Kinetis USB improvements and fixes

Make the following improvements and fixes:

1.
Update the Kinetis USB driver so that endpointReadResult only reads the
result of the last read and does not trigger a new read. Instead
move the code to trigger new reads into endpointRead.

2.
Fix the race condition in controlIn caused by a call to
EP0read() followed immediately by  EP0readStage(). This is done by
setting up to read the next setup packet (ignoring the status stage)
in endpointReadResult rather than in EP0readStage. This makes the
function EP0readStage unnecissary.

3.
Remove the Kinetis workaround in controlOut in USBDevice.cpp since
point 2 fixes this bug. For more info on this see the PR which
added this workaround - #414

Author: c1728p9

features/unsupported/USBDevice/USBDevice/USBDevice.cpp

@@ -187,27 +187,8 @@ bool USBDevice::controlOut(void)
     /* Check we should be transferring data OUT */
     if (transfer.direction != HOST_TO_DEVICE)
     {
-#if defined(TARGET_KL25Z) | defined(TARGET_KL43Z) | defined(TARGET_KL46Z) | defined(TARGET_K20D5M) | defined(TARGET_K64F) | defined(TARGET_K22F) | defined(TARGET_TEENSY3_1)
-        /*
-         * We seem to have a pending device-to-host transfer.  The host must have
-         * sent a new control request without waiting for us to finish processing
-         * the previous one.  This appears to happen when we're connected to certain 
-         * USB 3.0 host chip set. Do a zeor-length send to tell the host we're not
-         * ready for the new request - that'll make it resend - and then just
-         * pretend we were successful here so that the pending transfer can finish.
-         */
-         uint8_t buf[1] = { 0 };
-         EP0write(buf, 0);
-         
-         /* execute our pending ttransfer */
-         controlIn();
-         
-         /* indicate success */
-         return true;
- #else
          /* for other platforms, count on the HAL to handle this case */
          return false;
- #endif
     }
 
     /* Read from endpoint */

features/unsupported/USBDevice/targets/TARGET_Freescale/USBHAL_KL25Z.cpp

@@ -22,6 +22,7 @@
 #include "fsl_common.h"
 #endif
 #include "USBHAL.h"
+#include "mbed_critical.h"
 
 USBHAL * USBHAL::instance;
 
@@ -64,6 +65,13 @@ typedef struct BDT {
     uint32_t  address;    // Addr
 } BDT;
 
+typedef enum {
+    CTRL_XFER_READY,
+    CTRL_XFER_IN,
+    CTRL_XFER_NONE,
+    CTRL_XFER_OUT
+} ctrl_xfer_t;
+
 // there are:
 //    * 4 bidirectionnal endpt -> 8 physical endpt
 //    * as there are ODD and EVEN buffer -> 8*2 bdt
@@ -73,6 +81,7 @@ uint8_t * endpoint_buffer[NUMBER_OF_PHYSICAL_ENDPOINTS * 2];
 
 static uint8_t set_addr = 0;
 static uint8_t addr = 0;
+static ctrl_xfer_t ctrl_xfer = CTRL_XFER_READY;
 
 static uint32_t Data1  = 0x55555555;
 
@@ -223,11 +232,16 @@ bool USBHAL::realiseEndpoint(uint8_t endpoint, uint32_t maxPacket, uint32_t flag
                                               USB_ENDPT_EPRXEN_MASK;  // en RX (OUT) tran.
         bdt[EP_BDT_IDX(log_endpoint, RX, ODD )].byte_count = maxPacket;
         bdt[EP_BDT_IDX(log_endpoint, RX, ODD )].address    = (uint32_t) buf;
-        bdt[EP_BDT_IDX(log_endpoint, RX, ODD )].info       = BD_OWN_MASK | BD_DTS_MASK;
+        bdt[EP_BDT_IDX(log_endpoint, RX, ODD )].info       = BD_DTS_MASK;
         bdt[EP_BDT_IDX(log_endpoint, RX, EVEN)].info       = 0;
+        if (log_endpoint == 0) {
+            // Prepare for setup packet
+            bdt[EP_BDT_IDX(log_endpoint, RX, ODD )].info |= BD_OWN_MASK;
+        }
     }
 
-    Data1 |= (1 << endpoint);
+    // First transfer will be a DATA0 packet
+    Data1 &= ~(1 << endpoint);
 
     return true;
 }
@@ -239,13 +253,35 @@ void USBHAL::EP0setup(uint8_t *buffer) {
 }
 
 void USBHAL::EP0readStage(void) {
-    Data1 &= ~1UL;  // set DATA0
-    bdt[0].info = (BD_DTS_MASK | BD_OWN_MASK);
+    // Not needed
 }
 
 void USBHAL::EP0read(void) {
-    uint32_t idx = EP_BDT_IDX(PHY_TO_LOG(EP0OUT), RX, 0);
-    bdt[idx].byte_count = MAX_PACKET_SIZE_EP0;
+    if (ctrl_xfer == CTRL_XFER_READY) {
+        // Transfer is done so ignore call
+        return;
+    }
+    if (ctrl_xfer == CTRL_XFER_IN) {
+        ctrl_xfer = CTRL_XFER_READY;
+        // Control transfer with a data IN stage.
+        // The next packet received will be the status packet - an OUT packet using DATA1
+        //
+        // PROBLEM:
+        // If a Setup packet is received after status packet of
+        // a Control In transfer has been received in the RX buffer
+        // but before the processor has had a chance the prepare
+        // this buffer for the Setup packet, the Setup packet
+        // will be dropped.
+        //
+        // WORKAROUND:
+        // Set data toggle to DATA0 so if the status stage of a
+        // Control In transfer arrives it will be ACKed by hardware
+        // but will be discarded without filling the RX buffer.
+        // This allows a subsequent SETUP packet to be stored
+        // without any processor intervention.
+        Data1 &= ~1UL;  // set DATA0
+    }
+    endpointRead(EP0OUT, MAX_PACKET_SIZE_EP0);
 }
 
