On Tue, Oct 13, 2020 at 7:16 AM Rob Herring [off-list ref] wrote:

On Wed, Oct 7, 2020 at 8:07 PM Badhri Jagan Sridharan [off-list ref] wrote:

quoted

On Tue, Oct 6, 2020 at 11:29 AM Rob Herring [off-list ref] wrote:

quoted

On Mon, Sep 28, 2020 at 07:39:54PM -0700, Badhri Jagan Sridharan wrote:

quoted

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.

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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.

quoted

+
+    $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'.

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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