public inbox for devicetree@vger.kernel.org
 help / color / mirror / Atom feed
From: Arnd Bergmann <arnd-r2nGTMty4D4@public.gmane.org>
To: Maxime Ripard
	<maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
Cc: Ludovic Desroches
	<ludovic.desroches-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org>,
	dmaengine-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org,
	devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	vinod.koul-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org,
	plagnioj-sclMFOaUSTBWk0Htik3J/w@public.gmane.org,
	dan.j.williams-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org,
	nicolas.ferre-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org
Subject: Re: [RFC PATCH] dma: at_xdmac: creation of the atmel eXtended DMA Controller driver
Date: Tue, 10 Jun 2014 19:58:01 +0200	[thread overview]
Message-ID: <11151546.Z6056AoQxM@wuerfel> (raw)
In-Reply-To: <20140610154118.GA4254@lukather>

On Tuesday 10 June 2014 17:41:18 Maxime Ripard wrote:
> > +DMA clients connected to the Atmel XDMA controller must use the format
> > +described in the dma.txt file, using a three-cell specifier for each channel:
> > +a phandle plus two integer cells.
> > +The three cells in order are:
> > +
> > +1. A phandle pointing to the DMA controller.
> > +2. The memory interface (16 most significant bits), the peripheral interface
> > +(16 less significant bits).
> 
> Can you elaborate on this? What are they? The request IDs on both ends
> of the transfers?
> 
> > +3. Channel configuration register. Configurable fields are:
> > +  - bit 2-1: MBSIZE, memory burst size.
> > +  - bit 10-8: CSIZE, chunk size.
> > +  - bit 12-11: DWIDTH, data width.
> 
> I'd rather see those as generic properties.

Actually these are standard settings that a slave driver
configures using dma_slave_config. They don't belong into
DT at all, as they are slave driver specific.

	Arnd
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

  reply	other threads:[~2014-06-10 17:58 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-05-27  8:35 [RFC PATCH] dma: at_xdmac: creation of the atmel eXtended DMA Controller driver Ludovic Desroches
2014-05-29 10:04 ` Josh Wu
2014-06-10 15:41 ` Maxime Ripard
2014-06-10 17:58   ` Arnd Bergmann [this message]
2014-06-10 19:15   ` Arnd Bergmann
2014-06-11  7:35     ` Ludovic Desroches
2014-06-11  7:41       ` Arnd Bergmann
2014-06-11  8:12         ` Ludovic Desroches
2014-06-11  9:04           ` Arnd Bergmann
2014-06-11  7:59   ` Ludovic Desroches

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=11151546.Z6056AoQxM@wuerfel \
    --to=arnd-r2ngtmty4d4@public.gmane.org \
    --cc=dan.j.williams-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org \
    --cc=devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
    --cc=dmaengine-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
    --cc=linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org \
    --cc=ludovic.desroches-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org \
    --cc=maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org \
    --cc=nicolas.ferre-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org \
    --cc=plagnioj-sclMFOaUSTBWk0Htik3J/w@public.gmane.org \
    --cc=vinod.koul-ral2JQCrhuEAvxtiuMwx3w@public.gmane.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