) {
> +				int wret;
> +
> +				wret = drm_dp_dpcd_write(&mhdp->aux,
> +							 DP_SINK_COUNT_ESI+1,
> +							 &esi[1], 3);
> +				if (wret == 3)
> +					break;
> +			}
> +		}
> +	}
> +
> +}
> +
> +static irqreturn_t mhdp_irq_handler(int irq, void *data)
> +{
> +	struct cdns_mhdp_device *mhdp = (struct cdns_mhdp_device *)data;
> +
> +	if (readl(mhdp->regs + CDNS_SW_EVENT0) & CDNS_DPTX_HPD)
> +		schedule_delayed_work(&mhdp->hotplug_work, 0);
> +
> +	return IRQ_HANDLED;
> +}
> +
>  static ssize_t mhdp_transfer(struct drm_dp_aux *aux,
>  			     struct drm_dp_aux_msg *msg)
>  {
> @@ -300,10 +229,16 @@ static enum drm_connector_status cdns_mhdp_detect(struct drm_connector *conn,
>  	int ret;
>  
>  	ret = cdns_mhdp_get_hpd_status(mhdp);
> -	if (ret > 0)
> -		status = connector_status_connected;
> -	else if (ret < 0)
> +	if (ret > 0) {
> +		mhdp->plugged = true;
> +		cdns_mhdp_mst_probe(mhdp);
> +		// for MST mode this connector will be always disconnected
> +		if (!mhdp->is_mst)
> +			status = connector_status_connected;
> +	} else if (ret < 0)
>  		dev_err(mhdp->dev, "Failed to obtain HPD state\n");
> +	else
> +		mhdp->plugged = false;
>  
>  	return status;
>  }
> @@ -321,11 +256,15 @@ static const struct drm_connector_funcs cdns_mhdp_conn_funcs = {
>  static int cdns_mhdp_attach(struct drm_bridge *bridge)
>  {
>  	struct cdns_mhdp_device *mhdp = bridge_to_mhdp(bridge);
> -	struct drm_connector *conn = &mhdp->connector;
> +	struct drm_connector *conn = &mhdp->connector.base;
>  	int ret;
>  
> -	conn->polled = DRM_CONNECTOR_POLL_CONNECT |
> -		DRM_CONNECTOR_POLL_DISCONNECT;
> +	if (&mhdp->bridge.base != bridge)
> +		return -ENODEV;
> +
> +	cdns_mhdp_mst_init(mhdp);
> +
> +	conn->polled = DRM_CONNECTOR_POLL_HPD;
>  
>  	ret = drm_connector_init(bridge->dev, conn, &cdns_mhdp_conn_funcs,
>  				 DRM_MODE_CONNECTOR_DisplayPort);
> @@ -342,17 +281,12 @@ static int cdns_mhdp_attach(struct drm_bridge *bridge)
>  		return ret;
>  	}
>  
> +	/* enable interrupts */
> +	writel(~CDNS_APB_INT_MASK_SW_EVENT_INT, mhdp->regs + CDNS_APB_INT_MASK);
> +
>  	return 0;
>  }
>  
> -enum pixel_format {
> -	PIXEL_FORMAT_RGB = 1,
> -	PIXEL_FORMAT_YCBCR_444 = 2,
> -	PIXEL_FORMAT_YCBCR_422 = 4,
> -	PIXEL_FORMAT_YCBCR_420 = 8,
> -	PIXEL_FORMAT_Y_ONLY = 16,
> -};
> -
>  static void mhdp_link_training_init(struct cdns_mhdp_device *mhdp)
>  {
>  	u32 reg32;
> @@ -716,13 +650,11 @@ static int mhdp_link_training(struct cdns_mhdp_device *mhdp,
>  	cdns_mhdp_reg_write(mhdp, CDNS_DP_SW_RESET, 1);
>  	cdns_mhdp_reg_write(mhdp, CDNS_DP_SW_RESET, 0);
>  
> -	/* Enable framer */
> -	/* FIXME: update when MST supported, BIT(2) */
>  	cdns_mhdp_reg_write(mhdp, CDNS_DP_FRAMER_GLOBAL_CONFIG,
> -			    CDNS_DP_FRAMER_EN |
>  			    CDNS_DP_NUM_LANES(mhdp->link.num_lanes) |
>  			    CDNS_DP_DISABLE_PHY_RST |
>  			    CDNS_DP_WR_FAILING_EDGE_VSYNC |
> +			    (mhdp->is_mst ? CDNS_DP_MST_EN : 0) |
>  			    (!video_mode ? CDNS_DP_NO_VIDEO_MODE : 0));
>  
>  	/* Reset PHY config */
> @@ -751,31 +683,20 @@ static void cdns_mhdp_disable(struct drm_bridge *bridge)
>  
>  	cdns_mhdp_set_video_status(mhdp, 0);
>  
> +	mhdp->link_up = false;
> +
>  	drm_dp_link_power_down(&mhdp->aux, &mhdp->link);
> +	if (mhdp->is_mst)
> +		cdns_mhdp_mst_disable(bridge);
>  }
>  
> -static void cdns_mhdp_enable(struct drm_bridge *bridge)
> +static int cdns_mhdp_link_up(struct cdns_mhdp_device *mhdp)
>  {
> -	struct cdns_mhdp_device *mhdp = bridge_to_mhdp(bridge);
> -	struct drm_display_mode *mode;
> -	struct drm_display_info *disp_info = &mhdp->connector.display_info;
> -	enum pixel_format pxlfmt;
> -	int pxlclock;
> -	unsigned int rate, tu_size = 30, vs, vs_f, bpp, required_bandwidth,
> -		     available_bandwidth, dp_framer_sp = 0, msa_horizontal_1,
> -		     msa_vertical_1, bnd_hsync2vsync, hsync2vsync_pol_ctrl,
> -		     misc0 = 0, misc1 = 0, line_thresh = 0, pxl_repr,
> -		     front_porch, back_porch, msa_h0, msa_v0, hsync, vsync,
> -		     dp_vertical_1, line_thresh1, line_thresh2;
>  	u32 resp;
> -
> -	unsigned int size = DP_RECEIVER_CAP_SIZE, dp_framer_global_config,
> +	u32 size = DP_RECEIVER_CAP_SIZE, dp_framer_global_config,
>  		     video_mode, training_interval_us;
>  	u8 reg0[size], reg8, amp[2];
>  
> -	mode = &bridge->encoder->crtc->state->adjusted_mode;
> -	pxlclock = mode->crtc_clock;
> -
>  	/*
>  	 * Upon power-on reset/device disconnection: [2:0] bits should be 0b001
>  	 * and [7:5] bits 0b000.
