2019-09-29 21:20:03 -06:00

104 lines
2.3 KiB
C

#include <stdio.h>
#include <avr/io.h>
#include <arch/uart.h>
#include <board/cpu.h>
#define UART(N) \
{ \
&UCSR ## N ## A, \
&UCSR ## N ## B, \
&UCSR ## N ## C, \
&UDR ## N, \
&UBRR ## N ## L, \
&UBRR ## N ## H, \
_BV(RXC ## N), \
_BV(UDRE ## N), \
0, \
_BV(RXEN ## N) | _BV(TXEN ## N), \
_BV(UCSZ ## N ## 1) | _BV(UCSZ ## N ## 0) \
}
#if defined(__AVR_ATmega328P__)
static struct Uart UARTS[] = {
UART(0)
};
#elif defined(__AVR_ATmega32U4__)
static struct Uart UARTS[] = {
UART(1)
};
#elif defined(__AVR_ATmega1280__) || defined(__AVR_ATmega2560__)
static struct Uart UARTS[] = {
UART(0),
UART(1),
UART(2),
UART(3)
};
#else
#error "Could not find UART definitions"
#endif
int uart_count() {
return sizeof(UARTS)/sizeof(struct Uart);
}
struct Uart * uart_new(int num) {
if (num < uart_count()) {
return &UARTS[num];
} else {
return NULL;
}
}
void uart_init(struct Uart * uart, unsigned long baud) {
unsigned long baud_prescale = (F_CPU / (baud * 16UL)) - 1;
*(uart->baud_h) = (uint8_t)(baud_prescale>>8);
*(uart->baud_l) = (uint8_t)(baud_prescale);
*(uart->a) = uart->a_init;
*(uart->b) = uart->b_init;
*(uart->c) = uart->c_init;
}
unsigned char uart_can_read(struct Uart * uart) {
return (*(uart->a)) & uart->a_read;
}
unsigned char uart_read(struct Uart * uart) {
while (!uart_can_read(uart)) ;
return *(uart->data);
}
unsigned char uart_can_write(struct Uart * uart) {
return (*(uart->a)) & uart->a_write;
}
void uart_write(struct Uart * uart, unsigned char data) {
while (!uart_can_write(uart)) ;
*(uart->data) = data;
}
struct Uart * uart_stdio = NULL;
int uart_stdio_get(FILE * stream) {
return (int)uart_read(uart_stdio);
}
int uart_stdio_put(char data, FILE * stream) {
if (data == '\n') {
uart_write(uart_stdio, '\r');
}
uart_write(uart_stdio, (unsigned char)data);
return 0;
}
FILE uart_stdio_file = FDEV_SETUP_STREAM(uart_stdio_put, uart_stdio_get, _FDEV_SETUP_RW);
void uart_stdio_init(int num, unsigned long baud) {
struct Uart * uart = uart_new(num);
if(uart != NULL) {
uart_init(uart, baud);
uart_stdio = uart;
stdin = stdout = stderr = &uart_stdio_file;
}
}