Add new time property for battery charger type detection

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.

Signed-off-by Amit Sunil Dhamne <[email protected]>

Reviewed-by Badhri Jagan Sridharan <[email protected]>

Reviewed-by Krzysztof Kozlowski <[email protected]>

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

Quoted 5 lines · Amit Sunil Dhamne

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.

Quoted 7 lines

Signed-off-by Amit Sunil Dhamne <[email protected]>

Reviewed-by Badhri Jagan Sridharan <[email protected]>

Reviewed-by Krzysztof Kozlowski <[email protected]>

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

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#

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 controllers (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.

Signed-off-by Amit Sunil Dhamne <[email protected]>

Reviewed-by Badhri Jagan Sridharan <[email protected]>

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

drivers/usb/typec/tcpm/tcpm.c +11 -1

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 ?

Hi Heikki,

Quoted 54 lines · Amit Sunil Dhamne

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 controllers (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.

Signed-off-by Amit Sunil Dhamne <[email protected]>

Reviewed-by Badhri Jagan Sridharan <[email protected]>

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

drivers/usb/typec/tcpm/tcpm.c +13 -1

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);

drivers/usb/typec/tcpm/tcpm.c static void tcpm_fw_get_timings(struct tcpm_port *port, struct fwnode_handle *fw · line 7109

Quoted 4 lines

drivers/usb/typec/tcpm/tcpm.c +2 -0

+	if (!ret)
+		port->timings.snk_bc12_cmpletion_time = val;
  }
  static int tcpm_fw_get_caps(struct tcpm_port *port, struct fwnode_handle *fwnode)

I wanted to gently follow up with you on this patchset if this looks okay to you?