Commit 237d4e0f authored by Amit Sunil Dhamne's avatar Amit Sunil Dhamne Committed by Greg Kroah-Hartman
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usb: typec: tcpm: Add support for sink-bc12-completion-time-ms DT property 



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: default avatarAmit Sunil Dhamne <amitsd@google.com>
Reviewed-by: default avatarBadhri Jagan Sridharan <badhri@google.com>
Reviewed-by: default avatarHeikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20241103034402.2460252-4-amitsd@google.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 3b9d67e7

drivers/usb/typec/tcpm/tcpm.c

+15 −1
Original line number Diff line number Diff line
@@ -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 {
@@ -4979,7 +4980,16 @@ 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 ?
@@ -7095,6 +7105,10 @@ 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)