gpio: make gpioc a child of gpiobus

With gpioc being a direct child of the GPIO controller, it can't
allocate interrupts properly. It currently allocates interrupts using
it's parent dev (gpioX). This causes problems since the call never goes
through gpiobus. Instead, make gpioc a child of gpiobus and allocate
interrupts using our own dev. Also don't misuse pin->flags, it's not
meant to store the flags from sys/gpio.h

Reported by:	Evgenii Ivanov <[email protected]>
Reviewed by:	mmel
Approved by:	imp (mentor)
Differential Revision:	https://reviews.freebsd.org/D51932

Author: VexedUXR

sys/dev/gpio/gpiobus.c

@@ -319,10 +319,6 @@ gpiobus_add_bus(device_t dev)
 	busdev = device_add_child(dev, "gpiobus", DEVICE_UNIT_ANY);
 	if (busdev == NULL)
 		return (NULL);
-	if (device_add_child(dev, "gpioc", DEVICE_UNIT_ANY) == NULL) {
-		device_delete_child(dev, busdev);
-		return (NULL);
-	}
 #ifdef FDT
 	ofw_gpiobus_register_provider(dev);
 #endif
@@ -371,6 +367,37 @@ gpiobus_init_softc(device_t dev)
 	return (0);
 }
 
+int
+gpiobus_add_gpioc(device_t dev)
+{
+	struct gpiobus_ivar *devi;
+	struct gpiobus_softc *sc;
+	device_t gpioc;
+	int err;
+
+	gpioc = BUS_ADD_CHILD(dev, 0, "gpioc", DEVICE_UNIT_ANY);
+	if (gpioc == NULL)
+		return (ENXIO);
+
+	sc = device_get_softc(dev);
+	devi = device_get_ivars(gpioc);
+
+	devi->npins = sc->sc_npins;
+	err = gpiobus_alloc_ivars(devi);
+	if (err != 0) {
+		device_delete_child(dev, gpioc);
+		return (err);
+	}
+
+	err = GPIO_GET_PIN_LIST(sc->sc_dev, devi->pins);
+	if (err != 0) {
+		device_delete_child(dev, gpioc);
+		gpiobus_free_ivars(devi);
+	}
+
+	return (err);
+}
+
 int
 gpiobus_alloc_ivars(struct gpiobus_ivar *devi)
 {
@@ -562,6 +589,10 @@ gpiobus_attach(device_t dev)
 	if (err != 0)
 		return (err);
 
+	err = gpiobus_add_gpioc(dev);
+	if (err != 0)
+		return (err);
+
 	/*
 	 * Get parent's pins and mark them as unmapped
 	 */

sys/dev/gpio/gpiobus_internal.h

@@ -44,6 +44,7 @@ int gpiobus_acquire_pin(device_t, uint32_t);
 void gpiobus_release_pin(device_t, uint32_t);
 int gpiobus_child_location(device_t, device_t, struct sbuf *);
 device_t gpiobus_add_child_common(device_t, u_int, const char *, int, size_t);
+int gpiobus_add_gpioc(device_t);
 
 extern driver_t gpiobus_driver;
 #endif