Hello Fabio, On Wed, Dec 20, 2023 at 07:48:50AM -0300, Fabio Estevam wrote: > On Wed, Dec 20, 2023 at 7:39 AM Andrejs Cainikovs > <andrejs.cainik...@gmail.com> wrote: > > > diff --git a/arch/arm/dts/fsl-imx8qxp-colibri-u-boot.dtsi > > b/arch/arm/dts/fsl-imx8qxp-colibri-u-boot.dtsi > > index a6af4e5e2b7..6ab6b1f9ee6 100644 > > --- a/arch/arm/dts/fsl-imx8qxp-colibri-u-boot.dtsi > > +++ b/arch/arm/dts/fsl-imx8qxp-colibri-u-boot.dtsi > > @@ -84,6 +84,21 @@ > > bootph-some-ram; > > }; > > > > +&gpio_expander_43 { > > + usb-bypass-n-hog { > > + gpio-hog; > > + gpios = <5 GPIO_ACTIVE_LOW>; > > + line-name = "usb-bypass-n"; > > + output-high; > > + }; > > + usb-reset-n-hog { > > + gpio-hog; > > + gpios = <4 GPIO_ACTIVE_LOW>; > > + line-name = "usb-reset-n"; > > + output-low; > > + }; > > +}; > > Patch looks good from a U-Boot perspective, but just want to > understand why the imx8qxp/imx8qm boards > in U-Boot use devicetrees based on downstream NXP instead of the > mainline kernel dts? > > Shouldn't this 'hub out of reset' be added in mainline Linux first and > then just sync the dts in U-Boot?
Valid point. In general re-using the DTS for the kernel would not work. The bypass and reset signals are part of the USB HUB node [1], and we would need to add such a driver to U-Boot to be able to properly implement it (despite the recent plans to make SPL a full blown bootloader and U-Boot proper the operating system and kick out Linux I would not go into that direction ;-) Given that I believe that overriding the Linux DTS to use these 2 signals are simple GPIO HOG for U-Boot is the correct approach. Francesco [1] Linux: Documentation/devicetree/bindings/usb/smsc,usb3503.yaml