From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Fri, 5 Jul 2013 09:35:50 +0200 From: Johannes Stezenbach To: "Gupta, Pekon" Subject: Re: SPI: DUAL/QUAD support Message-ID: <20130705073550.GA24258@sig21.net> References: <20130704130017.GA25997@sig21.net> <20130704154927.GE27646@sirena.org.uk> <20980858CB6D3A4BAE95CA194937D5E73E9E4C2E@DBDE04.ent.ti.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20980858CB6D3A4BAE95CA194937D5E73E9E4C2E@DBDE04.ent.ti.com> Cc: linux-mtd , Grant Likely , Mark Brown , "linux-mtd@lists.infradead.org" , "Thomas.Betker@rohde-schwarz.com" , "spi-devel-general@lists.sourceforge.net" , Sourav Poddar , yuhang wang , "linux-arm-kernel@lists.infradead.org" List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Fri, Jul 05, 2013 at 06:45:01AM +0000, Gupta, Pekon wrote: > > > Just as Johannes said. In my patch m25p80's changes is incomplete. > > Because my inicial aim is to add the transfer width member to tell controller > > the mode flash in. And I will attach new patch about m25p80 later. > > Also you are right. There are really series of flashes do not support dual/quad > > transfer. So I don't know whether there are any standard for serial-flash just > > like the CFI for parallel-flash. Personally, to make a general standard and > > a general code for serial-flash is necessary. So that we do not need to add > > special function in m25p80.c. > > > [Pekon]: Does below generic framework for spianand, suit your driver? > http://lists.infradead.org/pipermail/linux-mtd/2013-July/047434.html > > you should be able to extend the generic spinand API for all > serial modes (SPI, Dual-SPI, Quad-SPI). > As QSPI and Dual-SPI devices should implicitly support SPI (MISO/MOSI) > So, you can do device probing using default SPI mode. And then based on > DT inputs and device support upgrade to QSPI / Dual-SPI mode. > And going forward extend it for direct memory-mapped device for XIP. Not sure what you have in mind since NAND and NOR flash work very differently, and SPI vs. memory-mapped is also very different. But to add to the spinand review comments two things caught my eye on quick glance over the code: > +#define mu_spi_nand_driver_version "Beagle-MTD_01.00_Linux2.6.33_20100507" seems like an unused leftover? if the version number is important then maybe better put it in commit message? > +/bin/bash: 4: command not found how did this get in there? Johannes