app/arm/can/can.c

   1 #include "can.h"
   2
   3 volatile int can_msg_received = 0;
   4 volatile can_msg_t can_rx_msg;
   5
   6 /* private global variables */
   7 uint32_t *can_rx_msg_data = (uint32_t*)can_rx_msg.data;
   8 can_rx_callback can_rx_cb;
   9
  10 void can_init(uint32_t btr, unsigned rx_isr_vect, can_rx_callback rx_cb) {
  11   /* enable CAN1 Rx pin */
  12   PINSEL1 |= 0x00040000;
  13   PINSEL1 &= 0xfff7ffff;
  14   /* receive all messages, no filtering */
  15   AFMR = 0x2;
  16   /* reset mode */
  17   C1MOD = 0x1;
  18   /* -- addition from lpc2000 maillist msg #3052: */
  19   C1CMR = 0x0e; //Clear receive buffer, data overrun, abort tx
  20   /* -- end of addition */
  21   C1IER = 0x0;
  22   C1GSR = 0x0;
  23   /* set baudrate & timing */
  24   C1BTR = btr;
  25   /* register Rx handler */
  26   can_rx_cb = rx_cb;
  27   /* set interrupt vector */
  28   ((uint32_t*)&VICVectAddr0)[rx_isr_vect] = (uint32_t)can_rx_isr;
  29   ((uint32_t*)&VICVectCntl0)[rx_isr_vect] = 0x20 | 26;
  30   /* enable Rx int */
  31   VICIntEnable = 0x04000000;
  32   C1IER = 0x1;
  33   /* normal (operating) mode */
  34   C1MOD = 0x0;
  35 #if 0
  36   /* LPC2119 CAN.5 erratum workaround */
  37   C1TFI1 = 0x00000000;
  38   C1TID1 = 0x0;
  39   C1CMR = 0x23;
  40 #endif
  41 }
  42
  43 void can_rx_isr() {
  44   can_rx_msg.flags = C1RFS;
  45   can_rx_msg.dlc = (can_rx_msg.flags>>16) & 0xf;
  46   can_rx_msg.id = C1RID;
  47   can_rx_msg_data[0] = C1RDA;
  48   can_rx_msg_data[1] = C1RDB;
  49   can_msg_received = 1;
  50   if (can_rx_cb != NULL)
  51     can_rx_cb((can_msg_t*)&can_rx_msg);
  52   /* release Rx buffer */
  53   C1CMR = 0x4;
  54   /* int acknowledge */
  55   VICVectAddr = 0;
  56 }
  57
  58 int can_tx_msg(can_msg_t *tx_msg) {
  59   uint32_t *data = (uint32_t*)tx_msg->data;
  60
  61   /* check, if buffer is ready (previous Tx completed) */
  62   if ((C1SR & 0x4) == 0)
  63     return -1; /* busy */
  64   C1TFI1 = (tx_msg->flags & 0xc0000000) |
  65     ((tx_msg->dlc<<16) & 0x000f0000);
  66   C1TID1 = tx_msg->id;
  67   C1TDA1 = data[0];
  68   C1TDB1 = data[1];
  69   /* start transmission */
  70   C1CMR = 0x21;
  71   return 0; /* OK */
  72 }
  73
  74 /*EOF*/