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Date:   Tue, 30 Aug 2022 17:15:54 -0700
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Message-ID: <20220831001555.285081-2-badhri@google.com>
Subject: [PATCH v2 2/3] usb: typec: tcpci: Add callback for evaluating
 contaminant presence
From:   Badhri Jagan Sridharan <badhri@google.com>
To:     Guenter Roeck <linux@roeck-us.net>,
        Heikki Krogerus <heikki.krogerus@linux.intel.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc:     linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
        Kyle Tso <kyletso@google.com>,
        Badhri Jagan Sridharan <badhri@google.com>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

This change adds callback to evaluate presence of contaminant in
the TCPCI layer.

Signed-off-by: Badhri Jagan Sridharan <badhri@google.com>
---
 drivers/usb/typec/tcpm/tcpci.c | 9 +++++++++
 include/linux/usb/tcpci.h      | 7 +++++++
 2 files changed, 16 insertions(+)

diff --git a/drivers/usb/typec/tcpm/tcpci.c b/drivers/usb/typec/tcpm/tcpci.c
index 50674ecf430d..53f6fad61781 100644
--- a/drivers/usb/typec/tcpm/tcpci.c
+++ b/drivers/usb/typec/tcpm/tcpci.c
@@ -403,6 +403,14 @@ static void tcpci_frs_sourcing_vbus(struct tcpc_dev *dev)
 		tcpci->data->frs_sourcing_vbus(tcpci, tcpci->data);
 }
 
+static void tcpci_check_contaminant(struct tcpc_dev *dev, bool disconnect_while_debouncing)
+{
+	struct tcpci *tcpci = tcpc_to_tcpci(dev);
+
+	if (tcpci->data->check_contaminant)
+		tcpci->data->check_contaminant(tcpci, tcpci->data, disconnect_while_debouncing);
+}
+
 static int tcpci_set_bist_data(struct tcpc_dev *tcpc, bool enable)
 {
 	struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
@@ -777,6 +785,7 @@ struct tcpci *tcpci_register_port(struct device *dev, struct tcpci_data *data)
 	tcpci->tcpc.enable_frs = tcpci_enable_frs;
 	tcpci->tcpc.frs_sourcing_vbus = tcpci_frs_sourcing_vbus;
 	tcpci->tcpc.set_partner_usb_comm_capable = tcpci_set_partner_usb_comm_capable;
+	tcpci->tcpc.check_contaminant = tcpci_check_contaminant;
 
 	if (tcpci->data->auto_discharge_disconnect) {
 		tcpci->tcpc.enable_auto_vbus_discharge = tcpci_enable_auto_vbus_discharge;
diff --git a/include/linux/usb/tcpci.h b/include/linux/usb/tcpci.h
index 17657451c762..250b34ccbf9c 100644
--- a/include/linux/usb/tcpci.h
+++ b/include/linux/usb/tcpci.h
@@ -188,6 +188,11 @@ struct tcpci;
  *		Optional; The USB Communications Capable bit indicates if port
  *		partner is capable of communication over the USB data lines
  *		(e.g. D+/- or SS Tx/Rx). Called to notify the status of the bit.
+ * @check_contaminant:
+ *		Optional;The callback is called when CC pins report open status
+ *		at the end of the deboumce period or when the port is still
+ *		toggling. Chip level drivers are expected to check for contaminant
+ *		and call tcpm_clean_port when the port is clean.
  */
 struct tcpci_data {
 	struct regmap *regmap;
@@ -204,6 +209,8 @@ struct tcpci_data {
 	void (*frs_sourcing_vbus)(struct tcpci *tcpci, struct tcpci_data *data);
 	void (*set_partner_usb_comm_capable)(struct tcpci *tcpci, struct tcpci_data *data,
 					     bool capable);
+	void (*check_contaminant)(struct tcpci *tcpci, struct tcpci_data *data,
+				  bool disconnect_while_debouncing);
 };
 
 struct tcpci *tcpci_register_port(struct device *dev, struct tcpci_data *data);
-- 
2.37.2.672.g94769d06f0-goog