diff mbox series

[v9,05/15] dt-bindings: connector: Add property to set initial current cap for FRS

Message ID 20200929024004.244992-6-badhri@google.com
State New
Headers show
Series TCPM support for FRS and AutoDischarge Disconnect | expand

Commit Message

Badhri Jagan Sridharan Sept. 29, 2020, 2:39 a.m. UTC
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.

Signed-off-by: Badhri Jagan Sridharan <badhri@google.com>
---
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(+)

Comments

Badhri Jagan Sridharan Oct. 8, 2020, 1:06 a.m. UTC | #1
On Tue, Oct 6, 2020 at 11:29 AM Rob Herring <robh@kernel.org> 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@st.com ? if so, just now CC'ed.

>

>

> > Signed-off-by: Badhri Jagan Sridharan <badhri@google.com>

> > ---

> > 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@google.com/
[2] https://lore.kernel.org/linux-usb/CAPTae5+Pe1m=TUhmPJY91eJbP+B6UroqBo3u7m0AC8YS1WPu9g@mail.gmail.com/
[3] https://lore.kernel.org/linux-arm-kernel/20200902075707.9052-2-amelie.delaunay@st.com/

>

> > +

> >  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

> >
Badhri Jagan Sridharan Oct. 20, 2020, 9:43 a.m. UTC | #2
On Tue, Oct 13, 2020 at 7:16 AM Rob Herring <robh@kernel.org> wrote:
>

> On Wed, Oct 7, 2020 at 8:07 PM Badhri Jagan Sridharan <badhri@google.com> wrote:

> >

> > On Tue, Oct 6, 2020 at 11:29 AM Rob Herring <robh@kernel.org> 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@st.com ? if so, just now CC'ed.

> >

> > >

> > >

> > > > Signed-off-by: Badhri Jagan Sridharan <badhri@google.com>

> > > > ---

> > > > 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".

>

> Then you don't need '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.

>

> Since the u32 values are based on the USB spec, I think I prefer that.

> Should be easier to deal with in the driver than doing strcmp's.

Done. Sent out as v11 of the patch.

Thanks,
Badhri

>

> Rob
diff mbox series

Patch

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
+
 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
+
 #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 */