From: sr@denx•de (Stefan Roese)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v6] spi: orion.c: Add direct access mode
Date: Mon, 2 May 2016 08:47:15 +0200 [thread overview]
Message-ID: <5726F7F3.9070700@denx.de> (raw)
In-Reply-To: <1461147068-4829-1-git-send-email-sr@denx.de>
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 <sr@denx•de>
> Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons•com>
> Cc: Gregory CLEMENT <gregory.clement@free-electrons•com>
> Cc: Andrew Lunn <andrew@lunn•ch>
> Cc: Arnd Bergmann <arnd@arndb•de>
> Cc: Mark Brown <broonie@kernel•org>
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
next prev parent reply other threads:[~2016-05-02 6:47 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-20 10:11 [PATCH v6] spi: orion.c: Add direct access mode Stefan Roese
2016-04-20 11:58 ` Gregory CLEMENT
2016-04-20 12:09 ` Stefan Roese
2016-06-16 9:23 ` Gregory CLEMENT
2016-06-16 9:42 ` Stefan Roese
2016-05-02 6:47 ` Stefan Roese [this message]
2016-05-02 7:28 ` Arnd Bergmann
2016-05-02 10:33 ` Stefan Roese
2016-05-02 15:40 ` Mark Brown
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