From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Roese Subject: Re: [PATCH v6] spi: orion.c: Add direct access mode Date: Mon, 2 May 2016 08:47:15 +0200 Message-ID: <5726F7F3.9070700@denx.de> References: <1461147068-4829-1-git-send-email-sr@denx.de> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Cc: Thomas Petazzoni , Gregory CLEMENT , Mark Brown , Arnd Bergmann , Andrew Lunn To: linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-spi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Return-path: In-Reply-To: <1461147068-4829-1-git-send-email-sr-ynQEQJNshbs@public.gmane.org> Sender: linux-spi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: On 20.04.2016 12:11, Stefan Roese wrote: > This patch adds support for the direct write mode to the Orion SPI > driver which is used on the Marvell Armada based SoCs. In this direct > mode, all data written to (or read from) a specifically mapped MBus > window (linked to one SPI chip-select on one of the SPI controllers) > will be transferred directly to the SPI bus. Without the need to control > the SPI registers in between. This can improve the SPI transfer rate in > such cases. > > Currently only the direct write mode is supported. This mode especially > benefits from the SPI direct mode, as the data bytes are written > head-to-head to the SPI bus, without any additional addresses, that > are also written in the direct read mode. > > One use-case for this direct write mode is, programming a FPGA bitstream > image into the FPGA connected to the SPI bus at maximum speed. > > This mode is described in chapter "22.5.2 Direct Write to SPI" in the > Marvell Armada XP Functional Spec Datasheet. > > It should be possible to support SPI-NOR and SPI-NAND devices via > this direct access mode as well. But this needs further work, e.g.: > - The mapping of the MBus window needs to get extended to span > the complete flash device size > - The address / control data needs to get inserted into the SPI > controller registers > > Signed-off-by: Stefan Roese > Cc: Thomas Petazzoni > Cc: Gregory CLEMENT > Cc: Andrew Lunn > Cc: Arnd Bergmann > Cc: Mark Brown Its been a while since v6 of this direct write access mode has been posted. This is a gentle ping on its status. Arnd / Mark, do you have any additional change requests or are you okay with the current version? Thanks, Stefan -- To unsubscribe from this list: send the line "unsubscribe linux-spi" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html From mboxrd@z Thu Jan 1 00:00:00 1970 From: sr@denx.de (Stefan Roese) Date: Mon, 2 May 2016 08:47:15 +0200 Subject: [PATCH v6] spi: orion.c: Add direct access mode In-Reply-To: <1461147068-4829-1-git-send-email-sr@denx.de> References: <1461147068-4829-1-git-send-email-sr@denx.de> Message-ID: <5726F7F3.9070700@denx.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 20.04.2016 12:11, Stefan Roese wrote: > This patch adds support for the direct write mode to the Orion SPI > driver which is used on the Marvell Armada based SoCs. In this direct > mode, all data written to (or read from) a specifically mapped MBus > window (linked to one SPI chip-select on one of the SPI controllers) > will be transferred directly to the SPI bus. Without the need to control > the SPI registers in between. This can improve the SPI transfer rate in > such cases. > > Currently only the direct write mode is supported. This mode especially > benefits from the SPI direct mode, as the data bytes are written > head-to-head to the SPI bus, without any additional addresses, that > are also written in the direct read mode. > > One use-case for this direct write mode is, programming a FPGA bitstream > image into the FPGA connected to the SPI bus at maximum speed. > > This mode is described in chapter "22.5.2 Direct Write to SPI" in the > Marvell Armada XP Functional Spec Datasheet. > > It should be possible to support SPI-NOR and SPI-NAND devices via > this direct access mode as well. But this needs further work, e.g.: > - The mapping of the MBus window needs to get extended to span > the complete flash device size > - The address / control data needs to get inserted into the SPI > controller registers > > Signed-off-by: Stefan Roese > Cc: Thomas Petazzoni > Cc: Gregory CLEMENT > Cc: Andrew Lunn > Cc: Arnd Bergmann > Cc: Mark Brown Its been a while since v6 of this direct write access mode has been posted. This is a gentle ping on its status. Arnd / Mark, do you have any additional change requests or are you okay with the current version? Thanks, Stefan