media: tegra-video: Compute settle times based on the clock rate

Settle time determines the number of cil clock cyles to wait after
LP00 when moving from LP to HS.

This patch computes T-CLK-SETTLE and T-HS-SETTLE times based on cil
clock rate and pixel rate from the sensor and programs them during
streaming.

T-CLK-SETTLE time is the interval during which receiver will ignore
any HS transitions on clock lane starting from the beginning of
T-CLK-PREPARE.

T-HS-SETTLE time is the interval during which recevier will ignore
any HS transitions on data lane starting from the beginning of
T-HS-PREPARE.

Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

media: tegra-video: Add CSI MIPI pads calibration

CSI MIPI pads need to be enabled and calibrated for capturing from
the external sensor or transmitter.

MIPI CAL unit calibrates MIPI pads pull-up, pull-down and termination
impedances. Calibration is done by co-work of MIPI BIAS pad and MIPI
CAL control unit.

Triggering calibration start can happen any time after MIPI pads are
enabled but calibration results will be latched and applied to MIPI
pads by MIPI CAL unit only when the link is in LP11 state and then
calibration status register gets updated.

This patch enables CSI MIPI pads and calibrates them during streaming.

Tegra CSI receiver is able to catch the very first clock transition.
So, CSI receiver is always enabled prior to sensor streaming and
trigger of calibration start is done during CSI subdev streaming and
status of calibration is verified after sensor stream on.

Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

media: tegra-video: Add support for external sensor capture

This patch adds support to capture from the external sensor
based on device graph in the device tree.

Driver walks through the device graph to create media links
between the entities and registers and unregisters video devices
when the corresponding sub-devices are bound and unbound.

Channel formats are enumerated based on available formats from
the sensor and the corresponding matched formats from the Tegra
supported video formats list.

Each Tegra CSI instance can be configured as 4-lane or 2-lane
based on supported lane configuration from the sensor through
the device tree.

Currently this driver supports V4L2 video node centric only.

[hverkuil: changed video_unregister_device to vb2_video_unregister_device]

Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

media: tegra-video: Add Tegra210 Video input driver

Tegra210 contains a powerful Video Input (VI) hardware controller
which can support up to 6 MIPI CSI camera sensors.

Each Tegra CSI port can be one-to-one mapped to VI channel and can
capture from an external camera sensor connected to CSI or from
built-in test pattern generator.

Tegra210 supports built-in test pattern generator from CSI to VI.

This patch adds a V4L2 capture driver with a media interface for
Tegra210 built-in CSI to VI test pattern generator.

This patch includes TPG support only and all the video pipeline
configuration happens through the video device node.

Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Thierry Reding <treding@nvidia.com>