USB improvements.

git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@2815 35acf78f-673a-0410-8e92-d51de3d6d3f4

6 files changed, 245 insertions, 100 deletions

diff --git a/os/hal/include/usb.h b/os/hal/include/usb.h
index 24b492e2f..9b8d863b1 100644
--- a/os/hal/include/usb.h
+++ b/os/hal/include/usb.h
@@ -395,6 +395,86 @@ typedef const USBDescriptor * (*usbgetdescriptor_t)(USBDriver *usbp,
   (usbp)->ep0endcb = (endcb);                                               \

 }

 

+/**

+ * @brief   Reads a setup packet from the dedicated packet buffer.

+ * @details This function must be invoked in the context of the @p setup_cb

+ *          callback in order to read the received setup packet.

+ * @pre     In order to use this function the endpoint must have been

+ *          initialized as a control endpoint.

+ * @post    The endpoint is ready to accept another packet.

+ *

+ * @param[in] usbp      pointer to the @p USBDriver object

+ * @param[in] ep        endpoint number

+ * @param[out] buf      buffer where to copy the packet data

+ *

+ * @special

+ */

+#define usbReadSetup(usbp, ep, buf) usb_lld_read_setup(usbp, ep, buf)

+

+/**

+ * @brief   Common ISR code, usb event callback.

+ *

+ * @param[in] usbp      pointer to the @p USBDriver object

+ * @param[in] ep        endpoint number

+ *

+ * @notapi

+ */

+#define _usb_isr_invoke_event_cb(usbp, evt) {                               \

+  if (((usbp)->config->event_cb) != NULL)                                   \

+    (usbp)->config->event_cb(usbp, evt);                                    \

+}

+

+/**

+ * @brief   Common ISR code, SOF callback.

+ *

+ * @param[in] usbp      pointer to the @p USBDriver object

+ * @param[in] ep        endpoint number

+ *

+ * @notapi

+ */

+#define _usb_isr_invoke_sof_cb(usbp) {                                      \

+  if (((usbp)->config->sof_cb) != NULL)                                     \

+    (usbp)->config->sof_cb(usbp);                                           \

+}

+

+/**

+ * @brief   Common ISR code, setup packet callback.

+ *

+ * @param[in] usbp      pointer to the @p USBDriver object

+ * @param[in] ep        endpoint number

+ *

+ * @notapi

+ */

+#define _usb_isr_invoke_setup_cb(usbp, ep) {                                \

+  (usbp)->epc[ep]->setup_cb(usbp, ep);                                      \

+}

+

+/**

+ * @brief   Common ISR code, IN endpoint callback.

+ *

+ * @param[in] usbp      pointer to the @p USBDriver object

+ * @param[in] ep        endpoint number

+ *

+ * @notapi

+ */

+#define _usb_isr_invoke_in_cb(usbp, ep) {                                   \

+  (usbp)->transmitting &= ~(1 << (ep));                                     \

+  (usbp)->epc[ep]->in_cb(usbp, ep);                                         \

+}

+

+/**

+ * @brief   Common ISR code, OUT endpoint event.

+ *

+ * @param[in] usbp      pointer to the @p USBDriver object

+ * @param[in] ep        endpoint number

+ *

+ * @notapi

+ */

+#define _usb_isr_invoke_out_cb(usbp, ep) {                                  \

+  (usbp)->receiving &= ~(1 << (ep));                                        \

+  (usbp)->epc[ep]->out_cb(usbp, ep);                                        \

+}

+

 /*===========================================================================*/

 /* External declarations.                                                    */

 /*===========================================================================*/

@@ -409,6 +489,7 @@ extern "C" {
   void usbInitEndpointI(USBDriver *usbp, usbep_t ep,

                         const USBEndpointConfig *epcp);

   void usbDisableEndpointsI(USBDriver *usbp);

+  void usbReadSetupI(USBDriver *usbp, usbep_t ep, uint8_t *buf);

   size_t usbReadPacketI(USBDriver *usbp, usbep_t ep,

                         uint8_t *buf, size_t n);

   size_t usbWritePacketI(USBDriver *usbp, usbep_t ep,

@@ -420,6 +501,7 @@ extern "C" {
   bool_t usbStallReceiveI(USBDriver *usbp, usbep_t ep);

   bool_t usbStallTransmitI(USBDriver *usbp, usbep_t ep);

   void _usb_reset(USBDriver *usbp);

