usbus: Add support for endpoint halt condition

sys/include/usb/descriptor.h

@@ -58,6 +58,15 @@ extern "C" {
 #define USB_TYPE_DESCRIPTOR_INTERFACE_ASSOC 0x0b    /**< Interface association     */
 /** @} */
 
+/**
+ * @name USB standard feature selectors
+ * @{
+ */
+#define USB_FEATURE_ENDPOINT_HALT           0x00    /**< Endpoint halt        */
+#define USB_FEATURE_DEVICE_REMOTE_WAKEUP    0x01    /**< Device remote wakeup */
+#define USB_FEATURE_TEST_MODE               0x02    /**< Test mode feature    */
+/** @} */
+
 /**
  * @name USB configuration attributes
  * @anchor USB_CONF_ATTR

sys/include/usb/usbus.h

@@ -327,6 +327,7 @@ typedef struct usbus_endpoint {
     uint8_t interval;               /**< Poll interval for interrupt endpoints */
     bool active;                    /**< If the endpoint should be activated after
                                          reset */
+    bool halted;                    /**< Endpoint is halted */
 } usbus_endpoint_t;
 
 /**
@@ -676,6 +677,22 @@ void usbus_urb_submit(usbus_t *usbus, usbus_endpoint_t *endpoint, usbus_urb_t *u
  */
 int usbus_urb_cancel(usbus_t *usbus, usbus_endpoint_t *endpoint, usbus_urb_t *urb);
 
+/**
+ * @brief Set the halt condition on an endpoint.
+ *
+ * The endpoint will respond with stall to all packets and must explicitly be
+ * cleared by the host by clearing the halt condition or switching interfaces
+ */
+void usbus_endpoint_halt(usbus_endpoint_t *ep);
+
+/**
+ * @brief Clear the halt condition on an endpoint
+ *
+ * @note Must only be used when the endpoint is halted and when the host issues
+ * a SetInterface request on the interface containing the endpoint
+ */
+void usbus_endpoint_clear_halt(usbus_endpoint_t *ep);
+
 /**
  * @brief Enable an endpoint
  *

sys/usb/usbus/usbus.c

@@ -470,6 +470,34 @@ static void *_usbus_thread(void *args)
     return NULL;
 }
 
+void usbus_endpoint_halt(usbus_endpoint_t *ep)
+{
+    assert(ep->ep->num != 0); /* Not valid for endpoint 0 */
+    DEBUG("Endpoint %u halted\n", ep->ep->num);
+    ep->halted = 1;
+    usbdev_ep_stall(ep->ep, true);
+}
+
+void usbus_endpoint_clear_halt(usbus_endpoint_t *ep)
+{
+    assert(ep->ep->num != 0); /* Not valid for endpoint 0 */
+    DEBUG("Endpoint %u unhalted\n", ep->ep->num);
+    ep->halted = 0;
+    usbdev_ep_stall(ep->ep, false);
+}
+
+/**
+ * @brief Reset the halted status on USB reset condition
+ */
+static void _usbus_endpoint_reset_halt(usbus_t *usbus)
+{
+    /* Clear halted state. No need to notify usbdev, USB reset already resets those */
+    for (size_t i = 0; i < USBDEV_NUM_ENDPOINTS; i++) {
+        usbus->ep_out[i].halted = 0;
+        usbus->ep_in[i].halted = 0;
+    }
+}
+
 /* USB event callback */
 static void _event_cb(usbdev_t *usbdev, usbdev_event_t event)
 {
@@ -487,6 +515,7 @@ static void _event_cb(usbdev_t *usbdev, usbdev_event_t event)
                 usbus->addr = 0;
                 usbdev_set(usbus->dev, USBOPT_ADDRESS, &usbus->addr,
                            sizeof(uint8_t));
+                _usbus_endpoint_reset_halt(usbus);
                 flag = USBUS_HANDLER_FLAG_RESET;
                 msg = USBUS_EVENT_USB_RESET;
                 DEBUG("usbus: USB reset detected\n");

