The scope of the s_stream video operation is now fully supported by
{enable,disable}_streams. Explicitly document the s_stream() op as
deprecated and update the related documentation.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

BT.601 is not actually a bus specification, leaving parallel bus without a
specification to refer to. Fix this.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

Document that sub-device initialisation needs to complete before the async
sub-device is registered as there is no further driver action needed
before the sensor becomes accessible via the UAPI.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

Split camera sensor documentation into user and kernel portions. This
should make it easier for the user space developers to find the relevant
documentation.

Also add a list of exemplary drivers and add imx219 driver to it, besides
those that were already mentioned.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

Camera sensor drivers are highly subject to cargo cult programming, with
back practices being copied from old to new drivers. In particular, many
drivers implement system and runtime PM incorrectly. As a first step
towards fixing this situation, refactor and expand the power management
documentation to detail correct usage of system and runtime PM.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

Move the power management section up, just after clocks, as it relates
to internal system resources and not features exposed to applications.
The text itself is otherwise unchanged.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

The Documentation/devicetree/bindings/clock/clock-bindings.txt file is
deprecated and points to clock-bindings.yaml, which is not hosted in the
kernel source tree. Use an HTTPS link to refer to the YAML binding
document.

While at it, drop "currently" from the paragraph, as the whole file
refers to the current recommended practices except where explicitly
noted.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

Drop an unneeded double colon, and use 'shall' instead of 'must' for
consistency with the rest of the file.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

Document how rotation and orientation should be taken into account in
writing camera sensor drivers.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

Modernise the documentation to make it more precise and update the use of
pixel rate control and various other changes. In particular:

- Use non-proportional font for file names, properties as well as
  controls.

- The unit of the HBLANK control is pixels, not lines.

- The unit of PIXEL_RATE control is pixels per second, not Hz.

- Merge common requirements for CSI-2 and parallel busses.

- Include all DT properties needed for assigned clocks.

- Fix referencing the link rate control.

- SMIA driver's new name is CCS driver.

- The PIXEL_RATE control denotes pixel rate on the pixel array on camera
  sensors. Do not suggest it is used to tell the maximum pixel rate on the
  bus anymore.

- Improve ReST syntax (plain struct and function names).

- Remove the suggestion to use s_power() in receiver drivers.

- Make MIPI website URL use HTTPS, add Wikipedia links to BT.601 and
  BT.656.

Fixes: e4cf8c58af75 ("media: Documentation: media: Document how to write camera sensor drivers")
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Andrey Konovalov <andrey.konovalov@linaro.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>