Firstly, there is no VC_EN bit present in the STREAM_DATA_CFG register.
Bit 31 is part of the VL_SELECT field. Remove it completely.

Secondly, it makes little sense to enable ith virtual channel for ith
stream. Sure, there might be a use-case that demands it. But there might
also be a use case that demands all streams to use the 0th virtual
channel. Prefer this case over the former because it is less arbitrary
and also makes it very clear what the limitations of the current driver
is instead of giving a false impression that multiple virtual channels
are supported.

Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
Signed-off-by: Vaishnav Achath <vaishnav.a@ti.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

The stream stop procedure says that the STOP bit should be set when the
stream is to be stopped, and then the ready bit in stream status
register polled to make sure the STOP operation is finished.

Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
Signed-off-by: Vaishnav Achath <vaishnav.a@ti.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

This resets the stream state machines and FIFOs, giving them a clean
slate. On J721E if the streams are not reset before starting the
capture, the captured frame gets wrapped around vertically on every run
after the first.

Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
Signed-off-by: Vaishnav Achath <vaishnav.a@ti.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

Some platforms like TI's J721E can have the CSI2RX paired with an
external DPHY. Add support to enable and configure the DPHY using the
generic PHY framework.

Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
Signed-off-by: Vaishnav Achath <vaishnav.a@ti.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

The format is needed to calculate the link speed for the external DPHY
configuration. It is not right to query the format from the source
subdev. Add get_fmt and set_fmt pad operations so that the format can be
configured and correct bpp be selected.

Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
Signed-off-by: Vaishnav Achath <vaishnav.a@ti.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

Call media_entity_cleanup() in probe error path and remove to make sure
the media entity is cleaned up properly.

Suggested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
Signed-off-by: Vaishnav Achath <vaishnav.a@ti.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

The notifier is added to the global notifier list when registered. When
the module is removed, the struct csi2rx_priv in which the notifier is
embedded, is destroyed. As a result the notifier list has a reference to
a notifier that no longer exists. This causes invalid memory accesses
when the list is iterated over. Similar for when the probe fails.
Unregister and clean up the notifier to avoid this.

Fixes: 1fc3b37f ("media: v4l: cadence: Add Cadence MIPI-CSI2 RX driver")

Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
Signed-off-by: Vaishnav Achath <vaishnav.a@ti.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

Use the devm_platform_ioremap_resource() helper instead of
calling platform_get_resource() and devm_ioremap_resource()
separately

Signed-off-by: Cai Huoqing <caihuoqing@baidu.com>
Acked-by: Maxime Ripard <maxime@cerno.tech>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

Rename V4L2 async notifier functions, replacing "notifier" with "nf" and
removing "_subdev" at the end of the function names adding subdevs as you
can only add subdevs to a notifier. Also wrap and otherwise clean up long
lines.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Rui Miguel Silva <rmfrfs@gmail.com> (imx7)
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

Handle errors of clk_prepare_enable() in csi2rx_get_resources().

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Evgeny Novikov <novikov@ispras.ru>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

The functions that add an async subdev to an async subdev notifier take
as an argument the size of the container structure they need to
allocate. This is error prone, as passing an invalid size will not be
caught by the compiler. Wrap those functions in macros that take a
container type instead of a size, and cast the returned pointer to the
desired type. The compiler will catch mistakes if the incorrect type is
passed to the macro, as the assignment types won't match.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Helen Koike <helen.koike@collabora.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com> (core+ti-cal)
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

The use of v4l2_async_notifier_add_subdev will be discouraged.
Drivers are instead encouraged to use a helper such as
v4l2_async_notifier_add_fwnode_remote_subdev.

This fixes a misuse of the API, as v4l2_async_notifier_add_subdev
should get a kmalloc'ed struct v4l2_async_subdev,
removing some boilerplate code while at it.

Use the appropriate helper v4l2_async_notifier_add_fwnode_remote_subdev,
which handles the needed setup, instead of open-coding it.

Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Reviewed-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Reviewed-by: Helen Koike <helen.koike@collabora.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

The 2nd parameter of 'find_first_zero_bit()' is a number of bits, not of
bytes. So use 'csi2rx->max_lanes' instead of 'sizeof(lanes_used)'.

Fixes: 1fc3b37f ("media: v4l: cadence: Add Cadence MIPI-CSI2 RX driver")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

Initialise the V4L2 fwnode endpoints to zero in all drivers using
v4l2_fwnode_endpoint_parse(). This prepares for setting default endpoint
flags as well as the bus type. Setting bus type to zero will continue to
guess the bus among the guessable set (parallel, Bt.656 and CSI-2 D-PHY).

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Tested-by: Steve Longerbeam <steve_longerbeam@mentor.com>
Tested-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

The CSI-2 bus may use either D-PHY or C-PHY. Make this visible in media
bus enum.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Tested-by: Steve Longerbeam <steve_longerbeam@mentor.com>
Tested-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

Switch all media platform drivers to call v4l2_async_notifier_add_subdev()
to add asd's to a notifier, in place of referencing the notifier->subdevs[]
array. These drivers also must now call v4l2_async_notifier_init() before
adding asd's to their notifiers.

There may still be cases where a platform driver maintains a list of
asd's that is a duplicate of the notifier asd_list, in which case its
possible the platform driver list can be removed, and can reference the
notifier asd_list instead. One example of where a duplicate list has
been removed in this patch is xilinx-vipp.c. If there are such cases
remaining, those drivers should be optimized to remove the duplicate
platform driver asd lists.

None of the changes to the platform drivers in this patch have been
tested. Verify that the async subdevices needed by the platform are
bound at load time, and that the driver unloads and reloads correctly
with no memory leaking of asd objects.

Suggested-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Steve Longerbeam <slongerbeam@gmail.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

I ran into a randconfig build error with the new driver:

drivers/media/platform/cadence/cdns-csi2tx.c: In function 'csi2tx_probe':
drivers/media/platform/cadence/cdns-csi2tx.c:477:11: error: implicit declaration of function 'kzalloc'; did you mean 'd_alloc'? [-Werror=implicit-function-declaration]

kzalloc() is declared in linux/slab.h, so let's include this to make it
build in all configurations.

Fixes: 84b477e6d4bc ("media: v4l: cadence: Add Cadence MIPI-CSI2 TX driver")

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

The clocks enabled by csi2rx_start function are intended to be disabled in
an error path but there are two issues:

1) the loop condition is always true and

2) the first clock disabled is the the one enabling of which failed.

Fix these two bugs by changing the loop condition as well as only disabling
the clocks that were actually enabled.

Reported-by: Mauro Chehab <mchehab@kernel.org>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

The Cadence CSI-2 RX Controller is an hardware block meant to be used as a
bridge between a CSI-2 bus and pixel grabbers.

It supports operating with internal or external D-PHY, with up to 4 lanes,
or without any D-PHY. The current code only supports the latter case.

It also support dynamic mapping of the CSI-2 virtual channels to the
associated pixel grabbers, but that isn't allowed at the moment either.

Acked-by: Benoit Parrot <bparrot@ti.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>