From: Vinod Koul <vkoul@kernel.org>
To: Peter Ujfalusi <peter.ujfalusi@ti.com>
Cc: robh+dt@kernel.org, dmaengine@vger.kernel.org,
linux-kernel@vger.kernel.org, dan.j.williams@intel.com,
devicetree@vger.kernel.org
Subject: Re: [RFC 1/3] dt-bindings: dma: Add documentation for DMA domains
Date: Thu, 12 Sep 2019 22:33:12 +0530 [thread overview]
Message-ID: <20190912170312.GD4392@vkoul-mobl> (raw)
In-Reply-To: <a452cd06-79ca-424d-b259-c8d60fc59772@ti.com>
On 09-09-19, 09:30, Peter Ujfalusi wrote:
> >> or domain-dma-controller?
> >
> > I feel dma-domain-controller sounds fine as we are defining domains for
> > dmaengine. Another thought which comes here is that why not extend this to
> > slave as well and define dma-domain-controller for them as use that for
> > filtering, that is what we really need along with slave id in case a
> > specific channel is to be used by a peripheral
> >
> > Thoughts..?
>
> I have thought about this, we should be able to drop the phandle to the
> dma controller from the slave binding just fine.
>
> However we have the dma routers for the slave channels and there is no
> clear way to handle them.
> They are not needed for non slave channels as there is no trigger to
> route. In DRA7 for example we have an event router for EDMA and another
> one for sDMA. If a slave device is to be serviced by EDMA, the EDMA
> event router needs to be specified, for sDMA clients should use the sDMA
> event router.
So you have dma, xbar and client? And you need to use a specfic xbar,
did i get that right?
> In DRA7 case we don't really have DMA controllers for domains, but we
> use the DMA which can service the peripheral better (sDMA is better to
> be used for UART, but can not be used for McASP for example)
>
> Then we have the other type of DMA router for daVinci/am33xx/am43xx
> where the crossbar is not for the whole EDMA controller like in DRA7,
> but we have small crossbars for some channels.
>
> Other vendors have their own dma router topology..
>
> Too many variables to handle the cases without gotchas, which would need
> heavy churn in the core or in drivers.
--
~Vinod
next prev parent reply other threads:[~2019-09-12 17:04 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-06 14:18 [RFC 0/3] dmaengine: Support for DMA domain controllers Peter Ujfalusi
2019-09-06 14:18 ` [RFC 1/3] dt-bindings: dma: Add documentation for DMA domains Peter Ujfalusi
2019-09-08 7:47 ` Peter Ujfalusi
2019-09-08 12:10 ` Vinod Koul
2019-09-09 6:30 ` Peter Ujfalusi
2019-09-12 17:03 ` Vinod Koul [this message]
2019-09-13 7:21 ` Peter Ujfalusi
2019-09-13 10:36 ` Vinod Koul
2019-09-13 12:19 ` Peter Ujfalusi
2019-09-13 13:33 ` Vinod Koul
2019-09-08 12:06 ` Vinod Koul
2019-09-09 6:00 ` Peter Ujfalusi
2019-09-06 14:18 ` [RFC 2/3] dmaengine: of_dma: Function to look up the DMA domain of a client Peter Ujfalusi
2019-09-08 12:12 ` Vinod Koul
2019-09-06 14:18 ` [RFC 3/3] dmaengine: Support for requesting channels preferring DMA domain controller Peter Ujfalusi
2019-09-08 7:46 ` Peter Ujfalusi
2019-09-08 12:15 ` Vinod Koul
2019-09-09 5:56 ` Peter Ujfalusi
2019-09-12 16:49 ` Vinod Koul
-- strict thread matches above, loose matches on Subject: below --
2019-09-06 14:17 [RFC 0/3] dmaengine: Support for DMA domain controllers Peter Ujfalusi
2019-09-06 14:17 ` [RFC 1/3] dt-bindings: dma: Add documentation for DMA domains Peter Ujfalusi
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190912170312.GD4392@vkoul-mobl \
--to=vkoul@kernel.org \
--cc=dan.j.williams@intel.com \
--cc=devicetree@vger.kernel.org \
--cc=dmaengine@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=peter.ujfalusi@ti.com \
--cc=robh+dt@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).