Handle usb interrupt flags in driver (#106)

Set interrupt enable flags in USB driver. The flags were already being cleared in the USB driver.
Update USB examples to remove interrupt flag set/check as it is no longer necessary.

boards/pico/examples/pico_usb_serial_interrupt.rs

@@ -84,20 +84,6 @@ fn main() -> ! {
         USB_DEVICE = Some(usb_dev);
     }
 
-    // The USB driver doesn't enable key interrupts yet, so manually do that here
-    unsafe {
-        let p = pac::Peripherals::steal();
-        // Enable interrupts for when a buffer is done, when the bus is reset,
-        // and when a setup packet is received
-        p.USBCTRL_REGS.inte.modify(|_, w| {
-            w.buff_status()
-                .set_bit()
-                .bus_reset()
-                .set_bit()
-                .setup_req()
-                .set_bit()
-        });
-    }
     // Enable the USB interrupt
     unsafe {
         pac::NVIC::unmask(hal::pac::Interrupt::USBCTRL_IRQ);
@@ -158,21 +144,4 @@ unsafe fn USBCTRL_IRQ() {
             }
         });
     }
-
-    // Clear pending interrupt flags here.
-    // We could also move some of our code into these states to handle events
-    let p = pac::Peripherals::steal();
-    let status = &p.USBCTRL_REGS.sie_status;
-    if status.read().ack_rec().bit_is_set() {
-        status.modify(|_r, w| w.ack_rec().set_bit());
-    }
-    if status.read().setup_rec().bit_is_set() {
-        status.modify(|_r, w| w.setup_rec().set_bit());
-    }
-    if status.read().trans_complete().bit_is_set() {
-        status.modify(|_r, w| w.trans_complete().set_bit());
-    }
-    if status.read().bus_reset().bit_is_set() {
-        status.modify(|_r, w| w.bus_reset().set_bit());
-    }
 }

boards/pico/examples/pico_usb_twitchy_mouse.rs

@@ -77,19 +77,6 @@ fn main() -> ! {
         USB_DEVICE = Some(usb_dev);
     }
 
-    unsafe {
-        let p = pac::Peripherals::steal();
-        // Enable interrupts for when a buffer is done, when the bus is reset,
-        // and when a setup packet is received
-        p.USBCTRL_REGS.inte.modify(|_, w| {
-            w.buff_status()
-                .set_bit()
-                .bus_reset()
-                .set_bit()
-                .setup_req()
-                .set_bit()
-        });
-    }
     unsafe {
         pac::NVIC::unmask(hal::pac::Interrupt::USBCTRL_IRQ);
     };
@@ -133,20 +120,4 @@ unsafe fn USBCTRL_IRQ() {
     let usb_dev = USB_DEVICE.as_mut().unwrap();
     let usb_hid = USB_HID.as_mut().unwrap();
     usb_dev.poll(&mut [usb_hid]);
-
-    // Clear pending interrupt flags
-    let p = pac::Peripherals::steal();
-    let status = &p.USBCTRL_REGS.sie_status;
-    if status.read().ack_rec().bit_is_set() {
-        status.modify(|_r, w| w.ack_rec().set_bit());
-    }
-    if status.read().setup_rec().bit_is_set() {
-        status.modify(|_r, w| w.setup_rec().set_bit());
-    }
-    if status.read().trans_complete().bit_is_set() {
-        status.modify(|_r, w| w.trans_complete().set_bit());
-    }
-    if status.read().bus_reset().bit_is_set() {
-        status.modify(|_r, w| w.bus_reset().set_bit());
-    }
 }

rp2040-hal/src/usb.rs

@@ -407,6 +407,18 @@ impl UsbBusTrait for UsbBus {
             // at this stage ep's are expected to be in their reset state
             // TODO: is it worth having a debug_assert for that here?
 
+            // Enable interrupt generation when a buffer is done, when the bus is reset,
+            // and when a setup packet is received
+            // this should be sufficient for device mode, will need more for host.
+            inner.ctrl_reg.inte.modify(|_, w| {
+                w.buff_status()
+                    .set_bit()
+                    .bus_reset()
+                    .set_bit()
+                    .setup_req()
+                    .set_bit()
+            });
+
             // enable pull up to let the host know we exist.
             inner
                 .ctrl_reg