media: platform: rzg2l-cru: rzg2l-csi2: Restructure vclk handling

As per section 35.3.1 Starting Reception for the MIPI CSI-2 Input on the
latest hardware manual (R01UH0914EJ0145 Rev.1.45) we need to disable the
vclk before enabling the LINK reception and enable the vclk after enabling
the link Reception. So restructure vclk handling as per the HW manual.

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Link: https://lore.kernel.org/r/20240213181233.242316-5-biju.das.jz@bp.renesas.com
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

media: v4l: async: Rename v4l2_async_subdev as v4l2_async_connection

Rename v4l2_async_subdev as v4l2_async_connection, in order to
differentiate between the sub-devices and their connections: one
sub-device can have many connections but the V4L2 async framework has so
far allowed just a single one. Connections in this context will later
translate into either MC ancillary or data links.

This patch prepares changing that relation by changing existing users of
v4l2_async_subdev to switch to v4l2_async_connection. Async sub-devices
themselves will not be needed anymore

Additionally, __v4l2_async_nf_add_subdev() has been renamed
__v4l2_async_nf_add_connection().

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Tested-by: Philipp Zabel <p.zabel@pengutronix.de> # imx6qp
Tested-by: Niklas Söderlund <niklas.soderlund@ragnatech.se> # rcar + adv746x
Tested-by: Aishwarya Kothari <aishwarya.kothari@toradex.com> # Apalis i.MX6Q with TC358743
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> # Renesas RZ/G2L SMARC
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

media: platform: renesas: rzg2l-cru: Add missing documentation for image_conv_irq

Add missing documentation for image_conv_irq element in
struct rzg2l_cru_dev.

Documentation needed to avoid build warning with W=1 builds. It doesn't
really add any non obvious information but good to have it anyway.

Reported-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

media: platform: Add Renesas RZ/G2L CRU driver

Add v4l driver for Renesas RZ/G2L Camera data Receiving Unit.

Based on a patch in the BSP by Hien Huynh
<hien.huynh.px@renesas.com>

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>