On 15.10.21 06:09, Shawn Guo wrote: > On Tue, Oct 05, 2021 at 07:06:57PM +0200, Frieder Schrempf wrote: >> On 05.10.21 09:09, Shawn Guo wrote: >>> On Thu, Sep 30, 2021 at 05:56:27PM +0200, Frieder Schrempf wrote: >>>> From: Frieder Schrempf <frieder.schrempf@xxxxxxxxxx> >>>> >>>> The regulator reg_vdd_5v represents the fixed 5V supply on the board which >>>> can't be switched off. Mark it as always-on. >>>> >>>> The regulator reg_rst_eth2 should keep the reset signal of the USB ethernet >>>> adapter deassertet anytime. Fix the polarity and mark it as always-on. >>> >>> It seems to be wrong from the beginning that the reset is modelled by a >>> regulator. >> >> Right, but at least at the time when I upstreamed this, there was no way >> to pass the reset GPIO to a USB device driver and using a regulator >> seems to be an accepted workaround as far as I understand. > > Do we have the solution in usb driver now? If so, we should probably > switch to that, instead of patching the workaround? I had a look, but couldn't find anything. I remember there have been efforts in the past to provide a generic way for usb devices to manage resources like reset GPIOs and clocks (e.g. [1]), but it seems like nothing of this ever got merged. So for the moment I'd like to fix the existing solution, but I totally agree that this should be solved properly in the future. [1] https://lkml.org/lkml/2017/6/21/90 > >> >>> >>>> >>>> Fixes: 21c4f45b335f ("arm64: dts: Add the Kontron i.MX8M Mini SoMs and baseboards") >>>> Cc: stable@xxxxxxxxxxxxxxx >>>> Signed-off-by: Frieder Schrempf <frieder.schrempf@xxxxxxxxxx> >>>> --- >>>> arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts | 5 ++++- >>>> 1 file changed, 4 insertions(+), 1 deletion(-) >>>> >>>> diff --git a/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts b/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts >>>> index 62ba3bd08a0c..f2c8ccefd1bf 100644 >>>> --- a/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts >>>> +++ b/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts >>>> @@ -70,7 +70,9 @@ reg_rst_eth2: regulator-rst-eth2 { >>>> regulator-name = "rst-usb-eth2"; >>>> pinctrl-names = "default"; >>>> pinctrl-0 = <&pinctrl_usb_eth2>; >>>> - gpio = <&gpio3 2 GPIO_ACTIVE_LOW>; >>>> + gpio = <&gpio3 2 GPIO_ACTIVE_HIGH>; >>>> + enable-active-high; >>>> + regulator-always-on; >>>> }; >>>> >>>> reg_vdd_5v: regulator-5v { >>>> @@ -78,6 +80,7 @@ reg_vdd_5v: regulator-5v { >>>> regulator-name = "vdd-5v"; >>>> regulator-min-microvolt = <5000000>; >>>> regulator-max-microvolt = <5000000>; >>>> + regulator-always-on; >>> >>> You do not have any on/off control over the regulator. So how does this >>> always-on property make any difference? >> >> Right, this doesn't make a difference and is definitely not a fix, I >> will drop it. Anyway, this regulator is just there for completeness of >> the hardware description. >> >>> >>>> }; >>>> }; >>>> >>>> -- >>>> 2.33.0 >>>>
