RE: [PATCH v4 4/6] regulator: Add Renesas RZ/G2L USB VBUS regulator driver

Biju Das
2024-07-12T13:45:21Z

Hi Geert,

> -----Original Message-----
> From: Geert Uytterhoeven <geert@linux-m68k.org>
> Sent: Thursday, July 11, 2024 4:14 PM
> Subject: Re: [PATCH v4 4/6] regulator: Add Renesas RZ/G2L USB VBUS regulator driver
>
> Hi Biju,
>
> On Thu, Jul 11, 2024 at 4:58 PM Biju Das <biju.das.jz@bp.renesas.com> wrote:
> > > -----Original Message-----
> > > From: Geert Uytterhoeven <geert@linux-m68k.org>
> > > Sent: Thursday, July 11, 2024 3:40 PM
> > > Subject: Re: [PATCH v4 4/6] regulator: Add Renesas RZ/G2L USB VBUS
> > > regulator driver
> > >
> > > Hi Biju,
> > >
> > > On Sun, Jun 16, 2024 at 12:54 PM Biju Das <biju.das.jz@bp.renesas.com> wrote:
> > > > As per the RZ/G2L HW manual, VBUSEN can be controlled by the VBOUT
> > > > bit of the VBUS Control Register. This register is mapped in the
> > > > reset framework. The reset driver expose this register as regmap
> > > > and instantiates this driver. The consumer will use the regulator
> > > > API to control the VBOUT bit as the control need to be done in the atomic context.
> > > >
> > > > Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
> > >
> > > Thanks for your patch, which is now commit 84fbd6198766336f
> > > ("regulator: Add Renesas RZ/G2L USB VBUS regulator driver") in regulator/for-next.
>
> > > > --- a/drivers/regulator/Kconfig
> > > > +++ b/drivers/regulator/Kconfig
> > > > @@ -1634,6 +1634,15 @@ config REGULATOR_UNIPHIER
> > > > help
> > > > Support for regulators implemented on Socionext UniPhier SoCs.
> > > >
> > > > +config REGULATOR_RZG2L_VBCTRL
> > > > + tristate "Renesas RZ/G2L USB VBUS regulator driver"
> > > > + depends on ARCH_RZG2L || COMPILE_TEST
> > > > + depends on OF
> > > > + select REGMAP_MMIO
> > > > + default ARCH_RZG2L
> > >
> > > As the "rzg2l-usb-vbus-regulator" platform device is only created by
> > > drivers/reset/reset-rzg2l- usbphy-ctrl.c, perhaps this should be made stricter by using "default
> RESET_RZG2L_USBPHY_CTRL"?
> >
> > OK.
> > >
> > > Alternatively, RESET_RZG2L_USBPHY_CTRL could select
> > > RESET_RZG2L_USBPHY_CTRL if REGULATOR. Can RESET_RZG2L_USBPHY_CTRL
> > > work without REGULATOR_RZG2L_VBCTRL? If not, RESET_RZG2L_USBPHY_CTRL should depend on REGULATOR,
> too.
> >
> > Yes, from functionality point it works for both host and device mode without
> REGULATOR_RZG2L_VBCTRL.
> > From specification point, some customers reported on device mode, VBUS is showing 5V.
> > So, by adding vbus regulator, I am controlling this voltage and
> > forcing to 0 for device mode and 5V for host mode.
> >
> > Please share your input how to proceed.
>
> As it works without, I think changing the default of REGULATOR_RZG2L_VBCTRL from ARCH_RZG2L to
> RESET_RZG2L_USBPHY_CTRL is the most appropriate option.

OK.

Thanks,
Biju