From: Amit Sunil Dhamne amitsd@google.com
[ Upstream commit a381c6d6f646226924809d0ad01a9465786da463 ]
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: 02b332a06397e ("usb: typec: maxim_contaminant: Implement check_contaminant callback") Cc: stable stable@kernel.org Signed-off-by: Amit Sunil Dhamne amitsd@google.com Reviewed-by: Badhri Jagan Sridharan badhri@google.com Link: https://lore.kernel.org/r/20250815-fix-upstream-contaminant-v2-2-6c8d6c3adaf... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/usb/typec/tcpm/maxim_contaminant.c | 48 ++++++++++++++++++++++ 1 file changed, 48 insertions(+)
diff --git a/drivers/usb/typec/tcpm/maxim_contaminant.c b/drivers/usb/typec/tcpm/maxim_contaminant.c index 60f90272fed3..279dfc84d178 100644 --- a/drivers/usb/typec/tcpm/maxim_contaminant.c +++ b/drivers/usb/typec/tcpm/maxim_contaminant.c @@ -322,6 +322,34 @@ 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_MASK, + ULTRA_LOW_POWER_MODE); + 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 | 0xA); + 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) { u8 cc_status, pwr_cntl; @@ -335,6 +363,12 @@ 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); @@ -367,6 +401,12 @@ 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); } return false; } else if (chip->contaminant_state == DETECTED) { @@ -375,6 +415,14 @@ 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; + } } } }