[linux-dvb] [PATCH] QT1010 - 125kHz step and fixes

Antti Palosaari crope at iki.fi
Wed Nov 29 03:18:48 CET 2006

- 125kHz step, register 0x1a
- tuner offset and fix register 0x07 calculation
- added some alternative values to registers 0x11, 0x1f and 0x20. Values 
  are hidden behind preprocessor macros, old values are used by default.

I don't know what is the real stepping supported by HW, probably it is 
less than 125kHz. 125kHz were used in both of the Sigmatek DVB-110 and 
MSI Megasky GL681 Windows drivers. Though, I guess, 125kHz is enough for 
tuning all frequencies in DVB-T bands supported by hw (48-860MHz). In my 
understanding it should be possible now to tune all DVB-T channels used 
worldwide, in theory at least. Locking is harder to get, because most of 
the register values are still only magic numbers, for example setting 
bandwidth is unknown. Frequency is set by: 0x07 (n*32MHz) + 0x0a 
(n*4MHz) + 0x1a (n*125kHz).

Patch should not change functionality of the other than frequency 
registers, eg. if your Megasky works before this patch, it should work 
also after. If not, there is a bug.

Patch tested with Megasky GL681 and Sigmatek DVB-110 against fi-Oulu 
frequencies. Megasky works always and Sigmatek as poor as without patch 
:) If I change defines to SIGMATEK, Sigmatek works better and also 
Megasky seems to work as expected. I still left old functionality to 
default, because Sigmatek stick is not so popular as Megasky. Please 
test different configurations and report.

If someone owns devices with QT1010 tuner, other than mentioned this 
mail, and can do USB-sniffing in windows, please help. I will give 
detailed information by email.

Aapo, could you test this patch with your hardware.

Antti Palosaari

Signed-off-by: Antti Palosaari <crope at iki.fi>

tel. +358 40 535 7322 | MSN Messenger crope at iki.fi | www.palosaari.fi
-Kahta asiaa en ymmärrä.. C-kielen syntaksi ja naisten logiikka.."

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