From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marek Vasut Date: Thu, 5 Nov 2015 16:51:55 +0100 Subject: [U-Boot] [PATCH v2 2/2] mtd: add altera quadspi driver In-Reply-To: References: <1446556932-14978-1-git-send-email-thomas@wytron.com.tw> <563B6B7D.5050208@wytron.com.tw> Message-ID: <201511051651.55980.marex@denx.de> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On Thursday, November 05, 2015 at 03:57:01 PM, Jagan Teki wrote: > Hi Thomas, > > On 5 November 2015 at 20:15, Thomas Chou wrote: > > Hi Jagan, > > > > On 2015?11?05? 22:25, Jagan Teki wrote: > >> On 5 November 2015 at 14:17, Thomas Chou wrote: > >>> Add Altera Generic Quad SPI Controller support. The controller > >>> converts SPI NOR flash to parallel flash interface. So it is > >>> not like other SPI flash, but rather like CFI flash. > >> > >> Can you wait till spi-nor ready? it doesn't make sense to have Serial > >> NOR to created as parallel NOR. > > > > The altera quad spi core is very special that the hardware handle the > > spi-nor protocol. The core is designed to replace the CFI flash > > interface. So there is nothing to do with SPI from the parallel flash > > interface. It is memory mapped. There is no SPI interface. There is > > nothing related to SPI programming. So please don't worry about the > > progress on spi-nor. The core should belong to parallel flash, but not > > serial flash. > > Agreed that this is not doing any generic spi things, but it's a > spi-nor controller all spi-nor controller should be part of spi-nor > subsystem Linux agreed and have a framework for that. The underlying technology is not exposed to the programmer, so this argument is moot. The behavior of this device is closer to CFI flash. > drivers/mtd/spi-nor/fsl-quadspi.c > drivers/mtd/spi-nor/nxp-spifi.c > > all these are spi-nor controller which doesn't do any generic spi > things but should be in spi-nor subsystem. Even Marek send altera_qspi > as spi-nor controller [1] This is because that thing communicates like a SPI controller. > Since I'm working on similar spi-nor subsystem what Linux have + > driver model little worried about this because once we have spi-nor > again it should be a re-work. Your work and this driver are orthogonal things. > [1] http://lists.infradead.org/pipermail/linux-mtd/2015-April/058650.html Best regards, Marek Vasut