+  void _usb_ep0setup(USBDriver *usbp, usbep_t ep);

   void _usb_ep0in(USBDriver *usbp, usbep_t ep);

   void _usb_ep0out(USBDriver *usbp, usbep_t ep);

 #ifdef __cplusplus

diff --git a/os/hal/platforms/STM32/usb_lld.c b/os/hal/platforms/STM32/usb_lld.c
index b2198a806..09a8d7975 100644
--- a/os/hal/platforms/STM32/usb_lld.c
+++ b/os/hal/platforms/STM32/usb_lld.c
@@ -68,6 +68,7 @@ static union {
  */

 static const USBEndpointConfig ep0config = {

   USB_EP_MODE_TYPE_CTRL | USB_EP_MODE_TRANSACTION,

+  _usb_ep0setup,

   _usb_ep0in,

   _usb_ep0out,

   0x40,

@@ -193,16 +194,14 @@ CH_IRQ_HANDLER(USB_LP_IRQHandler) {
   /* USB bus reset condition handling.*/

   if (istr & ISTR_RESET) {

     _usb_reset(usbp);

-    if (usbp->config->event_cb)

-      usbp->config->event_cb(usbp, USB_EVENT_RESET);

+    _usb_isr_invoke_event_cb(usbp, USB_EVENT_RESET);

     STM32_USB->ISTR = ~ISTR_RESET;

   }

 

   /* USB bus SUSPEND condition handling.*/

   if (istr & ISTR_SUSP) {

     STM32_USB->CNTR |= CNTR_FSUSP;

-    if (usbp->config->event_cb)

-      usbp->config->event_cb(usbp, USB_EVENT_SUSPEND);

+    _usb_isr_invoke_event_cb(usbp, USB_EVENT_SUSPEND);

 #if STM32_USB_LOW_POWER_ON_SUSPEND

     STM32_USB->CNTR |= CNTR_LP_MODE;

 #endif

@@ -214,8 +213,7 @@ CH_IRQ_HANDLER(USB_LP_IRQHandler) {
     uint32_t fnr = STM32_USB->FNR;

     if (!(fnr & FNR_RXDP)) {

       STM32_USB->CNTR &= ~CNTR_FSUSP;

-      if (usbp->config->event_cb)

-        usbp->config->event_cb(usbp, USB_EVENT_WAKEUP);

+      _usb_isr_invoke_event_cb(usbp, USB_EVENT_WAKEUP);

     }

 #if STM32_USB_LOW_POWER_ON_SUSPEND

     else {

@@ -229,8 +227,7 @@ CH_IRQ_HANDLER(USB_LP_IRQHandler) {
 

   /* SOF handling.*/

   if (istr & ISTR_SOF) {

-    if (usbp->config->sof_cb)

-      usbp->config->sof_cb(usbp);

+    _usb_isr_invoke_sof_cb(usbp);

     STM32_USB->ISTR = ~ISTR_SOF;

   }

 

@@ -245,8 +242,7 @@ CH_IRQ_HANDLER(USB_LP_IRQHandler) {
       EPR_CLEAR_CTR_TX(ep);

       if (epcp->ep_mode & USB_EP_MODE_PACKET) {

         /* Packet mode, just invokes the callback.*/

-        (usbp)->transmitting &= ~(1 << ep);

-        epcp->in_cb(usbp, ep);

+        _usb_isr_invoke_in_cb(usbp, ep);

       }

       else {

         /* Transaction mode.*/

@@ -264,43 +260,36 @@ CH_IRQ_HANDLER(USB_LP_IRQHandler) {
         }

         else {

           /* Transfer completed, invokes the callback.*/

-          (usbp)->transmitting &= ~(1 << ep);

-          epcp->in_cb(usbp, ep);

+          _usb_isr_invoke_in_cb(usbp, ep);

         }

       }

     }

     if (epr & EPR_CTR_RX) {

       EPR_CLEAR_CTR_RX(ep);

       /* OUT endpoint, receive.*/

-      if (epcp->ep_mode & USB_EP_MODE_PACKET) {

+      if (epr & EPR_SETUP) {

+        /* Setup packets handling, setup packets are handled using a

+           specific callback.*/

+        _usb_isr_invoke_setup_cb(usbp, ep);

