From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <51D678A7.6050402@ti.com> Date: Fri, 5 Jul 2013 13:11:27 +0530 From: Sourav Poddar MIME-Version: 1.0 To: Johannes Stezenbach Subject: Re: SPI: DUAL/QUAD support References: <20130704130017.GA25997@sig21.net> <20130704154927.GE27646@sirena.org.uk> <20980858CB6D3A4BAE95CA194937D5E73E9E4C2E@DBDE04.ent.ti.com> <20130705073550.GA24258@sig21.net> In-Reply-To: <20130705073550.GA24258@sig21.net> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Cc: linux-mtd , Grant Likely , Mark Brown , "linux-mtd@lists.infradead.org" , "Gupta, Pekon" , "Thomas.Betker@rohde-schwarz.com" , "spi-devel-general@lists.sourceforge.net" , 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 Friday 05 July 2013 01:05 PM, Johannes Stezenbach wrote: > 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? > Yes, actually its not required, should be removed. >> +/bin/bash: 4: command not found > how did this get in there? > > Yes, this is useless, will removed in the next version. > Johannes