Add an mbed API that allows the initialization of the CAN at the correct

CAN bus frequency

drivers/CAN.cpp

@@ -34,6 +34,17 @@ CAN::CAN(PinName rd, PinName td) : _can(), _irq() {
     can_irq_init(&_can, (&CAN::_irq_handler), (uint32_t)this);
 }
 
+CAN::CAN(PinName rd, PinName td, int f) : _can(), _irq() {
+    // No lock needed in constructor
+
+    for (int i = 0; i < sizeof _irq / sizeof _irq[0]; i++) {
+        _irq[i].attach(donothing);
+    }
+
+    can_init_freq(&_can, rd, td, f);
+    can_irq_init(&_can, (&CAN::_irq_handler), (uint32_t)this);
+}
+
 CAN::~CAN() {
     // No lock needed in destructor
     can_irq_free(&_can);

drivers/CAN.h

@@ -111,6 +111,15 @@ public:
      * @endcode
      */
     CAN(PinName rd, PinName td);
+
+    /** Initialize CAN interface and set the frequency
+      *
+      * @param rd the rd pin
+      * @param td the td pin
+      * @param f the bus frequency in hertz
+      */
+    CAN(PinName rd, PinName td, int f);
+
     virtual ~CAN();
 
     /** Set the frequency of the CAN interface

hal/can_api.h

@@ -58,6 +58,7 @@ typedef void (*can_irq_handler)(uint32_t id, CanIrqType type);
 typedef struct can_s can_t;
 
 void          can_init      (can_t *obj, PinName rd, PinName td);
+void          can_init_freq (can_t *obj, PinName rd, PinName td, int hz);
 void          can_free      (can_t *obj);
 int           can_frequency (can_t *obj, int hz);