From mboxrd@z Thu Jan 1 00:00:00 1970 From: Javier Martinez Canillas Subject: Re: [PATCH RESEND v2 3/7] mfd: cros_ec: Add cros_ec_lpc driver for x86 devices Date: Thu, 22 Jan 2015 12:17:02 +0100 Message-ID: <54C0DC2E.2030701@collabora.co.uk> References: <1420205572-2640-1-git-send-email-javier.martinez@collabora.co.uk> <1420205572-2640-4-git-send-email-javier.martinez@collabora.co.uk> <20150120081104.GT21886@x1> <54BE7B08.1010900@collabora.co.uk> <20150120163410.GC30656@x1> <54BE87C4.4040108@collabora.co.uk> <20150122084244.GP22024@x1> <54C0BE21.7020008@collabora.co.uk> <20150122094608.GA5769@x1> <54C0D29C.4010904@collabora.co.uk> <20150122105605.GB9129@x1> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: Received: from bhuna.collabora.co.uk ([93.93.135.160]:35491 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750727AbbAVLRK (ORCPT ); Thu, 22 Jan 2015 06:17:10 -0500 In-Reply-To: <20150122105605.GB9129@x1> Sender: linux-samsung-soc-owner@vger.kernel.org List-Id: linux-samsung-soc@vger.kernel.org To: Lee Jones Cc: Olof Johansson , Doug Anderson , Bill Richardson , Simon Glass , Gwendal Grignou , Jonathan Corbet , linux-samsung-soc@vger.kernel.org, linux-kernel@vger.kernel.org, arnd@arndb.de Hello Lee, On 01/22/2015 11:56 AM, Lee Jones wrote: >> > >> Yes, I completely understand your point, is that I didn't think that a ~300 >> lines driver was that bad specially since the communication bits that reads >> and writes the register is not a complex logic IMHO. > > This has nothing to do with LoC, it's the principle of the matter. > Ok, got it. >> >> > Are there any other Low Pin Count drivers in the kernel? >> >> > >> >> >> >> I don't know tbh, I didn't even know what LPC was before I picked this patch >> >> to push it upstream. I searched in the Linux codebase for other LPC drivers >> >> but I didn't find anything, that doesn't mean that it doesn't exist though. >> > >> > I agree. Perhaps a suitable driver should live in drivers/misc until >> > there are enough of them to warrant its own subsystem. >> > >> >> Yes, I can move the driver to drivers/misc if you think that is more suitable >> to be there. >> >> I've taken another look and AFAICT there are two other mfd drivers that use an >> LPC bus, these are drivers/mfd/lpc_{i,s}ch.c for Intel's I/O Controller HUB and >> System Controller Hub respectively. > > These looked like PCI aggregates when I looked at them last? > Yes, it seems the LPC bus is behind a PCI bus on these chips. Or at least that's what I understood on a quick read to the Intel SCH datasheet [0]. Now going back to the Cros EC LPC driver, you are right that this may not be suitable to drivers/mfd so I'll move it to drivers/misc instead. Thanks a lot for your feedback. Best regards, Javier [0]: http://www.intel.com/content/www/us/en/intelligent-systems/menlow/sch-datasheet.html