From mboxrd@z Thu Jan 1 00:00:00 1970 From: Huang Shijie Subject: Re: [PATCH v3 0/8] Add the Quadspi driver for vf610-twr Date: Wed, 11 Sep 2013 18:54:55 +0800 Message-ID: <52304BFF.4060007@freescale.com> References: <593AEF6C47F46446852B067021A273D6D984000B@MUCSE039.lantiq.com> <20130905020435.GA3970@gmail.com> <20980858CB6D3A4BAE95CA194937D5E73EA0C7F4@DBDE04.ent.ti.com> <522817D7.1010206@freescale.com> <522D3B79.3060707@freescale.com> <20130909151450.GI29403@sirena.org.uk> <522EC33B.9000009@freescale.com> <20130910180704.GB29403@sirena.org.uk> <522FD78A.6080900@freescale.com> <20130911104126.GN29403@sirena.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=GB2312 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <20130911104126.GN29403@sirena.org.uk> Sender: linux-doc-owner@vger.kernel.org To: Mark Brown Cc: Huang Shijie , "Gupta, Pekon" , "thomas.langer@lantiq.com" , "devicetree@vger.kernel.org" , "shawn.guo@linaro.org" , "b44548@freescale.com" , "dedekind1@gmail.com" , "linux-doc@vger.kernel.org" , "b18965@freescale.com" , "linux-spi@vger.kernel.org" , "linux-mtd@lists.infradead.org" , "kernel@pengutronix.de" , "lznuaa@gmail.com" , "computersforpeace@gmail.com" , "dwmw2@infradead.org" , "linux-arm-kernel@lists.infradead.org" List-Id: devicetree@vger.kernel.org =D3=DA 2013=C4=EA09=D4=C211=C8=D5 18:41, Mark Brown =D0=B4=B5=C0: > So why does the SPI driver have references to the opcodes in it? I admit that the Freescale's quadspi controller is very special (it is designed too coupled with the SPI Nor FLASH), it is driven by the LUT registers. I just quote the comment from the patch 1: ------------------------------------------------------------- (2) The definition of the LUT register shows below: --------------------------------------------------- | INSTR1 | PAD1 | OPRND1 | INSTR0 | PAD0 | OPRND0 | --------------------------------------------------- There are several types of INSTRx, such as: CMD : the SPI NOR command. ADDR : the address for the SPI NOR command. DUMMY : the dummy cycles needed by the SPI NOR command. =2E... ------------------------------------------------------------------- The LUT registers needs to be filled with the SPI NOR command, such =46ast-read/Quad-read. So the Quadspi driver needs to know the spi commands, and that's why th= e SPI driver has references to the spi command opcodes. =20 thanks Huang Shijie