ADV7533 is a DSI to HDMI encoder chip. It is a derivative of ADV7511,
with additional blocks to translate input DSI data to parallel RGB
data. Besides the ADV7511 I2C register map, it has additional registers
that require to be configured to activate the DSI Rx block.

Create a new config that enables ADV7533 support. Use DT compatible
strings to populate the ADV7533 type enum. Add minimal register
configurations belonging to the DSI/CEC register map. Keep the ADV7533
code in a separate file.

Originally worked on by Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NArchit Taneja <architt@codeaurora.org>

When the adv7511 i2c client doesn't have an interrupt line, we observe a
deadlock on caused by trying to lock drm device's mode_config.mutex twice
in the same context.

Here is the sequence that causes it:

ioctl DRM_IOCTL_MODE_GETCONNECTOR from userspace
  drm_mode_getconnector (acquires mode_config mutex)
    connector->fill_modes()
    drm_helper_probe_single_connector_modes
      connector_funcs->get_modes
	adv7511_encoder_get_modes
	  adv7511_get_edid_block
	    adv7511_irq_process
	      drm_helper_hpd_irq_event (acquires mode_config mutex again)

In adv7511_irq_process, don't call drm_helper_hpd_irq_event when not
called from the interrupt handler. It doesn't serve any purpose there
anyway.
Signed-off-by: NArchit Taneja <architt@codeaurora.org>

The driver has been converted to use drm_bridge instead of
drm_i2c_slave_encoder. We can now move it to the bridge folder.

Create a separate folder since we already have a couple of files and
expect more when we support audio and ADV7533.

Rename the driver to adv7511_drv.c. This will come in handy later
when the driver module will need to be built from multiple object
files.
Signed-off-by: NArchit Taneja <architt@codeaurora.org>

Add basic support for the sii902x RGB -> HDMI bridge.
This driver does not support audio output yet.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Tested-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: NArchit Taneja <architt@codeaurora.org>
Reviewed-by: NEmil Velikov <emil.l.velikov@gmail.com>
---
Changes in v8:
- remove useless headers inclusion
- fix macro names (s/SIL/SII)
- drop unneeded hotplug_work field from struct sii902x
- drop drm_connector_unregister() call in the ->destroy() method
- add a timeout when polling a register value

Changes in v6:
- use HDMI_INFOFRAME_SIZE(AVI)
- fix reset_gpio initialization
- reduce the reset time based on Ming feedback

Changes in v5:
- drop the best_encoder() implementation

Changes in v4:
- make reset GPIO optional
- only support attaching to DRM devices supporting atomic updates

Changes in v3:
- fix get_modes() implementation to avoid turning the screen in power
  save mode
- rename the driver (sil902x -> sii902x)

Changes in v2:
- fix errors reported by the kbuild robot

fixup! drm: bridge: Add sii902x driver

We have a 1:1 relationship between connectors and encoders, which means
we can rely on the drm_atomic_helper_best_encoder() behavior.

We still have to explicitly assign ->best_encoder() to
drm_atomic_helper_best_encoder(), because the automated fallback to
drm_atomic_helper_best_encoder() when ->best_encoder() is NULL is only
available when the DRM device is using the atomic helpers, and this bridge
is compatible with non-atomic and atomic devices.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1465300095-16971-21-git-send-email-boris.brezillon@free-electrons.com

We have a 1:1 relationship between connectors and encoders, and the driver
is relying on the atomic helpers: we can drop the custom ->best_encoder(),
and let the core call drm_atomic_helper_best_encoder() for us.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1465300095-16971-20-git-send-email-boris.brezillon@free-electrons.com

We have a 1:1 relationship between connectors and encoders, and the driver
is relying on the atomic helpers: we can drop the custom ->best_encoder(),
and let the core call drm_atomic_helper_best_encoder() for us.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1465300095-16971-19-git-send-email-boris.brezillon@free-electrons.com

We have a 1:1 relationship between connectors and encoders, and the driver
is relying on the atomic helpers: we can drop the custom ->best_encoder(),
and let the core call drm_atomic_helper_best_encoder() for us.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1465300095-16971-18-git-send-email-boris.brezillon@free-electrons.com

Although there are other chips from the same family that can reuse this
driver, at the moment we only tested ANX7814 chip.

