From owner-freebsd-multimedia@FreeBSD.ORG Mon Apr 16 22:51:38 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 B4D2B16A404 for ; Mon, 16 Apr 2007 22:51:38 +0000 (UTC) (envelope-from usleepless@gmail.com) Received: from wr-out-0506.google.com (wr-out-0506.google.com [64.233.184.238]) by mx1.freebsd.org (Postfix) with ESMTP id 72C4F13C455 for ; Mon, 16 Apr 2007 22:51:38 +0000 (UTC) (envelope-from usleepless@gmail.com) Received: by wr-out-0506.google.com with SMTP id 70so1716039wra for ; Mon, 16 Apr 2007 15:51:38 -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=eOJyo21bHGGrLSnVsAYM7TIsGB8UHaXQof0MPOhqrQRGiiIc0RdcdXBXRCAHnkqZU4YnQmF+yFqqyn1izAm+HBShLbgWys1ZEIbmoKr/QJ7i7rAtt4FvP2AddThiNrsP+F4MeKhHqO5Gw1mXbr+TbRx24gD1kBvBFDkOZmn49fU= 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=IoWwu7Lm5gKNrlRwDOmei8Nkj8n1UXpf3bze9JqjSzTZ2SsnhYHxVk7snmS3nmxqe0oLxhXz7WFcZrTHdtY5cckq+Rst2vb6jyTWX+YABcKUg14OGRXNWp7SFuklkDzi1Y87OMVdmSwZ+mWrmMfsF9/aBxTEZQmRCE8PCpdtRY4= Received: by 10.115.92.2 with SMTP id u2mr2112704wal.1176763897572; Mon, 16 Apr 2007 15:51:37 -0700 (PDT) Received: by 10.114.192.12 with HTTP; Mon, 16 Apr 2007 15:51:37 -0700 (PDT) Message-ID: Date: Tue, 17 Apr 2007 00:51:37 +0200 From: usleepless@gmail.com To: "John-Mark Gurney" , "Greg 'groggy' Lehey" , usleepless@gmail.com, freebsd-multimedia@freebsd.org In-Reply-To: <20070416212605.GV73385@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> 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: Mon, 16 Apr 2007 22:51:38 -0000 John, 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? > 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? regards, usleep