---
Changes since v10:
* Fall back to default state if enabling toggling fails when
* exiting CHECK_CONTAMINANT state
Changes since v9:
* Invoke tcpm_start_toggling before transitioning to TOGGLING from
* CHECK_CONTAMINANT.
Changes since v7:
* None. Skipped versions by mistake.
Changes since v6:
* folded the debounce logic into tcpm state machine and removed tcpm
* state export.
* Added a helper to determine whether the port is in toggling state.
* Excluded CHECK_CONTAMINANT from tcpm_log.
Changes since v5:
* Updated commit message. Removed change id.
Changes since v4:
* None
Changes since v3:
* None
Changes since V2:
* Offloaded tcpm from maintaining disconnect_while_debouncing logic
* to lower level maxim tcpc driver based on feedback.
---
drivers/usb/typec/tcpm/tcpm.c | 55 ++++++++++++++++++++++++++++++++++-
include/linux/usb/tcpm.h | 8 +++++
2 files changed, 62 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
index 904c7b4ce2f0..c624747f32df 100644
--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -36,6 +36,7 @@
#define FOREACH_STATE(S) \
S(INVALID_STATE), \
S(TOGGLING), \
+ S(CHECK_CONTAMINANT), \
S(SRC_UNATTACHED), \
S(SRC_ATTACH_WAIT), \
S(SRC_ATTACHED), \
@@ -249,6 +250,7 @@ enum frs_typec_current {
#define TCPM_RESET_EVENT BIT(2)
#define TCPM_FRS_EVENT BIT(3)
#define TCPM_SOURCING_VBUS BIT(4)
+#define TCPM_PORT_CLEAN BIT(5)
#define LOG_BUFFER_ENTRIES 1024
#define LOG_BUFFER_ENTRY_SIZE 128
@@ -483,6 +485,13 @@ struct tcpm_port {
* SNK_READY for non-pd link.
*/
bool slow_charger_loop;
+
+ /*
+ * When true indicates that the lower level drivers indicate potential presence
+ * of contaminant in the connector pins based on the tcpm state machine
+ * transitions.
+ */
+ bool potential_contaminant;
#ifdef CONFIG_DEBUG_FS
struct dentry *dentry;
struct mutex logbuffer_lock; /* log buffer access lock */
@@ -647,7 +656,7 @@ static void tcpm_log(struct tcpm_port *port, const char *fmt, ...)
/* Do not log while disconnected and unattached */
if (tcpm_port_is_disconnected(port) &&
(port->state == SRC_UNATTACHED || port->state == SNK_UNATTACHED ||
- port->state == TOGGLING))
+ port->state == TOGGLING || port->state == CHECK_CONTAMINANT))
return;
va_start(args, fmt);
@@ -3904,15 +3913,28 @@ static void run_state_machine(struct tcpm_port *port)
unsigned int msecs;
enum tcpm_state upcoming_state;
+ if (port->tcpc->check_contaminant && port->state != CHECK_CONTAMINANT)
+ port->potential_contaminant = ((port->enter_state == SRC_ATTACH_WAIT &&
+ port->state == SRC_UNATTACHED) ||
+ (port->enter_state == SNK_ATTACH_WAIT &&
+ port->state == SNK_UNATTACHED));
+
port->enter_state = port->state;
switch (port->state) {
case TOGGLING:
break;
+ case CHECK_CONTAMINANT:
+ port->tcpc->check_contaminant(port->tcpc);
+ break;
/* SRC states */
case SRC_UNATTACHED:
if (!port->non_pd_role_swap)
tcpm_swap_complete(port, -ENOTCONN);
tcpm_src_detach(port);
+ if (port->potential_contaminant) {
+ tcpm_set_state(port, CHECK_CONTAMINANT, 0);
