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: radio: don't use a menu just for wl128x driver

It doesn't make any sense to have a submenu just for this
driver. Drop it.

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

media: docs: move uAPI book to userspace-api/media

Since 2017, there is an space reserved for userspace API,
created by changeset 1d596dee3862 ("docs: Create a user-space API guide").

As the media subsystem was one of the first subsystems to use
Sphinx, until this patch, we were keeping things on a separate
place.

Let's just use the new location, as having all uAPI altogether
will likely make things easier for developers.

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: v4l: fix broken video4linux docs locations

There are several places pointing to old documentation files:

Documentation/video4linux/API.html
Documentation/video4linux/bttv/
Documentation/video4linux/cx2341x/fw-encoder-api.txt
Documentation/video4linux/m5602.txt
Documentation/video4linux/v4l2-framework.txt
Documentation/video4linux/videobuf
Documentation/video4linux/Zoran

Make them point to the new location where available, removing
otherwise.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Jonathan Corbet <corbet@lwn.net>

media: fix media Kconfig help syntax issues

The help text should be indented by at least two spaces after the
'help' separator. This is both good practice and the media_build system
for building media drivers makes this assumption.

I went through all Kconfigs under drivers/media and fixed any bad help
sections. This makes it conform to the common practice and should fix
problems with 'make menuconfig' when using media_build. This is due to
a "WARNING" message that media_build can insert in the Kconfig and that
assumes the help text is indented by at least two spaces. If not, then the
Kconfig becomes invalid and 'make menuconfig' fails.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Reported-by: Thomas Kaiser <linux-dvb@kaiser-linux.li>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

[media] wl128x: Allow compile test of GPIO consumers if !GPIOLIB

The GPIO subsystem provides dummy GPIO consumer functions if GPIOLIB is
not enabled. Hence drivers that depend on GPIOLIB, but use GPIO consumer
functionality only, can still be compiled if GPIOLIB is not enabled.

Relax the dependency on GPIOLIB if COMPILE_TEST is enabled, where
appropriate.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

[media] wl128x-radio really depends on TI_ST

All other drivers using the TI_ST infrastructure use
'depends on' for this symbol, and it makes no sense
to only enable that if CONFIG_NET is enable, because
the radio driver also depends on CONFIG_NET itself:

ERROR: "skb_queue_purge" [drivers/media/radio/wl128x/fm_drv.ko] undefined!
ERROR: "skb_push" [drivers/media/radio/wl128x/fm_drv.ko] undefined!
ERROR: "skb_pull" [drivers/media/radio/wl128x/fm_drv.ko] undefined!

Making the driver dependency explicit solves randconfig
build problems and makes it more obvious to the reader.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

tty: Added a CONFIG_TTY option to allow removal of TTY

The option allows you to remove TTY and compile without errors. This
saves space on systems that won't support TTY interfaces anyway.
bloat-o-meter output is below.

The bulk of this patch consists of Kconfig changes adding "depends on
TTY" to various serial devices and similar drivers that require the TTY
layer. Ideally, these dependencies would occur on a common intermediate
symbol such as SERIO, but most drivers "select SERIO" rather than
"depends on SERIO", and "select" does not respect dependencies.

bloat-o-meter output comparing our previous minimal to new minimal by
removing TTY. The list is filtered to not show removed entries with awk
'$3 != "-"' as the list was very long.

add/remove: 0/226 grow/shrink: 2/14 up/down: 6/-35356 (-35350)
function old new delta
chr_dev_init 166 170 +4
allow_signal 80 82 +2
static.__warned 143 142 -1
disallow_signal 63 62 -1
__set_special_pids 95 94 -1
unregister_console 126 121 -5
start_kernel 546 541 -5
register_console 593 588 -5
copy_from_user 45 40 -5
sys_setsid 128 120 -8
sys_vhangup 32 19 -13
do_exit 1543 1526 -17
bitmap_zero 60 40 -20
arch_local_irq_save 137 117 -20
release_task 674 652 -22
static.spin_unlock_irqrestore 308 260 -48

Signed-off-by: Joe Millenbach <jmillenbach@gmail.com>
Reviewed-by: Jamey Sharp <jamey@minilop.net>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

[media] wl128x: fix build errors when GPIOLIB is not enabled

From: Randy Dunlap <rdunlap@xenotime.net>

Fix wl128x Kconfig to depend on GPIOLIB since TI_ST also
depends on GPIOLIB.

(.text+0xe6d60): undefined reference to `st_register'
(.text+0xe7016): undefined reference to `st_unregister'
(.text+0xe70ce): undefined reference to `st_unregister'

Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Acked-by: Manjunatha Halli <manjunatha_halli@ti.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

[media] wl128x: fix build errors when GPIOLIB is not enabled

From: Randy Dunlap <rdunlap@xenotime.net>

Fix wl128x Kconfig to depend on GPIOLIB since TI_ST also
depends on GPIOLIB.

(.text+0xe6d60): undefined reference to `st_register'
(.text+0xe7016): undefined reference to `st_unregister'
(.text+0xe70ce): undefined reference to `st_unregister'

Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Acked-by: Manjunatha Halli <manjunatha_halli@ti.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

[media] drivers: media: radio: Fix dependencies for RADIO_WL128X

Fix the following build warning:

warning: (RADIO_WL128X) selects TI_ST which has unmet direct dependencies (MISC_DEVICES && NET && GPIOLIB)

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

[media] drivers:media:radio: wl128x: Kconfig & Makefile for wl128x driver

Signed-off-by: Manjunatha Halli <manjunatha_halli@ti.com>
Reviewed-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>