 uint32_t USBHAL::EP0getReadResult(uint8_t *buffer) {
@@ -255,20 +291,50 @@ uint32_t USBHAL::EP0getReadResult(uint8_t *buffer) {
 }
 
 void USBHAL::EP0write(uint8_t *buffer, uint32_t size) {
+    if (ctrl_xfer == CTRL_XFER_READY) {
+        // Transfer is done so ignore call
+        return;
+    }
+    if ((ctrl_xfer == CTRL_XFER_NONE) || (ctrl_xfer == CTRL_XFER_OUT)) {
+        // Prepare for next setup packet
+        endpointRead(EP0OUT, MAX_PACKET_SIZE_EP0);
+        ctrl_xfer = CTRL_XFER_READY;
+     }
     endpointWrite(EP0IN, buffer, size);
 }
 
 void USBHAL::EP0getWriteResult(void) {
 }
 
 void USBHAL::EP0stall(void) {
+    if (ctrl_xfer == CTRL_XFER_READY) {
+        // Transfer is done so ignore call
+        return;
+    }
+    ctrl_xfer = CTRL_XFER_READY;
+    core_util_critical_section_enter();
     stallEndpoint(EP0OUT);
+    // Prepare for next setup packet
+    // Note - time between stalling and setting up the endpoint
+    //      must be kept to a minimum to prevent a dropped SETUP
+    //      packet.
+    endpointRead(EP0OUT, MAX_PACKET_SIZE_EP0);
+    core_util_critical_section_exit();
 }
 
 EP_STATUS USBHAL::endpointRead(uint8_t endpoint, uint32_t maximumSize) {
-    endpoint = PHY_TO_LOG(endpoint);
-    uint32_t idx = EP_BDT_IDX(endpoint, RX, 0);
+    uint8_t log_endpoint = PHY_TO_LOG(endpoint);
+
+    uint32_t idx = EP_BDT_IDX(log_endpoint, RX, 0);
     bdt[idx].byte_count = maximumSize;
+    if ((Data1 >> endpoint) & 1) {
+        bdt[idx].info = BD_OWN_MASK | BD_DTS_MASK | BD_DATA01_MASK;
+    }
+    else {
+        bdt[idx].info = BD_OWN_MASK | BD_DTS_MASK;
+    }
+
+    Data1 ^= (1 << endpoint);
     return EP_PENDING;
 }
 
@@ -307,18 +373,14 @@ EP_STATUS USBHAL::endpointReadResult(uint8_t endpoint, uint8_t * buffer, uint32_
         buffer[n] = ep_buf[n];
     }
 
-    if (((Data1 >> endpoint) & 1) == ((bdt[idx].info >> 6) & 1)) {
-        if (setup && (buffer[6] == 0))  // if no setup data stage,
-            Data1 &= ~1UL;              // set DATA0
-        else
-            Data1 ^= (1 << endpoint);
-    }
-
-    if (((Data1 >> endpoint) & 1)) {
-        bdt[idx].info = BD_DTS_MASK | BD_DATA01_MASK | BD_OWN_MASK;
-    }
-    else {
-        bdt[idx].info = BD_DTS_MASK | BD_OWN_MASK;
+    if (setup) {
+        // Record the setup type
+        if (buffer[6] == 0)  {
+            ctrl_xfer = CTRL_XFER_NONE;
+        } else {
+            uint8_t in_xfer = (buffer[0] >> 7) & 1;
+            ctrl_xfer = in_xfer ? CTRL_XFER_IN : CTRL_XFER_OUT;
+        }
     }
 
     USB0->CTL &= ~USB_CTL_TXSUSPENDTOKENBUSY_MASK;
@@ -351,9 +413,9 @@ EP_STATUS USBHAL::endpointWrite(uint8_t endpoint, uint8_t *data, uint32_t size)
     }
 
     if ((Data1 >> endpoint) & 1) {
-        bdt[idx].info = BD_OWN_MASK | BD_DTS_MASK;
-    } else {
         bdt[idx].info = BD_OWN_MASK | BD_DTS_MASK | BD_DATA01_MASK;
+    } else {
+        bdt[idx].info = BD_OWN_MASK | BD_DTS_MASK;
     }
 
     Data1 ^= (1 << endpoint);
@@ -450,7 +512,7 @@ void USBHAL::usbisr(void) {
 
         // setup packet
         if ((num == 0) && (TOK_PID((EP_BDT_IDX(num, dir, ev_odd))) == SETUP_TOKEN)) {
-            Data1 &= ~0x02;
+            Data1 |= 0x02 | 0x01; // set DATA1 for TX and RX
             bdt[EP_BDT_IDX(0, TX, EVEN)].info &= ~BD_OWN_MASK;
             bdt[EP_BDT_IDX(0, TX, ODD)].info  &= ~BD_OWN_MASK;