On Tue, Oct 6, 2020 at 11:29 AM Rob Herring <robh@xxxxxxxxxx> wrote: > > On Mon, Sep 28, 2020 at 07:39:54PM -0700, Badhri Jagan Sridharan wrote: > > This change adds frs-typec-current which allows setting the initial current > > capability of the new source when vSafe5V is applied during PD3.0 > > sink Fast Role Swap. > > Shouldn't you Cc the person you copied this from? Not sure whether I get this comment. The patch wasn't copied. Maybe you were expecting me to CC amelie.delaunay@xxxxxx ? if so, just now CC'ed. > > > > Signed-off-by: Badhri Jagan Sridharan <badhri@xxxxxxxxxx> > > --- > > Changes since v1: > > - Changing patch version to v6 to fix version number confusion. > > > > Changes since v6: > > - Removed the redundant usb-connector.txt that I created by mistake. > > - Moved to yaml. > > > > Changes since v7: > > - Rebase > > > > Changes since v8: > > - Redefine new-source-frs-typec-current as string enums to address > > Rob Herring's comment. > > --- > > .../bindings/connector/usb-connector.yaml | 26 +++++++++++++++++++ > > include/dt-bindings/usb/pd.h | 10 +++++++ > > 2 files changed, 36 insertions(+) > > > > diff --git a/Documentation/devicetree/bindings/connector/usb-connector.yaml b/Documentation/devicetree/bindings/connector/usb-connector.yaml > > index 9bd52e63c935..0b8cd08a8678 100644 > > --- a/Documentation/devicetree/bindings/connector/usb-connector.yaml > > +++ b/Documentation/devicetree/bindings/connector/usb-connector.yaml > > @@ -142,6 +142,32 @@ properties: > > required: > > - port@0 > > > > + new-source-frs-typec-current: > > + description: Initial current capability of the new source when vSafe5V > > + is applied during PD3.0 Fast Role Swap. "Table 6-14 Fixed Supply PDO - Sink" > > + of "USB Power Delivery Specification Revision 3.0, Version 1.2" provides the > > + different power levels and "6.4.1.3.1.6 Fast Role Swap USB Type-C Current" > > + provides a detailed description of the field. The sink PDO from current source > > + reflects the current source's(i.e. transmitter of the FRS signal) power > > + requirement during fr swap. The current sink (i.e. receiver of the FRS signal), > > + a.k.a new source, should check if it will be able to satisfy the current source's, > > + new sink's, requirement during frswap before enabling the frs signal reception. > > + This property refers to maximum current capability that the current sink can > > + satisfy. During FRS, VBUS voltage is at 5V, as the partners are in implicit > > + contract, hence, the power level is only a function of the current capability. > > + "not-supported" implies sink to source fast role swap not supported. > > + "default" refers to default USB power level as described by > > + "Table 6-14 Fixed Supply PDO - Sink". > > + "1.5A" refers to 1.5A@5V. > > + "3.0A" refers to 3.0A@5V. > > > > + > > + $ref: /schemas/types.yaml#/definitions/string > > + enum: > > + - not-supported > > + - default > > + - 1.5A > > + - 3.0A > > What happens if the property is not present? The behavior would be the same as "not-supported". > > I'm not crazy about mixing strings and what could be a number. v8 version[1] of the patch was using uint32. I moved to using strings as you were asking to unify with the approach in [2]. Since [3] was using string enums, I moved to that. I don't have a strong preference here, so I can move back to using u32 if you feel so. [1] https://lore.kernel.org/linux-usb/20200921195555.1050731-5-badhri@xxxxxxxxxx/ [2] https://lore.kernel.org/linux-usb/CAPTae5+Pe1m=TUhmPJY91eJbP+B6UroqBo3u7m0AC8YS1WPu9g@xxxxxxxxxxxxxx/ [3] https://lore.kernel.org/linux-arm-kernel/20200902075707.9052-2-amelie.delaunay@xxxxxx/ > > > + > > required: > > - compatible > > > > diff --git a/include/dt-bindings/usb/pd.h b/include/dt-bindings/usb/pd.h > > index 985f2bbd4d24..db1ad4532197 100644 > > --- a/include/dt-bindings/usb/pd.h > > +++ b/include/dt-bindings/usb/pd.h > > @@ -35,6 +35,16 @@ > > > > #define VSAFE5V 5000 /* mv units */ > > > > +/* > > + * Based on "Table 6-14 Fixed Supply PDO - Sink" of "USB Power Delivery Specification Revision 3.0, > > + * Version 1.2" > > + * Initial current capability of the new source when vSafe5V is applied. > > + */ > > +#define FRS_NOT_SUPPORTED 0 > > +#define FRS_DEFAULT_POWER 1 > > +#define FRS_5V_1P5A 2 > > +#define FRS_5V_3A 3 > > Why are these in a DT header, but not used by the binding? Though This is a mistake on my part. v8 of the patch which had new-source-frs-typec-current defined as uint32 were making use of these constants. Now that new-source-frs-typec-current is a string, these constants dont have any more significance in the binding. Will remove in the next version of the patch. > perhaps they should be. Are these numbers from the spec or made up? Yes they are from the spec and are from "Table 6-14 Fixed Supply PDO - Sink" of "USB Power Delivery Specification Revision 3.0, Version 1.2". Not made up. > > > + > > #define PDO_BATT_MAX_VOLT_SHIFT 20 /* 50mV units */ > > #define PDO_BATT_MIN_VOLT_SHIFT 10 /* 50mV units */ > > #define PDO_BATT_MAX_PWR_SHIFT 0 /* 250mW units */ > > -- > > 2.28.0.709.gb0816b6eb0-goog > >