The ANX7814 is an ultra-low power Full-HD (1080p60) SlimPort transmitter
designed for portable devices. This driver adds initial support for HDMI
to DP pass-through mode.
Signed-off-by: NEnric Balletbo i Serra <enric.balletbo@collabora.com>
Tested-by: NNicolas Boichat <drinkcat@chromium.org>
Reviewed-by: NNicolas Boichat <drinkcat@chromium.org>
Cc: Emil Velikov <emil.l.velikov@gmail.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Daniel Kurtz <djkurtz@chromium.org>
Cc: Nicolas Boichat <drinkcat@chromium.org>
Cc: Thierry Reding <treding@nvidia.com>
[treding@nvidia.com: coding style, propagate regulator_get() errors]
Signed-off-by: NThierry Reding <treding@nvidia.com>

It may caused a dead lock if we flush the hpd work in bridge disable time.

The normal flow would like:
  IN --> DRM IOCTL
        1. Acquire crtc_ww_class_mutex (DRM IOCTL)
  IN --> analogix_dp_bridge
        2. Acquire hpd work lock (Flush hpd work)
        3. HPD work already in idle, no need to run the work function.
  OUT <-- analogix_dp_bridge
  OUT <-- DRM IOCTL

The dead lock flow would like:
  IN --> DRM IOCTL
        1. Acquire crtc_ww_class_mutex (DRM IOCTL)
  IN --> analogix_dp_bridge
        2. Acquire hpd work lock (Flush hpd work)
  IN --> analogix_dp_hotplug
  IN --> drm_helper_hpd_irq_event
        3. Acquire mode_config lock (This lock already have been acquired in previous step 1)
** Dead Lock Now **

It's wrong to flush the hpd work in bridge->disable time, I guess the
original code just want to ensure the delay work must be finish before
encoder disabled.

The flush work in bridge disable time is try to ensure the HPD event
won't be missed before display card disabled, actually we can take a
fast respond way(interrupt thread) to update DRM HPD event to fix the
delay update and possible dead lock.
Tested-by: NCaesar Wang <wxt@rock-chips.com>
Tested-by: NDouglas Anderson <dianders@chromium.org>
Tested-by: NHeiko Stuebner <heiko@sntech.de>
Tested-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NYakir Yang <ykk@rock-chips.com>

Turn off the panel power in suspend time would help to reduce
power waste.
Tested-by: NCaesar Wang <wxt@rock-chips.com>
Tested-by: NDouglas Anderson <dianders@chromium.org>
Tested-by: NHeiko Stuebner <heiko@sntech.de>
Tested-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NYakir Yang <ykk@rock-chips.com>

Display Port monitor could support kinds of mode which indicate
in monitor edid, not just one single display resolution which
defined in panel or devivetree property display timing.

Note: Gustavo Padovan try to remove the controller and phy
power on function in bind time at bellow commit:
	drm/exynos: do not start enabling DP at bind() phase

But for now driver need to read edid message in .get_modes()
function, so controller must be inited in bind time, so we
need to add controller init back.
Tested-by: NCaesar Wang <wxt@rock-chips.com>
Tested-by: NDouglas Anderson <dianders@chromium.org>
Tested-by: NHeiko Stuebner <heiko@sntech.de>
Tested-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NYakir Yang <ykk@rock-chips.com>

This change just make a little clean to make code more like
drm core expect, move hdp detect code from bridge->enable(),
and place them into connector->detect().

Note: Gustavo Padovan try to remove the controller and phy
power on function in bind time at bellow commit:
	drm/exynos: do not start enabling DP at bind() phase

But for now the connector status don't hardcode to connected,
need to operate dp phy in .detect function, so we need to revert
parts if Gustavo Padovan's changes, add phy poweron
function in bind time.
Tested-by: NCaesar Wang <wxt@rock-chips.com>
Tested-by: NDouglas Anderson <dianders@chromium.org>
Tested-by: NHeiko Stuebner <heiko@sntech.de>
Tested-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NYakir Yang <ykk@rock-chips.com>

Some edp screen do not have hpd signal, so we can't just return
failed when hpd plug in detect failed.

