Add new time property for battery charger type detection

This patchset adds a new time DT property to handle time taken by battery charger type detection completion.

Note that BC detection is based on
"Battery Charging Specification Revision 1.2".

This patchset depends on the patch series:
- https://lore.kernel.org/all/[email protected]/

Amit Sunil Dhamne (3):
dt-bindings: connector: Add time property for Sink BC12 detection
completion
dt-bindings: usb: maxim,max33359.yaml: add usage of sink bc12 time
property
usb: typec: tcpm: Add support for sink-bc12-completion-time-ms DT
property

 .../bindings/connector/usb-connector.yaml        | 11 +++++++++++
 .../devicetree/bindings/usb/maxim,max33359.yaml  |  1 +
 drivers/usb/typec/tcpm/tcpm.c                    | 16 +++++++++++++++-
 3 files changed, 27 insertions(+), 1 deletion(-)

base-commit: 0fc810ae3ae110f9e2fcccce80fc8c8d62f97907
prerequisite-patch-id: c08696694dabcbb86b458a935a9cbbcbabb75672
prerequisite-patch-id: 634924883df820956acb33941b659e8c9ef85d1e

2.47.0.199.ga7371fff76-goog

This commit adds a new time property for Battery charger (BC1.2) type detection completion process (based on BCv1.2 detection spec) when typec port connects in a potential sink role. BC1.2 detection is used by some Type C port controllers implementations (such as "maxim,max33359") to detect the type of charger port.

---
 .../devicetree/bindings/connector/usb-connector.yaml  | 11 +++++++++++
 1 file changed, 11 insertions(+)

index 21a0c58c65cd..67700440e23b 100644
@@ -283,6 +283,16 @@ properties:
     maximum: 200
     default: 200
 
+  sink-bc12-completion-time-ms:
+    description: Represents the max time in ms that a port in sink role takes
+      to complete Battery Charger (BC1.2) Detection. BC1.2 detection is a
+      hardware mechanism, which in some TCPC implementations, can run in
+      parallel once the Type-C connection state machine reaches the "potential
+      connect as sink" state. In TCPCs where this causes delays to respond to
+      the incoming PD messages, sink-bc12-completion-time-ms is used to delay
+      PD negotiation till BC1.2 detection completes.
+    default: 0
+
 dependencies:
   sink-vdos-v1: [ sink-vdos ]
   sink-vdos: [ sink-vdos-v1 ]

@@ -426,6 +436,7 @@ examples:
             sink-wait-cap-time-ms = <465>;
             ps-source-off-time-ms = <835>;
             cc-debounce-time-ms = <101>;
+            sink-bc12-completion-time-ms = <500>;
         };
     };
 

2.47.0.199.ga7371fff76-goog

Add usage of "sink-bc12-completion-time-ms" connector property to max33359 controller for delaying PD negotiation till BC1.2 detection completes. This overcomes the occasional delays observed while receiving PD messages where BC1.2 detection runs in parallel.

---
 Documentation/devicetree/bindings/usb/maxim,max33359.yaml | 1 +
 1 file changed, 1 insertion(+)

index 276bf7554215..20b62228371b 100644
@@ -69,6 +69,7 @@ examples:
                                        PDO_FIXED_DATA_SWAP |
                                        PDO_FIXED_DUAL_ROLE)
                                        PDO_FIXED(9000, 2000, 0)>;
+                sink-bc12-completion-time-ms = <500>;
             };
         };
     };

2.47.0.199.ga7371fff76-goog

My bot found errors running 'make dt_binding_check' on your patch:

yamllint warnings/errors:

dtschema/dtc warnings/errors:
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/usb/maxim,max33359.example.dtb: maxtcpc@25: connector: Unevaluated properties are not allowed ('sink-bc12-completion-time-ms' was unexpected)
from schema $id: http://devicetree.org/schemas/usb/maxim,max33359.yaml#
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/usb/maxim,max33359.example.dtb: connector: Unevaluated properties are not allowed ('sink-bc12-completion-time-ms' was unexpected)
from schema $id: http://devicetree.org/schemas/connector/usb-connector.yaml#

doc reference errors (make refcheckdocs):

See https://patchwork.ozlabs.org/project/devicetree-bindings/patch/[email protected]

The base for the series is generally the latest rc1. A different dependency should be noted in *this* patch.