> @@ -824,13 +745,17 @@ static void cdns_mhdp_enable(struct drm_bridge *bridge)
>  	default:
>  		dev_err(mhdp->dev,
>  			"wrong training interval returned by DPCD: %d\n", reg8);
> -		return;
> +		return -EIO;
>  	}
>  
>  	cdns_mhdp_reg_read(mhdp, CDNS_DP_FRAMER_GLOBAL_CONFIG, &resp);
>  
>  	dp_framer_global_config = be32_to_cpu(resp);
>  
> +	cdns_mhdp_mst_probe(mhdp);
> +	if (mhdp->is_mst)
> +		dp_framer_global_config |= CDNS_DP_MST_EN;
> +
>  	video_mode = !(dp_framer_global_config & CDNS_DP_NO_VIDEO_MODE);
>  
>  	if (dp_framer_global_config & CDNS_DP_FRAMER_EN)
> @@ -850,50 +775,168 @@ static void cdns_mhdp_enable(struct drm_bridge *bridge)
>  		if (mhdp_link_training(mhdp, video_mode,
>  				       training_interval_us)) {
>  			dev_err(mhdp->dev, "Link training failed. Exiting.\n");
> -			return;
> +			return -EIO;
>  		}
>  	}
>  
> +	mhdp->link_up = true;
> +
> +	return 0;
> +}
> +
> +static int cdns_mhdp_sst_enable(struct drm_bridge *bridge)
> +{
> +	struct cdns_mhdp_bridge *mhdp_bridge = to_mhdp_bridge(bridge);
> +	struct cdns_mhdp_device *mhdp = mhdp_bridge->mhdp;
> +	u32 rate, vs, vs_f, required_bandwidth, available_bandwidth;
> +	u32 bpp, tu_size = 30, line_thresh1, line_thresh2, line_thresh = 0;
> +	struct drm_display_mode *mode;
> +	int pxlclock;
> +	enum pixel_format pxlfmt;
> +	struct drm_display_info *disp_info = &mhdp->connector.base.display_info;
> +
> +
> +	mode = &bridge->encoder->crtc->state->adjusted_mode;
> +	pxlclock = mode->crtc_clock;
> +
> +	mhdp_bridge->stream_id = 0;
> +
>  	rate = mhdp->link.rate / 1000;
>  
> +	pxlfmt = cdns_mhdp_get_pxlfmt(disp_info->color_formats);
> +	bpp = cdns_mhdp_get_bpp(disp_info->bpc, pxlfmt);
> +
> +	/* find optimal tu_size */
> +	required_bandwidth = pxlclock * bpp / 8;
> +	available_bandwidth = mhdp->link.num_lanes * rate;
> +	do {
> +		tu_size += 2;
> +
> +		vs_f = tu_size * required_bandwidth / available_bandwidth;
> +		vs = vs_f / 1000;
> +		vs_f = vs_f % 1000;
> +		/*
> +		 * FIXME (CDNS): downspreading?
> +		 * It's unused is what I've been told.
> +		 */
> +	} while ((vs == 1 || ((vs_f > 850 || vs_f < 100) && vs_f != 0) ||
> +		  tu_size - vs < 2) && tu_size < 64);
> +
> +	if (vs > 64)
> +		return -EINVAL;
> +
> +
> +	cdns_mhdp_reg_write(mhdp, CDNS_DP_FRAMER_TU,
> +			    CDNS_DP_FRAMER_TU_VS(vs) |
> +			    CDNS_DP_FRAMER_TU_SIZE(tu_size) |
> +			    CDNS_DP_FRAMER_TU_CNT_RST_EN);
> +
> +	line_thresh1 = ((vs + 1) << 5) * 8 / bpp;
> +	line_thresh2 = (pxlclock << 5) / 1000 / rate * (vs + 1) - (1 << 5);
> +	line_thresh = line_thresh1 - line_thresh2 / mhdp->link.num_lanes;
> +	line_thresh = (line_thresh >> 5) + 2;
> +	cdns_mhdp_reg_write(mhdp, CDNS_DP_LINE_THRESH(0),
> +			    line_thresh & GENMASK(5, 0));
> +
> +	cdns_mhdp_reg_write(mhdp, CDNS_DP_STREAM_CONFIG_2(0),
> +			    CDNS_DP_SC2_TU_VS_DIFF((tu_size - vs > 3) ?
> +						       0 : tu_size - vs));
> +
> +	cdns_mhdp_configure_video(bridge);
> +
> +	cdns_mhdp_set_video_status(mhdp, 1);
> +
> +	return 0;
> +}
> +
> +enum pixel_format cdns_mhdp_get_pxlfmt(u32 color_formats)
> +{
> +	enum pixel_format pxlfmt;
> +
>  	/* FIXME: what about Y_ONLY? how is it handled in the kernel? */
> -	if (disp_info->color_formats & DRM_COLOR_FORMAT_YCRCB444)
> +	if (color_formats & DRM_COLOR_FORMAT_YCRCB444)
>  		pxlfmt = PIXEL_FORMAT_YCBCR_444;
> -	else if (disp_info->color_formats & DRM_COLOR_FORMAT_YCRCB422)
> +	else if (color_formats & DRM_COLOR_FORMAT_YCRCB422)
>  		pxlfmt = PIXEL_FORMAT_YCBCR_422;
> -	else if (disp_info->color_formats & DRM_COLOR_FORMAT_YCRCB420)
> +	else if (color_formats & DRM_COLOR_FORMAT_YCRCB420)
>  		pxlfmt = PIXEL_FORMAT_YCBCR_420;
>  	else
>  		pxlfmt = PIXEL_FORMAT_RGB;
>  
> +	return pxlfmt;
> +}
> +
> +
> +u32 cdns_mhdp_get_bpp(u32 bpc, enum pixel_format pxlfmt)
> +{
> +	u32 bpp;
> +
> +	switch (pxlfmt) {
> +	case PIXEL_FORMAT_RGB:
> +		bpp = bpc * 3;
> +		break;
> +	case PIXEL_FORMAT_YCBCR_444:
> +		bpp = bpc * 3;
> +		break;
> +	case PIXEL_FORMAT_YCBCR_422:
> +		bpp = bpc * 2;
> +		break;
> +	case PIXEL_FORMAT_YCBCR_420:
> +		bpp = bpc * 3 / 2;
> +		break;
> +	default:
> +		bpp = bpc;
> +	}
> +	return bpp;
> +}
> +
> +void cdns_mhdp_configure_video(struct drm_bridge *bridge)
> +{
> +	struct cdns_mhdp_bridge *mhdp_bridge = to_mhdp_bridge(bridge);
> +	struct cdns_mhdp_device *mhdp = mhdp_bridge->mhdp;
> +	struct drm_display_info *disp_info;
> +	unsigned int bpp,  dp_framer_sp = 0, msa_horizontal_1,
> +		     msa_vertical_1, bnd_hsync2vsync, hsync2vsync_pol_ctrl,
> +		     misc0 = 0, misc1 = 0, pxl_repr,
> +		     front_porch, back_porch, msa_h0, msa_v0, hsync, vsync,
> +		     dp_vertical_1;
> +	struct drm_display_mode *mode;
> +	enum pixel_format pxlfmt;
> +	int pxlclock;
> +	u32 tmp;
> +	u8 stream_id = mhdp_bridge->stream_id;
> +
> +	mode = &bridge->encoder->crtc->state->adjusted_mode;
> +	pxlclock = mode->crtc_clock;
> +
> +	disp_info = &mhdp_bridge->connector->base.display_info;
> +	pxlfmt = cdns_mhdp_get_pxlfmt(disp_info->color_formats);
> +
>  	/* if YCBCR supported and stream not SD, use ITU709 */
>  	/* FIXME: handle ITU version with YCBCR420 when supported */
>  	if ((pxlfmt == PIXEL_FORMAT_YCBCR_444 ||
>  	     pxlfmt == PIXEL_FORMAT_YCBCR_422) && mode->crtc_vdisplay >= 720)
>  		misc0 = DP_YCBCR_COEFFICIENTS_ITU709;
>  
> +	bpp = cdns_mhdp_get_bpp(disp_info->bpc, pxlfmt);
> +
>  	switch (pxlfmt) {
>  	case PIXEL_FORMAT_RGB:
> -		bpp = disp_info->bpc * 3;
>  		pxl_repr = CDNS_DP_FRAMER_RGB << CDNS_DP_FRAMER_PXL_FORMAT;
>  		misc0 |= DP_COLOR_FORMAT_RGB;
>  		break;
>  	case PIXEL_FORMAT_YCBCR_444:
> -		bpp = disp_info->bpc * 3;
>  		pxl_repr = CDNS_DP_FRAMER_YCBCR444 << CDNS_DP_FRAMER_PXL_FORMAT;
>  		misc0 |= DP_COLOR_FORMAT_YCbCr444 | DP_TEST_DYNAMIC_RANGE_CEA;
>  		break;
>  	case PIXEL_FORMAT_YCBCR_422:
> -		bpp = disp_info->bpc * 2;
>  		pxl_repr = CDNS_DP_FRAMER_YCBCR422 << CDNS_DP_FRAMER_PXL_FORMAT;
>  		misc0 |= DP_COLOR_FORMAT_YCbCr422 | DP_TEST_DYNAMIC_RANGE_CEA;
>  		break;
>  	case PIXEL_FORMAT_YCBCR_420:
> -		bpp = disp_info->bpc * 3 / 2;
>  		pxl_repr = CDNS_DP_FRAMER_YCBCR420 << CDNS_DP_FRAMER_PXL_FORMAT;
>  		break;
>  	default:
> -		bpp = disp_info->bpc;
>  		pxl_repr = CDNS_DP_FRAMER_Y_ONLY << CDNS_DP_FRAMER_PXL_FORMAT;
>  	}
>  
> @@ -920,30 +963,12 @@ static void cdns_mhdp_enable(struct drm_bridge *bridge)
>  		break;
>  	}
>  
> -	/* find optimal tu_size */
> -	required_bandwidth = pxlclock * bpp / 8;
> -	available_bandwidth = mhdp->link.num_lanes * rate;
> -	do {
> -		tu_size += 2;
> -
> -		vs_f = tu_size * required_bandwidth / available_bandwidth;
> -		vs = vs_f / 1000;
> -		vs_f = vs_f % 1000;
> -		/*
> -		 * FIXME (CDNS): downspreading?
