Commit 4288debe authored by Badhri Jagan Sridharan's avatar Badhri Jagan Sridharan Committed by Greg Kroah-Hartman
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usb: typec: tcpci: Fix up sink disconnect thresholds for PD 



"Table 4-3 VBUS Sink Characteristics" of "Type-C Cable and Connector
Specification" defines the disconnect voltage thresholds of various
configurations. This change fixes the disconnect threshold voltage
calculation based on vSinkPD_min and vSinkDisconnectPD as defined
by the table.

Fixes: e1a97bf8 ("usb: typec: tcpci: Implement Auto discharge disconnect callbacks")
Cc: stable <stable@vger.kernel.org>
Acked-by: default avatarHeikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: default avatarBadhri Jagan Sridharan <badhri@google.com>
Link: https://lore.kernel.org/r/20210615174323.1160132-1-badhri@google.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 73f3d945

drivers/usb/typec/tcpm/tcpci.c

+12 −6
Original line number Diff line number Diff line
@@ -21,8 +21,12 @@ 
#define	PD_RETRY_COUNT_DEFAULT			3

#define	PD_RETRY_COUNT_3_0_OR_HIGHER		2

#define	AUTO_DISCHARGE_DEFAULT_THRESHOLD_MV	3500

#define	AUTO_DISCHARGE_PD_HEADROOM_MV		850

#define	AUTO_DISCHARGE_PPS_HEADROOM_MV		1250

#define	VSINKPD_MIN_IR_DROP_MV			750

#define	VSRC_NEW_MIN_PERCENT			95

#define	VSRC_VALID_MIN_MV			500

#define	VPPS_NEW_MIN_PERCENT			95

#define	VPPS_VALID_MIN_MV			100

#define	VSINKDISCONNECT_PD_MIN_PERCENT		90



#define tcpc_presenting_rd(reg, cc) \

	(!(TCPC_ROLE_CTRL_DRP & (reg)) && \
@@ -351,11 +355,13 @@ static int tcpci_set_auto_vbus_discharge_threshold(struct tcpc_dev *dev, enum ty 
		threshold = AUTO_DISCHARGE_DEFAULT_THRESHOLD_MV;

	} else if (mode == TYPEC_PWR_MODE_PD) {

		if (pps_active)

			threshold = (95 * requested_vbus_voltage_mv / 100) -

				AUTO_DISCHARGE_PD_HEADROOM_MV;

			threshold = ((VPPS_NEW_MIN_PERCENT * requested_vbus_voltage_mv / 100) -

				     VSINKPD_MIN_IR_DROP_MV - VPPS_VALID_MIN_MV) *

				     VSINKDISCONNECT_PD_MIN_PERCENT / 100;

		else

			threshold = (95 * requested_vbus_voltage_mv / 100) -

				AUTO_DISCHARGE_PPS_HEADROOM_MV;

			threshold = ((VSRC_NEW_MIN_PERCENT * requested_vbus_voltage_mv / 100) -

				     VSINKPD_MIN_IR_DROP_MV - VSRC_VALID_MIN_MV) *

				     VSINKDISCONNECT_PD_MIN_PERCENT / 100;

	} else {

		/* 3.5V for non-pd sink */

		threshold = AUTO_DISCHARGE_DEFAULT_THRESHOLD_MV;