mbed/src/cpp/CAN.cpp

   1 /* mbed Microcontroller Library
   2  * Copyright (c) 2006-2013 ARM Limited
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  *     http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16 #include "CAN.h"
  17
  18 #if DEVICE_CAN
  19
  20 #include "cmsis.h"
  21
  22 namespace mbed {
  23
  24 CAN::CAN(PinName rd, PinName td) {
  25     can_init(&_can, rd, td);
  26 }
  27
  28 CAN::~CAN() {
  29     can_free(&_can);
  30 }
  31
  32 int CAN::frequency(int f) {
  33     return can_frequency(&_can, f);
  34 }
  35
  36 int CAN::write(CANMessage msg) {
  37     return can_write(&_can, msg, 0);
  38 }
  39
  40 int CAN::read(CANMessage &msg) {
  41     return can_read(&_can, &msg);
  42 }
  43
  44 void CAN::reset() {
  45     can_reset(&_can);
  46 }
  47
  48 unsigned char CAN::rderror() {
  49     return can_rderror(&_can);
  50 }
  51
  52 unsigned char CAN::tderror() {
  53     return can_tderror(&_can);
  54 }
  55
  56 void CAN::monitor(bool silent) {
  57     can_monitor(&_can, (silent) ? 1 : 0);
  58 }
  59
  60 static FunctionPointer* can_obj[2] = { NULL };
  61
  62 // Have to check that the CAN block is active before reading the Interrupt
  63 // Control Register, or the mbed hangs
  64 void can_irq(void) {
  65     uint32_t icr;
  66
  67     if(LPC_SC->PCONP & (1 << 13)) {
  68         icr = LPC_CAN1->ICR;
  69
  70         if(icr && (can_obj[0] != NULL)) {
  71             can_obj[0]->call();
  72         }
  73     }
  74
  75     if(LPC_SC->PCONP & (1 << 14)) {
  76         icr = LPC_CAN2->ICR;
  77         if(icr && (can_obj[1] != NULL)) {
  78             can_obj[1]->call();
  79         }
  80     }
  81
  82 }
  83
  84 void CAN::setup_interrupt(void) {
  85     switch ((int)_can.dev) {
  86         case CAN_1: can_obj[0] = &_rxirq; break;
  87         case CAN_2: can_obj[1] = &_rxirq; break;
  88     }
  89     _can.dev->MOD |= 1;
  90     _can.dev->IER |= 1;
  91     _can.dev->MOD &= ~1;
  92     NVIC_SetVector(CAN_IRQn, (uint32_t) &can_irq);
  93     NVIC_EnableIRQ(CAN_IRQn);
  94 }
  95
  96 void CAN::remove_interrupt(void) {
  97     switch ((int)_can.dev) {
  98         case CAN_1: can_obj[0] = NULL; break;
  99         case CAN_2: can_obj[1] = NULL; break;
 100     }
 101
 102     _can.dev->IER &= ~(1);
 103     if ((can_obj[0] == NULL) && (can_obj[1] == NULL)) {
 104         NVIC_DisableIRQ(CAN_IRQn);
 105     }
 106 }
 107
 108 void CAN::attach(void (*fptr)(void)) {
 109     if (fptr != NULL) {
 110         _rxirq.attach(fptr);
 111         setup_interrupt();
 112     } else {
 113         remove_interrupt();
 114     }
 115 }
 116
 117 } // namespace mbed
 118
 119 #endif