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!
prev parent 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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