In the media drivers, the v4l2 core knows about all submodules
and calls into them from a common function. However this cannot
work if the modules that get called are loadable and the
core is built-in. In that case we get
drivers/built-in.o: In function `set_type':
drivers/media/v4l2-core/tuner-core.c:301: undefined reference to `tea5767_attach'
drivers/media/v4l2-core/tuner-core.c:307: undefined reference to `tea5761_attach'
drivers/media/v4l2-core/tuner-core.c:349: undefined reference to `tda9887_attach'
drivers/media/v4l2-core/tuner-core.c:405: undefined reference to `xc4000_attach'
This was working previously, until the IS_ENABLED() macro was used
to replace the construct like
#if defined(CONFIG_DVB_CX24110) || (defined(CONFIG_DVB_CX24110_MODULE) && defined(MODULE))
with the difference that the new code no longer checks whether it is being
built as a loadable module itself.
To fix this, this new patch adds an 'IS_REACHABLE' macro, which evaluates
true in exactly the condition that was used previously. The downside
of this is that this trades an obvious link error for a more subtle
runtime failure, but it is clear that the change that introduced the
link error was unintentional and it seems better to revert it for
now. Also, a similar change was originally created by Trent Piepho
and then reverted by teh change to the IS_ENABLED macro.
Ideally Kconfig would be used to avoid the case of a broken dependency,
or the code restructured in a way to turn around the dependency, but either
way would require much larger changes here.
Fixes: 7b34be71db ("[media] use IS_ENABLED() macro")
See-also: c5dec9fb24 ("V4L/DVB (4751): Fix DBV_FE_CUSTOMISE for card drivers compiled into kernel")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Currently, the driver complains about the pre_detect var:
drivers/media/tuners/r820t.c: In function 'r820t_sysfreq_sel':
drivers/media/tuners/r820t.c:722:31: warning: variable 'pre_dect' set but not used [-Wunused-but-set-variable]
While rtl8232 code comments it, perhaps some other driver may use.
So, the better is to keep the code there, allowing to enable it
via r820t config data.
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
The rtl-sdr library, from where this driver was initially
based, doesn't use half PLL clock, but this is used on
the Realtek Kernel driver. So, also do the same here.
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Tested-by: Antti Palosaari <crope@iki.fi>
This is part of the original driver, and adding it doesn't hurt,
so add it, to better sync the code.
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Tested-by: Antti Palosaari <crope@iki.fi>
This driver was written from scratch, based on an existing driver
that it is part of rtl-sdr git tree, released under GPLv2:
https://groups.google.com/forum/#!topic/ultra-cheap-sdr/Y3rBEOFtHughttps://github.com/n1gp/gr-bazhttp://cgit.osmocom.org/rtl-sdr/plain/src/tuner_r820t.c
(there are also other variants of it out there)
>From what I understood from the threads, the original driver was converted
to userspace from a Realtek tree. I couldn't find the original tree.
However, the original driver look awkward on my eyes. So, I decided to
write a new version from it from the scratch, while trying to reproduce
everything found there.
TODO:
- After locking, the original driver seems to have some routines to
improve reception. This was not implemented here yet.
- RF Gain set/get is not implemented.
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Tested-by: Antti Palosaari <crope@iki.fi>
Arnd Bergmann