Re: [RFC] USB phy type C

From: Felipe Balbi
Date: Thu Feb 12 2015 - 13:46:10 EST


Hi,

On Thu, Feb 12, 2015 at 10:41:37AM -0800, David Cohen wrote:
> Hi Felipe, et al,
>
> Is there any on going discussion regarding to USB phy for type C connectors?
>
> We'd like to know the community's preferable direction for handling
> (still unsupported) cases like USB3.1 PD, Accessories and Alternate
> modes as a new layer or an extension of current USB phy layer.
>
> Comments are welcome :)

Not the USB phy layer, but the generic phy layer. All you need to do is
add a new phy provider and add support for it from within dwc3.
Something like below:

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 9f0e209b8f6c..55a85b40e43e 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -653,6 +653,19 @@ static int dwc3_core_get_phy(struct dwc3 *dwc)
}
}

+ dwc->usb3_typec_phy = devm_phy_get(dev, "usb3-typec-phy");
+ if (IS_ERR(dwc->usb3_typec_phy)) {
+ ret = PTR_ERR(dwc->usb3_typec_phy);
+ if (ret == -ENOSYS || ret == -ENODEV) {
+ dwc->usb3_typec_phy = NULL;
+ } else if (ret == -EPROBE_DEFER) {
+ return ret;
+ } else {
+ dev_err(dev, "no usb3 typeC phy, continuing without\n");
+ dwc->usb3_typec_phy = NULL;
+ }
+ }
+
return 0;
}


The only interesting part will be dealing with the other modes of
operation, I haven't wrapped my head around it yet.

--
balbi

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