This is an hardware property, so we need add a devicetree property
"analogix,need-force-hpd" to indicate this sutiation.
Acked-by: NRob Herring <robh@kernel.org>
Tested-by: NCaesar Wang <wxt@rock-chips.com>
Tested-by: NDouglas Anderson <dianders@chromium.org>
Tested-by: NHeiko Stuebner <heiko@sntech.de>
Tested-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NYakir Yang <ykk@rock-chips.com>

There are some IP limit on rk3288 that only support 4 physical lanes
of 2.7/1.6 Gbps/lane, so seprate them out by device_type flag.
Tested-by: NCaesar Wang <wxt@rock-chips.com>
Tested-by: NDouglas Anderson <dianders@chromium.org>
Tested-by: NHeiko Stuebner <heiko@sntech.de>
Signed-off-by: NYakir Yang <ykk@rock-chips.com>

RK3288 need some special registers setting, we can separate
them out by the dev_type of plat_data.
Tested-by: NCaesar Wang <wxt@rock-chips.com>
Tested-by: NDouglas Anderson <dianders@chromium.org>
Tested-by: NHeiko Stuebner <heiko@sntech.de>
Signed-off-by: NYakir Yang <ykk@rock-chips.com>

Both hsync/vsync polarity and interlace mode can be parsed from
drm display mode, and dynamic_range and ycbcr_coeff can be judge
by the video code.

But presumably Exynos still relies on the DT properties, so take
good use of mode_fixup() in to achieve the compatibility hacks.
Reviewed-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Tested-by: NCaesar Wang <wxt@rock-chips.com>
Tested-by: NDouglas Anderson <dianders@chromium.org>
Tested-by: NHeiko Stuebner <heiko@sntech.de>
Tested-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NYakir Yang <ykk@rock-chips.com>

link_rate and lane_count already configured in analogix_dp_set_link_train(),
so we don't need to config those repeatly after training finished, just
remove them out.

Beside Display Port 1.2 already support 5.4Gbps link rate, the maximum sets
would change from {1.62Gbps, 2.7Gbps} to {1.62Gbps, 2.7Gbps, 5.4Gbps}.
Tested-by: NCaesar Wang <wxt@rock-chips.com>
Tested-by: NDouglas Anderson <dianders@chromium.org>
Tested-by: NHeiko Stuebner <heiko@sntech.de>
Tested-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NYakir Yang <ykk@rock-chips.com>

Fix some obvious alignment problems, like alignment and line
over 80 characters problems, make this easy to be maintained
later.
Acked-by: NJingoo Han <jingoohan1@gmail.com>
Reviewed-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Tested-by: NCaesar Wang <wxt@rock-chips.com>
Tested-by: NDouglas Anderson <dianders@chromium.org>
Tested-by: NHeiko Stuebner <heiko@sntech.de>
Tested-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NYakir Yang <ykk@rock-chips.com>

In the original split we kept the register constants intact to keep the

diff small. Still the constants are Analogix-specific, so rename them now.
Tested-by: NCaesar Wang <wxt@rock-chips.com>
Tested-by: NDouglas Anderson <dianders@chromium.org>
Tested-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NHeiko Stuebner <heiko@sntech.de>
Signed-off-by: NYakir Yang <ykk@rock-chips.com>

Split the dp core driver from exynos directory to bridge directory,
and rename the core driver to analogix_dp_*, rename the platform
code to exynos_dp.

Beside the new analogix_dp driver would export six hooks.
"analogix_dp_bind()" and "analogix_dp_unbind()"
"analogix_dp_suspned()" and "analogix_dp_resume()"
"analogix_dp_detect()" and "analogix_dp_get_modes()"

The bind/unbind symbols is used for analogix platform driver to connect
with analogix_dp core driver. And the detect/get_modes is used for analogix
platform driver to init the connector.

