Re: [PATCH 09/18] arm64: dts: ulcb-kf: enable USB2 PHY of channel 0

[Vladimir Barinov <vladimir.barinov@cogentembedded.com>]

Hi Geert,

On 06.10.2017 10:15, Geert Uytterhoeven wrote:
> Hi Vladimir,
>
> CC Shimoda-san
>
> On Fri, Oct 6, 2017 at 4:38 AM, Vladimir Barinov
> <vladimir.barinov@cogentembedded.com> wrote:
>> On 20.09.2017 15:59, Geert Uytterhoeven wrote:
>>> On Thu, Sep 7, 2017 at 12:36 AM, Vladimir Barinov
>>> <vladimir.barinov@cogentembedded.com> wrote:
>>>> This supports USB2 PHY channel #0 on ULCB Kingfisher board
>>>>
>>>> Signed-off-by: Vladimir Barinov <vladimir.barinov@cogentembedded.com>
>>> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
>>>
>>>> index ca8de1a..0854600 100644
>>>> --- a/arch/arm64/boot/dts/renesas/ulcb-kf.dtsi
>>>> +++ b/arch/arm64/boot/dts/renesas/ulcb-kf.dtsi
>>>> @@ -60,6 +60,11 @@
>>>>                   groups = "scif1_data_b";
>>>>                   function = "scif1";
>>>>           };
>>>> +
>>>> +       usb0_pins: usb0 {
>>>> +               groups = "usb0";
>>>> +               function = "usb0";
>>>> +       };
>>>>    };
>>>>
>>>>    &scif1 {
>>>> @@ -68,3 +73,10 @@
>>>>
>>>>           status = "okay";
>>>>    };
>>>> +
>>>> +&usb2_phy0 {
>>>> +       pinctrl-0 = <&usb0_pins>;
>>>> +       pinctrl-names = "default";
>>>> +
>>> Don't you need
>>>
>>>       vbus-supply = <&vbus0_usb2>;
>>>
>>> with vbus0_usb2 a fixed regulator controlled by GPIO P11 (OTG_EXTLPn) from
>>> GPIO expander U11 (TCA9539)?
>>> May be optional, though. salvator-common.dtsi has it.
>> Yes, I need this gpio.
>> I need both OTG_EXTLPn and OTG_OFFVBUSn from the same gpio expander.
>>
>> I've been considering to use either vbus-supply + gpio hog or use gpio hog
>> for both of them for consistency.
>> What do you think about this?
> For OTG_EXTLPn you don't really need a hog, as it will be controlled by the
> USB driver/subsystem, like on Salvator-X(S), right?
Agreed.
>
> For OTG_OFFVBUSn, which is (optionally) driven from USB0_PWEN on
> Salvator-X(S) I don't know if you need a GPIO hog or not. I have to defer your
> question to Shimoda-san.
This pin should be tied permanently low to disable internal MAX3355 
internal VBUS charge pump.
Hence probably gpio hog is enough for OTG_OFFVBUSn.

KF has dedicated VBUS power supply controlled by USB0_PWEN.


-- 
Regards,
Vladimir