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From: davidb@codeaurora.org (David Brown)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v3 2/2] DMAEngine: Add DMAEngine driver based on old MSM DMA APIs
Date: Tue, 13 Mar 2012 12:34:32 -0700	[thread overview]
Message-ID: <20120313193432.GA13046@codeaurora.org> (raw)
In-Reply-To: <CAPDArRLs23VDJSWpX8xJsXfn+_SV2FcyzLYBF9UAxf=Rv9svGQ@mail.gmail.com>

On Tue, Mar 13, 2012 at 04:27:37PM +0530, Shantanu Gupta wrote:

> Any info available(publicly) on so as to what all chipsets have this capability
> ?

The ADM hardware is in every currently available MSM that can run
Linux.  It is being phased out, to be replaced by a new DMA system
(SPS/BAM).  Fortunately, there are some chips (MSM8960) that have both
ADM and SPS/BAM so there should be time to get those drivers in.

At least as my memory serves me:

  7201 - ADM
  8250 - ADM
  8660 - 2 ADMs, SPS/BAM
  8960 - 1 ADM, SPS/BAM

The ADM is mostly a regular DMA-type device.  Each channel can be
associated with a rate-control channel, which is needed for some
devices.  It also has a mode called "box mode", which works kind of
like a self-repeating scatter list.  This mode is needed for some of
the peripherals also on the MSM.

David

> On Tue, Mar 13, 2012 at 1:44 AM, Daniel Walker <dwalker@fifo99.com> wrote:
> 
>     On Mon, Mar 12, 2012 at 04:02:44PM +0530, Ravi Kumar V wrote:
>     > Add DMAEngine based driver using the old MSM DMA APIs internally.
> 
>     What do you mean by this?
> 
>     > The benefit of this approach is that not all the drivers
>     > have to get converted to DMAEngine APIs simultaneosly while
>     > both the drivers can stay enabled in the kernel. The client
>     > drivers using the old MSM APIs directly can now convert to
>     > DMAEngine one by one.
> 
>     Which drivers?
>    
>     Daniel
>     --
>     To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in
>     the body of a message to majordomo at vger.kernel.org
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> 
> 

-- 
Sent by an employee of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.

  parent reply	other threads:[~2012-03-13 19:34 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-03-12 10:32 [PATCH v3 2/2] DMAEngine: Add DMAEngine driver based on old MSM DMA APIs Ravi Kumar V
2012-03-12 20:14 ` Daniel Walker
2012-03-13 12:46   ` Ravi Kumar V
2012-03-14 15:05     ` Daniel Walker
2012-03-14 20:19       ` David Brown
2012-03-15 18:12         ` Ravi Kumar V
2012-08-14 11:00       ` Linus Walleij
     [not found]   ` <CAPDArRLs23VDJSWpX8xJsXfn+_SV2FcyzLYBF9UAxf=Rv9svGQ@mail.gmail.com>
2012-03-13 19:34     ` David Brown [this message]
2012-03-15 17:57     ` Ravi Kumar V
2012-03-14 16:26 ` Lars-Peter Clausen

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