+      }

+      else if (epcp->ep_mode & USB_EP_MODE_PACKET) {

         /* Packet mode, just invokes the callback.*/

-        (usbp)->receiving &= ~(1 << ep);

-        epcp->out_cb(usbp, ep);

+        _usb_isr_invoke_out_cb(usbp, ep);

       }

       else {

         /* Transaction mode.*/

-        if ((epr & EPR_SETUP) && (ep == 0)) {

-          /* Special case, setup packet for EP0, enforcing a reset of the

-             EP0 state machine for robustness.*/

-          usbp->ep0state = USB_EP0_WAITING_SETUP;

-          read_packet(0, usbp->setup, 8);

-          epcp->out_cb(usbp, ep);

+        n = read_packet(ep, epcp->out_state->rxbuf, epcp->out_state->rxsize);

+        epcp->out_state->rxbuf  += n;

+        epcp->out_state->rxcnt  += n;

+        epcp->out_state->rxsize -= n;

+        epcp->out_state->rxpkts -= 1;

+        if (epcp->out_state->rxpkts > 0) {

+          /* Transfer not completed, there are more packets to receive.*/

+          EPR_SET_STAT_RX(ep, EPR_STAT_RX_VALID);

         }

         else {

-          n = read_packet(ep, epcp->out_state->rxbuf, epcp->out_state->rxsize);

-          epcp->out_state->rxbuf  += n;

-          epcp->out_state->rxcnt  += n;

-          epcp->out_state->rxsize -= n;

-          epcp->out_state->rxpkts -= 1;

-          if (epcp->out_state->rxpkts > 0) {

-            /* Transfer not completed, there are more packets to receive.*/

-            EPR_SET_STAT_RX(ep, EPR_STAT_RX_VALID);

-          }

-          else {

-            /* Transfer completed, invokes the callback.*/

-            (usbp)->receiving &= ~(1 << ep);

-            epcp->out_cb(usbp, ep);

-          }

+          /* Transfer completed, invokes the callback.*/

+          _usb_isr_invoke_out_cb(usbp, ep);

         }

       }

     }

@@ -452,12 +441,12 @@ void usb_lld_init_endpoint(USBDriver *usbp, usbep_t ep) {
   }

 

   /* IN endpoint settings, always in NAK mode initially.*/

-  if (epcp->in_cb)

+  if (epcp->in_cb != NULL)

     epr |= EPR_STAT_TX_NAK;

 

   /* OUT endpoint settings. If the endpoint is in packet mode then it must

      start ready to accept data else it must start in NAK mode.*/

-  if (epcp->out_cb) {

+  if (epcp->out_cb != NULL) {

     if (epcp->ep_mode & USB_EP_MODE_PACKET) {

       usbp->receiving |= (1 << ep);

       epr |= EPR_STAT_RX_VALID;

@@ -554,6 +543,35 @@ usbepstatus_t usb_lld_get_status_in(USBDriver *usbp, usbep_t ep) {
 }

 

 /**

+ * @brief   Reads a setup packet from the dedicated packet buffer.

+ * @details This function must be invoked in the context of the @p setup_cb

+ *          callback in order to read the received setup packet.

+ * @pre     In order to use this function the endpoint must have been

+ *          initialized as a control endpoint.

+ * @post    The endpoint is ready to accept another packet.

+ *

+ * @param[in] usbp      pointer to the @p USBDriver object

+ * @param[in] ep        endpoint number

+ * @param[out] buf      buffer where to copy the packet data

+ *

+ * @notapi

+ */

+void usb_lld_read_setup(USBDriver *usbp, usbep_t ep, uint8_t *buf) {

+  uint32_t *pmap;

+  stm32_usb_descriptor_t *udp;

+  uint32_t n;

+

+  (void)usbp;

+  udp = USB_GET_DESCRIPTOR(ep);

+  pmap = USB_ADDR2PTR(udp->RXADDR);

+  for (n = 0; n < 4; n++) {

+    *(uint16_t *)buf = (uint16_t)*pmap++;

+    buf += 2;

+  }

+  EPR_SET_STAT_RX(ep, EPR_STAT_RX_VALID);

+}

+

+/**

  * @brief   Reads a packet from the dedicated packet buffer.

