Claculate the OS... even better! (aka many fixes to Host USB)

core/control.c

@@ -147,6 +147,15 @@ static void control_write(const uint16_t pio, const uint8_t byte, bool poke) {
                     control.readBatteryStatus = control.setBatteryStatus == BATTERY_DISCHARGED ? 0 : byte & 0x80 ? 0 : 3;
                     break;
             }
+            /*
+             * The comparator inputs remain enabled after the battery-level sequence configures port 7.
+             * TI-OS's USB power check reuses that configuration and only selects the high threshold through
+             * ports 0 and 9, so update the comparator even without another port 7 write.
+             */
+            if (!control.readBatteryStatus && control.setBatteryStatus != BATTERY_DISCHARGED &&
+                (control.ports[7] & 0x90) && (control.ports[0] & 0x80) && (byte & 0xA0) == 0xA0) {
+                control.readBatteryStatus = 1;
+            }
             if ((control.ports[index] & ~byte) >> 2 & 1) {
                 panel_hw_reset();
             }

core/usb/device.h

@@ -12,6 +12,15 @@ typedef enum usb_event_type {
     USB_INIT_EVENT,
     USB_POWER_EVENT,
     USB_RESET_EVENT,
+    USB_SESSION_START_EVENT,
+    USB_SESSION_END_EVENT,
+    USB_SESSION_REQUEST_EVENT,
+    USB_HNP_EVENT,
+    USB_ROLE_SWITCH_EVENT,
+    USB_ROLE_SWITCH_READY_EVENT,
+    USB_ROLE_RESTORE_REQUEST_EVENT,
+    USB_ROLE_RESTORE_EVENT,
+    USB_ROLE_RESTORE_READY_EVENT,
     USB_TRANSFER_REQUEST_EVENT,
     USB_TRANSFER_RESPONSE_EVENT,
     USB_TIMER_EVENT,
@@ -72,6 +81,11 @@ typedef struct usb_event {
     usb_progress_handler_t *progress_handler;
     void *progress_context, *context;
     bool host : 1;
+    /* Set by an asynchronous peer backend for the current dispatch only. */
+    bool deferred : 1;
+    /* Set during initialization by backends which coordinate OTG HNP. */
+    bool supports_hnp : 1;
+    bool pending : 1;
     uint8_t speed : 2; /* usb_speed_t */
     usb_event_type_t type;
     union {

core/usb/dusb.c

@@ -1247,6 +1247,9 @@ int usb_dusb_device(usb_event_t *event) {
             }
             event->context = context;
             break;
+        case USB_SESSION_REQUEST_EVENT:
+            event->type = USB_SESSION_START_EVENT;
+            return USB_SUCCESS;
         case USB_TRANSFER_REQUEST_EVENT:
         case USB_TRANSFER_RESPONSE_EVENT:
             command = context->command;

core/usb/msd.c

@@ -87,6 +87,9 @@ int usb_msd_device(usb_event_t *event) {
             context->address = 0;
             context->configured = false;
             break;
+        case USB_SESSION_START_EVENT:
+        case USB_SESSION_END_EVENT:
+            break;
         case USB_TRANSFER_REQUEST_EVENT:
             event->type = USB_TRANSFER_RESPONSE_EVENT;
             if (transfer->address != context->address ||