Hi, On Thursday 03 November 2016 10:56 PM, Alexandre Bailon wrote: > On 11/03/2016 05:34 PM, Kishon Vijay Abraham I wrote: >> Hi, >> >> On Thursday 03 November 2016 08:56 PM, Alexandre Bailon wrote: >>> The USB PHY is able to operate in OTG, host or peripheral. >>> Some board may be wired to work act only as host or peripheral. >>> In such case, the dr_mode property of controller must be set to >>> host or peripheral. But doing that will also configure the PHY >>> in host or peripheral mode whereas OTG is able to detect which >>> role the USB controller should take. >>> The PHY's host or peripheral mode are actually only useful when >>> hardware doesn't allow OTG to detect it's role. >>> >>> Add the usb20_force_mode property to force the PHY to operate >>> in host or peripheral mode. >> >> I think we do just that if we populate dr_mode with host or peripheral. Why do >> we need another property to control dr_mode property? > Because the phy doesn't work correctly when it is in host or > device mode. That would be the same even with usb20_force_mode property. How does usb20_force_mode property help? Thanks Kishon >>> When usb20_force_mode is used, dr_mode should also be configured >>> to host or peripheral. >>> The controller uses dr_mode to configure itself, but the phy use >>> it to get the mode to use to configure the PHY mode. >>> >>> Signed-off-by: Alexandre Bailon <abailon@xxxxxxxxxxxx> >>> --- >>> Documentation/devicetree/bindings/phy/phy-da8xx-usb.txt | 5 +++++ >>> 1 file changed, 5 insertions(+) >>> >>> diff --git a/Documentation/devicetree/bindings/phy/phy-da8xx-usb.txt b/Documentation/devicetree/bindings/phy/phy-da8xx-usb.txt >>> index c26478b..9fc87fb 100644 >>> --- a/Documentation/devicetree/bindings/phy/phy-da8xx-usb.txt >>> +++ b/Documentation/devicetree/bindings/phy/phy-da8xx-usb.txt >>> @@ -4,6 +4,11 @@ Required properties: >>> - compatible: must be "ti,da830-usb-phy". >>> - #phy-cells: must be 1. >>> >>> +Optional properties: >>> +- usb20-force-mode: Force the phy to operate in same mode than the USB OTG controller. >>> + It should only be defined if the hardware is not capable correctly >>> + detect the role of USB by using VBUS and ID pin. >> >> From what I understand from the previous patch, if VBUS sense and the session >> end comparator is enabled, the controller can work in host mode or device mode. > I but VBUS sense and and session end comparator only seems to work when > the phy is in otg mode. > In host mode, the phy stop to work after the first disconnect. > In device mode, the phy never detect a disconnect. > In otg mode, these issues go away. > I'm working on workaround for both of them but I think it is > better to keep the phy in otg when it is possible. >> >> Thanks >> Kishon >> > Thanks, > Alexandre > -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
