All of lore.kernel.org
 help / color / mirror / Atom feed
From: Rob Herring <robh@kernel.org>
To: John Youn <johnyoun@synopsys.com>
Cc: Felipe Balbi <balbi@kernel.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	linux-usb@vger.kernel.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org, Mark Rutland <mark.rutland@arm.com>,
	Thinh Nguyen <thinhn@synopsys.com>
Subject: Re: [PATCH 2/2] usb: dwc3: Added a property to set GFLADJ register
Date: Mon, 12 Sep 2016 10:30:18 -0500	[thread overview]
Message-ID: <20160912153018.GA14561@rob-hp-laptop> (raw)
In-Reply-To: <649b249e86e901b5bd2cf4cbe9db96d04a45f30d.1472764828.git.johnyoun@synopsys.com>

On Thu, Sep 01, 2016 at 02:32:33PM -0700, John Youn wrote:
> From: Thinh Nguyen <thinhn@synopsys.com>
> 
> Added gfladj variable to control the core behavior with respect to
> SOF, ITP, and frame timer functionality.
> 
> Currently there is dwc->fladj that holds a single field in GFLADJ
> register (GFLADJ.GFLADJ_30MHZ). A new variable gfladj is added to
> dwc structure to allow setting of the entire GFLADJ register. If
> dwc->gfladj is set, then it has a higher priority than dwc->fladj
> when writing to the GFLADJ register.

I'm not a fan of magic register values for DT properties.

How many fields in this register that you will ever need to touch?

> Synopsys HW setup (HAPS DX and phy board) requires a preset to this
> register to improve interoperablitity. For example, the value for
> GFLADJ_REFCLK_LPM_SEL should be set to 0 with ref_clk period of 50.

This sounds like it should be handled in the driver. Is it a simple, 
constant correlation of ref_clk period to this value?

> 
> Signed-off-by: Thinh Nguyen <thinhn@synopsys.com>
> Signed-off-by: John Youn <johnyoun@synopsys.com>
> ---
>  Documentation/devicetree/bindings/usb/dwc3.txt | 2 ++
>  drivers/usb/dwc3/core.c                        | 5 +++++
>  drivers/usb/dwc3/core.h                        | 1 +
>  drivers/usb/dwc3/dwc3-pci.c                    | 1 +
>  4 files changed, 9 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/usb/dwc3.txt b/Documentation/devicetree/bindings/usb/dwc3.txt
> index aa54ba7..cad4bf6 100644
> --- a/Documentation/devicetree/bindings/usb/dwc3.txt
> +++ b/Documentation/devicetree/bindings/usb/dwc3.txt
> @@ -52,6 +52,8 @@ Optional properties:
>     UTMI+ and "ulpi" for ULPI when the DWC_USB3_HSPHY_INTERFACE has value 3.
>   - snps,ref_clk_per: value for GUTCL.RefClkPer field that sets the period of
>  			ref_clk in nano seconds.
> + - snps,gfladj: if set, overides the value in the GFLADJ register. Takes
> + 			precedence over snps,quirk-frame-length-adjustment.
>   - snps,quirk-frame-length-adjustment: Value for GFLADJ_30MHZ field 
of GFLADJ
>  	register for post-silicon frame length adjustment when the
>  	fladj_30mhz_sdbnd signal is invalid or incorrect.

  reply	other threads:[~2016-09-12 15:30 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-09-01 21:32 [PATCH 1/2] usb: dwc3: Add ref clock period setting John Youn
2016-09-01 21:32 ` John Youn
     [not found] ` <ae2c9b5683820c6456f91a2ef631efa2de0bec28.1472764828.git.johnyoun-HKixBCOQz3hWk0Htik3J/w@public.gmane.org>
2016-09-01 21:32   ` [PATCH 2/2] usb: dwc3: Added a property to set GFLADJ register John Youn
2016-09-01 21:32 ` John Youn
2016-09-01 21:32   ` John Youn
2016-09-12 15:30   ` Rob Herring [this message]
2016-09-13  5:46     ` Felipe Balbi
2016-09-13 19:12     ` John Youn
2016-09-13 19:12       ` John Youn
2016-09-12 14:09 ` [PATCH 1/2] usb: dwc3: Add ref clock period setting Rob Herring
2016-09-12 14:09   ` Rob Herring
2016-09-13 19:06   ` John Youn

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=20160912153018.GA14561@rob-hp-laptop \
    --to=robh@kernel.org \
    --cc=balbi@kernel.org \
    --cc=devicetree@vger.kernel.org \
    --cc=gregkh@linuxfoundation.org \
    --cc=johnyoun@synopsys.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-usb@vger.kernel.org \
    --cc=mark.rutland@arm.com \
    --cc=thinhn@synopsys.com \
    /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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.