From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751898AbbCaFre (ORCPT ); Tue, 31 Mar 2015 01:47:34 -0400 Received: from mezzanine.sirena.org.uk ([106.187.55.193]:36435 "EHLO mezzanine.sirena.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750706AbbCaFrc (ORCPT ); Tue, 31 Mar 2015 01:47:32 -0400 Date: Tue, 31 Mar 2015 06:47:14 +0100 From: Mark Brown To: Michal Simek Cc: linux-kernel@vger.kernel.org, monstr@monstr.eu, =?iso-8859-1?Q?S=F6ren?= Brinkmann , linux-spi@vger.kernel.org, linux-arm-kernel@lists.infradead.org Message-ID: <20150331054714.GA2869@sirena.org.uk> References: <67f3c196833c427a489ca2c530d08987a6b5ee2a.1421412912.git.michal.simek@xilinx.com> <20150308190012.GV28806@sirena.org.uk> <2a81c738-f7e2-4387-b04c-05c9892ba8e4@BN1AFFO11FD026.protection.gbl> <20150327175318.GG1743@sirena.org.uk> <1bd88fda-314c-496a-ba8b-e9292f9c411b@BY2FFO11FD023.protection.gbl> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="WzyiqVXNYYkrrY2o" Content-Disposition: inline In-Reply-To: <1bd88fda-314c-496a-ba8b-e9292f9c411b@BY2FFO11FD023.protection.gbl> X-Cookie: Wanna buy a duck? User-Agent: Mutt/1.5.23 (2014-03-12) X-SA-Exim-Connect-IP: 94.175.94.161 X-SA-Exim-Mail-From: broonie@sirena.org.uk Subject: Re: [PATCH] spi: xilinx: Use standard num-cs binding X-SA-Exim-Version: 4.2.1 (built Mon, 26 Dec 2011 16:24:06 +0000) X-SA-Exim-Scanned: Yes (on mezzanine.sirena.org.uk) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --WzyiqVXNYYkrrY2o Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Mar 30, 2015 at 08:46:10AM +0200, Michal Simek wrote: > On 03/27/2015 06:53 PM, Mark Brown wrote: > > On Fri, Mar 27, 2015 at 11:55:49AM +0100, Michal Simek wrote: > > Please fix your mail client to word wrap within paragraphs at less than > > 80 columns - this makes your mails easier to read and reply to. > You are the first one who had problem with this. But I have setup lower > limit and hopefully it is better now. That looks better, yes... I may just be the first one who's bothered remarking on this. > >> On 03/08/2015 08:00 PM, Mark Brown wrote: > >>> On Fri, Jan 16, 2015 at 01:55:14PM +0100, Michal Simek wrote: > > Remember that we can at least in theory have additional chip selects > > that aren't controlled by the IP block but are instead GPIOs. =20 > I agree with you but this can be generic case for every SPI driver. Also > using external decoder is possible for every driver. Maybe there are > others options via I2C too. Remember that this in the context of me saying I don't think num-cs is a particularly good idea at all... > > There's > > also some potential confusion for users between the number of chip > > selects in use in a given system and the size of the bitfield that the > > driver needs to take care of. > num-ss-bits is autogenerated directly from design tools for particular > hardware design and this size is exactly setup and hardcoded. (num-cs > can be just the same case) > If there are 5 bits there are 5 wires from IP. And value of num-ss-bits > and num-cs will be the same. But what your patch did was *replace* num-ss-bits in the binding, not just add it. > If user wants to use less lines then physically available we could > potentially extend binding to say. num-ss-bit - number of chip selects > available in hardware. num-cs - number of chip selects used by the driver. > But I expect that this will be rejected because it is software setting > not hardware description. num-cs *is* a software setting. --WzyiqVXNYYkrrY2o Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQEcBAEBCAAGBQJVGjTiAAoJECTWi3JdVIfQYHcH/RRTD2Fgh+4eY4hAX1YNgqIe gnrABZVyglq8OTo5Xiyuw/NWENxFTKfQ3GD0yDujma1idrH5FE5c4w/nuzxSnrai CXkFefqkdVIGq79uGDzxhYkjFVHS7ZtKJgSLKXsJrEpiTWiSN+arUTjkAt73Kn8t jyYpEnxeEKp0MR0e3VJV+4iPTlRjBW5+CHQPEReb9jWZYk0aEN4UJRgqhpB9u+Li Rq0ITwzY+dad3EpmWQcPYMQUzFY09FUAaecOdO0vgZHUU1r+ecKFkOPNTYZolT5w 7G0XxyZ8OZ5AuHitlc7CwXM4SdyyrYO5vijIJC+7vRIKGL0G5PLA82byWRb0ULk= =eDPP -----END PGP SIGNATURE----- --WzyiqVXNYYkrrY2o--