  * @pre     In order to use this function he endpoint must have been

  *          initialized in packet mode.

diff --git a/os/hal/platforms/STM32/usb_lld.h b/os/hal/platforms/STM32/usb_lld.h
index 9c4c899b3..0a351f932 100644
--- a/os/hal/platforms/STM32/usb_lld.h
+++ b/os/hal/platforms/STM32/usb_lld.h
@@ -150,6 +150,17 @@ typedef struct {
    */

   uint32_t                      ep_mode;

   /**

+   * @brief   Setup packet notification callback.

+   * @details This callback is invoked when a setup packet has been

+   *          received.

+   * @post    The application must immediately call @p usbReadPacket() in

+   *          order to access the received packet.

+   * @note    This field is only valid for @p USB_EP_MODE_TYPE_CTRL

+   *          endpoints, it should be set to @p NULL for other endpoint

+   *          types.

+   */

+  usbepcallback_t               setup_cb;

+  /**

    * @brief   IN endpoint notification callback.

    * @details This field must be set to @p NULL if the IN endpoint is not

    *          used.

@@ -359,6 +370,7 @@ extern "C" {
   void usb_lld_disable_endpoints(USBDriver *usbp);

   usbepstatus_t usb_lld_get_status_in(USBDriver *usbp, usbep_t ep);

   usbepstatus_t usb_lld_get_status_out(USBDriver *usbp, usbep_t ep);

+  void usb_lld_read_setup(USBDriver *usbp, usbep_t ep, uint8_t *buf);

   size_t usb_lld_read_packet(USBDriver *usbp, usbep_t ep,

                              uint8_t *buf, size_t n);

   void usb_lld_write_packet(USBDriver *usbp, usbep_t ep,

diff --git a/os/hal/src/usb.c b/os/hal/src/usb.c
index 0dbe4b39d..b82af84d8 100644
--- a/os/hal/src/usb.c
+++ b/os/hal/src/usb.c
@@ -58,8 +58,7 @@ static void set_address(USBDriver *usbp) {
 

   usbp->address = usbp->setup[2];

   usb_lld_set_address(usbp);

-  if (usbp->config->event_cb)

-    usbp->config->event_cb(usbp, USB_EVENT_ADDRESS);

+  _usb_isr_invoke_event_cb(usbp, USB_EVENT_ADDRESS);

   usbp->state = USB_SELECTED;

 }

 

@@ -137,8 +136,7 @@ static bool_t default_handler(USBDriver *usbp) {
       usbp->state = USB_SELECTED;

     else

       usbp->state = USB_ACTIVE;

-    if (usbp->config->event_cb)

-      usbp->config->event_cb(usbp, USB_EVENT_CONFIGURED);

+    _usb_isr_invoke_event_cb(usbp, USB_EVENT_CONFIGURED);

     usbSetupTransfer(usbp, NULL, 0, NULL);

     return TRUE;

   case USB_RTYPE_RECIPIENT_INTERFACE | (USB_REQ_GET_STATUS << 8):

@@ -527,6 +525,77 @@ void _usb_reset(USBDriver *usbp) {
 }

 

 /**

+ * @brief   Default EP0 SETUP callback.

+ * @details This function is used by the low level driver as default handler

+ *          for EP0 SETUP events.

+ *

+ * @param[in] usbp      pointer to the @p USBDriver object

+ * @param[in] ep        endpoint number, always zero

+ *

+ * @notapi

+ */

+void _usb_ep0setup(USBDriver *usbp, usbep_t ep) {

+  size_t max;

+

+  usbp->ep0state = USB_EP0_WAITING_SETUP;

+  usbReadSetup(usbp, ep, usbp->setup);

+

+  /* First verify if the application has an handler installed for this

+     request.*/

+  if (!(usbp->config->requests_hook_cb) ||

+      !(usbp->config->requests_hook_cb(usbp))) {

+    /* Invoking the default handler, if this fails then stalls the

+       endpoint zero as error.*/

+    if (((usbp->setup[0] & USB_RTYPE_TYPE_MASK) != USB_RTYPE_TYPE_STD) ||

+        !default_handler(usbp)) {

+      /* Error response, the state machine goes into an error state, the low

+         level layer will have to reset it to USB_EP0_WAITING_SETUP after

+         receiving a SETUP packet.*/

+      usb_lld_stall_in(usbp, 0);

+      usb_lld_stall_out(usbp, 0);

+      _usb_isr_invoke_event_cb(usbp, USB_EVENT_STALLED);

