(EXT) RE: [PATCH v2 0/3] i.MX8MP: more USB3 glue layer feature support

Alexander Stein alexander.stein at ew.tq-group.com
Fri Jan 7 05:43:02 PST 2022


Hi,

Am Mittwoch, 22. Dezember 2021, 04:18:57 CET schrieb Jun Li:
> > -----Original Message-----
> > From: Alexander Stein <alexander.stein at ew.tq-group.com>
> > Sent: Friday, December 17, 2021 12:06 AM
> > To: Kishon Vijay Abraham I <kishon at ti.com>; Vinod Koul <vkoul at kernel.org>;
> > Rob Herring <robh+dt at kernel.org>; Shawn Guo <shawnguo at kernel.org>; Sascha
> > Hauer <s.hauer at pengutronix.de>; Fabio Estevam <festevam at gmail.com>
> > Cc: Alexander Stein <alexander.stein at ew.tq-group.com>; dl-linux-imx
> > <linux-imx at nxp.com>; linux-phy at lists.infradead.org;
> > devicetree at vger.kernel.org; linux-arm-kernel at lists.infradead.org
> > Subject: [PATCH v2 0/3] i.MX8MP: more USB3 glue layer feature support
> > 
> > This patchset aims to support flags for e.g. over-current active low or
> > port permanantly attached which are provided in the USB3 glue layer.
> > 
> > There is already a glue layer driver dwc3-imx8mp, but unfortunately this
> > driver does not use the glue area at all, it only handles wakeup-support
> > which is done in the HSIO BLK_CTRL area (0x32f10100), accordingly the
> > driver only uses the hsio clock.
> > 
> > The driver which actually uses the USB3 glue area is phy-fsl-imx8mq-usb.
> > As the name indicates PHY is configured in the corresponding registers,
> > which are part of the USB3 glue layer.
> > 
> > This make is it unclear for me which driver should handle the required
> > features above.
> > dwc3-imx8mp, the glue layer driver, does not touch the glue area at all,
> > but the HSIO BLK_CTRL area.
> > phy-fsl-imx8mq-usb only touches the PHY registers in the glue layer.
> > Neither does map the USB3 control register from the glue layer.
> > 
> > Thanks for any feedback and best regards, Alexander
> 
> Which driver handle what function is decided by the driver *function*,
> not where the actual HW logic is located, iMX8MP do have a "glue" layer
> in SoC HW, some part is for phy config, and some part is for controller,
> so we need put the part of phy config into the phy driver, the changes
> you are adding is for controller so should be put in dwc3-imx8mp.c from
> my point view.

Thanks for that feedback. This makes things clearer to me.
Yes, dwc3-imx8mp.c seems the right place for that. I'll do that.

Best regards,
Alexander






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