sys/usb/usbus/usbus_control.c

@@ -105,13 +105,39 @@ static usbus_string_t *_get_descriptor(usbus_t *usbus, uint16_t idx)
 
 static int _req_status(usbus_t *usbus)
 {
-    uint8_t status[2];
+    /* Signal self powered */
+    uint16_t status = (CONFIG_USB_SELF_POWERED) ? 1 : 0;
+    usbus_control_slicer_put_bytes(usbus, (uint8_t*)&status, sizeof(status));
+    return sizeof(status);
+}
+
+static int _req_iface_status(usbus_t *usbus)
+{
+    uint16_t status = 0; /* always zero */
+    usbus_control_slicer_put_bytes(usbus, (uint8_t*)&status, sizeof(status));
+    return sizeof(status);
+}
 
-    memset(status, 0, sizeof(status));
-    usbus_control_slicer_put_bytes(usbus, status, sizeof(status));
+static int _req_endpoint_status(usbus_t *usbus, usbus_endpoint_t *ep)
+{
+    uint16_t status = ep->halted ? 1 : 0;
+    usbus_control_slicer_put_bytes(usbus, (uint8_t*)&status, sizeof(status));
     return sizeof(status);
 }
 
+static int _req_endpoint_feature(usbus_endpoint_t *ep, uint16_t feature, bool enable)
+{
+    switch (feature) {
+        case USB_FEATURE_ENDPOINT_HALT:
+            enable ? usbus_endpoint_halt(ep) : usbus_endpoint_clear_halt(ep);
+            break;
+        default:
+            DEBUG("usbus: unknown endpoint feature request: %u\n", feature);
+            return -1;
+    }
+    return 1;
+}
+
 static int _req_str(usbus_t *usbus, uint16_t idx)
 {
     /* Return an error condition by default */
@@ -238,6 +264,11 @@ static int _recv_interface_setup(usbus_t *usbus, usb_setup_t *pkt)
         (usbus_control_handler_t *)usbus->control;
     uint16_t destination = pkt->index & 0x0f;
 
+    /* Globally handle the iface get status request */
+    if (pkt->request == USB_SETUP_REQ_GET_STATUS) {
+        return _req_iface_status(usbus);
+    }
+
     /* Find interface handler */
     for (usbus_interface_t *iface = usbus->iface; iface; iface = iface->next) {
         if (destination == iface->idx &&
@@ -251,6 +282,26 @@ static int _recv_interface_setup(usbus_t *usbus, usb_setup_t *pkt)
     return -1;
 }
 
+static int _recv_endpoint_setup(usbus_t *usbus, usb_setup_t *pkt)
+{
+    uint8_t destination = pkt->index & 0x0f;
+    bool in = pkt->index & (1 << 7); /* Bit seven is 1 for IN, 0 for OUT */
+    usbus_endpoint_t *ep = in ? &usbus->ep_in[destination] :
+                                &usbus->ep_out[destination];
+
+    switch (pkt->request) {
+        case USB_SETUP_REQ_GET_STATUS:
+            return _req_endpoint_status(usbus, ep);
+        case USB_SETUP_REQ_SET_FEATURE:
+            return _req_endpoint_feature(ep, pkt->value, true);
+        case USB_SETUP_REQ_CLEAR_FEATURE:
+            return _req_endpoint_feature(ep, pkt->value, false);
+        default:
+            DEBUG("usbus: Unknown endpoint request %u\n", pkt->request);
+            return -1;
+    }
+}
+
 static void _recv_setup(usbus_t *usbus, usbus_control_handler_t *handler)
 {
     usb_setup_t *pkt = &handler->setup;
@@ -272,6 +323,9 @@ static void _recv_setup(usbus_t *usbus, usbus_control_handler_t *handler)
             case USB_SETUP_REQUEST_RECIPIENT_INTERFACE:
                 res = _recv_interface_setup(usbus, pkt);
                 break;
+            case USB_SETUP_REQUEST_RECIPIENT_ENDPOINT:
+                res = _recv_endpoint_setup(usbus, pkt);
+                break;
             default:
                 DEBUG("usbus_control: Unhandled setup request\n");
         }