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From: lhthanh <lhthanh@kobekara.com>
To: Timur Tabi <timur@freescale.com>
Cc: Scott Wood <scottwood@freescale.com>, linuxppc-dev@ozlabs.org
Subject: Re: MPC8349E's DMA controller like ISA controller but with more feature?
Date: Thu, 07 May 2009 08:59:57 +0700	[thread overview]
Message-ID: <4A02409D.80500@kobekara.com> (raw)
In-Reply-To: <49F1CF7B.2080703@freescale.com>

lhthanh wrote:
>   
>> Thanks for your explaination! So if I want to transfer a buffer of data 
>> from a single I/O port,  will not DMA framework
>> also be able ?
>>     
>
> No.
>
>   
>> Have I to write aother driver?
>>     
>
> Yes.
>
>   
>> Actually, I don't want write all because there are  serveral DMA code at 
>> hand. I only want to use a framework instead of re-writing.
>>     
>
> There is no framework for what you want to do.  There is only one other
> driver that does what you want (sound/soc/fsl/fsl_dma.c), and that is a
> complicated driver that does many things besides transferring data to an
> I/O port.
>
>   
>> And I afraid that I can not write code which assure sharing DMA channels.
>>     
>
> Look at arch/powerpc/boot/dts/mpc8610_hpcd.dts.  The DMA channels that
> are needed by the 8610 audio driver have a different 'compatible'
> property.  This is how you prevent the generic DMA driver from using a
> channel that you want.
>
> I'm afraid that you're going to have to study the DMA programming model,
> and my device driver, and write a brand new driver from scratch.
>
>   
Thank Scott and Timur very much! I will study more DMA driver and come 
back later. :)

Regard!

      reply	other threads:[~2009-05-07  2:02 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-04-20 12:38 MPC8349E's DMA controller like ISA controller but with more feature? lhthanh
2009-04-20 15:55 ` Scott Wood
2009-04-20 17:23   ` Timur Tabi
     [not found]   ` <49EFEA26.2010602@kobekara.com>
     [not found]     ` <20090423154311.GA19717@ld0162-tx32.am.freescale.net>
     [not found]       ` <49F08FBC.9010903@freescale.com>
2009-04-24  6:12         ` lhthanh
2009-04-24 14:40           ` Timur Tabi
2009-05-07  1:59             ` lhthanh [this message]

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