> -		 * It's unused is what I've been told.
> -		 */
> -	} while ((vs == 1 || ((vs_f > 850 || vs_f < 100) && vs_f != 0) ||
> -		  tu_size - vs < 2) && tu_size < 64);
> -
> -	if (vs > 64)
> -		return;
> -
>  	bnd_hsync2vsync = CDNS_IP_BYPASS_V_INTERFACE;
>  	if (mode->flags & DRM_MODE_FLAG_INTERLACE)
>  		bnd_hsync2vsync |= CDNS_IP_DET_INTERLACE_FORMAT;
>  
> -	cdns_mhdp_reg_write(mhdp, CDNS_BND_HSYNC2VSYNC, bnd_hsync2vsync);
> +	cdns_mhdp_reg_write(mhdp, CDNS_BND_HSYNC2VSYNC(stream_id),
> +			    bnd_hsync2vsync);
>  
>  	if (mode->flags & DRM_MODE_FLAG_INTERLACE &&
>  	    mode->flags & DRM_MODE_FLAG_PHSYNC)
> @@ -952,15 +977,10 @@ static void cdns_mhdp_enable(struct drm_bridge *bridge)
>  	else
>  		hsync2vsync_pol_ctrl = 0;
>  
> -	cdns_mhdp_reg_write(mhdp, CDNS_HSYNC2VSYNC_POL_CTRL,
> +	cdns_mhdp_reg_write(mhdp, CDNS_HSYNC2VSYNC_POL_CTRL(stream_id),
>  			    hsync2vsync_pol_ctrl);
>  
> -	cdns_mhdp_reg_write(mhdp, CDNS_DP_FRAMER_TU,
> -			    CDNS_DP_FRAMER_TU_VS(vs) |
> -			    CDNS_DP_FRAMER_TU_SIZE(tu_size) |
> -			    CDNS_DP_FRAMER_TU_CNT_RST_EN);
> -
> -	cdns_mhdp_reg_write(mhdp, CDNS_DP_FRAMER_PXL_REPR, pxl_repr);
> +	cdns_mhdp_reg_write(mhdp, CDNS_DP_FRAMER_PXL_REPR(stream_id), pxl_repr);
>  
>  	if (mode->flags & DRM_MODE_FLAG_INTERLACE)
>  		dp_framer_sp |= CDNS_DP_FRAMER_INTERLACE;
> @@ -968,19 +988,19 @@ static void cdns_mhdp_enable(struct drm_bridge *bridge)
>  		dp_framer_sp |= CDNS_DP_FRAMER_HSYNC_POL_LOW;
>  	if (mode->flags & DRM_MODE_FLAG_NVSYNC)
>  		dp_framer_sp |= CDNS_DP_FRAMER_VSYNC_POL_LOW;
> -	cdns_mhdp_reg_write(mhdp, CDNS_DP_FRAMER_SP, dp_framer_sp);
> +	cdns_mhdp_reg_write(mhdp, CDNS_DP_FRAMER_SP(stream_id), dp_framer_sp);
>  
>  	front_porch = mode->crtc_hsync_start - mode->crtc_hdisplay;
>  	back_porch = mode->crtc_htotal - mode->crtc_hsync_end;
> -	cdns_mhdp_reg_write(mhdp, CDNS_DP_FRONT_BACK_PORCH,
> +	cdns_mhdp_reg_write(mhdp, CDNS_DP_FRONT_BACK_PORCH(stream_id),
>  			    CDNS_DP_FRONT_PORCH(front_porch) |
>  			    CDNS_DP_BACK_PORCH(back_porch));
>  
> -	cdns_mhdp_reg_write(mhdp, CDNS_DP_BYTE_COUNT,
> +		cdns_mhdp_reg_write(mhdp, CDNS_DP_BYTE_COUNT(stream_id),
>  			    mode->crtc_hdisplay * bpp / 8);
>  
>  	msa_h0 = mode->crtc_htotal - mode->crtc_hsync_start;
> -	cdns_mhdp_reg_write(mhdp, CDNS_DP_MSA_HORIZONTAL_0,
> +	cdns_mhdp_reg_write(mhdp, CDNS_DP_MSA_HORIZONTAL_0(stream_id),
>  			    CDNS_DP_MSAH0_H_TOTAL(mode->crtc_htotal) |
>  			    CDNS_DP_MSAH0_HSYNC_START(msa_h0));
>  
> @@ -989,11 +1009,11 @@ static void cdns_mhdp_enable(struct drm_bridge *bridge)
>  		CDNS_DP_MSAH1_HDISP_WIDTH(mode->crtc_hdisplay);
>  	if (mode->flags & DRM_MODE_FLAG_NHSYNC)
>  		msa_horizontal_1 |= CDNS_DP_MSAH1_HSYNC_POL_LOW;
> -	cdns_mhdp_reg_write(mhdp, CDNS_DP_MSA_HORIZONTAL_1,
> +	cdns_mhdp_reg_write(mhdp, CDNS_DP_MSA_HORIZONTAL_1(stream_id),
>  			    msa_horizontal_1);
>  
>  	msa_v0 = mode->crtc_vtotal - mode->crtc_vsync_start;
> -	cdns_mhdp_reg_write(mhdp, CDNS_DP_MSA_VERTICAL_0,
> +	cdns_mhdp_reg_write(mhdp, CDNS_DP_MSA_VERTICAL_0(stream_id),
>  			    CDNS_DP_MSAV0_V_TOTAL(mode->crtc_vtotal) |
>  			    CDNS_DP_MSAV0_VSYNC_START(msa_v0));
>  
> @@ -1002,7 +1022,8 @@ static void cdns_mhdp_enable(struct drm_bridge *bridge)
>  		CDNS_DP_MSAV1_VDISP_WIDTH(mode->crtc_vdisplay);
>  	if (mode->flags & DRM_MODE_FLAG_NVSYNC)
>  		msa_vertical_1 |= CDNS_DP_MSAV1_VSYNC_POL_LOW;
> -	cdns_mhdp_reg_write(mhdp, CDNS_DP_MSA_VERTICAL_1, msa_vertical_1);
> +	cdns_mhdp_reg_write(mhdp, CDNS_DP_MSA_VERTICAL_1(stream_id),
> +			    msa_vertical_1);
>  
>  	if ((mode->flags & DRM_MODE_FLAG_INTERLACE) &&
>  	    mode->crtc_vtotal % 2 == 0)
> @@ -1014,16 +1035,14 @@ static void cdns_mhdp_enable(struct drm_bridge *bridge)
>  	if (pxlfmt == PIXEL_FORMAT_YCBCR_420)
>  		misc1 = CDNS_DP_TEST_VSC_SDP;
>  
> -	cdns_mhdp_reg_write(mhdp, CDNS_DP_MSA_MISC, misc0 | (misc1 << 8));
