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From: "David Laight" <David.Laight@ACULAB.COM>
To: "Ira W. Snyder" <iws@ovro.caltech.edu>, <linuxppc-dev@lists.ozlabs.org>
Cc: <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH 1/2] misc: add CARMA DATA-FPGA Access Driver
Date: Wed, 9 Feb 2011 16:30:23 -0000	[thread overview]
Message-ID: <AE90C24D6B3A694183C094C60CF0A2F6D8AC45@saturn3.aculab.com> (raw)
In-Reply-To: <1297121021-3522-2-git-send-email-iws@ovro.caltech.edu>

 
> This driver allows userspace to access the data processing 
> FPGAs on the OVRO CARMA board. It has two modes of operation:
> 
> 1) random access
> 
> This allows users to poke any DATA-FPGA registers by using mmap to map
> the address region directly into their memory map.

I needed something similar, but used pread() and pwrite()
to request the transfers.
While this does require a system call per transfer, it allows
the driver to use dma (if available) to speed up the request.
In my case doing single cycle transfers would be too slow.

	David



WARNING: multiple messages have this Message-ID (diff)
From: "David Laight" <David.Laight@ACULAB.COM>
To: "Ira W. Snyder" <iws@ovro.caltech.edu>, <linuxppc-dev@lists.ozlabs.org>
Cc: linux-kernel@vger.kernel.org
Subject: RE: [PATCH 1/2] misc: add CARMA DATA-FPGA Access Driver
Date: Wed, 9 Feb 2011 16:30:23 -0000	[thread overview]
Message-ID: <AE90C24D6B3A694183C094C60CF0A2F6D8AC45@saturn3.aculab.com> (raw)
In-Reply-To: <1297121021-3522-2-git-send-email-iws@ovro.caltech.edu>

=20
> This driver allows userspace to access the data processing=20
> FPGAs on the OVRO CARMA board. It has two modes of operation:
>=20
> 1) random access
>=20
> This allows users to poke any DATA-FPGA registers by using mmap to map
> the address region directly into their memory map.

I needed something similar, but used pread() and pwrite()
to request the transfers.
While this does require a system call per transfer, it allows
the driver to use dma (if available) to speed up the request.
In my case doing single cycle transfers would be too slow.

	David

  parent reply	other threads:[~2011-02-09 16:32 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-02-07 23:23 [PATCH RFCv4 0/2] CARMA Board Support Ira W. Snyder
2011-02-07 23:23 ` [PATCH 1/2] misc: add CARMA DATA-FPGA Access Driver Ira W. Snyder
2011-02-08  7:33   ` Dmitry Torokhov
2011-02-08 17:20     ` Ira W. Snyder
2011-02-08 17:29       ` Dave Jones
2011-02-08 17:50       ` Dmitry Torokhov
2011-02-08 19:11         ` Ira W. Snyder
2011-02-08 19:33           ` Dmitry Torokhov
2011-02-09 16:30   ` David Laight [this message]
2011-02-09 16:30     ` David Laight
2011-02-09 17:03     ` Ira W. Snyder
2011-02-07 23:23 ` [PATCH 2/2] misc: add CARMA DATA-FPGA Programmer support Ira W. Snyder
2011-02-08 23:37 [PATCH RFCv5 0/2] CARMA Board Support Ira W. Snyder
2011-02-08 23:37 ` [PATCH 1/2] misc: add CARMA DATA-FPGA Access Driver Ira W. Snyder
2011-02-08 23:37   ` Ira W. Snyder
2011-02-09  8:33   ` Dmitry Torokhov
2011-02-09 17:35     ` Ira W. Snyder
2011-02-09 18:27       ` Dmitry Torokhov
2011-02-09 23:35         ` Ira W. Snyder
2011-02-09 23:42           ` Dmitry Torokhov
2011-02-10  0:10             ` Ira W. Snyder
2011-02-10  0:39               ` Dmitry Torokhov
2011-02-10  9:02                 ` David Laight
2011-02-10  9:02                   ` David Laight

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