Re: [PATCH 2/2] arm64: allwinner: a64: bananapi-m64: add usb otg

From: Jagan Teki
Date: Thu Dec 07 2017 - 01:54:25 EST


On Thu, Dec 7, 2017 at 11:56 AM, Chen-Yu Tsai <wens@xxxxxxxx> wrote:
> On Thu, Dec 7, 2017 at 2:18 PM, Jagan Teki <jagannadh.teki@xxxxxxxxx> wrote:
>> On Thu, Dec 7, 2017 at 8:54 AM, Chen-Yu Tsai <wens@xxxxxxxx> wrote:
>>> On Thu, Dec 7, 2017 at 1:51 AM, Jagan Teki <jagannadh.teki@xxxxxxxxx> wrote:
>>>> usb otg on bananapi-m64 has configured with USB-ID with PH9
>>>> and USB-DRVVBUS attached with dcdc1 regulatort.
>>>
>>> That is not how you read the schematic...
>>>
>>> Intersecting lines that are tied together will have a dot representing
>>> the connection. The DCDC1 line is a pull-up for the ID pin. This is very
>>> clear because it has a resistor connected in series.
>>>
>>> VBUS for OTG is controlled by the IC displayed to the right in the
>>> schematic, which is powered from 5V, and controlled by the DRVVBUS
>>> pin from the PMIC. Please take a look at how the A31/A33/A83T board
>>> dts files represent this.
>>
>> This is where I confused, USB-DRVVBUS is connected to pin 51 of PMIC
>> if we add 5v regulator how can configure gpio number for this? I saw
>
> From the axp20x bindings:
>
> - x-powers,drive-vbus-en: boolean, set this when the N_VBUSEN pin is
> used as an output pin to control an external
> regulator to drive the OTG VBus, rather then
> as an input pin which signals whether the
> board is driving OTG VBus or not.
> (axp221 / axp223 / axp813 only)
>
> Setting this allows you to use the "drivevbus" regulator under the PMIC.
> As I said, look at how other boards are doing it.
>
>> sun8i-a33-olinuxino.dts which is also similar but it has gpio = <&pio
>> 1 9 GPIO_ACTIVE_HIGH>;
>
> I have no idea where you saw this. It does not exist in my tree.
>
> Why don't you just trace backwards from the usb0_vbus-supply property
> under the usbphy node, and see where it all leads.

This what exactly I did, usb0_vbus-supply = <&reg_drivevbus>; on
sun8i-a33-olinuxino.dts is using usb0-vbus from
sunxi-common-regulators.dtsi. reg_usb0_vbus regulator using gpio9
which I couldn't find it on schematics.

thanks!
--
Jagan Teki
Free Software Engineer | www.openedev.com
U-Boot, Linux | Upstream Maintainer
Hyderabad, India.

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