From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Brown Subject: Re: support DUAL and QUAD[patch v1] Date: Mon, 22 Jul 2013 10:33:42 +0100 Message-ID: <20130722093342.GJ9858@sirena.org.uk> References: <20980858CB6D3A4BAE95CA194937D5E73E9E84D2@DBDE04.ent.ti.com> <20980858CB6D3A4BAE95CA194937D5E73E9E851E@DBDE04.ent.ti.com> <593AEF6C47F46446852B067021A273D6D93B49E1@MUCSE039.lantiq.com> <20980858CB6D3A4BAE95CA194937D5E73E9E85D0@DBDE04.ent.ti.com> <20980858CB6D3A4BAE95CA194937D5E73E9E967D@DBDE04.ent.ti.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============5423557569479053209==" Cc: "thomas.langer@lantiq.com" , "linux-mtd@lists.infradead.org" , "spi-devel-general@lists.sourceforge.net" , "Poddar, Sourav" , Trent Piepho , yuhang wang To: "Gupta, Pekon" Return-path: In-Reply-To: <20980858CB6D3A4BAE95CA194937D5E73E9E967D@DBDE04.ent.ti.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-mtd" Errors-To: linux-mtd-bounces+gldm-linux-mtd-36=gmane.org@lists.infradead.org List-Id: linux-spi.vger.kernel.org --===============5423557569479053209== Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="QPZaqi6af6gbSrAE" Content-Disposition: inline --QPZaqi6af6gbSrAE Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Fri, Jul 19, 2013 at 07:34:45PM +0000, Gupta, Pekon wrote: > > Maybe it would make more sense to have a spi-rx-width and spi-tx-width > > than can be set to 1, 2, 4, etc. bits instead of a bunch of properties > > that are mutually exclusive? Sooner or later someone is going to want > > 8 bits. > Then it would not remain a serial interface (Serial Peripheral Interface), > rather it would be more of parallel memory like interface. > And you would not like to use SPI controller for it, instead you would use > On-chip General Purpose External Interface controllers (like GPMC) > because it gives you more options to tweak and configure. It's still not beyoond the bounds of possibility, and of course some bright spark might decide to use 3 wires. Unless it's expensive to do so in some way it seems better to keep the interface as generic as possible even if we've no expectation that some of the flexibility will be used. --QPZaqi6af6gbSrAE Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.20 (GNU/Linux) iQIcBAEBAgAGBQJR7PxzAAoJELSic+t+oim93zMP/iaSGf2AwMeCLjtodncJwdlT 2J1tksjA4Cssv6Mdr1IZZTnP/5pbnP3WzTzJImHl9HrNAz7RDSBRm0VowUmZu0Ss kB5wKwEfuKTz0Xb8Oc65hEKG6rVWQDf9DY4/7sp92NDvke7BwjWW8NtP50W58bj9 UN4uQFe/EwjaS4WjcIQ5tqLYXdHAXMo19U3JDR44QyhVuvsThDAoxRhGu02v21cE QkTF6zvOP6SO9T8TN2NIoD8JUrMX+QMzRqJbYMkvjp9es/74gyYJU+vRNUf3sBwL AliYZut7XQG+33CBqShlGsD6Y/ELBJ5LIyCDbKMf1FZkW/+kVu+WstRjmyvjvdKI Tyfl9Uz1drmqsCBIrOIabwVboMsvwY3zjWZx4Fg3CLGUnGt8KpMX2vb8m6CVtHHj a55KCZ8XG1J7pziwG+pYPOy3vwJB/caa1Bcublp5VE7Pxt4OB5TteptxH9NXG/F7 EdjBxzK4giv5dSj8OR4SWm8bGuAoXzp+rJYVCPR9Bxywloo7mhyEChGNgkrW9Orl 0Xch5SCAqe7isHDICEhEGNn0m7QuvbHOAVhE5HrnAhJZlUIJBIu/2ZSBH3tz1bR6 W1+myS7DFQ8xFjUNVxjAtnFcBeAM/YV12/x+chP7CuDvauuWfLD48NDL+MJgQijd /oToHw/iqMJ7K+0rfmXs =sv+M -----END PGP SIGNATURE----- --QPZaqi6af6gbSrAE-- --===============5423557569479053209== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/ --===============5423557569479053209==-- From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [2001:41c8:1:5384::2] (helo=cassiel.sirena.org.uk) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1V1CVa-0002sJ-FB for linux-mtd@lists.infradead.org; Mon, 22 Jul 2013 09:34:24 +0000 Date: Mon, 22 Jul 2013 10:33:42 +0100 From: Mark Brown To: "Gupta, Pekon" Message-ID: <20130722093342.GJ9858@sirena.org.uk> References: <20980858CB6D3A4BAE95CA194937D5E73E9E84D2@DBDE04.ent.ti.com> <20980858CB6D3A4BAE95CA194937D5E73E9E851E@DBDE04.ent.ti.com> <593AEF6C47F46446852B067021A273D6D93B49E1@MUCSE039.lantiq.com> <20980858CB6D3A4BAE95CA194937D5E73E9E85D0@DBDE04.ent.ti.com> <20980858CB6D3A4BAE95CA194937D5E73E9E967D@DBDE04.ent.ti.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="QPZaqi6af6gbSrAE" Content-Disposition: inline In-Reply-To: <20980858CB6D3A4BAE95CA194937D5E73E9E967D@DBDE04.ent.ti.com> Subject: Re: support DUAL and QUAD[patch v1] Cc: "thomas.langer@lantiq.com" , "linux-mtd@lists.infradead.org" , "spi-devel-general@lists.sourceforge.net" , "Poddar, Sourav" , Trent Piepho , yuhang wang List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , --QPZaqi6af6gbSrAE Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Fri, Jul 19, 2013 at 07:34:45PM +0000, Gupta, Pekon wrote: > > Maybe it would make more sense to have a spi-rx-width and spi-tx-width > > than can be set to 1, 2, 4, etc. bits instead of a bunch of properties > > that are mutually exclusive? Sooner or later someone is going to want > > 8 bits. > Then it would not remain a serial interface (Serial Peripheral Interface), > rather it would be more of parallel memory like interface. > And you would not like to use SPI controller for it, instead you would use > On-chip General Purpose External Interface controllers (like GPMC) > because it gives you more options to tweak and configure. It's still not beyoond the bounds of possibility, and of course some bright spark might decide to use 3 wires. Unless it's expensive to do so in some way it seems better to keep the interface as generic as possible even if we've no expectation that some of the flexibility will be used. --QPZaqi6af6gbSrAE Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.20 (GNU/Linux) iQIcBAEBAgAGBQJR7PxzAAoJELSic+t+oim93zMP/iaSGf2AwMeCLjtodncJwdlT 2J1tksjA4Cssv6Mdr1IZZTnP/5pbnP3WzTzJImHl9HrNAz7RDSBRm0VowUmZu0Ss kB5wKwEfuKTz0Xb8Oc65hEKG6rVWQDf9DY4/7sp92NDvke7BwjWW8NtP50W58bj9 UN4uQFe/EwjaS4WjcIQ5tqLYXdHAXMo19U3JDR44QyhVuvsThDAoxRhGu02v21cE QkTF6zvOP6SO9T8TN2NIoD8JUrMX+QMzRqJbYMkvjp9es/74gyYJU+vRNUf3sBwL AliYZut7XQG+33CBqShlGsD6Y/ELBJ5LIyCDbKMf1FZkW/+kVu+WstRjmyvjvdKI Tyfl9Uz1drmqsCBIrOIabwVboMsvwY3zjWZx4Fg3CLGUnGt8KpMX2vb8m6CVtHHj a55KCZ8XG1J7pziwG+pYPOy3vwJB/caa1Bcublp5VE7Pxt4OB5TteptxH9NXG/F7 EdjBxzK4giv5dSj8OR4SWm8bGuAoXzp+rJYVCPR9Bxywloo7mhyEChGNgkrW9Orl 0Xch5SCAqe7isHDICEhEGNn0m7QuvbHOAVhE5HrnAhJZlUIJBIu/2ZSBH3tz1bR6 W1+myS7DFQ8xFjUNVxjAtnFcBeAM/YV12/x+chP7CuDvauuWfLD48NDL+MJgQijd /oToHw/iqMJ7K+0rfmXs =sv+M -----END PGP SIGNATURE----- --QPZaqi6af6gbSrAE--