> +	cdns_mhdp_reg_write(mhdp, CDNS_DP_MSA_MISC(stream_id),
> +			    misc0 | (misc1 << 8));
>  
> -	/* FIXME: to be changed if MST mode */
> -	cdns_mhdp_reg_write(mhdp, CDNS_DP_STREAM_CONFIG, 1);
> -
> -	cdns_mhdp_reg_write(mhdp, CDNS_DP_HORIZONTAL,
> +	cdns_mhdp_reg_write(mhdp, CDNS_DP_HORIZONTAL(stream_id),
>  			    CDNS_DP_H_HSYNC_WIDTH(hsync) |
>  			    CDNS_DP_H_H_TOTAL(mode->crtc_hdisplay));
>  
> -	cdns_mhdp_reg_write(mhdp, CDNS_DP_VERTICAL_0,
> +	cdns_mhdp_reg_write(mhdp, CDNS_DP_VERTICAL_0(stream_id),
>  			    CDNS_DP_V0_VHEIGHT(mode->crtc_vdisplay) |
>  			    CDNS_DP_V0_VSTART(msa_v0));
>  
> @@ -1032,30 +1051,51 @@ static void cdns_mhdp_enable(struct drm_bridge *bridge)
>  	    mode->crtc_vtotal % 2 == 0)
>  		dp_vertical_1 |= CDNS_DP_V1_VTOTAL_EVEN;
>  
> -	cdns_mhdp_reg_write(mhdp, CDNS_DP_VERTICAL_1, dp_vertical_1);
> +	cdns_mhdp_reg_write(mhdp, CDNS_DP_VERTICAL_1(stream_id), dp_vertical_1);
>  
> -	cdns_mhdp_reg_write_bit(mhdp, CDNS_DP_VB_ID, 2, 1,
> +	cdns_mhdp_reg_write_bit(mhdp, CDNS_DP_VB_ID(stream_id), 2, 1,
>  				(mode->flags & DRM_MODE_FLAG_INTERLACE) ?
>  				CDNS_DP_VB_ID_INTERLACED : 0);
>  
> -	line_thresh1 = ((vs + 1) << 5) * 8 / bpp;
> -	line_thresh2 = (pxlclock << 5) / 1000 / rate * (vs + 1) - (1 << 5);
> -	line_thresh = line_thresh1 - line_thresh2 / mhdp->link.num_lanes;
> -	line_thresh = (line_thresh >> 5) + 2;
> -	cdns_mhdp_reg_write(mhdp, CDNS_DP_LINE_THRESH,
> -			    line_thresh & GENMASK(5, 0));
>  
> -	cdns_mhdp_reg_write(mhdp, CDNS_DP_RATE_GOVERNOR_STATUS,
> -			    CDNS_DP_RG_TU_VS_DIFF((tu_size - vs > 3) ?
> -						       0 : tu_size - vs));
> +	cdns_mhdp_reg_read(mhdp, CDNS_DP_FRAMER_GLOBAL_CONFIG, &tmp);
> +	tmp |= CDNS_DP_FRAMER_EN;
> +	cdns_mhdp_reg_write(mhdp, CDNS_DP_FRAMER_GLOBAL_CONFIG, tmp);
> +}
>  
> -	cdns_mhdp_set_video_status(mhdp, 1);
> +void cdns_mhdp_enable(struct drm_bridge *bridge)
> +{
> +	struct cdns_mhdp_bridge *mhdp_bridge = to_mhdp_bridge(bridge);
> +	struct cdns_mhdp_device *mhdp = mhdp_bridge->mhdp;
> +	int ret = 0;
> +
> +	bool link_up = mhdp->link_up;
> +
> +	if (!link_up)
> +		cdns_mhdp_link_up(mhdp);
> +
> +
> +	if (!mhdp->is_mst)
> +		ret = cdns_mhdp_sst_enable(bridge);
> +	else
> +		cdns_mhdp_mst_enable(bridge);
> +


ret unused, link_up not neccessary, requires cleanup.


> +}
> +
> +static void cdns_mhdp_detach(struct drm_bridge *bridge)
> +{
> +	struct cdns_mhdp_device *mhdp = bridge_to_mhdp(bridge);
> +	struct cdns_mhdp_mst_cbs cbs_null = {0};
> +
> +	cdns_mhdp_mst_deinit(mhdp);
> +	mhdp->cbs = cbs_null;
>  }
>  
>  static const struct drm_bridge_funcs cdns_mhdp_bridge_funcs = {
>  	.enable = cdns_mhdp_enable,
>  	.disable = cdns_mhdp_disable,
>  	.attach = cdns_mhdp_attach,
> +	.detach = cdns_mhdp_detach,
>  };
>  
>  static int load_firmware(struct cdns_mhdp_device *mhdp, const char *name,
> @@ -1127,8 +1167,8 @@ static int cdns_mhdp_audio_get_eld(struct device *dev, void *data,
>  {
>  	struct cdns_mhdp_device *mhdp = dev_get_drvdata(dev);
>  
> -	memcpy(buf, mhdp->connector.eld,
> -	       min(sizeof(mhdp->connector.eld), len));
> +	memcpy(buf, mhdp->connector.base.eld,
> +	       min(sizeof(mhdp->connector.base.eld), len));
>  
>  	return 0;
>  }
> @@ -1149,6 +1189,7 @@ static int mhdp_probe(struct platform_device *pdev)
>  	unsigned int reg;
>  	unsigned long rate;
>  	u32 resp;
> +	int irq;
>  
>  	struct hdmi_codec_pdata codec_data = {
>  		.i2s = 1,
> @@ -1192,6 +1233,14 @@ static int mhdp_probe(struct platform_device *pdev)
>  	/* Leave debug mode */
>  	writel(0, mhdp->regs + CDNS_APB_CTRL);
>  
> +	irq = platform_get_irq(pdev, 0);
> +	ret = request_irq(irq, mhdp_irq_handler, 0, "mhdp8546", mhdp);


No free_irq, why dont you use devm_request_irq.


> +	if (ret) {
> +		dev_err(&pdev->dev,
> +			"cannot install IRQ %d\n", irq);
> +		return -EIO;
> +	}
> +
>  	/*
>  	 * Wait for the KEEP_ALIVE "message" on the first 8 bits.
