From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932963AbbIDPiI (ORCPT ); Fri, 4 Sep 2015 11:38:08 -0400 Received: from mezzanine.sirena.org.uk ([106.187.55.193]:51371 "EHLO mezzanine.sirena.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932931AbbIDPiF (ORCPT ); Fri, 4 Sep 2015 11:38:05 -0400 Date: Fri, 4 Sep 2015 16:37:18 +0100 From: Mark Brown To: Martin Sperl Cc: Ranjit Waghmode , dwmw2@infradead.org, computersforpeace@gmail.com, michal.simek@xilinx.com, soren.brinkmann@xilinx.com, zajec5@gmail.com, ben@decadent.org.uk, marex@denx.de, b32955@freescale.com, knut.wohlrab@de.bosch.com, juhosg@openwrt.org, beanhuo@micron.com, linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org, linux-spi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, harinik@xilinx.com, punnaia@xilinx.com Message-ID: <20150904153718.GO5313@sirena.org.uk> References: <1440570367-22569-1-git-send-email-ranjit.waghmode@xilinx.com> <1440570367-22569-2-git-send-email-ranjit.waghmode@xilinx.com> <20150903121232.GW12027@sirena.org.uk> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="44EoV7tf2AX9r8hV" Content-Disposition: inline In-Reply-To: X-Cookie: Short people get rained on last. 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: [LINUX RFC v2 1/4] spi: add support of two chip selects & data stripe 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 --44EoV7tf2AX9r8hV Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Fri, Sep 04, 2015 at 02:35:52PM +0200, Martin Sperl wrote: > > On 03.09.2015, at 14:12, Mark Brown wrote: > > This isn't saying that the controller supports more than one chip, it's > > saying that the controller supports asserting more than one chip select > > at once which isn't the same thing. I'm also not entirely sure that > > this makes sense as a separate feature to the data striping one - I'm > > struggling to think of a way to use this sensibly separately to that. > Well - there is one use-case that I can think of: > fbtft has the requirement for some devices to control a GPIO to > differentiate between command and data getting transferred > - sort of 9 bit. That's another thing again, isn't it? It's one device switching between two different control interfaces at runtime rather than two devices controlled in lockstep. --44EoV7tf2AX9r8hV Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQEcBAEBCAAGBQJV6bqtAAoJECTWi3JdVIfQSWAH/RyMGYvMDGzkghmldJhBGlIe znV2if8kHCD8A+HmG0ARvY/7DWz0qX3SAJoiGXhacIIN/cGBIdvzpeQ9JJQfH6oM vnY7BZHZTP399C15beITAHiX7f4IlEnvlwbCOKDRKAhd4h4Aq1BhiKjM2ZvTmxH1 q5eI0cc7CHRPt1eMczPhh64tvYlA81L/N2+zqDedWjDf+ddGdoUv/3JwRTgTUClX 53atP1Jh7wYLRrao5T0SAwlkYz/JQRvxxwf1lah3dpB1bmFyHfRUBW1N/NG66fnn Ca9dDuXEu+AZ+Ph/sUbqs3vitGZ0cdAqm3EpV4M9iDOKz/J/s7auV+zWuG++Kr8= =eRVV -----END PGP SIGNATURE----- --44EoV7tf2AX9r8hV--