From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sourav Poddar Subject: Re: [PATCH 1/3] spi/qspi: Add memory mapped read support. Date: Thu, 10 Oct 2013 15:47:45 +0530 Message-ID: <52567EC9.1020708@ti.com> References: <52566ACC.1080100@ti.com> <20131010101410.GG21581@sirena.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Cc: Peter Korsgaard , Trent Piepho , balbi@ti.com, "linux-mtd@lists.infradead.org" , "spi-devel-general@lists.sourceforge.net" , computersforpeace@gmail.com, dwmw2@infradead.org To: Mark Brown Return-path: In-Reply-To: <20131010101410.GG21581@sirena.org.uk> 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 On Thursday 10 October 2013 03:44 PM, Mark Brown wrote: > On Thu, Oct 10, 2013 at 02:22:28PM +0530, Sourav Poddar wrote: > >> [Trent]: With mapping driver, I believe you are hinting at >> drivers/mtd/maps? I had >> a look at it and what I got is that it is used/suitable for parallel >> flashes and not the >> serial flashes. > Essentially what it looks like this hardware is trying to do is adapt a > serial flash so it looks more like a parallel flash. It's not clear > that this is a good idea if we are already able to understand serial > flash though. hmm.. one more point I want to add is that QSPI controller has two parts to it: 1. SPI mode (used for SPI based external devices) 2. SFI mode (Serial flash interface) used for flash devices attached. Memory mapped mode is the one more applicable to the second one. ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/ From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from comal.ext.ti.com ([198.47.26.152]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1VUDKe-0008Sw-3P for linux-mtd@lists.infradead.org; Thu, 10 Oct 2013 10:19:00 +0000 Message-ID: <52567EC9.1020708@ti.com> Date: Thu, 10 Oct 2013 15:47:45 +0530 From: Sourav Poddar MIME-Version: 1.0 To: Mark Brown Subject: Re: [PATCH 1/3] spi/qspi: Add memory mapped read support. References: <52566ACC.1080100@ti.com> <20131010101410.GG21581@sirena.org.uk> In-Reply-To: <20131010101410.GG21581@sirena.org.uk> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Cc: Peter Korsgaard , Trent Piepho , balbi@ti.com, "linux-mtd@lists.infradead.org" , "spi-devel-general@lists.sourceforge.net" , computersforpeace@gmail.com, dwmw2@infradead.org List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Thursday 10 October 2013 03:44 PM, Mark Brown wrote: > On Thu, Oct 10, 2013 at 02:22:28PM +0530, Sourav Poddar wrote: > >> [Trent]: With mapping driver, I believe you are hinting at >> drivers/mtd/maps? I had >> a look at it and what I got is that it is used/suitable for parallel >> flashes and not the >> serial flashes. > Essentially what it looks like this hardware is trying to do is adapt a > serial flash so it looks more like a parallel flash. It's not clear > that this is a good idea if we are already able to understand serial > flash though. hmm.. one more point I want to add is that QSPI controller has two parts to it: 1. SPI mode (used for SPI based external devices) 2. SFI mode (Serial flash interface) used for flash devices attached. Memory mapped mode is the one more applicable to the second one.