Re: [PATCH resend 02/12] usb: typec: add basic typec properties

On Mon, Oct 9, 2017 at 6:21 AM, Jun Li [off-list ref] wrote:

Hi Rob,

quoted

-----Original Message-----
From: Rob Herring [mailto:robh-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org]
Sent: Friday, October 06, 2017 4:44 AM
To: Jun Li <redacted>
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Subject: Re: [PATCH resend 02/12] usb: typec: add basic typec properties

On Tue, Sep 26, 2017 at 12:05:13PM +0800, Li Jun wrote:

quoted

port-type is required for any typec port; default-role is only
required for drp; power source capable needs src-pdos; power sink
capable needs snk-pdos, max-snk-mv, max-snk-ma, op-snk-mw.

"dt-bindings: usb: ..." for the subject prefix.

Will update in next version.

quoted

quoted

Signed-off-by: Li Jun <redacted>
---
 Documentation/devicetree/bindings/usb/typec.txt | 46
+++++++++++++++++++++++++
 1 file changed, 46 insertions(+)

diff --git a/Documentation/devicetree/bindings/usb/typec.txt

b/Documentation/devicetree/bindings/usb/typec.txt
new file mode 100644
index 0000000..36d4467

--- /dev/null
+++ b/Documentation/devicetree/bindings/usb/typec.txt

@@ -0,0 +1,46 @@
+Generic typec and power delivery properties
+-------------------------------------------

What node do these apply to? A type C connector node? The PD microcontroller?

My initial thinking is those are general type-c properties, which can be applied to
type-C connector or used by PD microcontroller directly (my example),  I want
to get inputs on how this can be handled properly, so do you think a separated
node(e.g. type-c connector) is required to describe all the capability of the type-c
port has, then a type-c related driver get the phandle of it?

quoted

I'm reluctant to accept just a random list of properties without a more complete
Type-C binding which I'd expect to have a connector node, OF graph ports to
connect to video outputs, connection to USB controller, and connection to the
PD controller.

As type-C with PD has many properties to complete the description for diff usage,
so this is just a first step to have the basic power related bindings.

We need something more complete, not something that just evolves. At
least the basic relationships between connectors, PD controller,
alternate modes, and USB controllers needs to be defined.

Andrzej started on defining USB connectors[1]. That's where we need to
start for Type-C bindings. Work together on this.

Rob

quoted

quoted

+Required properties:
+- port-type:    should be one of "source", "sink" or "dual".
+- default-role: preferred power role if drp, should be "sink" or "source".
+- src-pdos:     An array of u32 with each entry providing supported power
+                source data object(PDO), the detailed bit definitions of
+                PDO can be found in "Universal Serial Bus Power Delivery
+                Specification" chapter 6.4.1.2 Source_Capabilities Message,
+                the order of each entry(PDO) should follow the PD spec chapter
+                6.4.1. Required only for power source and power dual role with
+                power delivery support.
+- snk-pdos:     An array of u32 with each entry providing supported power
+                sink data object(PDO), the detailed bit definitions of PDO
+                can be found in "Universal Serial Bus Power Delivery
+                Specification" chapter 6.4.1.3 Sink Capabilities Message,
+                the order of each entry(PDO) should follow the PD spec chapter
+                6.4.1. Required only for power sink and power dual role with
+                power delivery support.

quoted

+- max-snk-mv:   The max voltage the sink can support in millivoltage, required
+                only for power sink and power dual role with power delivery
+                support.
+- max-snk-ma:   The max current the sink can support in milliampere, required
+                only for power sink and power dual role with power delivery
+                support.
+- op-snk-mw:    Sink required operating power in milliwatts, if source offered
+                power is less then it, Capability Mismatch is set, required
+                only for power sink and power dual role with power delivery
+                support.

Use the standard unit suffixes as defined in property-units.txt

Thanks, will update in next version.

Li Jun

quoted

quoted

+
+Example:
+
+ptn5110@50 {
+   compatible = "usb,tcpci";
+   reg = <0x50>;
+   interrupt-parent = <&gpio3>;
+   interrupts = <3 IRQ_TYPE_LEVEL_LOW>;
+   port-type = "dual";
+   default-role = "sink";
+   src-pdos = <0x380190c8>;
+   snk-pdos = <0x380190c8 0x3802d0c8>;
+   max-snk-mv = <9000>;
+   max-snk-ma = <1000>;
+   op-snk-mw = <9000>;
+};

[1] http://www.spinics.net/lists/devicetree/msg197601.html
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