Re: [PATCH v2] add support for DeLOCK-USB-2.0-DVB-T-Receiver-61744

[poma <pomidorabelisima@gmail.com>]

On 05/04/2012 08:50 AM, Thomas Mair wrote:
> Am 04.05.2012 03:27 schrieb "poma" <pomidorabelisima@gmail.com>:
>>
>> On 05/03/2012 11:03 AM, Gianluca Gennari wrote:
>>> Hi poma,
>>> I have a 0BDA:2838 (Easycap EZTV646) and a 0BDA:2832 (no name 20x20mm
>>> mini DVB-T stick) and both are based on the E4000 tuner, which is not
>>> supported in the kernel at the moment.
>>> I have no idea if there are sticks with the same USB PID and the fc0012
>>> tuner.
>>
>> OK, second one - no name device is "Realtek RTL2832U reference design"**.
>>
>> First one:
>> Once upon a time there was a "EasyCAP"…
>> "After while crocodile!"
>> …and "EzCAP" was born.
>> http://szforwardvideo.en.alibaba.com/aboutus.html
>> Obviously Easycap EZTV646 != EzCAP EzTV646
>>
> http://www.reddit.com/r/RTLSDR/comments/s6ddo/rtlsdr_compatibility_list_v2_work_in_progress/
>> ezcap EzTV646   0BDA:2838       RTL2832U/FC0012         Some revisions
> may have the E4000*
>> http://i.imgur.com/mFD1X.jpg
>> (Generic)       0BDa:2838       RTL2832U/E4000*
>> …
>> And, in addition:
>> http://sdr.osmocom.org/trac/wiki/rtl-sdr
>> 0x0bda  0x2832  all of them     Generic RTL2832U (e.g. hama nano)**
>> 0x0bda  0x2838  E4000   ezcap USB 2.0 DVB-T/DAB/FM dongle
>> …
>> Maybe?
>> https://sites.google.com/site/myrtlsdr/
>> "EzCap EZTV646 has got RTL2832U/FC0012. However rtl-sdr must be tweaked
>> to force FC0012 tuner because it has the same PID as EZTV668 (PID:
>> 0x2838) so running it whithout a tweak will select Elonics E4000 tuner.
>> Works, not so good at filtering."
>> …
>> Conclusion:
>> At least two devices share same vid/pid with different tuners - fc0012
>> vs e4000.
>> How to resolve this from a drivers perspective in a proper way?
> The handling of the different tuners of devices with the same vid/pid
> should not be a problem, because rtl28xxu driver probes for the tuner when
> the device is initialized.
> 
Thanks for clarifying!
rtl28xxu.c:
…
* Probe used tuner. We need to know used tuner before demod attach
* since there is some demod params needed to set according to tuner.
…
/* check FC0012 ID register; reg=00 val=a1 */
…

>> Beside,
>> there is GPL'ed 'e4k' tuner source code aka 'e4000 improved'*** (Elonics
>> E4000)
>> by Harald Welte
>> http://cgit.osmocom.org/cgit/osmo-sdr/tree/firmware/src/tuner_e4k.c
>> http://sdr.osmocom.org/trac/
>> http://sdr.osmocom.org/trac/wiki/rtl-sdr
>> http://wiki.spench.net/wiki/RTL2832U***
> So what is missing is the e4000 tuner driver.
> 
True.

> Btw i do have a list of devices that include the Rtl2832 demod. I will send
> that list on the weekend.
> 
Groovy!

> Regards
> Thomas
> 

regards,
poma