+      usbp->ep0state = USB_EP0_ERROR;

+    }

+  }

+

+  /* Transfer preparation. The request handler must have populated

+     correctly the fields ep0next, ep0n and ep0endcb using the macro

+     usbSetupTransfer().*/

+  max = usb_lld_fetch_word(&usbp->setup[6]);

+  /* The transfer size cannot exceed the specified amount.*/

+  if (usbp->ep0n > max)

+    usbp->ep0n = max;

+  if ((usbp->setup[0] & USB_RTYPE_DIR_MASK) == USB_RTYPE_DIR_DEV2HOST) {

+    /* IN phase.*/

+    if (usbp->ep0n > 0) {

+      /* Starts the transmit phase.*/

+      usbp->ep0state = USB_EP0_TX;

+      usb_lld_start_in(usbp, 0, usbp->ep0next, usbp->ep0n);

+    }

+    else {

+      /* No transmission phase, directly receiving the zero sized status

+         packet.*/

+      usbp->ep0state = USB_EP0_WAITING_STS;

+      usb_lld_start_out(usbp, 0, NULL, 0);

+    }

+  }

+  else {

+    /* OUT phase.*/

+    if (usbp->ep0n > 0) {

+      /* Starts the receive phase.*/

+      usbp->ep0state = USB_EP0_RX;

+      usb_lld_start_out(usbp, 0, usbp->ep0next, usbp->ep0n);

+    }

+    else {

+      /* No receive phase, directly sending the zero sized status

+         packet.*/

+      usbp->ep0state = USB_EP0_SENDING_STS;

+      usb_lld_start_in(usbp, 0, NULL, 0);

+    }

+  }

+}

+

+/**

  * @brief   Default EP0 IN callback.

  * @details This function is used by the low level driver as default handler

  *          for EP0 IN events.

@@ -558,7 +627,7 @@ void _usb_ep0in(USBDriver *usbp, usbep_t ep) {
     return;

   case USB_EP0_SENDING_STS:

     /* Status packet sent, invoking the callback if defined.*/

-    if (usbp->ep0endcb)

+    if (usbp->ep0endcb != NULL)

       usbp->ep0endcb(usbp);

     usbp->ep0state = USB_EP0_WAITING_SETUP;

     return;

@@ -570,8 +639,7 @@ void _usb_ep0in(USBDriver *usbp, usbep_t ep) {
      receiving a SETUP packet.*/

   usb_lld_stall_in(usbp, 0);

   usb_lld_stall_out(usbp, 0);

-  if (usbp->config->event_cb)

-    usbp->config->event_cb(usbp, USB_EVENT_STALLED);

+  _usb_isr_invoke_event_cb(usbp, USB_EVENT_STALLED);

   usbp->ep0state = USB_EP0_ERROR;

 }

 

@@ -586,62 +654,9 @@ void _usb_ep0in(USBDriver *usbp, usbep_t ep) {
  * @notapi

  */

 void _usb_ep0out(USBDriver *usbp, usbep_t ep) {

-  size_t max;

 

   (void)ep;

   switch (usbp->ep0state) {

-  case USB_EP0_WAITING_SETUP:

-    /* SETUP packet handling. The setup packet is expected to be already

-       placed into the setup[8] field of the USBDriver structure, the low

-       level layer has to take care of this.*/

-

-    /* First verify if the application has an handler installed for this

-       request.*/

-    if (!(usbp->config->requests_hook_cb) ||

-        !(usbp->config->requests_hook_cb(usbp))) {

-      /* Invoking the default handler, if this fails then stalls the

-         endpoint zero as error.*/

-      if (((usbp->setup[0] & USB_RTYPE_TYPE_MASK) != USB_RTYPE_TYPE_STD) ||

-          !default_handler(usbp))

-        break;

-    }

-

-    /* Transfer preparation. The request handler must have populated

-       correctly the fields ep0next, ep0n and ep0endcb using the macro

-       usbSetupTransfer().*/

-    max = usb_lld_fetch_word(&usbp->setup[6]);

-    /* The transfer size cannot exceed the specified amount.*/

-    if (usbp->ep0n > max)

-      usbp->ep0n = max;

