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Date: Thu, 25 Mar 2010 16:20:55 +0100
Message-ID: <63386a3d1003250820x3cf81000i9d27e95c755b9ca8@mail.gmail.com>
Subject: Re: [PATCH v2] PL330: Add PL330 DMA controller driver
From: Linus Walleij <linus.ml.walleij@gmail.com>
To: jassi brar <jassisinghbrar@gmail.com>
Cc: Joonyoung Shim <jy0922.shim@samsung.com>, dan.j.williams@intel.com,
       kyungmin.park@samsung.com, linux-kernel@vger.kernel.org,
       linux-arm-kernel@lists.infradead.org,
       Russell King - ARM Linux <linux@arm.linux.org.uk>,
       Ben Dooks <ben-linux@fluff.org>
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2010/3/25 jassi brar <jassisinghbrar@gmail.com>:

> My approach is to write a separate PL330 core driver as the backend which
> can be reused by any DMA API implementer driver. That will avoid
> having two copies of the PL330 driver, among other benefits.

Seems like a rather good approach.

> And if this patch is accepted, there
> _will_ exist two copies of the PL330 driver -- one in drivers/dma/pl330_dmac.c
> and another in arch/arm/plat-samsung/. Only the former will be lying unused
> until some other SoC vendor decided to use PL330, because S3C has come too
> long a way to change its drivers to driver/dma/ API and modify DMA
> drivers for every SoC.

What's wrong with merging them later then? Refactoring FTW.

> I have the pl330-core part almost ready, but i need time to implement
> some _testable_
> implementation of the scheme. If maintainers want to see structure of
> my code, I can
> share it too, but I think I pretty much made it clear.

Why not just post it on the list? I'm curious! Since I'm working on a PrimeCell
DMA API I would love to look at PrimeCell DMA engine drivers.

Yours,
Linus Walleij