>  	 * Updated each sched "tick" (~2ms)
> @@ -1222,8 +1271,8 @@ static int mhdp_probe(struct platform_device *pdev)
>  	mhdp->host.lane_mapping = CDNS_LANE_MAPPING_FLIPPED;
>  	mhdp->host.enhanced = true;
>  
> -	mhdp->bridge.of_node = pdev->dev.of_node;
> -	mhdp->bridge.funcs = &cdns_mhdp_bridge_funcs;
> +	mhdp->bridge.base.of_node = pdev->dev.of_node;
> +	mhdp->bridge.base.funcs = &cdns_mhdp_bridge_funcs;
>  
>  	/* Init events to 0 as it's not cleared by FW at boot but on read */
>  	readl(mhdp->regs + CDNS_SW_EVENT0);
> @@ -1247,21 +1296,14 @@ static int mhdp_probe(struct platform_device *pdev)
>  	cdns_mhdp_reg_write(mhdp, CDNS_DPTX_CAR,
>  			    resp | CDNS_VIF_CLK_EN | CDNS_VIF_CLK_RSTN);
>  
> -	/* Loop over HDP change */
> -	/*
> -	 * FIXME: does not work when put in mhdp_bridge_enable.
> -	 * Where should we put it?
> -	 */
> -	/* Is it still needed with use of mb message HPD STATUS? */
> -	ret = readl_poll_timeout(mhdp->regs + CDNS_SW_EVENT0, reg,
> -				 reg & CDNS_DPTX_HPD, 500,
> -				 CDNS_SW_EVENT0_TIMEOUT);
> -	if (ret) {
> -		dev_err(mhdp->dev, "no HPD received %d\n", reg);
> -		return -ENODEV;
> -	}
> +	INIT_DELAYED_WORK(&mhdp->hotplug_work, mhdp_hotplug_work_func);


You are removing lot of the code introduced by previous patch, kinda ugly.

I am not sure if merging both patches wouldn't be better, otherwise it
would be better to split this big patch to smaller chunks - according to
rule - one change per one patch.


Regards

Andrzej


> +
> +	mhdp->bridge.connector = &mhdp->connector;
> +	mhdp->connector.bridge = &mhdp->bridge;
> +	mhdp->bridge.mhdp = mhdp;
> +	mhdp->bridge.is_active = false;
>  
> -	drm_bridge_add(&mhdp->bridge);
> +	drm_bridge_add(&mhdp->bridge.base);
>  
>  	return 0;
>  }
> @@ -1273,9 +1315,11 @@ static int mhdp_remove(struct platform_device *pdev)
>  	struct cdns_mhdp_device *mhdp = dev_get_drvdata(&pdev->dev);
>  	int ret;
>  
> +	flush_delayed_work(&mhdp->hotplug_work);
>  	platform_device_unregister(mhdp->audio_pdev);
>  
> -	drm_bridge_remove(&mhdp->bridge);
> +	cdns_mhdp_mst_deinit(mhdp);
> +	drm_bridge_remove(&mhdp->bridge.base);
>  
>  	ret = cdns_mhdp_set_firmware_active(mhdp, false);
>  	if (ret) {
> @@ -1288,6 +1332,17 @@ static int mhdp_remove(struct platform_device *pdev)
>  	return 0;
>  }
>  
> +int mhdp_bridge_attach_mst_cbs(struct drm_bridge *bridge,
> +			       struct cdns_mhdp_mst_cbs *cbs)
> +{
> +	struct cdns_mhdp_device *mhdp = bridge_to_mhdp(bridge);
> +
> +	mhdp->cbs = *cbs;
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(mhdp_bridge_attach_mst_cbs);
> +
>  static struct platform_driver mhdp_driver = {
>  	.driver	= {
>  		.name		= "cdns-mhdp",
> @@ -1299,6 +1354,9 @@ static struct platform_driver mhdp_driver = {
>  module_platform_driver(mhdp_driver);
>  
>  MODULE_AUTHOR("Quentin Schulz <quentin.schulz@free-electrons.com>");
> +MODULE_AUTHOR("Przemyslaw Gaj <pgaj@cadence.com>");
> +MODULE_AUTHOR("Damian Kos <dkos@cadence.com>");
> +MODULE_AUTHOR("Piotr Sroka <piotrs@cadence.com>");
>  MODULE_DESCRIPTION("Cadence MHDP DP bridge driver");
>  MODULE_LICENSE("GPL");
>  MODULE_ALIAS("platform:cdns-mhdp");
> diff --git a/drivers/gpu/drm/bridge/cdns-mhdp.h b/drivers/gpu/drm/bridge/cdns-mhdp.h
> new file mode 100644
> index 000000000000..abc1fa3f51a6
> --- /dev/null
> +++ b/drivers/gpu/drm/bridge/cdns-mhdp.h
> @@ -0,0 +1,209 @@
> +/* SPDX-License-Identifier: GPL v2 */
> +/*
> + * Cadence MHDP DP MST bridge driver.
> + *
> + * Copyright: 2018 Cadence Design Systems, Inc.
> + *
> + * Author: Quentin Schulz <quentin.schulz@free-electrons.com>
> + */
> +
> +
> +#ifndef CDNS_MHDP_H
> +#define CDNS_MHDP_H
> +
> +#include <drm/drm_dp_mst_helper.h>
> +
> +#define CDNS_APB_CFG				0x00000
> +#define CDNS_APB_CTRL				(CDNS_APB_CFG + 0x00)
> +#define CDNS_MAILBOX_FULL			(CDNS_APB_CFG + 0x08)
> +#define CDNS_MAILBOX_EMPTY			(CDNS_APB_CFG + 0x0c)
> +#define CDNS_MAILBOX_TX_DATA			(CDNS_APB_CFG + 0x10)
> +#define CDNS_MAILBOX_RX_DATA			(CDNS_APB_CFG + 0x14)
> +#define CDNS_KEEP_ALIVE				(CDNS_APB_CFG + 0x18)
> +#define CDNS_KEEP_ALIVE_MASK			GENMASK(7, 0)
> +
> +#define CDNS_MB_INT_MASK			(CDNS_APB_CFG + 0x34)
> +
> +#define CDNS_SW_CLK_L				(CDNS_APB_CFG + 0x3c)
> +#define CDNS_SW_CLK_H				(CDNS_APB_CFG + 0x40)
> +#define CDNS_SW_EVENT0				(CDNS_APB_CFG + 0x44)
> +#define CDNS_DPTX_HPD				BIT(0)
> +
> +#define CDNS_SW_EVENT1				(CDNS_APB_CFG + 0x48)
> +#define CDNS_SW_EVENT2				(CDNS_APB_CFG + 0x4c)
> +#define CDNS_SW_EVENT3				(CDNS_APB_CFG + 0x50)
> +
> +#define CDNS_APB_INT_MASK			(CDNS_APB_CFG + 0x6C)
> +#define CDNS_APB_INT_MASK_MAILBOX_INT		BIT(0)
> +#define CDNS_APB_INT_MASK_SW_EVENT_INT		BIT(1)
> +
> +#define CDNS_DPTX_CAR				(CDNS_APB_CFG + 0x904)
> +#define CDNS_VIF_CLK_EN				BIT(0)
> +#define CDNS_VIF_CLK_RSTN			BIT(1)
> +
> +#define CDNS_SOURCE_VIDEO_IF(s)			(0x00b00 + (s * 0x20))
> +#define CDNS_BND_HSYNC2VSYNC(s)			(CDNS_SOURCE_VIDEO_IF(s) + \
> +						 0x00)
> +#define CDNS_IP_DTCT_WIN			GENMASK(11, 0)
