media: i2c: Remove common dependencies from sensor drivers

As selecting V4L2_FWNODE, MEDIA_CONTROLLER and VIDEO_V4L2_SUBDEV_API are
now selected by the top level menu, they can be dropped from the
individual drivers. Also dropped selecting V4L2_ASYNC for a single driver
as this is already implied by V4L2_FWNODE.

Similarly, the I2C dependency is now also in the top level menu, so remove
it, as well as VIDEO_DEV which isn't needed by camera sensor drivers.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

media: Kconfig: cleanup VIDEO_DEV dependencies

media Kconfig has two entries associated to V4L API:
VIDEO_DEV and VIDEO_V4L2.

On Kernel 2.6.x, there were two V4L APIs, each one with its own flag.
VIDEO_DEV were meant to:
1) enable Video4Linux and make its Kconfig options to appear;
2) it makes the Kernel build the V4L core.

while VIDEO_V4L2 where used to distinguish between drivers that
implement the newer API and drivers that implemented the former one.

With time, such meaning changed, specially after the removal of
all V4L version 1 drivers.

At the current implementation, VIDEO_DEV only does (1): it enables
the media options related to V4L, that now has:

menu "Video4Linux options"
visible if VIDEO_DEV

source "drivers/media/v4l2-core/Kconfig"
endmenu

but it doesn't affect anymore the V4L core drivers.

The rationale is that the V4L2 core has a "soft" dependency
at the I2C bus, and now requires to select a number of other
Kconfig options:

config VIDEO_V4L2
tristate
depends on (I2C || I2C=n) && VIDEO_DEV
select RATIONAL
select VIDEOBUF2_V4L2 if VIDEOBUF2_CORE
default (I2C || I2C=n) && VIDEO_DEV

In the past, merging them would be tricky, but it seems that it is now
possible to merge those symbols, in order to simplify V4L dependencies.

Let's keep VIDEO_DEV, as this one is used on some make *defconfig
configurations.

Suggested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com> # for meson-vdec & meson-ge2d
Acked-by: Andrzej Pietrasiewicz <andrzejtp2010@gmail.com>
Acked-by: Łukasz Stelmach <l.stelmach@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

media: Kconfig files: use select for V4L2 subdevs and MC

There are lots of drivers that only work when the media controller
and/or the V4L2 subdev APIs are present.

Right now, someone need to first enable those APIs before
using those drivers.

Well, ideally, drivers, should, instead *optionally*
depend on it, in order for PC camera drivers to be able to use
them, but nowadays most drivers are UVC cameras, with don't
require a sensor driver.

So, be it.

Let's instead make them select the MEDIA_CONTROLLER and the
SUBDEV API, in order to make easier for people to be able
of enabling them.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

treewide: Add SPDX license identifier - Makefile/Kconfig

Add SPDX license identifiers to all Make/Kconfig files which:

- Have no license information of any form

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

GPL-2.0-only

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

media: Kconfig files: use the right help coding style

Checkpatch wants to use 'help' instead of '---help---':

WARNING: prefer 'help' over '---help---' for new help texts

Let's change it globally at the media subsystem, as otherwise people
would keep using the old way.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

media: et8ek8: select V4L2_FWNODE

v4l2_async_register_subdev_sensor_common() is only provided when
CONFIG_V4L2_FWNODE is enabled, otherwise we get a link failure:

drivers/media/i2c/et8ek8/et8ek8_driver.o: In function `et8ek8_probe':
et8ek8_driver.c:(.text+0x884): undefined reference to `v4l2_async_register_subdev_sensor_common'

This adds a Kconfig 'select' statement like all the other users of
this interface have.

Fixes: d8932f38c10f ("media: et8ek8: Add support for flash and lens devices")

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

[media] media: Driver for Toshiba et8ek8 5MP sensor

Add driver for et8ek8 sensor, found in Nokia N900 main camera. Can be
used for taking photos in 2.5MP resolution with fcam-dev.

Signed-off-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com>
Signed-off-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>