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Date:   Tue, 21 Nov 2023 20:38:47 +0000
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Subject: [PATCH v1 1/2] usb: typec: tcpm: add tcpm_port_error_recovery symbol
From:   RD Babiera <rdbabiera@google.com>
To:     linux@roeck-us.net, heikki.krogerus@linux.intel.com,
        gregkh@linuxfoundation.org
Cc:     linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
        badhri@google.com, RD Babiera <rdbabiera@google.com>
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Add tcpm_port_error_recovery symbol and corresponding event that runs in
tcpm_pd_event handler to set the port to the ERROR_RECOVERY state. tcpci
drivers can use the symbol to reset the port when tcpc faults affect port
functionality.

Signed-off-by: RD Babiera <rdbabiera@google.com>
---
 drivers/usb/typec/tcpm/tcpm.c | 14 ++++++++++++++
 include/linux/usb/tcpm.h      |  1 +
 2 files changed, 15 insertions(+)

diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
index 058d5b853b57..2e553dc63619 100644
--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -251,6 +251,7 @@ enum frs_typec_current {
 #define TCPM_FRS_EVENT		BIT(3)
 #define TCPM_SOURCING_VBUS	BIT(4)
 #define TCPM_PORT_CLEAN		BIT(5)
+#define TCPM_PORT_ERROR		BIT(6)
 
 #define LOG_BUFFER_ENTRIES	1024
 #define LOG_BUFFER_ENTRY_SIZE	128
@@ -5477,6 +5478,10 @@ static void tcpm_pd_event_handler(struct kthread_work *work)
 					tcpm_set_state(port, tcpm_default_state(port), 0);
 			}
 		}
+		if (events & TCPM_PORT_ERROR) {
+			tcpm_log(port, "port triggering error recovery");
+			tcpm_set_state(port, ERROR_RECOVERY, 0);
+		}
 
 		spin_lock(&port->pd_event_lock);
 	}
@@ -5544,6 +5549,15 @@ bool tcpm_port_is_toggling(struct tcpm_port *port)
 }
 EXPORT_SYMBOL_GPL(tcpm_port_is_toggling);
 
+void tcpm_port_error_recovery(struct tcpm_port *port)
+{
+	spin_lock(&port->pd_event_lock);
+	port->pd_events |= TCPM_PORT_ERROR;
+	spin_unlock(&port->pd_event_lock);
+	kthread_queue_work(port->wq, &port->event_work);
+}
+EXPORT_SYMBOL_GPL(tcpm_port_error_recovery);
+
 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 ab7ca872950b..65fac5e1f317 100644
--- a/include/linux/usb/tcpm.h
+++ b/include/linux/usb/tcpm.h
@@ -173,5 +173,6 @@ 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);
+void tcpm_port_error_recovery(struct tcpm_port *port);
 
 #endif /* __LINUX_USB_TCPM_H */
-- 
2.43.0.rc1.413.gea7ed67945-goog