Subversion Repositories minsoc

#include <board.h>

#include <support.h>

#include "can.h"

int can_rx_done, can_tx_done;

int can_rx_rd_ptr;

int can_rx_wr_ptr;

int can_rx_buf_overflow;

can_type can_rx_data[CAN_BUF_LEN], can_tx_data;

can_type * can_get(void)

{

        if ( !can_rx_done )

                return NULL;

        can_rx_done--;

        int tmp;

        tmp = can_rx_rd_ptr;

        if (can_rx_rd_ptr < CAN_BUF_LEN-1)

                can_rx_rd_ptr++;

        else

                can_rx_rd_ptr = 0;

        return &can_rx_data[tmp];

}

void can_init(void)

{

        unsigned char sync_jmp, baudrate_presc, timing_seg1, timing_seg2, tripple_samp = 0;

        unsigned char acpt_code, acpt_mask = 0;

        unsigned char clk_div = 0 & CAN_BUS_CLKDIV_MASK;

        sync_jmp = 1;

        baudrate_presc = 1;

        timing_seg1 = 11;

        timing_seg2 = 2;

        tripple_samp = 1;

        acpt_code = 0x81;

        acpt_mask = 0xFF;

        char timing0, timing1 = 0;

        timing0 = (sync_jmp << CAN_BUS_TIMING_0_SYNC_JMP_SHIFT) & CAN_BUS_TIMING_0_SYNC_JMP;

        timing0 |= baudrate_presc & CAN_BUS_TIMING_0_BAUD_PRESC;

        timing1 = (tripple_samp << CAN_BUS_TIMING_1_TRIPLE_SAMP_SHIFT) & CAN_BUS_TIMING_1_TRIPLE_SAMP;

        timing1 |= (timing_seg2 << CAN_BUS_TIMING_1_TIME_SEG2_SHIFT) & CAN_BUS_TIMING_1_TIME_SEG2;

        timing1 |= timing_seg1 & CAN_BUS_TIMING_1_TIME_SEG1;

        REG8(CAN_BASE+CAN_MODE) = CAN_MODE_RESET;

        REG8(CAN_BASE+CAN_BUS_TIMING_0) = timing0;

        REG8(CAN_BASE+CAN_BUS_TIMING_1) = timing1;

        REG8(CAN_BASE+CAN_ACPT_CODE0) = acpt_code;

        REG8(CAN_BASE+CAN_ACPT_MASK0) = acpt_mask;

        REG8(CAN_BASE+CAN_BUS_MODE) &= ~CAN_BUS_MODE_CLOCK_OFF & ~CAN_BUS_MODE_EXTENDED_MODE;

        REG8(CAN_BASE+CAN_MODE) &= ~CAN_MODE_RESET;

        REG8(CAN_BASE+CAN_BUS_CLKDIV) = clk_div;

        REG8(CAN_BASE+CAN_MODE) |= CAN_MODE_TX_IRQ_EN | CAN_MODE_RECV_IRQ_EN;

        can_tx_done = 1;

        can_rx_done = 0;

        can_rx_rd_ptr = 0;

        can_rx_wr_ptr = 0;

        can_rx_buf_overflow = 0;

}

void can_recv_basic()

{

        unsigned char byte0, byte1;

        byte0 = REG8(CAN_BASE+CAN_RX_BUF);

        byte1 = REG8(CAN_BASE+CAN_RX_BUF+1);

        can_rx_data[can_rx_wr_ptr].data[0] = REG8(CAN_BASE+CAN_RX_BUF+2);

        can_rx_data[can_rx_wr_ptr].data[1] = REG8(CAN_BASE+CAN_RX_BUF+3);

        can_rx_data[can_rx_wr_ptr].data[2] = REG8(CAN_BASE+CAN_RX_BUF+4);

        can_rx_data[can_rx_wr_ptr].data[3] = REG8(CAN_BASE+CAN_RX_BUF+5);

        can_rx_data[can_rx_wr_ptr].data[4] = REG8(CAN_BASE+CAN_RX_BUF+6);

        can_rx_data[can_rx_wr_ptr].data[5] = REG8(CAN_BASE+CAN_RX_BUF+7);

        can_rx_data[can_rx_wr_ptr].data[6] = REG8(CAN_BASE+CAN_RX_BUF+8);

        can_rx_data[can_rx_wr_ptr].data[7] = REG8(CAN_BASE+CAN_RX_BUF+9);

        REG8(CAN_BASE+CAN_CMD) = CAN_CMD_RELEASE_BUFFER;

        can_rx_data[can_rx_wr_ptr].identifier = (byte0 << 3) | (byte1 >> 5);

        can_rx_data[can_rx_wr_ptr].rtr = byte1 & 0x10;

        can_rx_data[can_rx_wr_ptr].len = byte1 & 0x0F;

        if (can_rx_wr_ptr < CAN_BUF_LEN-1)

                can_rx_wr_ptr++;

        else

                can_rx_wr_ptr = 0;

        if (can_rx_wr_ptr == can_rx_rd_ptr+1)       //buffer overflow

        {

                can_rx_done = 1;

                can_rx_buf_overflow++;

        }

        else

                can_rx_done++;

}

int can_send_basic()

{

        if (!can_tx_done)       //if previous command not fully processed, bail out

                return -1;

        can_tx_done = 0;

        REG8(CAN_BASE+CAN_TX_BUF) = can_tx_data.identifier >> 3;

        REG8(CAN_BASE+CAN_TX_BUF+1) = (can_tx_data.identifier << 5) | ((can_tx_data.rtr << 4) & 0x10) | (can_tx_data.len & 0x0F);

        REG8(CAN_BASE+CAN_TX_BUF+2) = can_tx_data.data[0];

        REG8(CAN_BASE+CAN_TX_BUF+3) = can_tx_data.data[1];

        REG8(CAN_BASE+CAN_TX_BUF+4) = can_tx_data.data[2];

        REG8(CAN_BASE+CAN_TX_BUF+5) = can_tx_data.data[3];

        REG8(CAN_BASE+CAN_TX_BUF+6) = can_tx_data.data[4];

        REG8(CAN_BASE+CAN_TX_BUF+7) = can_tx_data.data[5];

        REG8(CAN_BASE+CAN_TX_BUF+8) = can_tx_data.data[6];

        REG8(CAN_BASE+CAN_TX_BUF+9) = can_tx_data.data[7];

        REG8(CAN_BASE+CAN_CMD) = CAN_CMD_TX_REQ;

        return can_tx_data.len;

}

void can_irq(void)

{

        unsigned char irq_req, rx_done;

        irq_req = REG8(CAN_BASE+IRQ_READ);

        rx_done = irq_req & CAN_IRQ_READ_RX;

        can_tx_done = irq_req & CAN_IRQ_READ_TX;

        if (rx_done)

                can_recv_basic();

}

void can_abort(void)

{

        REG8(CAN_BASE+CAN_CMD) = CAN_CMD_ABORT_TX;

}