Added workaround for "unloading" IN endpoints after unstalling. Disable and then reenable when USBPhyHw::endpoint_unhalt() is called.

Author: AGlass0fMilk

usb/device/targets/TARGET_NORDIC/TARGET_MCU_NRF52840/USBPhy_Nordic.cpp

@@ -21,6 +21,27 @@
 
 #include "nrf_clock.h"
 
+/*
+ * TODO list for nRF52840 USBD driver
+ *
+ * 1.) Properly enable/disable start-of-frame interrupt.
+ *
+ * Description: Currently, start-of-frame interrupts are masked by a flag at this layer
+ * but still cause the processor to be interrupted for no purpose.
+ *
+ * The Nordic driver requires you to call nrf_drv_start(bool)
+ * with a boolean flag indicating whether it should enable start-of-frame
+ * interrupts or not. From the datasheet it seems to be possible to
+ * enable/disable SoF interrupts on the fly, but the fact that they
+ * force you to make the SoF decision during "start" makes me suspicious
+ * the underlying driver may manage/use the SoF flag in other ways.
+ *
+ * Next steps: Investigate how the SoF flag is used during "nrf_drv_start" and
+ * determine if enabling/disabling this interrupt would cause internal problems
+ * with the Nordic USBD driver
+ *
+ *
+ */
 #define MAX_PACKET_SIZE_SETUP NRF_DRV_USBD_EPSIZE
 #define MAX_PACKET_NON_ISO    NRF_DRV_USBD_EPSIZE
 #define MAX_PACKET_ISO        NRF_DRV_USBD_ISOSIZE
@@ -46,10 +67,19 @@ void USBD_HAL_IRQHandler(void);
 static USBPhyHw *instance = 0;
 
 static volatile bool virtual_status_xfer_event;
+static volatile bool irq_already_pending;
 
 static void usbd_event_handler(nrf_drv_usbd_evt_t const * const p_event);
 static void power_usb_event_handler(nrf_drv_power_usb_evt_t event);
 
+#if USBD_DEBUG
+
+// Static array of saved events to track what happens
+static nrf_drv_usbd_evt_t debug_events[32];
+static uint8_t debug_evt_index = 0;
+
+#endif
+
 USBPhy *get_usb_phy() {
 	static USBPhyHw usbphy;
 	return &usbphy;
@@ -97,15 +127,22 @@ void USBPhyHw::init(USBPhyEvents *events) {
 	instance = this;
 
 	virtual_status_xfer_event = false;
+	irq_already_pending = false;
 
 	/*
-	 * Configure ISOIN endpoint to respond with ZLP when
+	 * TODO - Configure ISOIN endpoint to respond with ZLP when
 	 * no data is ready to be sent
+	 *
+	 * This is a feature available in the Nordic SDK15.2
+	 * For now we just configure the appropriate register on initialization
 	 */
 	NRF_USBD->ISOINCONFIG |= 0x01; // set RESPONSE to 1 (respond with ZLP)
 
 	// Enable IRQ
+	//NVIC_SetVector(USBD_IRQn, (uint32_t)USBD_IRQHandler);
 	NVIC_SetVector(USBD_IRQn, (uint32_t)USBD_HAL_IRQHandler);
+	//NVIC_SetPriority(USBD_IRQn, 7);
+	//NVIC_EnableIRQ(USBD_IRQn); // This is handled by the Nordic driver
 }
 
 void USBPhyHw::deinit() {
@@ -177,7 +214,6 @@ void USBPhyHw::sof_enable() {
 	// TODO - Enable SOF interrupt
 	// Can this safely be done if
 	// nrf_drv_usbd_start is called with SoF enabled?
-	// For now just mask the interrupt with a boolean flag
 	sof_enabled = true;
 }
 
@@ -268,6 +304,8 @@ void USBPhyHw::ep0_read(uint8_t *data, uint32_t size) {
 
 			virtual_status_xfer_event = true;
 
+			irq_already_pending = NVIC_GetPendingIRQ(USBD_IRQn);
+
 			// Trigger an interrupt to process the virtual status event
 			NVIC_SetPendingIRQ(USBD_IRQn);
 
@@ -311,6 +349,8 @@ void USBPhyHw::ep0_write(uint8_t *buffer, uint32_t size) {
 
 			virtual_status_xfer_event = true;
 
+			irq_already_pending = NVIC_GetPendingIRQ(USBD_IRQn);
+
 			// Trigger an interrupt to process the virtual status event
 			NVIC_SetPendingIRQ(USBD_IRQn);
 
@@ -356,7 +396,10 @@ void USBPhyHw::endpoint_stall(usb_ep_t endpoint) {
 }
 
 void USBPhyHw::endpoint_unstall(usb_ep_t endpoint) {
-	nrf_drv_usbd_ep_stall_clear(get_nordic_endpoint(endpoint));
+	nrf_drv_usbd_ep_t ep = get_nordic_endpoint(endpoint);
+	nrf_drv_usbd_ep_stall_clear(ep);
+	nrf_drv_usbd_ep_disable(ep);
+	nrf_drv_usbd_ep_enable(ep);
 }
 
 bool USBPhyHw::endpoint_read(usb_ep_t endpoint, uint8_t *data, uint32_t size) {
@@ -389,7 +432,8 @@ bool USBPhyHw::endpoint_write(usb_ep_t endpoint, uint8_t *data, uint32_t size) {
 }
 
 void USBPhyHw::endpoint_abort(usb_ep_t endpoint) {
-	nrf_drv_usbd_ep_abort(get_nordic_endpoint(endpoint));
+	nrf_drv_usbd_ep_t nrf_ep = get_nordic_endpoint(endpoint);
+	nrf_drv_usbd_ep_abort(nrf_ep);
 }
 
 void USBPhyHw::process() {
@@ -561,9 +605,7 @@ void USBPhyHw::_reset(void)
 
 	usb_event_type = USB_HW_EVENT_NONE;
 
-	// Clear all endpoint interrupts
-	NVIC_ClearPendingIRQ(USBD_IRQn);
-	nrf_usbd_event_clear((nrf_usbd_event_t)0x01FFFFFF);
+	// TODO - Clear all endpoint interrupts?
 }
 
 void USBPhyHw::enable_usb_interrupts(void) {
@@ -602,15 +644,15 @@ void USBD_HAL_IRQHandler(void)
 	if(virtual_status_xfer_event)
 	{
 		if(instance) {
-			//if(!irq_already_pending)
-			//	return;
-
-			//irq_already_pending = false;
 			instance->_usb_virtual_status_event_handler();
 		}
 
 		virtual_status_xfer_event = false;
 
+		if(!irq_already_pending)
+			return;
+
+		irq_already_pending = false;
 	}
 	// Call Nordic driver IRQ handler
 	USBD_IRQHandler();