Re: [PATCH 1/5] dt-bindings: connector: add optional properties for Type-B

From: Hans de Goede
Date: Mon Mar 11 2019 - 07:00:17 EST


On 11-03-19 09:06, Hans de Goede wrote:

On 11-03-19 06:33, Chunfeng Yun wrote:

On Fri, 2019-03-08 at 13:07 +0100, Hans de Goede wrote:

On 08-03-19 07:13, Chunfeng Yun wrote:
Add id-gpios, vbus-gpios, vbus-supply and pinctrl properties for

Signed-off-by: Chunfeng Yun <>
ÂÂ .../devicetree/bindings/connector/usb-connector.txtÂÂÂ | 10 ++++++++++
ÂÂ 1 file changed, 10 insertions(+)

diff --git a/Documentation/devicetree/bindings/connector/usb-connector.txt b/Documentation/devicetree/bindings/connector/usb-connector.txt
index a9a2f2fc44f2..7a07b0f4f973 100644
--- a/Documentation/devicetree/bindings/connector/usb-connector.txt
+++ b/Documentation/devicetree/bindings/connector/usb-connector.txt
@@ -17,6 +17,16 @@ Optional properties:
ÂÂ - self-powered: Set this property if the usb device that has its own power
ÂÂÂÂ source.
+Optional properties for usb-b-connector:
+- id-gpios: gpio for USB ID pin.

What about boards where the ID pin is *not* connected to a GPIO,
but e.g. to a special pin on the PMIC which can also detect
an ACA adapter ? Currently this case is handled by extcon
drivers, but we have no way to set e.g. vbus-supply for the
connector. Maybe in this case the usb-connector node should
be a child of the PMIC node ?
Yes, it would be, PMIC is in charger of detecting the status of ID pin

Ok, then I think this should be documented too.

And in many cases there also is a mux to switch the datalines
between the host and device(gadget) controllers, how should
that be described in this model? See the new usb-role-switch
code under drivers/usb/roles

In some cases the mux is controlled through a gpio, so we
may want to add a "mux-gpios" here in which case we also
need to define what 0/1 means.
I'm not sure, the mux seems not belong to this connector,
and may need another driver to register usb-role-switch,
similar to:

[v2,2/2] usb: typec: add typec switch via GPIO control

Right the mux/role-switch will need a driver, but the "owner"
of the usb_connector, e.g. the PMIC or the owner of the
id GPIO pin needs to know which device is the role-switch so
that it can set the role correctly based on the id-pin.

Your binding already contains Vbus info, allowing the owner
of the usb_connector to enable/disable Vbus based on the id-pin,
but the owner will also be responsible for setting the role-switch.

Note we cannot simply assume there will be only one role-switch,
we really need some link from the usb_connector to the role-switch
(or if it is a GPIO driven role-switch simply a role-switch-gpios
member in the usb_connector).

I see now in your "[PATCH v3 1/2] dt-bindings: usb: add documentation for
typec switch via GPIO" that you plan to use a
Documentation/devicetree/bindings/graph.txt style binding for this,
adding a remote-endpoint to the orientation-switch (in that patch), or
to the role-switch.

But a Type-C port can have both an orientation-switch and a role-switch
(and a mux if it supports e.g. DP-altmode), how is the driver driving
the device which has the actual usb_c_connecter child-node to which
the remote-endpoints for both the orientation- and the role-switch points
supposed to figure out which is which ?

Also it feels the wrong-way around to me to have the orientation-switch
point to the usb_c_connector, to me it would make more sense to have
the usb_c_connector point to a port on the orientation-switch.