[PATCH v3 2/3] usb: typec: tcpci: Add callback for evaluating contaminant presence

From: Badhri Jagan Sridharan
Date: Sun Dec 04 2022 - 03:49:00 EST


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

Signed-off-by: Badhri Jagan Sridharan <badhri@xxxxxxxxxx>
---
Changes since v2:
* Added tcpci_is_potential_contaminant to offload
* disconnect_while_debounce logic
---
drivers/usb/typec/tcpm/tcpci.c | 20 ++++++++++++++++++++
include/linux/usb/tcpci.h | 13 +++++++++++++
2 files changed, 33 insertions(+)

diff --git a/drivers/usb/typec/tcpm/tcpci.c b/drivers/usb/typec/tcpm/tcpci.c
index fe781a38dc82..2aadf785970f 100644
--- a/drivers/usb/typec/tcpm/tcpci.c
+++ b/drivers/usb/typec/tcpm/tcpci.c
@@ -403,6 +403,24 @@ static void tcpci_frs_sourcing_vbus(struct tcpc_dev *dev)
tcpci->data->frs_sourcing_vbus(tcpci, tcpci->data);
}

+static bool tcpci_is_potential_contaminant(struct tcpc_dev *dev, enum tcpm_state current_state)
+{
+ struct tcpci *tcpci = tcpc_to_tcpci(dev);
+
+ if (tcpci->data->is_potential_contaminant)
+ return tcpci->data->is_potential_contaminant(tcpci, tcpci->data, current_state);
+
+ return false;
+}
+
+static void tcpci_check_contaminant(struct tcpc_dev *dev)
+{
+ struct tcpci *tcpci = tcpc_to_tcpci(dev);
+
+ if (tcpci->data->check_contaminant)
+ tcpci->data->check_contaminant(tcpci, tcpci->data);
+}
+
static int tcpci_set_bist_data(struct tcpc_dev *tcpc, bool enable)
{
struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
@@ -777,6 +795,8 @@ 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.is_potential_contaminant = tcpci_is_potential_contaminant;
+ 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..548e85fdc7fa 100644
--- a/include/linux/usb/tcpci.h
+++ b/include/linux/usb/tcpci.h
@@ -188,6 +188,16 @@ 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 invoked when chiplevel drivers indicated
+ * that the USB port needs to be checked for contaminant presence.
+ * Chip level drivers are expected to check for contaminant and call
+ * tcpm_clean_port when the port is clean to put the port back into
+ * toggling state.
+ * @is_potential_contaminant:
+ * Optional; TCPM invokes the callback for every TCPM state machine
+ * transition. Chiplevel drivers can monitor the state machine
+ * transitions to flag for potential contaminant presence.
*/
struct tcpci_data {
struct regmap *regmap;
@@ -204,6 +214,9 @@ 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 (*is_potential_contaminant)(struct tcpci *tcpci, struct tcpci_data *data,
+ enum tcpm_state current_state);
};

struct tcpci *tcpci_register_port(struct device *dev, struct tcpci_data *data);
--
2.39.0.rc0.267.gcb52ba06e7-goog