Commit a381c6d6 authored by Amit Sunil Dhamne's avatar Amit Sunil Dhamne Committed by Greg Kroah-Hartman
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usb: typec: maxim_contaminant: re-enable cc toggle if cc is open and port is clean 



Presently in `max_contaminant_is_contaminant()` if there's no
contaminant detected previously, CC is open & stopped toggling and no
contaminant is currently present, TCPC.RC would be programmed to do DRP
toggling. However, it didn't actively look for a connection. This would
lead to Type-C not detect *any* new connections. Hence, in the above
situation, re-enable toggling & program TCPC to look for a new
connection.

Also, return early if TCPC was looking for connection as this indicates
TCPC has neither detected a potential connection nor a change in
contaminant state.

In addition, once dry detection is complete (port is dry), restart
toggling.

Fixes: 02b332a0 ("usb: typec: maxim_contaminant: Implement check_contaminant callback")
Cc: stable <stable@kernel.org>
Signed-off-by: default avatarAmit Sunil Dhamne <amitsd@google.com>
Reviewed-by: default avatarBadhri Jagan Sridharan <badhri@google.com>
Link: https://lore.kernel.org/r/20250815-fix-upstream-contaminant-v2-2-6c8d6c3adafb@google.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent cabb6c5f

drivers/usb/typec/tcpm/maxim_contaminant.c

+53 −0
Original line number Diff line number Diff line
@@ -329,6 +329,39 @@ static int max_contaminant_enable_dry_detection(struct max_tcpci_chip *chip) 
	return 0;

}



static int max_contaminant_enable_toggling(struct max_tcpci_chip *chip)

{

	struct regmap *regmap = chip->data.regmap;

	int ret;



	/* Disable dry detection if enabled. */

	ret = regmap_update_bits(regmap, TCPC_VENDOR_CC_CTRL2, CCLPMODESEL,

				 FIELD_PREP(CCLPMODESEL,

					    LOW_POWER_MODE_DISABLE));

	if (ret)

		return ret;



	ret = regmap_update_bits(regmap, TCPC_VENDOR_CC_CTRL1, CCCONNDRY, 0);

	if (ret)

		return ret;



	ret = max_tcpci_write8(chip, TCPC_ROLE_CTRL, TCPC_ROLE_CTRL_DRP |

			       FIELD_PREP(TCPC_ROLE_CTRL_CC1,

					  TCPC_ROLE_CTRL_CC_RD) |

			       FIELD_PREP(TCPC_ROLE_CTRL_CC2,

					  TCPC_ROLE_CTRL_CC_RD));

	if (ret)

		return ret;



	ret = regmap_update_bits(regmap, TCPC_TCPC_CTRL,

				 TCPC_TCPC_CTRL_EN_LK4CONN_ALRT,

				 TCPC_TCPC_CTRL_EN_LK4CONN_ALRT);

	if (ret)

		return ret;



	return max_tcpci_write8(chip, TCPC_COMMAND, TCPC_CMD_LOOK4CONNECTION);

}



bool max_contaminant_is_contaminant(struct max_tcpci_chip *chip, bool disconnect_while_debounce,

				    bool *cc_handled)

{
@@ -345,6 +378,12 @@ bool max_contaminant_is_contaminant(struct max_tcpci_chip *chip, bool disconnect 
	if (ret < 0)

		return false;



	if (cc_status & TCPC_CC_STATUS_TOGGLING) {

		if (chip->contaminant_state == DETECTED)

			return true;

		return false;

	}



	if (chip->contaminant_state == NOT_DETECTED || chip->contaminant_state == SINK) {

		if (!disconnect_while_debounce)

			msleep(100);
@@ -377,6 +416,12 @@ bool max_contaminant_is_contaminant(struct max_tcpci_chip *chip, bool disconnect 
				max_contaminant_enable_dry_detection(chip);

				return true;

			}



			ret = max_contaminant_enable_toggling(chip);

			if (ret)

				dev_err(chip->dev,

					"Failed to enable toggling, ret=%d",

					ret);

		}

	} else if (chip->contaminant_state == DETECTED) {

		if (!(cc_status & TCPC_CC_STATUS_TOGGLING)) {
@@ -384,6 +429,14 @@ bool max_contaminant_is_contaminant(struct max_tcpci_chip *chip, bool disconnect 
			if (chip->contaminant_state == DETECTED) {

				max_contaminant_enable_dry_detection(chip);

				return true;

			} else {

				ret = max_contaminant_enable_toggling(chip);

				if (ret) {

					dev_err(chip->dev,

						"Failed to enable toggling, ret=%d",

						ret);

					return true;

				}

			}

		}

	}