Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755280Ab1DVMxV (ORCPT ); Fri, 22 Apr 2011 08:53:21 -0400 Received: from mtaout02-winn.ispmail.ntl.com ([81.103.221.48]:65098 "EHLO mtaout02-winn.ispmail.ntl.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750851Ab1DVMxR (ORCPT ); Fri, 22 Apr 2011 08:53:17 -0400 Message-ID: <4DB17A3B.3060609@blueyonder.co.uk> Date: Fri, 22 Apr 2011 13:53:15 +0100 From: Sid Boyce Reply-To: sboyce@blueyonder.co.uk Organization: blueyonder.co.uk User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-GB; rv:1.9.2.14) Gecko/20110221 SUSE/3.1.8 Thunderbird/3.1.8 ThunderBrowse/3.3.5 MIME-Version: 1.0 To: LKML Mailing List Subject: Re: [PATCH v2] misc: Driver for Silicon Labs Si570 and compatibles Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Cloudmark-Analysis: v=1.1 cv=JvdXmxIgLJv2/GthKqHpGJEEHukvLcvELVXUanXFreg= c=1 sm=0 a=RQ36K_f0x-kA:10 a=jP4ZM9dVWk4A:10 a=3NElcqgl2aoA:10 a=k1j_C7plYBUA:10 a=8nJEP1OIZ-IA:10 a=CfAdl1vy_98PchHglTcA:9 a=ZqaCy0LOAm4tKVGwBowA:7 a=wPNLvfGTeEIA:10 a=HpAAvcLHHh0Zw7uRqdWCyQ==:117 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2137 Lines: 43 Guenter Roeck wrote: Depends. In our case, turns out the devices consuming the clock have user mode drivers. Lots of history there, but the chip vendors provide those user mode drivers, and the teams responsible for integrating the drivers decided to not rewrite it to kernel mode drivers. Also, for special purposes such as margining, it is necessary to control the clock from userspace. So, for our use case, I need the user-visible interface. I _don't_ need the kernel interface, at least not right now, which is why I did not add it. Browsing through the web, it seems the chip is somewhat popular with Amateur Radio. No idea if it would ever be controlled for such a purpose from Linux, but if so, it would also require a user configurable frequency. If there is a better place for such a driver than misc, please let me know. Thanks, Guenter ============================================================================= Support for these devices included in several Amateur radio programs tend to differ greatly which means reinventing the wheel in most of them. Programs like Linrad, sdr-shell, quisk, lysdr, ghpsdr3, etc. It's a small addition to the kernel that would significantly help in the development of software for the myriad of SDR (Software Defined Radio) designs based on this chip family. I have 5 Amateur Radio transceivers using this chip and 2 more soon to be added. They are all open hardware heavily reliant on Linux. The addition of UAC2 (USB Audio Class 2) kernel support has helped our SDR hardware design efforts significantly. I and the rest of the Linux SDR community would be happy to see it included. Regards Sid. -- Sid Boyce ... Hamradio License G3VBV, Licensed Private Pilot Emeritus IBM/Amdahl Mainframes and Sun/Fujitsu Servers Tech Support Senior Staff Specialist, Cricket Coach Microsoft Windows Free Zone - Linux used for all Computing Tasks -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/