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/*
* debugging routines
*
* Copyright (C) 2014 Michael Buesch <m@bues.ch>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include "debug.h"
#include "util.h"
#include <avr/io.h>
#include <avr/interrupt.h>
enum {
ENODATA,
ERXFE,
ERXPE,
ERXOV,
};
struct usart_rx_result {
int8_t error;
uint8_t data;
};
void usart_tx(uint8_t data)
{
while (!(UCSRA & (1 << UDRE)));
UDR = data;
}
void usart_tx_hex8(uint8_t number)
{
usart_tx('0');
usart_tx('x');
usart_tx(hexdigit_to_ascii((number & 0xF0) >> 4));
usart_tx(hexdigit_to_ascii(number & 0x0F));
}
void usart_tx_hex16(uint16_t number)
{
usart_tx('0');
usart_tx('x');
usart_tx(hexdigit_to_ascii((number & 0xF000) >> 12));
usart_tx(hexdigit_to_ascii((number & 0x0F00) >> 8));
usart_tx(hexdigit_to_ascii((number & 0x00F0) >> 4));
usart_tx(hexdigit_to_ascii(number & 0x000F));
}
void usart_tx_1num_8bit(const char PROGPTR *d, uint8_t n)
{
usart_tx_1num_16bit(d, n);
}
void usart_tx_2num_8bit(const char PROGPTR *d1, uint8_t n1, const char PROGPTR *d2, uint8_t n2)
{
usart_tx_2num_16bit(d1, n1, d2, n2);
}
void usart_tx_1num_16bit(const char PROGPTR *d, uint16_t n)
{
usart_tx_string(d);
usart_tx(':');
usart_tx(' ');
if (n & 0xFF00)
usart_tx_hex16(n);
else
usart_tx_hex8(n);
usart_tx_string(PSTR("\n"));
}
void usart_tx_2num_16bit(const char PROGPTR *d1, uint16_t n1, const char PROGPTR *d2, uint16_t n2)
{
usart_tx_string(d1);
usart_tx(' ');
if (n1 & 0xFF00)
usart_tx_hex16(n1);
else
usart_tx_hex8(n1);
usart_tx(' ');
usart_tx_string(d2);
usart_tx(' ');
if (n2 & 0xFF00)
usart_tx_hex16(n2);
else
usart_tx_hex8(n2);
usart_tx_string(PSTR("\n"));
}
void usart_tx_string(const char PROGPTR *flash_string)
{
uint8_t c;
for ( ; ; flash_string++) {
c = pgm_read_byte(flash_string);
if (c == '\0')
break;
if (c == '\n')
usart_tx('\r');
usart_tx(c);
}
}
void usart_dump_mem(const void *_mem, uint8_t size)
{
const uint8_t *mem = _mem;
uint8_t i;
for (i = 0; i < size; i++) {
if (i % 16 == 0) {
if (i != 0)
usart_tx_string(PSTR("\n"));
usart_tx_string(PSTR("0x"));
usart_tx(hexdigit_to_ascii((i & 0xF0) >> 4));
usart_tx(hexdigit_to_ascii(i & 0x0F));
usart_tx_string(PSTR(": "));
}
if (i % 2 == 0)
usart_tx(' ');
usart_tx(hexdigit_to_ascii((mem[i] & 0xF0) >> 4));
usart_tx(hexdigit_to_ascii(mem[i] & 0x0F));
}
usart_tx_string(PSTR("\n"));
}
static struct usart_rx_result usart_rx(void)
{
struct usart_rx_result res = {
.error = 0,
.data = 0,
};
uint8_t status;
status = UCSRA;
if (!(status & (1 << RXC))) {
res.error = -ENODATA;
goto out;
}
if (status & ((1 << FE) | (1 << PE) | (1 << DOR))) {
if (status & (1 << DOR))
res.error = -ERXOV;
else if (status & (1 << PE))
res.error = -ERXPE;
else if (status & (1 << FE))
res.error = -ERXFE;
goto out;
}
res.data = UDR;
out:
return res;
}
ISR(USART_RXC_vect)
{
struct usart_rx_result res;
while (1) {
res = usart_rx();
if (res.error)
break;
/* We simply echo the data */
usart_tx(res.data);
if (res.data == '\r')
usart_tx('\n');
}
}
#define USART_BAUD 19200
#if USART_USE_2X
# define UBRR_FACTOR 2
#else
# define UBRR_FACTOR 1
#endif
void usart_init(void)
{
/* Set baud rate */
UBRRL = ((F_CPU / 16 / USART_BAUD) * UBRR_FACTOR) & 0xFF;
UBRRH = (((F_CPU / 16 / USART_BAUD) * UBRR_FACTOR) >> 8) & ~(1 << URSEL);
#if USART_USE_2X
UCSRA = (1 << U2X);
#endif
/* 8 Data bits, 1 Stop bit, No parity */
UCSRC = (1 << UCSZ0) | (1 << UCSZ1) | (1 << URSEL);
/* Enable transceiver */
UCSRB = (1 << RXEN) | (1 << TXEN) | (1 << RXCIE);
}
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