> +#define CDNS_IP_DET_INTERLACE_FORMAT		BIT(12)
> +#define CDNS_IP_BYPASS_V_INTERFACE		BIT(13)
> +
> +#define CDNS_HSYNC2VSYNC_POL_CTRL(s)		(CDNS_SOURCE_VIDEO_IF(s) + \
> +						 0x10)
> +#define CDNS_H2V_HSYNC_POL_ACTIVE_LOW		BIT(1)
> +#define CDNS_H2V_VSYNC_POL_ACTIVE_LOW		BIT(2)
> +
> +#define CDNS_DPTX_PHY_CONFIG			0x02000
> +#define CDNS_PHY_TRAINING_EN			BIT(0)
> +#define CDNS_PHY_TRAINING_TYPE(x)		(((x) & GENMASK(3, 0)) << 1)
> +#define CDNS_PHY_SCRAMBLER_BYPASS		BIT(5)
> +#define CDNS_PHY_ENCODER_BYPASS			BIT(6)
> +#define CDNS_PHY_SKEW_BYPASS			BIT(7)
> +#define CDNS_PHY_TRAINING_AUTO			BIT(8)
> +#define CDNS_PHY_LANE0_SKEW(x)			(((x) & GENMASK(2, 0)) << 9)
> +#define CDNS_PHY_LANE1_SKEW(x)			(((x) & GENMASK(2, 0)) << 12)
> +#define CDNS_PHY_LANE2_SKEW(x)			(((x) & GENMASK(2, 0)) << 15)
> +#define CDNS_PHY_LANE3_SKEW(x)			(((x) & GENMASK(2, 0)) << 18)
> +#define CDNS_PHY_COMMON_CONFIG			(CDNS_PHY_LANE1_SKEW(1) | \
> +						CDNS_PHY_LANE2_SKEW(2) |  \
> +						CDNS_PHY_LANE3_SKEW(3))
> +#define CDNS_PHY_10BIT_EN			BIT(21)
> +
> +#define CDNS_DPTX_FRAMER			0x02200
> +#define CDNS_DP_FRAMER_GLOBAL_CONFIG		(CDNS_DPTX_FRAMER + 0x00)
> +#define CDNS_DP_NUM_LANES(x)			(x - 1)
> +#define CDNS_DP_MST_EN				BIT(2)
> +#define CDNS_DP_FRAMER_EN			BIT(3)
> +#define CDNS_DP_RATE_GOVERNOR_EN		BIT(4)
> +#define CDNS_DP_NO_VIDEO_MODE			BIT(5)
> +#define CDNS_DP_DISABLE_PHY_RST			BIT(6)
> +#define CDNS_DP_WR_FAILING_EDGE_VSYNC		BIT(7)
> +
> +#define CDNS_DP_SW_RESET			(CDNS_DPTX_FRAMER + 0x04)
> +#define CDNS_DP_FRAMER_TU			(CDNS_DPTX_FRAMER + 0x08)
> +#define CDNS_DP_FRAMER_TU_SIZE(x)		(((x) & GENMASK(6, 0)) << 8)
> +#define CDNS_DP_FRAMER_TU_VS(x)			((x) & GENMASK(5, 0))
> +#define CDNS_DP_FRAMER_TU_CNT_RST_EN		BIT(15)
> +
> +#define CDNS_DPTX_STREAM(s)			(0x03000 + s * 0x80)
> +#define CDNS_DP_MSA_HORIZONTAL_0(s)		(CDNS_DPTX_STREAM(s) + 0x00)
> +#define CDNS_DP_MSAH0_H_TOTAL(x)		(x)
> +#define CDNS_DP_MSAH0_HSYNC_START(x)		((x) << 16)
> +
> +#define CDNS_DP_MSA_HORIZONTAL_1(s)		(CDNS_DPTX_STREAM(s) + 0x04)
> +#define CDNS_DP_MSAH1_HSYNC_WIDTH(x)		(x)
> +#define CDNS_DP_MSAH1_HSYNC_POL_LOW		BIT(15)
> +#define CDNS_DP_MSAH1_HDISP_WIDTH(x)		((x) << 16)
> +
> +#define CDNS_DP_MSA_VERTICAL_0(s)		(CDNS_DPTX_STREAM(s) + 0x08)
> +#define CDNS_DP_MSAV0_V_TOTAL(x)		(x)
> +#define CDNS_DP_MSAV0_VSYNC_START(x)		((x) << 16)
> +
> +#define CDNS_DP_MSA_VERTICAL_1(s)		(CDNS_DPTX_STREAM(s) + 0x0c)
> +#define CDNS_DP_MSAV1_VSYNC_WIDTH(x)		(x)
> +#define CDNS_DP_MSAV1_VSYNC_POL_LOW		BIT(15)
> +#define CDNS_DP_MSAV1_VDISP_WIDTH(x)		((x) << 16)
> +
> +#define CDNS_DP_MSA_MISC(s)			(CDNS_DPTX_STREAM(s) + 0x10)
> +#define CDNS_DP_STREAM_CONFIGs(s)		(CDNS_DPTX_STREAM(s) + 0x14)
> +#define CDNS_DP_STREAM_CONFIG_2(s)		(CDNS_DPTX_STREAM(s) + 0x2c)
> +#define CDNS_DP_SC2_TU_VS_DIFF(x)		((x) << 8)
> +
> +#define CDNS_DP_HORIZONTAL(s)			(CDNS_DPTX_STREAM(s) + 0x30)
> +#define CDNS_DP_H_HSYNC_WIDTH(x)		(x)
> +#define CDNS_DP_H_H_TOTAL(x)			((x) << 16)
> +
> +#define CDNS_DP_VERTICAL_0(s)			(CDNS_DPTX_STREAM(s) + 0x34)
> +#define CDNS_DP_V0_VHEIGHT(x)			(x)
> +#define CDNS_DP_V0_VSTART(x)			((x) << 16)
> +
> +#define CDNS_DP_VERTICAL_1(s)			(CDNS_DPTX_STREAM(s) + 0x38)
> +#define CDNS_DP_V1_VTOTAL(x)			(x)
> +#define CDNS_DP_V1_VTOTAL_EVEN			BIT(16)
> +
> +#define CDNS_DP_FRAMER_PXL_REPR(s)		(CDNS_DPTX_STREAM(s) + 0x4c)
> +#define CDNS_DP_FRAMER_6_BPC			BIT(0)
> +#define CDNS_DP_FRAMER_8_BPC			BIT(1)
> +#define CDNS_DP_FRAMER_10_BPC			BIT(2)
> +#define CDNS_DP_FRAMER_12_BPC			BIT(3)
> +#define CDNS_DP_FRAMER_16_BPC			BIT(4)
> +#define CDNS_DP_FRAMER_PXL_FORMAT		0x8
> +#define CDNS_DP_FRAMER_RGB			BIT(0)
> +#define CDNS_DP_FRAMER_YCBCR444			BIT(1)
> +#define CDNS_DP_FRAMER_YCBCR422			BIT(2)
> +#define CDNS_DP_FRAMER_YCBCR420			BIT(3)
> +#define CDNS_DP_FRAMER_Y_ONLY			BIT(4)
> +
> +#define CDNS_DP_FRAMER_SP(s)			(CDNS_DPTX_STREAM(s) + 0x10)
> +#define CDNS_DP_FRAMER_VSYNC_POL_LOW		BIT(0)
> +#define CDNS_DP_FRAMER_HSYNC_POL_LOW		BIT(1)
> +#define CDNS_DP_FRAMER_INTERLACE		BIT(2)
> +
> +#define CDNS_DP_LINE_THRESH(s)			(CDNS_DPTX_STREAM(s) + 0x64)
> +#define CDNS_DP_ACTIVE_LINE_THRESH(x)		(x)
> +
> +#define CDNS_DP_VB_ID(s)			(CDNS_DPTX_STREAM(s) + 0x68)
> +#define CDNS_DP_VB_ID_INTERLACED		BIT(2)
> +#define CDNS_DP_VB_ID_COMPRESSED		BIT(6)
> +
> +#define CDNS_DP_FRONT_BACK_PORCH(s)		(CDNS_DPTX_STREAM(s) + 0x78)
> +#define CDNS_DP_BACK_PORCH(x)			(x)
> +#define CDNS_DP_FRONT_PORCH(x)			((x) << 16)
> +
> +#define CDNS_DP_BYTE_COUNT(s)			(CDNS_DPTX_STREAM(s) + 0x7c)
> +#define CDNS_DP_BYTE_COUNT_BYTES_IN_CHUNK_SHIFT	16
> +
> +#define CDNS_DP_MST_STREAM_CONFIG(s)		(CDNS_DPTX_STREAM(s) + 0x14)
> +#define CDNS_DP_MST_STRM_CFG_STREAM_EN		BIT(0)
> +#define CDNS_DP_MST_STRM_CFG_NO_VIDEO		BIT(1)
> +
> +#define CDNS_DP_MST_SLOT_ALLOCATE(s)		(CDNS_DPTX_STREAM(s) + 0x44)
> +#define CDNS_DP_S_ALLOC_START_SLOT(x)		(x)
> +#define CDNS_DP_S_ALLOC_END_SLOT(x)		((x) << 8)
> +
> +#define CDNS_DP_RATE_GOVERNING(s)		(CDNS_DPTX_STREAM(s) + 0x48)