+ break;
+ }
if (tcpm_start_toggling(port, tcpm_rp_cc(port))) {
tcpm_set_state(port, TOGGLING, 0);
break;
@@ -4150,6 +4172,10 @@ static void run_state_machine(struct tcpm_port *port)
tcpm_swap_complete(port, -ENOTCONN);
tcpm_pps_complete(port, -ENOTCONN);
tcpm_snk_detach(port);
+ if (port->potential_contaminant) {
+ tcpm_set_state(port, CHECK_CONTAMINANT, 0);
+ break;
+ }
if (tcpm_start_toggling(port, TYPEC_CC_RD)) {
tcpm_set_state(port, TOGGLING, 0);
break;
@@ -4926,6 +4952,9 @@ static void _tcpm_cc_change(struct tcpm_port *port, enum typec_cc_status cc1,
else if (tcpm_port_is_sink(port))
tcpm_set_state(port, SNK_ATTACH_WAIT, 0);
break;
+ case CHECK_CONTAMINANT:
+ /* Wait for Toggling to be resumed */
+ break;
case SRC_UNATTACHED:
case ACC_UNATTACHED:
if (tcpm_port_is_debug(port) || tcpm_port_is_audio(port) ||
@@ -5425,6 +5454,15 @@ static void tcpm_pd_event_handler(struct kthread_work *work)
port->vbus_source = true;
_tcpm_pd_vbus_on(port);
}
+ if (events & TCPM_PORT_CLEAN) {
+ tcpm_log(port, "port clean");
+ if (port->state == CHECK_CONTAMINANT) {
+ if (tcpm_start_toggling(port, tcpm_rp_cc(port)))
+ tcpm_set_state(port, TOGGLING, 0);
+ else
+ tcpm_set_state(port, tcpm_default_state(port), 0);
+ }
+ }
spin_lock(&port->pd_event_lock);
}
@@ -5477,6 +5515,21 @@ void tcpm_sourcing_vbus(struct tcpm_port *port)
}
EXPORT_SYMBOL_GPL(tcpm_sourcing_vbus);
+void tcpm_port_clean(struct tcpm_port *port)
+{
+ spin_lock(&port->pd_event_lock);
+ port->pd_events |= TCPM_PORT_CLEAN;
+ spin_unlock(&port->pd_event_lock);
+ kthread_queue_work(port->wq, &port->event_work);
+}
+EXPORT_SYMBOL_GPL(tcpm_port_clean);
+
+bool tcpm_port_is_toggling(struct tcpm_port *port)
+{
+ return port->port_type == TYPEC_PORT_DRP && port->state == TOGGLING;
+}
+EXPORT_SYMBOL_GPL(tcpm_port_is_toggling);
+
static void tcpm_enable_frs_work(struct kthread_work *work)
{
struct tcpm_port *port = container_of(work, struct tcpm_port, enable_frs);
diff --git a/include/linux/usb/tcpm.h b/include/linux/usb/tcpm.h
index bffc8d3e14ad..ab7ca872950b 100644
--- a/include/linux/usb/tcpm.h
+++ b/include/linux/usb/tcpm.h
@@ -114,6 +114,11 @@ enum tcpm_transmit_type {
* 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 tcpc_dev {
struct fwnode_handle *fwnode;
@@ -148,6 +153,7 @@ struct tcpc_dev {
bool pps_active, u32 requested_vbus_voltage);
bool (*is_vbus_vsafe0v)(struct tcpc_dev *dev);
void (*set_partner_usb_comm_capable)(struct tcpc_dev *dev, bool enable);
+ void (*check_contaminant)(struct tcpc_dev *dev);
};
struct tcpm_port;
@@ -165,5 +171,7 @@ void tcpm_pd_transmit_complete(struct tcpm_port *port,
enum tcpm_transmit_status status);
void tcpm_pd_hard_reset(struct tcpm_port *port);
void tcpm_tcpc_reset(struct tcpm_port *port);
+void tcpm_port_clean(struct tcpm_port *port);
+bool tcpm_port_is_toggling(struct tcpm_port *port);
#endif /* __LINUX_USB_TCPM_H */
base-commit: 6feb57c2fd7c787aecf2846a535248899e7b70fa
--
2.39.0.314.g84b9a713c41-goog
