diff --git a/drivers/net/phy/dp83640.c b/drivers/net/phy/dp83640.c
index ac72a324fcd1..415c27310982 100644
--- a/drivers/net/phy/dp83640.c
+++ b/drivers/net/phy/dp83640.c
@@ -628,7 +628,7 @@ static void recalibrate(struct dp83640_clock *clock)
 	u16 cal_gpio, cfg0, evnt, ptp_trig, trigger, val;
 
 	trigger = CAL_TRIGGER;
-	cal_gpio = 1 + ptp_find_pin(clock->ptp_clock, PTP_PF_PHYSYNC, 0);
+	cal_gpio = 1 + ptp_find_pin_unlocked(clock->ptp_clock, PTP_PF_PHYSYNC, 0);
 	if (cal_gpio < 1) {
 		pr_err("PHY calibration pin not available - PHY is not calibrated.");
 		return;
diff --git a/drivers/ptp/ptp_chardev.c b/drivers/ptp/ptp_chardev.c
index 9d72ab593f13..93d574faf1fe 100644
--- a/drivers/ptp/ptp_chardev.c
+++ b/drivers/ptp/ptp_chardev.c
@@ -175,7 +175,10 @@ long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg)
 		}
 		req.type = PTP_CLK_REQ_EXTTS;
 		enable = req.extts.flags & PTP_ENABLE_FEATURE ? 1 : 0;
+		if (mutex_lock_interruptible(&ptp->pincfg_mux))
+			return -ERESTARTSYS;
 		err = ops->enable(ops, &req, enable);
+		mutex_unlock(&ptp->pincfg_mux);
 		break;
 
 	case PTP_PEROUT_REQUEST:
@@ -206,7 +209,10 @@ long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg)
 		}
 		req.type = PTP_CLK_REQ_PEROUT;
 		enable = req.perout.period.sec || req.perout.period.nsec;
+		if (mutex_lock_interruptible(&ptp->pincfg_mux))
+			return -ERESTARTSYS;
 		err = ops->enable(ops, &req, enable);
+		mutex_unlock(&ptp->pincfg_mux);
 		break;
 
 	case PTP_ENABLE_PPS:
@@ -217,7 +223,10 @@ long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg)
 			return -EPERM;
 		req.type = PTP_CLK_REQ_PPS;
 		enable = arg ? 1 : 0;
+		if (mutex_lock_interruptible(&ptp->pincfg_mux))
+			return -ERESTARTSYS;
 		err = ops->enable(ops, &req, enable);
+		mutex_unlock(&ptp->pincfg_mux);
 		break;
 
 	case PTP_SYS_OFFSET_PRECISE:
diff --git a/drivers/ptp/ptp_clock.c b/drivers/ptp/ptp_clock.c
index ac1f2bf9e888..acabbe72e55e 100644
--- a/drivers/ptp/ptp_clock.c
+++ b/drivers/ptp/ptp_clock.c
@@ -348,7 +348,6 @@ int ptp_find_pin(struct ptp_clock *ptp,
 	struct ptp_pin_desc *pin = NULL;
 	int i;
 
-	mutex_lock(&ptp->pincfg_mux);
 	for (i = 0; i < ptp->info->n_pins; i++) {
 		if (ptp->info->pin_config[i].func == func &&
 		    ptp->info->pin_config[i].chan == chan) {
@@ -356,12 +355,26 @@ int ptp_find_pin(struct ptp_clock *ptp,
 			break;
 		}
 	}
-	mutex_unlock(&ptp->pincfg_mux);
 
 	return pin ? i : -1;
 }
 EXPORT_SYMBOL(ptp_find_pin);
 
+int ptp_find_pin_unlocked(struct ptp_clock *ptp,
+			  enum ptp_pin_function func, unsigned int chan)
+{
+	int result;
+
+	mutex_lock(&ptp->pincfg_mux);
+
+	result = ptp_find_pin(ptp, func, chan);
+
+	mutex_unlock(&ptp->pincfg_mux);
+
+	return result;
+}
+EXPORT_SYMBOL(ptp_find_pin_unlocked);
+
 int ptp_schedule_worker(struct ptp_clock *ptp, unsigned long delay)
 {
 	return kthread_mod_delayed_work(ptp->kworker, &ptp->aux_work, delay);
diff --git a/include/linux/ptp_clock_kernel.h b/include/linux/ptp_clock_kernel.h
index c64a1ef87240..121a7eda4593 100644
--- a/include/linux/ptp_clock_kernel.h
+++ b/include/linux/ptp_clock_kernel.h
@@ -223,6 +223,12 @@ extern s32 scaled_ppm_to_ppb(long ppm);
 /**
  * ptp_find_pin() - obtain the pin index of a given auxiliary function
  *
+ * The caller must hold ptp_clock::pincfg_mux.  Drivers do not have
+ * access to that mutex as ptp_clock is an opaque type.  However, the
+ * core code acquires the mutex before invoking the driver's
+ * ptp_clock_info::enable() callback, and so drivers may call this
+ * function from that context.
+ *
  * @ptp:    The clock obtained from ptp_clock_register().
  * @func:   One of the ptp_pin_function enumerated values.
  * @chan:   The particular functional channel to find.
@@ -233,6 +239,19 @@ extern s32 scaled_ppm_to_ppb(long ppm);
 int ptp_find_pin(struct ptp_clock *ptp,
 		 enum ptp_pin_function func, unsigned int chan);
 
+/**
+ * ptp_find_pin_unlocked() - wrapper for ptp_find_pin()
+ *
+ * This function acquires the ptp_clock::pincfg_mux mutex before
+ * invoking ptp_find_pin().  Instead of using this function, drivers
+ * should most likely call ptp_find_pin() directly from their
+ * ptp_clock_info::enable() method.
+ *
+ */
+
+int ptp_find_pin_unlocked(struct ptp_clock *ptp,
+			  enum ptp_pin_function func, unsigned int chan);
+
 /**
  * ptp_schedule_worker() - schedule ptp auxiliary work
  *