media: atomisp: Remove remaining deferred firmware loading code

There is a bunch of dead code left from the deferred firmware loading
support which was removed in commit 8972ed6ea7a0 ("media: atomisp: Remove
deferred firmware loading support").

Remove this dead code:
- Remove the skip_fwload module parameter
- Remove the now always NULL fw argument from ia_css_init()
- Remove the fw_explicitly_loaded boolean from sh_css.c
(this was always true now)
- Adjust some function kernel-doc comments to match

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

media: atomisp: fix Wvisiblity warning

Some randconfig builds include ia_css_firmware.h without first
including linux/device.h:

In file included from atomisp/pci/mmu/sh_mmu_mrfld.c:23:
In file included from atomisp/pci/atomisp_compat.h:22:
In file included from atomisp/pci/atomisp_compat_css20.h:24:
In file included from atomisp/pci/ia_css.h:28:
In file included from atomisp/pci/ia_css_control.h:25:
drivers/staging/media/atomisp//pci/ia_css_firmware.h:52:29: error: declaration of 'struct device' will not be visible outside of this function [-Werror,-Wvisibility]

Add a forward declaration to avoid the warning.

Link: https://lore.kernel.org/linux-media/20210108082337.2305938-1-arnd@kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

media: atomisp/pci: add missing include

Fix two smatch warnings:

drivers/staging/media/atomisp//pci/ia_css_firmware.h:52:29: warning: 'struct device' declared inside parameter list will not be visible outside of this definition or declaration
drivers/staging/media/atomisp//pci/ia_css_control.h:49:24: warning: 'struct device' declared inside parameter list will not be visible outside of this definition or declaration

Add '#include <linux/device.h>' to ia_css_firmware.h so struct device is defined.

ia_css_control.h includes ia_css_firmware.h, so it is sufficient to
just modify ia_css_firmware.h.

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

media: atomisp: add SPDX headers

This driver is licensed under GPL 2.0, as stated inside their
headers.

Add the proper tag there. We should probably latter cleanup
the reduntant licensing text, but this could be done later,
after we get rid of other abstraction layers.

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

media: atomisp: get rid of non-Linux error codes

The atomisp driver has its own error codes under the
ia_css_err.h file. On several places, those got already
replaced by standard error codes, but there are still a
lot more to be fixed.

Let's get rid of all of those, mapping them into
the already-existing set of Linux error codes.

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

media: atomisp: print a better message when fw version is wrong

The printed message when a firmware version is wrong says nothing
usefull:

atomisp-isp2 0000:00:03.0: Fw version check failed.
atomisp-isp2: probe of 0000:00:03.0 failed with error -22

Print the expected and the received firmware version instead.

In order to do that, the firmware functions will need at least
a struct device pointer, so pass it.

While writing this patch, it was noticed that some of the
abstraction layers of this driver have functions that are never
called, but use this interface. Get rid of them.

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

media: atomisp: cleanup directory hierarchy

This driver has very long directories without a good
reason (IMHO). Let's drop two directories from such hierarchy,
in order to simplify things a little bit and make the dir
output a bit more readable.

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