The rtl-sdr library disabled IMR callibration. While I'm not sure
yet why, it could be a good idea to add a modprobe parameter here,
to allow to also disable it. There are two rationale behind it:
- It helps to compare USB dumps between rtl-sdr and the Kernel module;
- If rtl-sdr disabled it, perhaps there's a good reason (e. g. it
might not be actually working, or it might be causing some trouble).
For both cases, it seems useful to add a modprobe parameter to allow
testing the device with both configurations.
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Tested-by: Antti Palosaari <crope@iki.fi>
Add the code to set the GPIO for this tuner. This code is
currently unused, so it is kept there only for completeness.
With this patch there are just two things that got left from
the original driver:
- At standby, there's another mode, not used by rtl2832u.
Not sure if it might be needed in the future, but I suspect
it is not used at all;
- There is a "fast tune" mode. As nor DVB or V4L API supports
it, it seems an overkill to implement it.
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Tested-by: Antti Palosaari <crope@iki.fi>
This code seems to calibrate I/Q phase and gain during the
device initialization.
This is done only once, and it doesn't seem to be needed to
happen after resuming.
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Tested-by: Antti Palosaari <crope@iki.fi>
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>
Instead of using msleep(), use sleep_range(), as it provides
a closer sleep time.
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Tested-by: Antti Palosaari <crope@iki.fi>
Just cosmetic changes: all other functions are prefixed
by r820t. Do the same for r820t_read().
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Tested-by: Antti Palosaari <crope@iki.fi>
As we'll need to retrieve cached registers, make this
function explicit.
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Tested-by: Antti Palosaari <crope@iki.fi>
If signal is zero, shows it as a zero, not as 0xff.
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>
As the driver's logic uses the bit-reversed order for read,
use it as well when displaying the debug messages.
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Tested-by: Antti Palosaari <crope@iki.fi>
The Realtek Kernel driver uses the second DVB-T 7MHz table instead
of the first one. Use it as well.
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Tested-by: Antti Palosaari <crope@iki.fi>
IF is set at r820t_set_tv_standard(). So, we can't calculate
LO frequency before calling it.
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Tested-by: Antti Palosaari <crope@iki.fi>
Scale used at get_if_freq and LO freq calculus is Hz.
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Tested-by: Antti Palosaari <crope@iki.fi>
As this tuner can be used by analog and digital parts of the
driver, be sure that all ops that access the hardware will
be be properly locked.
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Tested-by: Antti Palosaari <crope@iki.fi>
This tuner works with 2 modes: automatic gain mode and manual
gain mode. Put it into automatic mode, as we currently don't
have any API for manual gain adjustment.
The logic to allow setting the manual mode is there, as it is
just a few extra code. This way, if/when we latter add support
for setting the gain mode, the code is already there.
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Tested-by: Antti Palosaari <crope@iki.fi>
Instead of a binary signal strength measure, use the tuner gain
to obtain a better estimation of the signal strength.
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>
