dw_uart.c

#include <stdint.h>
#include <stdbool.h>
#include <stdio.h>

#include "uart.h"

#define AXS101_UART_BASE	0xF0000000U
#define AXS101_UART_BAUDRATE	115200
#define AXS101_REF_CLOCK	50000000
#define MAX_DEBUG_MSG_FPGA	128

#include "dw_uart_reg.h"

#include "arc.h"

spinlock_t uart_lock;

void dw_uart_initDevice(DW_UART_STRUCT_PTR uartRegs, uint32_t ip_clk, int baudrate) 
{
	unsigned int divisor = ip_clk / (16*baudrate);

	spinlock_acquire(&uart_lock);

	uartRegs->LCR.DATA32 = 0x3;	// 0xc
	uartRegs->IER.DATA32 = uartRegs->IER.DATA32 & DW_UART_IER_UUE; /* 0x4: no interrupt */
	uartRegs->IIR.DATA32 = 0;	/* 0x8: Intends FCR: no fifo */
	uartRegs->MCR.DATA32 = 0x3;	/* 0x10: DTR + RTS */

	uartRegs->LCR.DATA32 = 0x3 | DW_UART_LCR_DLAB;
	uartRegs->DATA.DATA32 = divisor & 0xff;		// DLL
	uartRegs->IER.DATA32 = (divisor >> 8) & 0xff;	// DLM
	uartRegs->LCR.DATA32 = 0x3 & ~DW_UART_LCR_DLAB;

	spinlock_release(&uart_lock);
}


void uart_open(void)
{
	DW_UART_STRUCT_PTR   uart  = (DW_UART_STRUCT_PTR)  (AXS101_UART_BASE);

        dw_uart_initDevice(uart, AXS101_REF_CLOCK, AXS101_UART_BAUDRATE);

#if 0
	uart_put_char('@');
	uart_print_s("hello\n");
#endif
}

void dw_uart_print(DW_UART_STRUCT_PTR uartRegs, const char * pBuf)
{
	unsigned int i = MAX_DEBUG_MSG_FPGA;
	unsigned char byte = *pBuf++;

	spinlock_acquire(&uart_lock);

	while(byte && i--)
	{
		uartRegs->DATA.DATA32 = byte;
		while((uartRegs->LSR.DATA32 & BOTH_EMPTY) != BOTH_EMPTY);

		byte = *pBuf++;
	}

	spinlock_release(&uart_lock);

}

void uart_print_s(const char *str)
{
	DW_UART_STRUCT_PTR   uart  = (DW_UART_STRUCT_PTR)  (AXS101_UART_BASE);
	dw_uart_print(uart, str);
}

void uart_put_char(unsigned char ch)
{
	char str[2];

	str[0] = ch;
	str[1] = '\0';

	uart_print_s(str);
}

char dw_uart_getChar (DW_UART_STRUCT_PTR uartRegs)
{
   return ((char)uartRegs->DATA.DATA32);
}

char uart_get_char(void)
{
	char ch;

	DW_UART_STRUCT_PTR   uart  = (DW_UART_STRUCT_PTR)  (AXS101_UART_BASE);

	ch = dw_uart_getChar(uart);
	return ch;
}

void uart_isr(void)
{
	char ch = uart_get_char();

	uart_put_char(ch);
	if (ch == '\r')
		uart_put_char('\n');
		
}

void uart_print_s_n(const char *str, int n)
{
	uart_print_s(str);
	uart_print_n(n);
	uart_put_char('\r');
	uart_put_char('\n');
}

static char dec_to_hex[] = {'0','1','2','3','4','5','6','7','8','9',
                            'A','B','C','D','E','F'};

void uart_print_n(int n)
{
	int i, nibble;
	int leading_zeroes = 1;
	int zero_ok = 1;
	unsigned int num = n;

    /* If @num is Zero don't print it */
    if ( zero_ok || num != 0 ) {

    	uart_put_char('0');
    	uart_put_char('x');

        /* break num into 8 nibbles */
        for (i = 7; i >=0; i--) {
            nibble = (num >> (i << 2)) & 0xF;
            if ( nibble == 0 ) {
                if ( leading_zeroes && i != 0 ) continue;
            }
            else {
                if ( leading_zeroes )
                    leading_zeroes = 0;
            }
            uart_put_char(dec_to_hex[nibble]);
        }
    }

    uart_put_char(' ');
}