They reason why connector need register in helper driver is rockchip drm
haven't implement the atomic API, but Exynos drm have implement it, so
there would need two different connector helper functions, that's why we
leave the connector register in helper driver.
Acked-by: NInki Dae <inki.dae@samsung.com>
Tested-by: NCaesar Wang <wxt@rock-chips.com>
Tested-by: NDouglas Anderson <dianders@chromium.org>
Tested-by: NHeiko Stuebner <heiko@sntech.de>
Tested-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NYakir Yang <ykk@rock-chips.com>
Signed-off-by: NHeiko Stuebner <heiko@sntech.de>

We don't need to keep empty callbacks for the (pre/post) enable/disable
drm_bridge ops anymore. Remove the nop callback used here for
pre_enable and post_disable ops.
Signed-off-by: NArchit Taneja <architt@codeaurora.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1459329804-10488-1-git-send-email-architt@codeaurora.org

Other bridge drivers don't implement this optional function.
Removed dummy code from dw-hdmi brigde driver.
Signed-off-by: NCarlos Palminha <palminha@synopsys.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1455120639-29934-1-git-send-email-palminha@synopsys.com

An encoder is associated with a connector by the DRM core as a result of
setting up a configuration. Drivers using the atomic or legacy helpers
should never set up this link, even if it is a static one.

While at it, try to catch this kind of error in the future by adding a
WARN_ON() in drm_mode_connector_attach_encoder(). Note that this doesn't
cover all the cases, since drivers could set this up after attaching.
Drivers that use the atomic helpers will get a warning later on, though,
so hopefully the two combined cover enough to help people avoid this in
the future.

Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Philipp Zabel <p.zabel@pengutronix.de>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Liviu Dudau <Liviu.Dudau@arm.com>
Cc: Mark yao <mark.yao@rock-chips.com>
Signed-off-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1447694393-24700-1-git-send-email-thierry.reding@gmail.com

Fill atomic needed funcs with default atomic helper library.

Rockchip use dw_hdmi, and drm/rockchip will covert to atomic api,
we need dw_hdmi support atomic funcs.

Now another drm driver use dw_hdmi is imx, not yet atomic, so
check DRIVER_ATOMIC at runtime to spilt atomic and not atomic.
Signed-off-by: NMark Yao <mark.yao@rock-chips.com>

Moves a bunch of junk to .rodata from .data.

 drivers/gpu/drm/bridge/nxp-ptn3460.ko:
-.rodata                      440
+.rodata                      536
-.data                        208
+.data                        112
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1450178476-26284-16-git-send-email-boris.brezillon@free-electrons.comSigned-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Moves a bunch of junk to .rodata from .data.

 drivers/gpu/drm/bridge/dw_hdmi.ko:
-.rodata                      120
+.rodata                      216
-.data                         96
+.data                          0
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1450178476-26284-15-git-send-email-boris.brezillon@free-electrons.comSigned-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

A single blank line is enough to separate Kconfig entries.
Signed-off-by: NThierry Reding <treding@nvidia.com>

For consistency with other drivers, use dashes instead of underscores in
filenames.
Signed-off-by: NThierry Reding <treding@nvidia.com>

The platform_no_drv_owner.cocci coccinelle script generates the
following warning:

	drivers/gpu/drm/bridge/nxp-ptn3460.c:403:3-8: No need to set .owner here. The core will do it.

Remove .owner field if calls are used which set it automatically. Patch
generated by scripts/coccinelle/api/platform_no_drv_owner.cocci.
Signed-off-by: NFengguang Wu <fengguang.wu@intel.com>
Signed-off-by: NThierry Reding <treding@nvidia.com>

The platform_no_drv_owner.cocci coccinelle script generates the
following warning:

	drivers/gpu/drm/bridge/parade-ps8622.c:671:3-8: No need to set .owner here. The core will do it.

Remove .owner field if calls are used which set it automatically. Patch
generated by scripts/coccinelle/api/platform_no_drv_owner.cocci.
Signed-off-by: NFengguang Wu <fengguang.wu@intel.com>
Signed-off-by: NThierry Reding <treding@nvidia.com>

Given the TDMS clock, audio sample rate, and the N parameter, we can
calculate the CTS value for the audio clock regenerator (ACR) using the
following calculation given in the HDMI specification:

	CTS = ftdms * N / (128 * fs)

The specification says that the CTS value is an average value, which is
true if the source hardware measures it.  Where source hardware needs it
to be programmed, it is particularly difficult to alternate between two
values correctly to ensure that we achieve a correct "average"
fractional value at the sink.

