Re: [PATCH v6] usb: common: add API to set usb otg capabilities by device tree

[Li Jun <b47624-KZfg59tc24xl57MIdRCFDg@public.gmane.org>]

On Tue, Jun 23, 2015 at 02:56:06PM +0300, Roger Quadros wrote:
> + Kukjin, Stephen,
> 
> for board specific USB question.
> 
> On Tue, 23 Jun 2015 16:35:49 +0800
> Li Jun <b47624-KZfg59tc24xl57MIdRCFDg@public.gmane.org> wrote:
> 
> > On Tue, Jun 23, 2015 at 10:43:28AM +0300, Roger Quadros wrote:
> > > > > 
> > > > > If the dr_mode was "otg" for such case and we want OTG disabled then it is really the DT fault.
> > > > 
> > > > It's ID pin detect for dual role switch as many current OTG controllers have.
> > > > not DT fault, its dt only has a dr_mode = "otg".
> > > > 
> > > > > We don't need to tackle this case. Just fix up the DT to dr_mode = "peripheral" if
> > > > > OTG behaviour is not needed.
> > > > > 
> > > > OTG behaviour is not needed, so we need disable HNP/SRP/ADP. but dr_mode =
> > > > "otg" as it already works fine with ID pin detect.
> > > 
> > > Do you know which platform has plain non-otg dual-role working as of today
> > > with dr_mode set to "otg"?
> > 
> > I don't know.
> > The dt property dr_mode is already there, and currently there are some platforms
> > as its user, so I assume those platforms either are non-otg dual-role, or real OTG
> > with HNP supported, I guess most are the former cases; chipidea is the later case.
> > 
> > > For TI platforms none of them have it working currently.
> > > 
> > So for Ti platforms, some enables non-otg dual-role function but do not use
> > dr_mode = "otg"?
> 
> for TI we have only musb based and dwc3 based platforms. MUSB based are OTG.
> dwc3 doesn't support dual-role or OTG yet so we use either "peripheral" or "Host"
> 
> > 
> > For those only have non-otg dual-role platforms, no matter using dr_mode or not,
> > we need keep it's real OTG disabled for legacy users after it's controller
> > driver adds real OTG later.
> 
> I wouldn't even bother about platforms expecting dual-role behaviour
> with dr_mode not set to "otg". That is just plain wrong and can't be supported.
> 
Some platforms may not pass dr_mode in it DT, and treat that means
otg controller will work at otg mode by default, at least I know
current chipidea platforms do so. Therefore we may not list all otg
controller drivers just by grep "dr_mode = "otg"" in its dts files.

> These are the dts files having dr_mode == "otg".
> I've sorted them as per Soc vendor and USB controller
> 
> Freescale:
> ----------
> powerpc/boot/dts/mpc5121.dtsi:			dr_mode = "otg";
> 	compatible = "fsl,mpc5121-usb2-dr";
> powerpc/boot/dts/asp834x-redboot.dts:			dr_mode = "otg";
> 	compatible = "fsl-usb2-dr"
> powerpc/boot/dts/mpc834x_mds.dts:			dr_mode = "otg";
> 	compatible = "fsl-usb2-dr";
> powerpc/boot/dts/mpc8349emitxgp.dts:			dr_mode = "otg";
> 	compatible = "fsl-usb2-dr";
> 
> arm/boot/dts/imx25-pdk.dts:	dr_mode = "otg";
> 	compatible = "fsl,imx25-usb", "fsl,imx27-usb";
> arm/boot/dts/imx25-eukrea-mbimxsd25-baseboard.dts:	dr_mode = "otg";
> 	compatible = "fsl,imx25-usb", "fsl,imx27-usb";
> arm/boot/dts/imx27-eukrea-cpuimx27.dtsi:	dr_mode = "otg";
> 	compatible = "fsl,imx27-usb";
> arm/boot/dts/imx27-phytec-phycore-som.dtsi:	dr_mode = "otg";
> 	compatible = "fsl,imx27-usb";
> arm/boot/dts/imx27-pdk.dts:	dr_mode = "otg";
> 	compatible = "fsl,imx27-usb";
> arm/boot/dts/imx35-eukrea-mbimxsd35-baseboard.dts:	dr_mode = "otg";
> 	compatible = "fsl,imx35-usb", "fsl,imx27-usb";
> arm/boot/dts/imx51-eukrea-mbimxsd51-baseboard.dts:	dr_mode = "otg";
> 	compatible = "fsl,imx51-usb", "fsl,imx27-usb";
> arm/boot/dts/imx51-babbage.dts:	dr_mode = "otg";
> 	compatible = "fsl,imx51-usb", "fsl,imx27-usb";
> arm/boot/dts/imx51-digi-connectcore-jsk.dts:	dr_mode = "otg";
> 	compatible = "fsl,imx51-usb", "fsl,imx27-usb";
> arm/boot/dts/imx6dl-riotboard.dts:	dr_mode = "otg";
> 	compatible = "fsl,imx6q-usb", "fsl,imx27-usb";
> 
> Li, can you please comment on all the above Freesacle platforms?
> 

AFAIK, those FSL platforms are legacy OTG.

Li Jun
 
> STE:
> ---
> arm/boot/dts/ste-dbx5x0.dtsi:			dr_mode = "otg";
> 	compatible = "stericsson,db8500-musb";
> 
> MUSB so legacy OTG.
> 
> TI:
> ---
> arm/boot/dts/am33xx.dtsi:				dr_mode = "otg";
> 	compatible = "ti,musb-am33xx";
> 
> MUSB so legacy OTG.
> 
> arm/boot/dts/dra7.dtsi:				dr_mode = "otg";
> 	compatible = "snps,dwc3";	/* board dts overrides to dr_mode = "peripheral" or "host" */
> arm/boot/dts/dra74x.dtsi:				dr_mode = "otg";
> 	compatible = "snps,dwc3";	/* board dts overrides to dr_mode = "peripheral" or "host" */
> arm/boot/dts/am4372.dtsi:				dr_mode = "otg";
> 	compatible = "snps,dwc3";	/* board dts overrides to dr_mode = "peripheral" or "host" */
> arm/boot/dts/am4372.dtsi:				dr_mode = "otg";
> 	compatible = "snps,dwc3";	/* board dts overrides to dr_mode = "peripheral" or "host" */
> 
> All these will eventually use dr_mode = "otg" with all 3 disable flags for simple dual-role operation.
> 
> Samsung
> -------
> arm/boot/dts/exynos5422-odroidxu3.dts:	dr_mode = "otg";
> 	compatible = "snps,dwc3";
> 
> I think that this board expects dual-role only behaviour. But that is not functional for DWC3.
> Kukjin/Felipe, any comment?
> 
> Nvidia
> ------
> arm/boot/dts/tegra20-seaboard.dts:		dr_mode = "otg";
> 	compatible = "nvidia,tegra20-ehci", "usb-ehci";
> arm/boot/dts/tegra30-colibri-eval-v3.dts:		dr_mode = "otg";
> 	compatible = "nvidia,tegra30-ehci", "usb-ehci";
> 
> I couldn't find gadget side implementation for this.
> Stephen, any comments on whether this board supports true OTG operation or just dual-role operation?
> 
> Cambridge Silicon
> -----------------
> arm/boot/dts/atlas7.dtsi:				dr_mode = "otg";
> 	compatible = "sirf,atlas7-usb";
> 
> I couldn't find the USB controller driver for this.
> 
> cheers,
> -roger
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