If you already ran 'make dt_binding_check' and didn't see the above error(s), then make sure 'yamllint' is installed and dt-schema is up to date:

pip3 install dtschema --upgrade

Please check and re-submit after running the above command yourself. Note that DT_SCHEMA_FILES can be set to your schema file to speed up checking your schema. However, it must be unset to test all examples with your schema.

There is no such property. You cannot add it. You did not even test this patch before sending :/

Your Reviewed-by tag is pretty wrong. I don't believe any review happened here. If it did, it was pretty useless.

Best regards,
Krzysztof

Sorry, now I see that's the patch 2, not 1. Somehow I thought you started with it and I got confused.

Best regards,
Krzysztof

The question is why patch 2 generated the error even if it had patch 1 in front of it?

With best wishes
Dmitry

I suspect patch #1 did not apply, because it depends on USB next tree.

Best regards,
Krzysztof

Hi Krzysztof,

Thanks for the review! That's right, as indicated in the cover, this patch series is dependent on a patch series
(https://lore.kernel.org/all/[email protected]/)
that's in the pipeline.

Regards,

Amit

Add support for parsing DT time property "sink-bc12-completion-time-ms". This timer is used to relax the PD state machine during Sink attach to allow completion of Battery Charging (BC1.2) charger type detection in TCPC before PD negotiations. BC1.2 detection is a hardware mechanism to detect charger port type that is run by some conrollers (such as "maxim,max33359") in parallel to Type-C connection state machines. This is to ensure that BC1.2 completes before PD is enabled as running BC1.2 in parallel with PD negotiation results in delays violating timer constraints in PD spec.

This is an optional timer and will not add any delay unless explicitly set.

---
 drivers/usb/typec/tcpm/tcpm.c | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

index b3d5d1d48937..8b325b93b5a9 100644
@@ -319,6 +319,7 @@ struct pd_timings {
 	u32 sink_wait_cap_time;
 	u32 ps_src_off_time;
 	u32 cc_debounce_time;
+	u32 snk_bc12_cmpletion_time;
 };
 
 struct tcpm_port {

@@ -4978,7 +4979,16 @@ static void run_state_machine(struct tcpm_port *port)
 		if (ret < 0)
 			tcpm_set_state(port, SNK_UNATTACHED, 0);
 		else
-			tcpm_set_state(port, SNK_STARTUP, 0);
+			/*
+			 * For Type C port controllers that use Battery Charging
+			 * Detection (based on BCv1.2 spec) to detect USB
+			 * charger type, add a delay of "snk_bc12_cmpletion_time"
+			 * before transitioning to SNK_STARTUP to allow BC1.2
+			 * detection to complete before PD is eventually enabled
+			 * in later states.
+			 */
+			tcpm_set_state(port, SNK_STARTUP,
+				       port->timings.snk_bc12_cmpletion_time);
 		break;
 	case SNK_STARTUP:
 		opmode =  tcpm_get_pwr_opmode(port->polarity ?

@@ -7090,6 +7100,10 @@ static void tcpm_fw_get_timings(struct tcpm_port *port, struct fwnode_handle *fw
 		port->timings.cc_debounce_time = val;
 	else
 		port->timings.cc_debounce_time = PD_T_CC_DEBOUNCE;
+
+	ret = fwnode_property_read_u32(fwnode, "sink-bc12-completion-time-ms", &val);
+	if (!ret)
+		port->timings.snk_bc12_cmpletion_time = val;
 }
 
 static int tcpm_fw_get_caps(struct tcpm_port *port, struct fwnode_handle *fwnode)

2.47.0.199.ga7371fff76-goog