Also, there's the problem that our "ftdms" is not a fully accurate
value; it is rounded to a kHz value.  This introduces an unnecessary
(and harmless) fractional value into the above equation for combinations
like 148.5MHz/1.001 for 44100Hz - we still calculate the correct CTS
value.
Tested-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

We never set the ratio for CTS/N calculation for the audio clock
regenerator (ACR) to anything but 100, so this adds pointless
complexity.  Should we support pixel repetition, we should update the
CTS/N calculation code to use those parameters or the actual TMDS clock
rate instead of a ratio.
Tested-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Adjust the pixel clock values in the N calculation to match the more
accurate clock values we're given by the DRM subsystem, which are the
kHz pixel rate, with any fractional kHz rounded down in the case of
the non-240, non-480 line modes, or rounded up for the others.  So,

	 25.20 / 1.001 =>  25175
	 27.00 * 1.001 =>  27027
	 74.25 / 1.001 =>  74176
	148.50 / 1.001 => 148352

DRM derives these rates from the EDID CEA mode identifiers, which are
looked up in the tables in drivers/gpu/drm/drm_edid.c.  The values on
the right are the clock values found in these tables, and are
currently expected to be passed to the HDMI driver unchanged.
Tested-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

There's no need to be recursive when computing the N value for the ACR
packet - we can instead calculate the multiplier prior to our switch()
based lookup, and multiply the N value appropriately afterwards.
Tested-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

With multichannel audio, we need to allow larger buffer sizes to avoid
XRUNs during playback.  Push the buffer size up to 1024K, but as we
maintain two buffers, ensure that the vmalloc buffer does not exceed
the userspace buffer size.
Tested-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Add basic support for multi-channel PCM audio, with fixed speaker
mappings.  This has been tested with an AV receiver, and appears to
work for low sample rates up to 8 channels.

It should be noted that multi-channel mode using the IEC958 alsa-lib
conversion plugin requires correct AES channel status for the AV
receiver to recognise the stream, especially the sample rate bits.
"Not identified" does not work there.
Tested-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Parse the ELD (EDID like data) stored from the HDMI driver to restrict
the sample rates and channels which are available to ALSA.  This causes
the ALSA device to reflect the capabilities of the overall audio path,
not just what is supported at the HDMI source interface level.
Tested-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Add ALSA based HDMI AHB audio driver for dw_hdmi.  The only buffer
format supported by the hardware is its own special IEC958 based format,
which is not compatible with any ALSA format.  To avoid doing too much
data manipulation within the driver, we support only ALSAs IEC958 LE and
24-bit PCM formats for 2 to 6 channels, which we convert to its hardware
format.

A more desirable solution would be to have this conversion in userspace,
but ALSA does not appear to allow such transformations outside of
libasound itself.
Reviewed-by: NTakashi Iwai <tiwai@suse.de>
Tested-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

HDMI sinks are permitted to de-assert and re-assert the HPD signal to
indicate that their EDID has been updated, which may not involve a
change of video information.

An example of where such a situation can arise is when an AV receiver
is connected between the source and the display device.  Events which
can cause the HPD to be deasserted include:

 * turning on or switching to standby the AV receiver.
 * turning on or switching to standby the display device.

Each of these can change the entire EDID data, or just a part of the
EDID data - it's up to the connected HDMI sink to do what they desire
here.  For example

 - with the AV receiver and display device both in standby, a source
   connected to the AV receiver may provide its own EDID to the source.
 - turning on the display device causes the display device's EDID to be
   made available in an unmodified form to the source.
 - subsequently turning on the AV receiver then provides a modified
   version of the display device's EDID.

Moreover, HPD doesn't tell us whether something is actually listening
on the HDMI TDMS signals.  The phy gives us a set of RXSENSE indications
which tell us whether there is a sink connected to the TMDS signals.

Currently, we use the HPD signal to enable or disable the HDMI block,
which is questionable when HPD is used in this manner.  Using the
RXSENSE would be more appropriate, but there is some bad behaviour
which needs to be coped with.  The iMX6 implementation lets the TMDS
signals float when the phy is "powered down", which cause spurious
interrupts.  Rather than just using RXSENSE, use RXSENSE and HPD
becoming both active to signal the presence of a device, but loss
of RXSENSE to indicate that the device has been unplugged.

The side effect of this change is that a sink deasserting the HPD
signal to cause a re-read of the EDID data will not cause the bridge
to immediately disable the video signal.
Tested-by: NPhilipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>