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From: Jon Hunter <jon-hunter@ti.com>
To: Stephen Warren <swarren@wwwdotorg.org>
Cc: device-tree <devicetree-discuss@lists.ozlabs.org>,
	linux-omap <linux-omap@vger.kernel.org>,
	linux-arm <linux-arm-kernel@lists.infradead.org>,
	Stephen Warren <swarren@nvidia.com>,
	Vinod Koul <vinod.koul@intel.com>,
	Rob Herring <rob.herring@calxeda.com>, Dan Williams <djbw@fb.com>,
	Russell King <linux@arm.linux.org.uk>
Subject: Re: [PATCH V4 1/2] of: Add generic device tree DMA helpers
Date: Fri, 14 Sep 2012 12:19:04 -0500	[thread overview]
Message-ID: <50536708.6040508@ti.com> (raw)
In-Reply-To: <50535B49.7070706@wwwdotorg.org>


On 09/14/2012 11:28 AM, Stephen Warren wrote:
> On 09/13/2012 04:00 PM, Jon Hunter wrote:
>> This is based upon the work by Benoit Cousson [1] and Nicolas Ferre [2]
>> to add some basic helpers to retrieve a DMA controller device_node and the
>> DMA request/channel information.
> 
>> diff --git a/Documentation/devicetree/bindings/dma/dma.txt b/Documentation/devicetree/bindings/dma/dma.txt
> 
>> +* Generic DMA Controller and DMA request bindings
>> +
>> +Generic binding to provide a way for a driver using DMA Engine to retrieve the
>> +DMA request or channel information that goes from a hardware device to a DMA
>> +controller.
>> +
>> +
>> +* DMA controller
>> +
>> +Required property:
>> +- #dma-cells: 		Must be at least 1. Used to provide DMA controller
>> +			specific information. See DMA client binding below for
> ...
>> +* DMA client
>> +
>> +Client drivers should specify the DMA property using a phandle to the controller
>> +followed by DMA controller specific data.
>> +
>> +Required property:
>> +- dmas:			List of one or more DMA specifiers, each consisting of
>> +			- A phandle pointing to DMA controller node
>> +			- A single integer cell containing DMA controller
>> +			  specific information. This typically contains a dma
>> +			  request line number or a channel number, but can
>> +			  contain any data that is used required for configuring
>> +			  a channel.
> 
> "A single integer cell" doesn't sound correct; shouldn't this be
> something like "a number of integer cells, as determined by the
> #dma-cells property in the node referenced by phandle"?

Thanks for catching that. I had been re-working this a few times and
must have forgotten to update that.

Cheers
Jon

  reply	other threads:[~2012-09-14 17:19 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-09-13 22:00 [PATCH V4 0/2] of: Add generic device tree DMA helpers Jon Hunter
2012-09-13 22:00 ` [PATCH V4 1/2] " Jon Hunter
2012-09-14  9:43   ` Arnd Bergmann
2012-09-14 13:27     ` Jon Hunter
2012-09-14 13:32       ` Arnd Bergmann
2012-09-14 14:03         ` Jon Hunter
2012-09-14 16:28   ` Stephen Warren
2012-09-14 17:19     ` Jon Hunter [this message]
2012-09-13 22:00 ` [PATCH V4 2/2] dmaengine: add helper function to request a slave DMA channel Jon Hunter

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