> +#define CDNS_DP_RG_TARG_AV_SLOTS_Y(x)		(x)
> +#define CDNS_DP_RG_TARG_AV_SLOTS_X(x)		(x << 4)
> +#define CDNS_DP_RG_ENABLE			BIT(10)
> +
> +#define CDNS_DP_MTPH_CONTROL			0x2264
> +#define CDNS_DP_MTPH_ECF_EN			BIT(0)
> +#define CDNS_DP_MTPH_ACT_EN			BIT(1)
> +#define CDNS_DP_MTPH_LVP_EN			BIT(2)
> +
> +#define CDNS_DP_MTPH_STATUS			0x226C
> +#define CDNS_DP_MTPH_ACT_STATUS			BIT(0)
> +
> +
> +#define CDNS_DPTX_GLOBAL			0x02300
> +#define CDNS_DP_LANE_EN				(CDNS_DPTX_GLOBAL + 0x00)
> +#define CDNS_DP_LANE_EN_LANES(x)		GENMASK(x - 1, 0)
> +#define CDNS_DP_ENHNCD				(CDNS_DPTX_GLOBAL + 0x04)
> +
> +
> +#define to_mhdp_connector(x) container_of(x, struct cdns_mhdp_connector, base)
> +#define to_mhdp_bridge(x) container_of(x, struct cdns_mhdp_bridge, base)
> +#define mgr_to_mhdp(x) container_of(x, struct cdns_mhdp_device, mst_mgr)
> +
> +#define CDNS_MHDP_MAX_STREAMS   4
> +
> +enum pixel_format {
> +	PIXEL_FORMAT_RGB = 1,
> +	PIXEL_FORMAT_YCBCR_444 = 2,
> +	PIXEL_FORMAT_YCBCR_422 = 4,
> +	PIXEL_FORMAT_YCBCR_420 = 8,
> +	PIXEL_FORMAT_Y_ONLY = 16,
> +};
> +
> +
> +int cdns_mhdp_mst_init(struct cdns_mhdp_device *mhdp);
> +void cdns_mhdp_mst_deinit(struct cdns_mhdp_device *mhdp);
> +bool cdns_mhdp_mst_probe(struct cdns_mhdp_device *mhdp);
> +enum pixel_format cdns_mhdp_get_pxlfmt(u32 color_formats);
> +u32 cdns_mhdp_get_bpp(u32 bpc, u32 color_formats);
> +void cdns_mhdp_configure_video(struct drm_bridge *bridge);
> +void cdns_mhdp_mst_enable(struct drm_bridge *bridge);
> +void cdns_mhdp_mst_disable(struct drm_bridge *bridge);
> +void cdns_mhdp_enable(struct drm_bridge *bridge);
> +
> +#endif
> diff --git a/drivers/gpu/drm/rockchip/cdn-dp-core.c b/drivers/gpu/drm/rockchip/cdn-dp-core.c
> index 343f381e3440..a5a668f1912b 100644
> --- a/drivers/gpu/drm/rockchip/cdn-dp-core.c
> +++ b/drivers/gpu/drm/rockchip/cdn-dp-core.c
> @@ -34,7 +34,7 @@
>  #include "rockchip_drm_vop.h"
>  
>  #define connector_to_dp(c) \
> -		container_of(c, struct cdn_dp_device, mhdp.connector)
> +		container_of(c, struct cdn_dp_device, mhdp.connector.base)
>  
>  #define encoder_to_dp(c) \
>  		container_of(c, struct cdn_dp_device, encoder)
> @@ -291,7 +291,7 @@ static int cdn_dp_connector_mode_valid(struct drm_connector *connector,
>  {
>  	struct cdn_dp_device *dp = connector_to_dp(connector);
>  	struct drm_display_info *display_info =
> -		&dp->mhdp.connector.display_info;
> +		&dp->mhdp.connector.base.display_info;
>  	u32 requested, actual, rate, sink_max, source_max = 0;
>  	u8 lanes, bpc;
>  
> @@ -387,7 +387,7 @@ static int cdn_dp_get_sink_capability(struct cdn_dp_device *dp)
>  	}
>  
>  	kfree(dp->edid);
> -	dp->edid = drm_do_get_edid(&dp->mhdp.connector,
> +	dp->edid = drm_do_get_edid(&dp->mhdp.connector.base,
>  				   cdns_mhdp_get_edid_block, &dp->mhdp);
>  	return 0;
>  }
> @@ -559,7 +559,7 @@ static void cdn_dp_encoder_mode_set(struct drm_encoder *encoder,
>  {
>  	struct cdn_dp_device *dp = encoder_to_dp(encoder);
>  	struct drm_display_info *display_info =
> -		&dp->mhdp.connector.display_info;
> +		&dp->mhdp.connector.base.display_info;
>  	struct video_info *video = &dp->mhdp.video_info;
>  
>  	switch (display_info->bpc) {
> @@ -863,8 +863,8 @@ static int cdn_dp_audio_get_eld(struct device *dev, void *data,
>  {
>  	struct cdn_dp_device *dp = dev_get_drvdata(dev);
>  
> -	memcpy(buf, dp->mhdp.connector.eld,
> -	       min(sizeof(dp->mhdp.connector.eld), len));
> +	memcpy(buf, dp->mhdp.connector.base.eld,
> +	       min(sizeof(dp->mhdp.connector.base.eld), len));
>  
>  	return 0;
>  }
> @@ -936,7 +936,7 @@ static void cdn_dp_pd_event_work(struct work_struct *work)
>  {
>  	struct cdn_dp_device *dp = container_of(work, struct cdn_dp_device,
>  						event_work);
> -	struct drm_connector *connector = &dp->mhdp.connector;
> +	struct drm_connector *connector = &dp->mhdp.connector.base;
>  	enum drm_connector_status old_status;
>  	struct device *dev = dp->mhdp.dev;
>  
> @@ -1062,7 +1062,7 @@ static int cdn_dp_bind(struct device *dev, struct device *master, void *data)
>  
>  	drm_encoder_helper_add(encoder, &cdn_dp_encoder_helper_funcs);
>  
> -	connector = &dp->mhdp.connector;
> +	connector = &dp->mhdp.connector.base;
>  	connector->polled = DRM_CONNECTOR_POLL_HPD;
>  	connector->dpms = DRM_MODE_DPMS_OFF;
>  
> @@ -1113,7 +1113,7 @@ static void cdn_dp_unbind(struct device *dev, struct device *master, void *data)
>  {
>  	struct cdn_dp_device *dp = dev_get_drvdata(dev);
>  	struct drm_encoder *encoder = &dp->encoder;
> -	struct drm_connector *connector = &dp->mhdp.connector;
> +	struct drm_connector *connector = &dp->mhdp.connector.base;
>  
>  	cancel_work_sync(&dp->event_work);
>  	cdn_dp_encoder_disable(encoder);
> diff --git a/include/drm/bridge/cdns-mhdp-cbs.h b/include/drm/bridge/cdns-mhdp-cbs.h
> new file mode 100644
> index 000000000000..af07cbfcb729
> --- /dev/null
> +++ b/include/drm/bridge/cdns-mhdp-cbs.h
> @@ -0,0 +1,27 @@
> +/* SPDX-License-Identifier: GPL v2 */
> +/*
> + * Cadence MHDP DP bridge callbacks.
