Messages in this thread | | | Subject | Re: [RESEND PATCH v3 1/4] dt-bindings: connector: add power-opmode optional property to usb-connector | From | Amelie DELAUNAY <> | Date | Thu, 5 Nov 2020 12:36:46 +0100 |
| |
On 11/4/20 10:08 PM, Rob Herring wrote: > On Fri, Oct 30, 2020 at 04:27:14PM +0100, Amelie DELAUNAY wrote: >> >> >> On 10/30/20 3:29 PM, Rob Herring wrote: >>> On Thu, Oct 29, 2020 at 11:49 AM Amelie DELAUNAY <amelie.delaunay@st.com> wrote: >>>> >>>> >>>> >>>> On 10/29/20 4:40 PM, Rob Herring wrote: >>>>> On Thu, Oct 29, 2020 at 10:58:03AM +0100, Amelie Delaunay wrote: >>>>>> Power operation mode may depends on hardware design, so, add the optional >>>>>> property power-opmode for usb-c connector to select the power operation >>>>>> mode capability. >>>>>> >>>>>> Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com> >>>>>> --- >>>>>> .../bindings/connector/usb-connector.yaml | 18 ++++++++++++++++++ >>>>>> 1 file changed, 18 insertions(+) >>>>>> >>>>>> diff --git a/Documentation/devicetree/bindings/connector/usb-connector.yaml b/Documentation/devicetree/bindings/connector/usb-connector.yaml >>>>>> index 728f82db073d..200d19c60fd5 100644 >>>>>> --- a/Documentation/devicetree/bindings/connector/usb-connector.yaml >>>>>> +++ b/Documentation/devicetree/bindings/connector/usb-connector.yaml >>>>>> @@ -93,6 +93,24 @@ properties: >>>>>> - device >>>>>> - dual >>>>>> >>>>>> + power-opmode: >>>>> >>>>> I've acked this version: >>>>> >>>>> https://lore.kernel.org/r/20201020093627.256885-2-badhri@google.com >>>>> >>>> >>>> frs is used for Fast Role Swap defined in USB PD spec. >>>> I understand it allows to get the same information but I'm wondering why >>>> the property name is limited to -frs- in this case. What about a >>>> non-power delivery USB-C connector ? >>> >>> I've got no idea. The folks that know USB-C and PD details need to get >>> together and work all this out. To me, it looks like the same thing... >>> >> >> It looks but... >> >> The purpose of power-opmode property is to configure the USB-C controllers, >> especially the non-PD USB-C controllers to determine the power operation >> mode that the Type C connector will support and will advertise through CC >> pins when it has no power delivery support, whatever the power role: Sink, >> Source or Dual >> The management of the property is the same that data-role and power-role >> properties, and done by USB Type-C Connector Class. >> >> new-source-frs-typec-current specifies initial current capability of the new >> source when vSafe5V is applied during PD3.0 Fast Role Swap. So here, this >> property is not applied at usb-c controller configuration level, but during >> PD Fast Role Swap, so when the Sink become the Source. >> Moreover, the related driver code says FRS can only be supported by DRP >> ports. So new-source-frs-typec-current property, in addition to being >> specific to PD, is also dedicated to DRP usb-c controller. >> The property is managed by Type-C Port Controller Manager for PD. > > But it's the same set of possible values, right? So we can align the > values at least. >
USB Power Delivery FRS values are defined in include/dt-bindings/usb/pd.h to fit with drivers/usb/typec/tcpm/tcpm.c frs_typec_current enum.
USB-C power operation mode values are defined in include/linux/usb/typec.h with typec_pwr_opmode enum and matching with string values of typec_pwr_opmodes tab.
USB PD requires USB-C. USB-C doesn't requires USB PD.
drivers/usb/typec/tcpm/tcpm.c already used typec_pwr_opmode values.
USB PD specification Table 6-14 Fixed Supply PDO says: Fast Role Swap required USB Type-C Current (see also [USB Type-C 2.0]): Value | Description 00b | Fast Swap not supported (default) 01b | Default USB Power 10b | 1.5A @ 5V 11b | 3.0A @ 5V
Note the *see also USB Type-C 2.0*.
USB Type-C specification 4.6.2.1 USB Type-C Current says: The USB Type-C connector uses CC pins for configuration including an ability for a Source to advertise to its port partner (Sink) the amount of current it shall supply: • Default is the as-configured for high-power operation current value as defined by the USB Specification (500 mA for USB 2.0 ports; 900 mA or 1,500 mA for USB 3.2 ports in single-lane or dual-lane operation, respectively) • 1.5 A • 3.0 A
> Can we align the names in some way? power-opmode and frs-source-opmode > or ?? >
I let USB PD specialists answer.
*frs* property fits with USB PD specification, so with USB PD protocol. *power-opmode fits with USB Type-C specification, so with USB-C hardware support.
> Are these 2 properties mutually exclusive? If so, that should be > captured.
FRS is specific to products with Power Delivery Support.
power-opmode is dedicated to products with USB-C connector support.
Regards, Amelie
| |