Organize into arch, board, and ec modules

src/arch/avr/uart.c

@@ -0,0 +1,99 @@
+#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_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;
+    }
+}