From owner-freebsd-multimedia@FreeBSD.ORG Tue Apr 17 06:47:17 2007 Return-Path: X-Original-To: freebsd-multimedia@freebsd.org Delivered-To: freebsd-multimedia@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 3E42316A404 for ; Tue, 17 Apr 2007 06:47:17 +0000 (UTC) (envelope-from usleepless@gmail.com) Received: from wx-out-0506.google.com (wx-out-0506.google.com [66.249.82.230]) by mx1.freebsd.org (Postfix) with ESMTP id EE26D13C459 for ; Tue, 17 Apr 2007 06:47:16 +0000 (UTC) (envelope-from usleepless@gmail.com) Received: by wx-out-0506.google.com with SMTP id s18so1866242wxc for ; Mon, 16 Apr 2007 23:47:16 -0700 (PDT) DKIM-Signature: a=rsa-sha1; c=relaxed/relaxed; d=gmail.com; s=beta; h=domainkey-signature:received:received:message-id:date:from:to:subject:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=ndJFyjPVVnqUP/lQ+A9onXPAOsAanVPOMoPmpczYx8EbVNsm9JDxG7cp4Lf8xelb2v8fCD/Gxyt1EjA8t/zgN5+THuq545GptJrPKm5vBdCXmr9nerDctl4rezu34Tf2BkxQLayyg4U7wqSmZbueDjwM/g4u+oYwPBTTF6DPpio= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=k13JJSZbO11565kkLfMMmP7uyP/XmCld5HZVLcjaCE6177+FSeLnb2ES8DGt/UopaIP28P8a6+Z/nhseLcjvhSq6Iw/sLFeIRnsXDTTsP978bbAV5MSNUUyyxBDXuhs2JSCTnQZ71n+t2Oz/JNI1WYzLYIMaACFb0Fz4S9gfGAY= Received: by 10.114.61.1 with SMTP id j1mr192845waa.1176792435876; Mon, 16 Apr 2007 23:47:15 -0700 (PDT) Received: by 10.114.192.12 with HTTP; Mon, 16 Apr 2007 23:47:15 -0700 (PDT) Message-ID: Date: Tue, 17 Apr 2007 08:47:15 +0200 From: usleepless@gmail.com To: "John-Mark Gurney" , usleepless@gmail.com, "Greg 'groggy' Lehey" , freebsd-multimedia@freebsd.org In-Reply-To: <20070417001817.GZ73385@funkthat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <20070416055055.GC1593@wantadilla.lemis.com> <20070416212605.GV73385@funkthat.com> <20070417001817.GZ73385@funkthat.com> Cc: Subject: Re: pvrxxx, linux code and modules X-BeenThere: freebsd-multimedia@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Multimedia discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 17 Apr 2007 06:47:17 -0000 John-Mark, On 4/17/07, John-Mark Gurney wrote: > usleepless@gmail.com wrote this message on Tue, Apr 17, 2007 at 00:51 +0200: > > On 4/16/07, John-Mark Gurney wrote: > > >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... > > > > which driver is this? > > The DViCO FusionHDTV 5 Lite driver: > http://www.freebsd.org/news/status/report-2006-10-2006-12.html#Bt878-Audio-Driver-(aka-FusionHDTV-5-Lite-driver) > > I have two tuners working in my system at home. how does one build this driver? where can i fetch it? > > >It was > > >a lot easier to get it working using userland than having to constantly > > >load/unload kernel modules, and risk crashing the machine... > > > > you are absolutely spot on about this. it's that i did build upon > > pvr250 which had the tuner in kernel space, so i didn't think about > > it. otherwise i might have been influenced by the linux source, and i > > would have implemented in kernel space as well :-) > > > > but considering V4L(2), which has to support ioctl's changing the > > frequency, how could this work from userland? > > Kill the V4L(2) API? :) I have thought about doing a cdev bridge to > userland.. Effectively FUSE, but for cdev's instead of file systems... > This would put most/all the logic in userland, and w/ some mmapping > magic, can have similar/same performance for high speed devices like > bktr... well, i am certainly not gonna kill the v4l(2) API since i intend to use the pvrxxx cards with mythtv. regards, usleep