-    if ((usbp->setup[0] & USB_RTYPE_DIR_MASK) == USB_RTYPE_DIR_DEV2HOST) {

-      /* IN phase.*/

-      if (usbp->ep0n > 0) {

-        /* Starts the transmit phase.*/

-        usbp->ep0state = USB_EP0_TX;

-        usb_lld_start_in(usbp, 0, usbp->ep0next, usbp->ep0n);

-      }

-      else {

-        /* No transmission phase, directly receiving the zero sized status

-           packet.*/

-        usbp->ep0state = USB_EP0_WAITING_STS;

-        usb_lld_start_out(usbp, 0, NULL, 0);

-      }

-    }

-    else {

-      /* OUT phase.*/

-      if (usbp->ep0n > 0) {

-        /* Starts the receive phase.*/

-        usbp->ep0state = USB_EP0_RX;

-        usb_lld_start_out(usbp, 0, usbp->ep0next, usbp->ep0n);

-      }

-      else {

-        /* No receive phase, directly sending the zero sized status

-           packet.*/

-        usbp->ep0state = USB_EP0_SENDING_STS;

-        usb_lld_start_in(usbp, 0, NULL, 0);

-      }

-    }

-    return;

   case USB_EP0_RX:

     /* Receive phase over, sending the zero sized status packet.*/

     usbp->ep0state = USB_EP0_SENDING_STS;

@@ -652,7 +667,7 @@ void _usb_ep0out(USBDriver *usbp, usbep_t ep) {
        if defined.*/

     if (usbGetReceiveTransactionSizeI(usbp, 0) != 0)

       break;

-    if (usbp->ep0endcb)

+    if (usbp->ep0endcb != NULL)

       usbp->ep0endcb(usbp);

     usbp->ep0state = USB_EP0_WAITING_SETUP;

     return;

@@ -664,8 +679,7 @@ void _usb_ep0out(USBDriver *usbp, usbep_t ep) {
      receiving a SETUP packet.*/

   usb_lld_stall_in(usbp, 0);

   usb_lld_stall_out(usbp, 0);

-  if (usbp->config->event_cb)

-    usbp->config->event_cb(usbp, USB_EVENT_STALLED);

+  _usb_isr_invoke_event_cb(usbp, USB_EVENT_STALLED);

   usbp->ep0state = USB_EP0_ERROR;

 }

 

diff --git a/os/hal/templates/usb_lld.c b/os/hal/templates/usb_lld.c
index d2750d2e5..823946385 100644
--- a/os/hal/templates/usb_lld.c
+++ b/os/hal/templates/usb_lld.c
@@ -204,6 +204,24 @@ usbepstatus_t usb_lld_get_status_in(USBDriver *usbp, usbep_t ep) {
 }

 

 /**

+ * @brief   Reads a setup packet from the dedicated packet buffer.

+ * @details This function must be invoked in the context of the @p setup_cb

+ *          callback in order to read the received setup packet.

+ * @pre     In order to use this function the endpoint must have been

+ *          initialized as a control endpoint.

+ * @post    The endpoint is ready to accept another packet.

+ *

+ * @param[in] usbp      pointer to the @p USBDriver object

+ * @param[in] ep        endpoint number

+ * @param[out] buf      buffer where to copy the packet data

+ *

+ * @notapi

+ */

+void usb_lld_read_setup(USBDriver *usbp, usbep_t ep, uint8_t *buf) {

+

+}

+

+/**

  * @brief   Reads a packet from the dedicated packet buffer.

  * @pre     In order to use this function he endpoint must have been

  *          initialized in packet mode.

diff --git a/os/hal/templates/usb_lld.h b/os/hal/templates/usb_lld.h
index 254f6c5da..5b235eaa4 100644
--- a/os/hal/templates/usb_lld.h
+++ b/os/hal/templates/usb_lld.h
@@ -282,6 +282,7 @@ extern "C" {
   void usb_lld_disable_endpoints(USBDriver *usbp);

   usbepstatus_t usb_lld_get_status_in(USBDriver *usbp, usbep_t ep);

   usbepstatus_t usb_lld_get_status_out(USBDriver *usbp, usbep_t ep);

+  void usb_lld_read_setup(USBDriver *usbp, usbep_t ep, uint8_t *buf);

   size_t usb_lld_read_packet(USBDriver *usbp, usbep_t ep,

                              uint8_t *buf, size_t n);

   void usb_lld_write_packet(USBDriver *usbp, usbep_t ep,