Linux-OMAP Archive on
 help / color / Atom feed
From: Sekhar Nori <>
To: Adam Ford <>, Linux-OMAP <>
Cc: Tero Kristo <>, Tony Lindgren <>,
	"Liu, Bin" <>
Subject: Re: AM3517 MUSB and CPPI
Date: Mon, 18 May 2020 11:05:17 +0530
Message-ID: <> (raw)
In-Reply-To: <>

+ Bin who maintains MUSB controller support

On 5/18/20 8:17 AM, Adam Ford wrote:
> From what I can tell, the MUSB controller on the AM3517 hasn't worked
> in a very long time.
> I have been going through the TRM for the AM3517, and I am convinced
> the device tree for the OTG port is wrong, but I am struggling to fix
> it.
> From what I can see the USB OTG Port support the CPPI 4.1 DMA
> controller, but the CPPI 4.1 only appears to support the
> DA850/OMAP-L138 and the AM335x family.
> It appears as if the AM35xx is a bit closer in behavior to the AM335x
> than the L138, but I was hoping either Tony, Tero or someone from TI
> might have a suggestion.
> The compatible flag need to be something like "compatible =
> "ti,am35xx-musb" and not omap3, because OMAP3 doesn't support the CPPI
> 4.1 DMA controller and the AM3517 does.
> Secondly, we need to update a couple of the tables in the cppi driver
> to support the am3517, and lastly, the device tree node needs to
> support the CPPI driver.
> It looks like the DA850/L138 makes the CPPI driver a sub-node of the
> OTG port, while the am335x has it as a separate node from the USB
> controller.
> From what I can tell on the AM3517, the CPPI DMA node should be a
> sub-node of the OTG.
> What I am struggling with now is the register offsets for controller,
> scheduler and queue manager.
> On both DA850 the 335x, there is an explicit table entry showing the
> offset of DMAREVID, which tells the DMA revision ID.  I cannot find a
> corresponding register for the AM3517, yet the AM3517
> FWICT, the scheduler is offset 0x2000 with respect to the OTG
> controller, and the Queue Manager register is at 0ffset 0x4000, both
> with respect to the OTG base address.  Unfortunately, I am not finding
> the offset for the CDMA controller itself.
> Can someone tell me what it should be?  I am guessing it would be near
> the 0x1000 offset, but it's a pure guess.
> adam

  reply index

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-18  2:47 Adam Ford
2020-05-18  5:35 ` Sekhar Nori [this message]
2020-05-18 10:19   ` Adam Ford
2020-05-19 15:42     ` Tony Lindgren
2020-05-21  2:44     ` Bin Liu
2020-05-22 10:16       ` Adam Ford

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:

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \ \ \ \ \ \ \ \

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-OMAP Archive on

Archives are clonable:
	git clone --mirror linux-omap/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-omap linux-omap/ \
	public-inbox-index linux-omap

Example config snippet for mirrors

Newsgroup available over NNTP:

AGPL code for this site: git clone