Re: Driver for GL861+AF9003+MT2060]

[Antti Palosaari <crope@iki.fi>]

heis Claudio and Vortice,
I added Vortice since he was also asking that driver some months ago.

Claudio Chimera wrote:
> Hello Antti,
> 
> Il giorno mer, 01/04/2009 alle 19.33 +0300, Antti Palosaari ha scritto: 
>> C Khmer1 wrote:
>>> Hello,
>>> I'm trying to write a linux driver for my A-Data DT1 USB2 DVB-T card.
>>> This card has the GL861+AF9003+MT2060 chips.
>>> I've the specification of AF9002/3/5 family, and there is a linux driver
>>> for AF9005 chip that is an USB back-end plus AF9003 front-end.
>>> There is already a front-end driver for AF9003 inside the AF9005 code
>>> (should be the file AF9005-fe.c in the linux kernel tree).
>>> The real problem is that i don't know how to perform the boot process
>>> because it is different from AF9005 and how to handle the chip GL861
>>> +AF9003 together.
>> It is not mission impossible. Basically all chips are supported. The 
>> biggest you have to is split demodulator code to own module. Very 
>> similar situation is used by af9015+af9013. You can look example from there.
> 
> You are right. I've checked the af90015+af9013 driver. what i've
> understood is that the demoduletor (frontend) needs following interface
> functions:
> 
> .release = af9003_release,
> 
> .init = af9003_init,
> .sleep = af9003_sleep,
> .i2c_gate_ctrl = af9003_i2c_gate_ctrl,
> 
> .set_frontend = af9003_set_frontend,
> .get_frontend = af9003_get_frontend,
> 
> .get_tune_settings = af9003_get_tune_settings,
> 
> .read_status = af9003_read_status,
> .read_ber = af9003_read_ber,
> .read_signal_strength = af9003_read_signal_strength,
> .read_snr = af9003_read_snr,
> .read_ucblocks = af9003_read_ucblocks,
> 
> 
> These functions are almost inside the af9005-fe.c file from the the
> af9005 driver. I've taken some missing one from the af9013 driver.

You don't need to implement all those in most cases.
read_ber, read_signal_strength, read_snr, read_ucblocks and get_frontend 
are not obligatory *required* in any? case.

>>> I've seen the GL861 linux driver code. It is very simple and support
>>> only two commands_
>>>
>>> C0 02 for reading
>>> 40 01 for writing
>>>
>>> Sniffing the USB data using windows driver I've discovered that the
>>> windows driver is using following commands:
>>>
>>> 40 01
>>> 40 03
>>> 40 05
>>> c0 02
>>> c0 08
>> 4 x read and 2 x write. There is IR-table which can be uploaded to the 
>> gl861, since one or two commands are probably for that. Should be easy 
>> to detect, for example comparing IR-table from driver to data seen in 
>> sniffs.
>> Other possibilities could be for example GPIO, streaming control, 
>> USB-controller register/memory read/write, eeprom... Look existing 
>> dvb-usb -drivers for some hints about used commands.
>>
>>> I don't know what do they mean and how I should use it.
>> First "emulate" as Windows driver does (seen from sniff). After you get 
>> picture you can test whether or not all commands are needed and what is 
>> effect of commands. For example remove one command and remote does not 
>> work => should be remote command.
> 
> I'll try to do that. 
>>> Maybe with the GL861 specification I can understand. Sadly I've no
>>> specification for GL861.
>> DVB-USB -protocols are typically rather easy to reverse-engineer and 
>> guess. :) GL861 is one of the simplest ones.
>>
>>> Also the commands '40 01' and 'c0 02' are used in a different way not
>>> foreseen from the GL861 driver (the GL861 driver support up to 2 bytes
>>> to write but I see more data to write).
>> You should add multibyte i2c support then. Many existing drivers to see 
>> help.
> 
> Could you please suggest me some driver to check?

ce6230.

>>> I'm trying to understand the USB data before to writing the GL861 code
>>> to handle the AF9003 front-end (demod).
>>> Could someone help me?
>> There was someone else with similar device some months ago. Look ML 
>> archives and put your helping hands together.
> 
> I didn't find anything about af9003 in the ML.
> 
>> If you post one simple sniff to me I can try to look.
> 
> Please find attached the simplest log file, just plug the DVB-T in and
> out.

hmm, It looks a little bit weird :o I will try when got some more time...

regards
Antti
-- 
http://palosaari.fi/