Re: [PATCH v2 06/11] phy: da8xx-usb: new driver for DA8XX SoC USB PHY

From	Bin Liu <b-liu@ti.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH v2 06/11] phy: da8xx-usb: new driver for DA8XX SoC USB PHY
Date	2016-04-01 22:00 +0200
Message-ID	<rjdoD-Hb-39@gated-at.bofh.it> (permalink)
References	(1 earlier) <rdwWZ-1LR-1@gated-at.bofh.it> <rj79w-4RA-15@gated-at.bofh.it> <rj8yB-5ND-3@gated-at.bofh.it> <rj9O1-6S2-1@gated-at.bofh.it> <rjdeW-DG-1@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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Hi,

On Fri, Apr 01, 2016 at 10:45:47PM +0300, Sergei Shtylyov wrote:
> On 04/01/2016 07:02 PM, David Lechner wrote:
> 
> >>>>+EXPORT_SYMBOL_GPL(da8xx_usb20_phy_set_mode);
> >>>
> >>>Don't prefer export symbols from PHY driver. That'll create unnecessary
> >>>dependencies between the controller and the PHY.
> >>
> >>Agreed.
> >>
> >>>I think it'll be better to create a new attribute and use it?
> >>
> >>Another simpler option is to not support _set_mode() for DA8xx, and the
> >>phy driver set the otgmode bit in probe() based on dr_mode of the
> >>controller.
> >>
> >>Regards,
> >>-Bin.
> >
> >This certainly works for my particular use case, however, Sergei Shtylyov, who
> >wrote the da8xx musb glue layer originally, seemed to recall in his review of
> >the patch series that this really is necessary for OTG mode to work properly.
> 
>    No, it's still not necessary, however this method is now called
> from musb_init_controller() (it wasn't in my time). ISTR however
> that you needed to enforce the mode override in CFGCHIP2 for the
> host mode to function properly.

Yes, but I think we don't have to rely on musb_init_controller(), what
we can do is the phy probe() calls of_usb_get_dr_mode_by_phy() to get
the dr_mode of the controller then sets CFGCHIP2 bits accordingly, so
that we can drop _set_mode() in the phy driver.

Regards,
-Bin.

Thread

Re: [PATCH v2 06/11] phy: da8xx-usb: new driver for DA8XX SoC USB PHY Kishon Vijay Abraham I <kishon@ti.com> - 2016-04-01 15:20 +0200
  Re: [PATCH v2 06/11] phy: da8xx-usb: new driver for DA8XX SoC USB PHY Bin Liu <b-liu@ti.com> - 2016-04-01 16:50 +0200
    Re: [PATCH v2 06/11] phy: da8xx-usb: new driver for DA8XX SoC USB PHY David Lechner <david@lechnology.com> - 2016-04-01 18:10 +0200
      Re: [PATCH v2 06/11] phy: da8xx-usb: new driver for DA8XX SoC USB PHY Bin Liu <b-liu@ti.com> - 2016-04-01 18:30 +0200
        Re: [PATCH v2 06/11] phy: da8xx-usb: new driver for DA8XX SoC USB PHY Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> - 2016-04-01 21:50 +0200
      Re: [PATCH v2 06/11] phy: da8xx-usb: new driver for DA8XX SoC USB PHY Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> - 2016-04-01 21:50 +0200
        Re: [PATCH v2 06/11] phy: da8xx-usb: new driver for DA8XX SoC USB PHY Bin Liu <b-liu@ti.com> - 2016-04-01 22:00 +0200
  Re: [PATCH v2 06/11] phy: da8xx-usb: new driver for DA8XX SoC USB PHY David Lechner <david@lechnology.com> - 2016-04-13 23:00 +0200
    Re: [PATCH v2 06/11] phy: da8xx-usb: new driver for DA8XX SoC USB PHY Kishon Vijay Abraham I <kishon@ti.com> - 2016-04-14 14:40 +0200

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