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From: Matt Sealey <matt@genesi-usa•com>
To: linuxppc-embedded@ozlabs•org
Cc: arieswar24b@yahoo•de
Subject: Re: Using Bestcomm API (DMA) on MPC5200b with Linux?
Date: Thu, 23 Oct 2008 17:28:02 -0500	[thread overview]
Message-ID: <4900FA72.1040201@genesi-usa.com> (raw)
In-Reply-To: <406316.49476.qm@web25808.mail.ukl.yahoo.com>

You need to write a task that does the DMA operation you want; 
GenBD is actually pretty generic and lets you just copy from 
one place to another.

The API is pretty simple; make sure genbd is compiled in, get 
the task structure using bcom_gen_bd_[tr]x_init, and then.. 
uhh.. this is where I always forget.

There is a way to submit a buffer descriptor and have the 
engine basically perform that transfer. I think it's 
bcom_prepare_next_buffer and then bcom_submit_next_buffer.

Actually I can't even FIND those functions in the Linux tree 
right now, but they have to be in there because the FEC driver 
uses them..

-- 
Matt Sealey <matt@genesi-usa•com>
Genesi, Manager, Developer Relations

Dave Best wrote:
> I am trying to connect a FPGA/FIFO with my MPC5200b on a phytec PCM 030 board  while running a 2.6.23.1 Linux.
> 
> The Linux Kernel source contains an implementation for the Bestcomm API in the form of a driver for ethernet (fec) and ATA.(situated in the arch-powerpc/sysdev/bestcomm path) I tried to make use of it but i've run into some problems.
> 
> So i tried to include the API in a module to utilize its functionality but no luck till now.
> 
> Freescale supports the Bestcomm DMA API not on an OS level. So the problem is adopting this API into a Linux environment, which distinguishes between kernel space and user space while writing to the appropriate registers.
> 
> Further information is very hard to find for such a common task as starting a DMA transfer.
> 
> Dave
> 
> 
> 
>       
> _______________________________________________
> Linuxppc-embedded mailing list
> Linuxppc-embedded@ozlabs•org
> https://ozlabs.org/mailman/listinfo/linuxppc-embedded

  reply	other threads:[~2008-10-23 22:28 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-10-23 13:00 Using Bestcomm API (DMA) on MPC5200b with Linux? Dave Best
2008-10-23 22:28 ` Matt Sealey [this message]
2008-10-24 15:14   ` Jon Smirl
2008-10-27 16:18     ` Matt Sealey
2008-12-04 17:04       ` Juergen Beisert
2008-12-04 10:01   ` Dave Best

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