> + *
> + * Copyright: 2018 Cadence Design Systems, Inc.
> + *
> + * Author: Piotr Sroka <piotrs@cadence.com>
> + */
> +
> +#ifndef CDNS_MHDP_CBS_H
> +#define CDNS_MHDP_CBS_H
> +
> +struct cdns_mhdp_mst_cbs_funcs {
> +	struct drm_encoder *(*create_mst_encoder)(void *priv_data,
> +						  struct drm_bridge *bridge);
> +	void (*destroy_mst_encoder)(void *priv_data, struct drm_bridge *bridge);
> +};
> +
> +struct cdns_mhdp_mst_cbs {
> +	struct cdns_mhdp_mst_cbs_funcs funcs;
> +	void *priv_data;
> +};
> +
> +int mhdp_bridge_attach_mst_cbs(struct drm_bridge *bridge,
> +			       struct cdns_mhdp_mst_cbs *cbs);
> +
> +#endif
> diff --git a/include/drm/bridge/cdns-mhdp-common.h b/include/drm/bridge/cdns-mhdp-common.h
> index c5a5c4fa7fc4..d4711091ff2b 100644
> --- a/include/drm/bridge/cdns-mhdp-common.h
> +++ b/include/drm/bridge/cdns-mhdp-common.h
> @@ -15,10 +15,12 @@
>  #ifndef CDNS_MHDP_COMMON_H_
>  #define CDNS_MHDP_COMMON_H_
>  
> +#include <drm/drm_dp_mst_helper.h>
>  #include <linux/bitops.h>
>  #include <drm/drm_dp_helper.h>
>  #include <drm/drm_connector.h>
>  #include <drm/drm_bridge.h>
> +#include <drm/bridge/cdns-mhdp-cbs.h>
>  
>  #define ADDR_IMEM		0x10000
>  #define ADDR_DMEM		0x20000
> @@ -326,11 +328,11 @@
>  #define MB_MODULE_ID_GENERAL		0x0a
>  
>  /* general opcode */
> -#define GENERAL_MAIN_CONTROL            0x01
> -#define GENERAL_TEST_ECHO               0x02
> -#define GENERAL_BUS_SETTINGS            0x03
> -#define GENERAL_TEST_ACCESS             0x04
> -#define GENERAL_REGISTER_READ           0x07
> +#define GENERAL_MAIN_CONTROL		0x01
> +#define GENERAL_TEST_ECHO		0x02
> +#define GENERAL_BUS_SETTINGS		0x03
> +#define GENERAL_TEST_ACCESS		0x04
> +#define GENERAL_REGISTER_READ		0x07
>  
>  #define DPTX_SET_POWER_MNG			0x00
>  #define DPTX_SET_HOST_CAPABILITIES		0x01
> @@ -512,13 +514,34 @@ struct cdns_mhdp_sink {
>  	u8	enhanced;
>  };
>  
> +struct cdns_mhdp_bridge;
> +struct cdns_mhdp_connector;
> +
> +struct cdns_mhdp_bridge {
> +	struct cdns_mhdp_device *mhdp;
> +	struct drm_bridge base;
> +	int pbn;
> +	int8_t stream_id;
> +	struct cdns_mhdp_connector *connector;
> +	bool is_active;
> +};
> +
> +
> +struct cdns_mhdp_connector {
> +	struct drm_connector base;
> +	bool is_mst_connector;
> +	struct drm_dp_mst_port *port;
> +	struct cdns_mhdp_bridge *bridge;
> +};
> +
> +
>  struct cdns_mhdp_device {
>  	void __iomem		*regs;
>  
>  	struct device		*dev;
>  
>  	struct drm_dp_link	link;
> -	struct drm_connector	connector;
> +	struct cdns_mhdp_connector  connector;
>  	struct clk		*spdif_clk;
>  	struct reset_control	*spdif_rst;
>  
> @@ -528,13 +551,22 @@ struct cdns_mhdp_device {
>  	struct drm_dp_aux	aux;
>  	struct cdns_mhdp_host	host;
>  	struct cdns_mhdp_sink	sink;
> -	struct drm_bridge	bridge;
> +	struct cdns_mhdp_bridge	bridge;
>  	struct phy		*phy;
>  	void __iomem		*dbg_regs;
>  
>  	struct video_info	video_info;
>  	struct drm_display_mode	mode;
>  	unsigned int		fw_version;
> +
> +	struct drm_dp_mst_topology_mgr mst_mgr;
> +	struct delayed_work hotplug_work;
> +
> +	struct cdns_mhdp_mst_cbs cbs;
> +	bool is_mst;
> +	bool can_mst;
> +	bool link_up;
> +	bool plugged;
>  };
>  
>  void cdns_mhdp_clock_reset(struct cdns_mhdp_device *mhdp);
> @@ -562,7 +594,7 @@ int cdns_mhdp_audio_config(struct cdns_mhdp_device *mhdp,
>  int cdns_mhdp_reg_read(struct cdns_mhdp_device *mhdp, u32 addr, u32 *value);
>  int cdns_mhdp_reg_write(struct cdns_mhdp_device *mhdp, u16 addr, u32 val);
>  int cdns_mhdp_reg_write_bit(struct cdns_mhdp_device *mhdp, u16 addr,
> -				   u8 start_bit, u8 bits_no, u32 val);
> +			    u8 start_bit, u8 bits_no, u32 val);
>  int cdns_mhdp_adjust_lt(struct cdns_mhdp_device *mhdp, u8 nlanes,
>  			u16 udelay, u8 *lanes_data,
>  			u8 *dpcd);