Fix for drivers that require polling.

- Now sof_timer will only be set to go to sleep if no drivers need to poll.
- Added option to perform polling manually.

Author: marcio-ao

libraries/UHS_host/USB_HOST_SHIELD/USB_HOST_SHIELD.h

@@ -357,6 +357,9 @@ public UHS_USB_HOST_BASE
         volatile bool counted;
         volatile bool condet;
         volatile bool doingreset;
+
+        bool UHS_NI pollDevices(void);
+
 public:
         SPISettings MAX3421E_SPI_Settings;
         uint8_t ss_pin;

libraries/UHS_host/USB_HOST_SHIELD/USB_HOST_SHIELD_INLINE.h

@@ -128,12 +128,15 @@ uint8_t UHS_NI MAX3421E_HOST::gpioRd(void) {
 uint16_t UHS_NI MAX3421E_HOST::reset(void) {
         uint16_t i = 0;
 
+        // Initiate chip reset
         regWr(rUSBCTL, bmCHIPRES);
         regWr(rUSBCTL, 0x00);
 
         int32_t now;
         uint32_t expires = micros() + 65535;
 
+        // Enable full-duplex SPI so we can read rUSBIRQ
+        regWr(rPINCTL, bmFDUPSPI);
         while((int32_t)(micros() - expires) < 0L) {
                 if((regRd(rUSBIRQ) & bmOSCOKIRQ)) {
                         break;
@@ -308,8 +311,6 @@ int16_t UHS_NI MAX3421E_HOST::Init(int16_t mseconds) {
         uint32_t spd = UHS_MAX3421E_SPD;
 again:
         MAX3421E_SPI_Settings = SPISettings(spd, MSBFIRST, SPI_MODE0);
-        /* MAX3421E - full-duplex SPI, interrupt kind, vbus off */
-        regWr(rPINCTL, (bmFDUPSPI | bmIRQ_SENSE | GPX_VBDET));
         if(reset() == 0) {
                 MAX_HOST_DEBUG("Fail SPI speed %lu\r\n", spd);
                 if(spd > 1999999) {
@@ -340,11 +341,13 @@ int16_t UHS_NI MAX3421E_HOST::Init(int16_t mseconds) {
 
         MAX_HOST_DEBUG("Pass SPI speed %lu\r\n", spd);
 #endif
-        /* MAX3421E - full-duplex SPI, interrupt kind, vbus off */
+
         if(reset() == 0) { //OSCOKIRQ hasn't asserted in time
                 MAX_HOST_DEBUG("OSCOKIRQ hasn't asserted in time");
                 return ( -1);
         }
+
+        /* MAX3421E - full-duplex SPI, interrupt kind, vbus off */
         regWr(rPINCTL, (bmFDUPSPI | bmIRQ_SENSE | GPX_VBDET));
 
         // Delay a minimum of 1 second to ensure any capacitors are drained.
@@ -356,9 +359,9 @@ int16_t UHS_NI MAX3421E_HOST::Init(int16_t mseconds) {
 
         regWr(rMODE, bmDPPULLDN | bmDMPULLDN | bmHOST); // set pull-downs, Host
 
-        // Enable interrupts on condition detections and bus events
+        // Set the MAX3421e to issue interrupts on bus condition detections and events
         regWr(rHIEN, bmCONDETIE | bmBUSEVENTIE);
-        // Enable interrupt pin, set pulse width for edge
+        // Enable interrupt pin on the MAX3421e, set pulse width for edge
         regWr(rCPUCTL, (bmIE | bmPULSEWIDTH));
 
         /* check if device is connected */
@@ -687,7 +690,7 @@ UHS_EpInfo * UHS_NI MAX3421E_HOST::ctrlReqOpen(uint8_t addr, uint64_t Request, u
 
 uint8_t UHS_NI MAX3421E_HOST::ctrlReqRead(UHS_EpInfo *pep, uint16_t *left, uint16_t *read, uint16_t nbytes, uint8_t *dataptr) {
         *read = 0;
-        uint16_t nak_limit = 0;
+        uint16_t nak_limit = USB_HOST_NAK_LIMIT;
         MAX_HOST_DEBUG("ctrlReqRead left: %i\r\n", *left);
         if(*left) {
 again:
@@ -821,13 +824,17 @@ void UHS_NI MAX3421E_HOST::ISRbottom(void) {
                         usb_task_state = UHS_USB_HOST_STATE_RUNNING;
                         break;
                 case UHS_USB_HOST_STATE_RUNNING:
-                        Poll_Others();
-                        for(x = 0; (usb_task_state == UHS_USB_HOST_STATE_RUNNING) && (x < UHS_HOST_MAX_INTERFACE_DRIVERS); x++) {
-                                if(devConfig[x]) {
-                                        if(devConfig[x]->bPollEnable) devConfig[x]->Poll();
+                        #if USB_HOST_MANUAL_POLL && USB_HOST_SHIELD_USE_ISR
+                                sof_timer.sleep();
+                        #else
+                                // If no device requires polling, it is okay to shutoff
+                                // the sof_timer to free up some CPU cycles until the
+                                // next device insertion/removal
+                                if(!pollDevices()) {
+                                        sof_timer.sleep();
                                 }
-                        }
-                        // fall-thru
+                        #endif
+                        break;
                 case UHS_USB_HOST_STATE_ERROR:
                 case UHS_USB_HOST_STATE_IDLE:
                 case UHS_USB_HOST_STATE_ILLEGAL:
@@ -856,6 +863,24 @@ void UHS_NI MAX3421E_HOST::ISRbottom(void) {
         DDSB();
 }
 
+/* Allows devices to run periodic tasks. Returns "true" if any devices
+ * have polling enabled. */
+bool UHS_NI MAX3421E_HOST::pollDevices(void) {
+        bool is_polling = false;
+        #if defined(UHS_LOAD_BT) || defined(UHS_LOAD_HID)
+                Poll_Others();
+                is_polling = true;
+        #endif
+
+        for(uint8_t x = 0; x < UHS_HOST_MAX_INTERFACE_DRIVERS; x++) {
+                if(devConfig[x] && devConfig[x]->bPollEnable) {
+                        devConfig[x]->Poll();
+                        is_polling = true;
+                }
+        }
+        return is_polling;
+}
+
 
 /* USB main task. Services the MAX3421e */
 #if !USB_HOST_SHIELD_USE_ISR
@@ -866,6 +891,13 @@ void UHS_NI MAX3421E_HOST::Task(void)
 #else
 
 void UHS_NI MAX3421E_HOST::Task(void) {
+        #if USB_HOST_MANUAL_POLL
+                if(usb_task_state == UHS_USB_HOST_STATE_RUNNING) {
+                        noInterrupts();
+                        pollDevices();
+                        interrupts();
+                }
+        #endif
 }
 
 void UHS_NI MAX3421E_HOST::ISRTask(void)