Date: Mon, 16 Apr 2007 14:26:05 -0700 From: John-Mark Gurney <gurney_j@resnet.uoregon.edu> To: "Greg 'groggy' Lehey" <grog@FreeBSD.org> Cc: freebsd-multimedia@FreeBSD.org Subject: Re: pvrxxx, linux code and modules Message-ID: <20070416212605.GV73385@funkthat.com> In-Reply-To: <20070416055055.GC1593@wantadilla.lemis.com> References: <c39ec84c0704151508t126cf975gaa1957b9205d3244@mail.gmail.com> <20070416055055.GC1593@wantadilla.lemis.com>
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Greg 'groggy' Lehey wrote this message on Mon, Apr 16, 2007 at 15:20 +0930:
> - I need to understand better how tuners work. I've been thinking of
> writing a document on the subject, something that people could use
> for help when writing drivers. If you know of anything, even
> partial or badly laid out, please let me know.
Just to reiterate, tuner code really should be located in userland..
it's not time sensitive, and can't corrupted state of the kernel..
As for tuners, most/all of them communicate through the i2c bus...
The tuner is programed w/ the frequency to tune, and depending upon
the range of frequence will turn on/off various transistors to change
some of the analog curcuit behavior...
My HDTV device drive does all the tuning from userland... It was
a lot easier to get it working using userland than having to constantly
load/unload kernel modules, and risk crashing the machine...
--
John-Mark Gurney Voice: +1 415 225 5579
"All that I will do, has been done, All that I have, has not."
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