usb: chipidea: Handle extcon events properly

We're currently emulating the vbus and id interrupts in the OTGSC
read API, but we also need to make sure that if we're handling
the events with extcon that we don't enable the interrupts for
those events in the hardware. Therefore, properly emulate this
register if we're using extcon, but don't enable the interrupts.
This allows me to get my cable connect/disconnect working
properly without getting spurious interrupts on my device that
uses an extcon for these two events.

Acked-by: Peter Chen <peter.chen@nxp.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Ivan T. Ivanov" <iivanov.xz@gmail.com>
Fixes: 3ecb3e09b042 ("usb: chipidea: Use extcon framework for VBUS and ID detect")
Signed-off-by: Stephen Boyd <stephen.boyd@linaro.org>
Signed-off-by: Peter Chen <peter.chen@nxp.com>

drivers/usb/chipidea/otg.c

@@ -44,12 +44,15 @@ u32 hw_read_otgsc(struct ci_hdrc *ci, u32 mask)
 		else
 			val &= ~OTGSC_BSVIS;
 
-		cable->changed = false;
-
 		if (cable->state)
 			val |= OTGSC_BSV;
 		else
 			val &= ~OTGSC_BSV;
+
+		if (cable->enabled)
+			val |= OTGSC_BSVIE;
+		else
+			val &= ~OTGSC_BSVIE;
 	}
 
 	cable = &ci->platdata->id_extcon;
@@ -59,15 +62,18 @@ u32 hw_read_otgsc(struct ci_hdrc *ci, u32 mask)
 		else
 			val &= ~OTGSC_IDIS;
 
-		cable->changed = false;
-
 		if (cable->state)
 			val |= OTGSC_ID;
 		else
 			val &= ~OTGSC_ID;
+
+		if (cable->enabled)
+			val |= OTGSC_IDIE;
+		else
+			val &= ~OTGSC_IDIE;
 	}
 
-	return val;
+	return val & mask;
 }
 
 /**
@@ -77,6 +83,36 @@ u32 hw_read_otgsc(struct ci_hdrc *ci, u32 mask)
  */
 void hw_write_otgsc(struct ci_hdrc *ci, u32 mask, u32 data)
 {
+	struct ci_hdrc_cable *cable;
+
+	cable = &ci->platdata->vbus_extcon;
+	if (!IS_ERR(cable->edev)) {
+		if (data & mask & OTGSC_BSVIS)
+			cable->changed = false;
+
+		/* Don't enable vbus interrupt if using external notifier */
+		if (data & mask & OTGSC_BSVIE) {
+			cable->enabled = true;
+			data &= ~OTGSC_BSVIE;
+		} else if (mask & OTGSC_BSVIE) {
+			cable->enabled = false;
+		}
+	}
+
+	cable = &ci->platdata->id_extcon;
+	if (!IS_ERR(cable->edev)) {
+		if (data & mask & OTGSC_IDIS)
+			cable->changed = false;
+
+		/* Don't enable id interrupt if using external notifier */
+		if (data & mask & OTGSC_IDIE) {
+			cable->enabled = true;
+			data &= ~OTGSC_IDIE;
+		} else if (mask & OTGSC_IDIE) {
+			cable->enabled = false;
+		}
+	}
+
 	hw_write(ci, OP_OTGSC, mask | OTGSC_INT_STATUS_BITS, data);
 }
 

include/linux/usb/chipidea.h

@@ -14,6 +14,7 @@ struct ci_hdrc;
  * struct ci_hdrc_cable - structure for external connector cable state tracking
  * @state: current state of the line
  * @changed: set to true when extcon event happen
+ * @enabled: set to true if we've enabled the vbus or id interrupt
  * @edev: device which generate events
  * @ci: driver state of the chipidea device
  * @nb: hold event notification callback
@@ -22,6 +23,7 @@ struct ci_hdrc;
 struct ci_hdrc_cable {
 	bool				state;
 	bool				changed;
+	bool				enabled;
 	struct extcon_dev		*edev;
 	struct ci_hdrc			*ci;
 	struct notifier_block		nb;