STM32: auto bit rate in silent mode

libuavcan_drivers/stm32/driver/include/uavcan_stm32/can.hpp

@@ -56,6 +56,8 @@ class CanIface : public uavcan::ICanIface, uavcan::Noncopyable
         void push(const uavcan::CanFrame& frame, const uint64_t& utc_usec, uavcan::CanIOFlags flags);
         void pop(uavcan::CanFrame& out_frame, uavcan::uint64_t& out_utc_usec, uavcan::CanIOFlags& out_flags);
 
+        void reset();
+
         unsigned getLength() const { return len_; }
 
         uavcan::uint32_t getOverflowCount() const { return overflow_cnt_; }
@@ -127,6 +129,12 @@ class CanIface : public uavcan::ICanIface, uavcan::Noncopyable
 public:
     enum { MaxRxQueueCapacity = 254 };
 
+    enum OperatingMode
+    {
+        NormalMode,
+        SilentMode
+    };
+
     CanIface(bxcan::CanType* can, BusEvent& update_event, uavcan::uint8_t self_index,
              CanRxItem* rx_queue_buffer, uavcan::uint8_t rx_queue_capacity)
         : rx_queue_(rx_queue_buffer, rx_queue_capacity)
@@ -149,7 +157,7 @@ public:
      *   - Iface has been resetted via RCC
      *   - Caller will configure NVIC by itself
      */
-    int init(uavcan::uint32_t bitrate);
+    int init(const uavcan::uint32_t bitrate, const OperatingMode mode);
 
     void handleTxInterrupt(uavcan::uint64_t utc_usec);
     void handleRxInterrupt(uavcan::uint8_t fifo_index, uavcan::uint64_t utc_usec);
@@ -241,7 +249,7 @@ public:
      * Returns zero if OK.
      * Returns negative value if failed (e.g. invalid bitrate).
      */
-    int init(uavcan::uint32_t bitrate);
+    int init(const uavcan::uint32_t bitrate, const CanIface::OperatingMode mode);
 
     virtual CanIface* getIface(uavcan::uint8_t iface_index);
 
@@ -277,8 +285,6 @@ public:
      * This function can either initialize the driver at a fixed bit rate, or it can perform
      * automatic bit rate detection. For theory please refer to the CiA application note #801.
      *
-     * TODO FIXME: During bit rate detection, the CAN controller must be initialized in listen-only mode.
-     *
      * @param delay_callable    A callable entity that suspends execution for strictly more than one second.
      *                          The callable entity will be invoked without arguments.
      *                          @ref getRecommendedListeningDelay().
@@ -294,7 +300,7 @@ public:
     {
         if (inout_bitrate > 0)
         {
-            return driver.init(inout_bitrate);
+            return driver.init(inout_bitrate, CanIface::NormalMode);
         }
         else
         {
@@ -310,8 +316,7 @@ public:
             {
                 inout_bitrate = StandardBitRates[br];
 
-                // TODO: listen-only mode
+                const int res = driver.init(inout_bitrate, CanIface::SilentMode);
-                const int res = driver.init(inout_bitrate);
 
                 delay_callable();
 
@@ -321,7 +326,8 @@ public:
                     {
                         if (!driver.getIface(iface)->isRxBufferEmpty())
                         {
-                            return res;
+                            // Re-initializing in normal mode
+                            return driver.init(inout_bitrate, CanIface::NormalMode);
                         }
                     }
                 }

libuavcan_drivers/stm32/driver/src/uc_stm32_can.cpp

@@ -160,6 +160,14 @@ void CanIface::RxQueue::pop(uavcan::CanFrame& out_frame, uavcan::uint64_t& out_u
     else { UAVCAN_ASSERT(0); }
 }
 
+void CanIface::RxQueue::reset()
+{
+    in_ = 0;
+    out_ = 0;
+    len_ = 0;
+    overflow_cnt_ = 0;
+}
+
 /*
  * CanIface
  */
@@ -446,10 +454,21 @@ bool CanIface::waitMsrINakBitStateChange(bool target_state)
     return false;
 }
 
-int CanIface::init(uavcan::uint32_t bitrate)
+int CanIface::init(const uavcan::uint32_t bitrate, const OperatingMode mode)
 {
     int res = 0;
 
+    /*
+     * Object state
+     */
+    rx_queue_.reset();
+    error_cnt_ = 0;
+    served_aborts_cnt_ = 0;
+    uavcan::fill_n(pending_tx_, NumTxMailboxes, TxItem());
+    last_hw_error_code_ = 0;
+    peak_tx_mailbox_index_ = 0;
+    had_activity_ = false;
+
     /*
      * CAN timings for this bitrate
      */
@@ -480,7 +499,8 @@ int CanIface::init(uavcan::uint32_t bitrate)
     can_->BTR = ((timings.sjw & 3U)  << 24) |
                 ((timings.bs1 & 15U) << 16) |
                 ((timings.bs2 & 7U)  << 20) |
-                (timings.prescaler & 1023U);
+                (timings.prescaler & 1023U) |
+                ((mode == SilentMode) ? bxcan::BTR_SILM : 0);
 
     can_->IER = bxcan::IER_TMEIE |   // TX mailbox empty
                 bxcan::IER_FMPIE0 |  // RX FIFO 0 is not empty
@@ -812,7 +832,7 @@ uavcan::int16_t CanDriver::select(uavcan::CanSelectMasks& inout_masks,
     return 1;                                   // Return value doesn't matter as long as it is non-negative
 }
 
-int CanDriver::init(uavcan::uint32_t bitrate)
+int CanDriver::init(const uavcan::uint32_t bitrate, const CanIface::OperatingMode mode)
 {
     int res = 0;
 
@@ -835,7 +855,7 @@ int CanDriver::init(uavcan::uint32_t bitrate)
     }
 
     UAVCAN_STM32_LOG("Initing iface 0...");
-    res = if0_.init(bitrate);
+    res = if0_.init(bitrate, mode);
     if (res < 0)
     {
         UAVCAN_STM32_LOG("Iface 0 init failed %i", res);
@@ -861,7 +881,7 @@ int CanDriver::init(uavcan::uint32_t bitrate)
     }
 
     UAVCAN_STM32_LOG("Initing iface 1...");
-    res = if1_.init(bitrate);
+    res = if1_.init(bitrate, mode);
     if (res < 0)
     {
         UAVCAN_STM32_LOG("Iface 1 init failed %i", res);