[PATCH RFC 1/2] MUSB: CPPI 4.1 DMA driver (take 4)

Subbrathnam, Swaminathan swami.iyer at ti.com
Wed Dec 30 08:02:56 EST 2009


Felipe,

This code is also being used for other architectures such as OMAP3517,
OMAPL13x etc.

Given this I do not think we can locate it under a mach-* directory.

Have corrected the wrap issue.  Thanks for point it out.

regards
swami

________________________________________
From: Felipe Balbi [me at felipebalbi.com]
Sent: Wednesday, December 30, 2009 5:54 PM
To: Subbrathnam, Swaminathan
Cc: felipe.balbi at nokia.com; Gupta, Ajay Kumar; linux-usb at vger.kernel.org; linux-arm-kernel at lists.infradead.org; Sergei Shtylyov
Subject: Re: [PATCH RFC 1/2] MUSB: CPPI 4.1 DMA driver (take 4)

Hi,

please wrap your mails at 80 characters

On Wed, Dec 30, 2009 at 09:16:08AM +0530, Subbrathnam, Swaminathan
wrote:
> We have been on this front months together now!!! Ideally the place
> holder would be a place independant of platforms as this piece of code
> is more of a platform independant library relating to TI CPPI DMA
> operations.  This would be used during initialization and confiuration
> of CPPI4.x based peripherals.  Though today USB is the only peripheral
> that falls in that catagory ideally other like TI EMAC could fall in
> the same space.
>
> Having said that I also see that there seems to be no roadmap/plan for
> any other peripheral other than USB to use CPPI4.x in the near future.
> TI EMAC seems to continue use CPPI3.x.
>
> This was the reason I had recommended earlier to locate this generic
> CPPI 4.x functionality within MUSB.  This definitely helps in having a
> functional peripheral in the near (and most probably long) term.
>
> I think it is prudent to locate this functionality in the musb
> directory for now.  In future if need arises we can relook at this
> later (I am sure this in all probabilities would not be required).
>
> In either way I would really appreiciate if we can come to a
> conclusion at the earliest.  Appreciate everybody's feedback and
> direction.

You can do like omap and have the generic dma interface sitting in
mach-davinci, then for musb, you'd have a series of wrappers to use the
cppi dma code. Just look at arch/arm/plat-omap/dma.c and
drivers/usb/musb/tusb6010_omap.c

--
balbi


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