media: i2c: isl7998x: Add driver for Intersil ISL7998x

This is v10 of the series to for adding the isl7998x driver [0].

The isl7998x is an analog video to MIPI CSI-2 or BT.656 converter. The dt
binding describes only the isl79987 chip, which supports MIPI CSI-2. The
driver could be extended to handle isl79988 (for BT.656), too, but this isn't
implemented.

v10 drops patch 0001-media-imx6-mipi-csi2-use-pre_streamon-callback-to.patch,
because it has already been merged into master.

v10 addresses the review comments from v9 [1] and adds a lock for the subdev
calls, fixes check-patch checks, adds the PAL Nc format, and reworks how video
standards are looked up in the driver. Full changelog is in the respective
patch.

Michael

[0] https://lore.kernel.org/linux-media/20190520201812.7937-1...
[1] https://lore.kernel.org/all/20211129112708.3219754-1-m.tr...

Changelog:

v10:

- add a lock for subdev calls
- remove unnecessary pm_runtime_enabled
- fix indentation and format
- free controls on error
- fix set_standard call
- remove camel case in macro definitions
- add macros for video formats
- rework lookup of video standards
- add support for PAL Nc
- add explicit trigger for format detection

v9:

- remove clock-lanes from dt binding example
- add data-lanes to dt binding example

v8:

- rebase on v5.16-rc1
- fix warning about ignored type qualifier

v7:

- add reservation and documentation for custom V4L2 controls
- implement g_input_status, g_tvnorms, querystd, s_std, g_std
- use v4l2_norm_to_name instead of custom implementation
- fix off-by-one with 4 inputs
- fix polling condition for standard detection

v6:

- incorporate review feedback by Philipp Zabel into isl7998x.c

v5:

- ignore -ENOIOCTLCMD of pre_streamon for backwards compatibility

v4:

- add patch for imx6-mipi-csi2 to request LP-11 mode
- update isl7998x driver with review feedback on v3

v3:

- rename pd-gpios property to powerdown-gpios
- reference graph.yaml for port/ports property
- remove reference to video-interfaces.txt

v2:

- convert dt binding to yaml
- change binding to ISL79987 only
- general driver cleanup
- convert driver to pm_runtime
- use ports in device tree for specifying inputs
- add reset gpio


Marek Vasut (2):
  media: dt-bindings: Add Intersil ISL79987 DT bindings
  media: i2c: isl7998x: Add driver for Intersil ISL7998x

 .../bindings/media/i2c/isil,isl79987.yaml     |  113 ++
 MAINTAINERS                                   |    8 +
 drivers/media/i2c/Kconfig                     |   10 +
 drivers/media/i2c/Makefile                    |    1 +
 drivers/media/i2c/isl7998x.c                  | 1633 +++++++++++++++++
 include/uapi/linux/v4l2-controls.h            |    6 +
 6 files changed, 1771 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/media/i2c/isil,isl79987.yaml
 create mode 100644 drivers/media/i2c/isl7998x.c

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2.30.2