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https://opencores.org/ocsvn/minsoc/minsoc/trunk
Subversion Repositories minsoc
[/] [minsoc/] [trunk/] [sw/] [drivers/] [can.c] - Rev 53
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#include "../support/board.h" #include "../support/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; }
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