Turn off frame IRQ when it is not in use.

Author: marcio-ao

libraries/UHS_host/UHS_settings.h

@@ -76,6 +76,16 @@ e-mail   :  [email protected]
 #define DEBUG_PRINTF_EXTRA_HUGE 0
 #endif
 
+////////////////////////////////////////////////////////////////////////////////
+// Special Cases
+////////////////////////////////////////////////////////////////////////////////
+
+/* Set this to 1 to disable device polling within the IRQ. If you enable this,
+ * you will need to call usb.Task() periodically instead. */
+#ifndef USB_HOST_MANUAL_POLL
+#define USB_HOST_MANUAL_POLL 0
+#endif
+
 ////////////////////////////////////////////////////////////////////////////////
 // Manual board activation
 ////////////////////////////////////////////////////////////////////////////////

libraries/UHS_host/USB_HOST_SHIELD/USB_HOST_SHIELD.h

@@ -309,6 +309,25 @@ public UHS_USB_HOST_BASE
         volatile bool counted;
         volatile bool condet;
         volatile bool doingreset;
+
+        bool UHS_NI pollDevices(void);
+        // Frame timer control
+
+        volatile bool frame_irq_enabled = false;
+
+        bool enable_frame_irq(bool enable) {
+                const bool prev_state = frame_irq_enabled;
+                if(prev_state != enable) {
+                        if(enable)
+                                regWr(rHIEN, regRd(rHIEN) |  bmFRAMEIE);
+                        else
+                                regWr(rHIEN, regRd(rHIEN) & ~bmFRAMEIE);
+                        frame_irq_enabled = enable;
+                }
+                return prev_state;
+        }
+
+
 public:
         SPISettings MAX3421E_SPI_Settings;
         uint8_t ss_pin;
@@ -356,6 +375,7 @@ public UHS_USB_HOST_BASE
         };
 
         virtual bool UHS_NI sof_delay(uint16_t x) {
+                const bool saved_state = enable_frame_irq(true);
                 sof_countdown = x;
                 while((sof_countdown != 0) && !condet) {
 
@@ -364,6 +384,7 @@ public UHS_USB_HOST_BASE
 #endif
                 }
                 //                Serial.println("...Wake");
+                enable_frame_irq(saved_state);
                 return (!condet);
         };
 
@@ -421,6 +442,7 @@ public UHS_USB_HOST_BASE
                         // Enable interrupts
                 noInterrupts();
 #endif
+                enable_frame_irq(true);
                 sofevent = true;
 #if USB_HOST_SHIELD_USE_ISR
                 DDSB();

libraries/UHS_host/USB_HOST_SHIELD/USB_HOST_SHIELD_INLINE.h

@@ -206,6 +206,7 @@ void UHS_NI MAX3421E_HOST::busprobe(void) {
                                 regWr(rMODE, MODE_LS_HOST); // start low-speed host
                                 vbusState = LSHOST;
                         }
+                        enable_frame_irq(true);
                         tmpdata = regRd(rMODE) | bmSOFKAENAB; // start SOF generation
                         regWr(rHIRQ, bmFRAMEIRQ); // see data sheet.
                         regWr(rMODE, tmpdata);
@@ -219,6 +220,7 @@ void UHS_NI MAX3421E_HOST::busprobe(void) {
                                 regWr(rMODE, MODE_FS_HOST); // start full-speed host
                                 vbusState = FSHOST;
                         }
+                        enable_frame_irq(true);
                         tmpdata = regRd(rMODE) | bmSOFKAENAB; // start SOF generation
                         regWr(rHIRQ, bmFRAMEIRQ); // see data sheet.
                         regWr(rMODE, tmpdata);
@@ -814,13 +816,22 @@ 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
+                                enable_frame_irq(false);
+                        #else
+                                // If no device requires polling, it is okay to shutoff
+                                // the frame irq to free up some CPU cycles until the
+                                // next device insertion/removal
+                                if(!pollDevices()) {
+                                        enable_frame_irq(false);
                                 }
-                        }
-                        // fall thru
+                        #endif
+                        break;
+                case UHS_USB_HOST_STATE_ERROR:
+                case UHS_USB_HOST_STATE_IDLE:
+                case UHS_USB_HOST_STATE_ILLEGAL:
+                        enable_frame_irq(false);
+                        break;
                 default:
                         // Do nothing
                         break;
@@ -844,6 +855,24 @@ 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
@@ -854,6 +883,13 @@ 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)