o start usb uploadr avr

poc/avr_usbload/uart.c

@@ -0,0 +1,79 @@
+#include <avr/io.h>
+#include <avr/interrupt.h>
+#include <avr/pgmspace.h>
+#include <stdio.h>
+#include "uart.h"
+#include "fifo.h"
+
+volatile struct
+{
+    uint8_t tmr_int: 1;
+    uint8_t adc_int: 1;
+    uint8_t rx_int: 1;
+}
+intflags;
+
+/*
+ *  * Last character read from the UART.
+ *   
+ */
+volatile char rxbuff;
+
+
+FILE uart_stdout = FDEV_SETUP_STREAM(uart_stream, NULL, _FDEV_SETUP_WRITE);
+
+void uart_init(void)
+{
+    UCSRA = _BV(U2X);     /* improves baud rate error @ F_CPU = 1 MHz */
+    UCSRB = _BV(TXEN)|_BV(RXEN)|_BV(RXCIE); /* tx/rx enable, rx complete intr */
+    UBRRL = (F_CPU / (8 * 115200UL)) - 1;  /* 9600 Bd */
+
+}
+
+
+ISR(USART_RXC_vect)
+{
+    uint8_t c;
+    c = UDR;
+    if (bit_is_clear(UCSRA, FE)){
+        rxbuff = c;
+        intflags.rx_int = 1;
+    }
+}
+
+
+void  uart_putc(uint8_t c)
+{
+    loop_until_bit_is_set(UCSRA, UDRE);
+    UDR = c;
+}
+
+
+void uart_puts(const char *s)
+{
+    do {
+        uart_putc(*s);
+    }
+    while (*s++);
+}
+
+void uart_puts_P(PGM_P s)
+{
+    while (1) {
+        unsigned char c = pgm_read_byte(s);
+        s++;
+        if ('\0' == c)
+            break;
+        uart_putc(c);
+    }
+}
+
+static int uart_stream(char c, FILE *stream)
+{
+    if (c == '\n')
+        uart_putc('\r');
+    loop_until_bit_is_set(UCSRA, UDRE);
+    UDR = c;
+    return 0;
+}
+