[RFC] USB phy type C

[RFC] USB phy type C

[David Cohen]

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 :)

Br, David

Re: [RFC] USB phy type C

[Felipe Balbi]

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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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Re: [RFC] USB phy type C

[David Cohen]

On Thu, Feb 12, 2015 at 12:45:53PM -0600, Felipe Balbi wrote:
> 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;
>  }

Thanks. That's a nice direction.

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

We'll probably get back to here with more questions/proposals about
that.

Br, David

Re: [RFC] USB phy type C

[Felipe Balbi]

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On Thu, Feb 12, 2015 at 11:27:28AM -0800, David Cohen wrote:
> On Thu, Feb 12, 2015 at 12:45:53PM -0600, Felipe Balbi wrote:
> > 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;
> >  }
> 
> Thanks. That's a nice direction.

btw, for typec, let's support only the new phy framework, that ought to
get people to move :-)

-- 
balbi

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