Add implementation of USART and more ground changes

2 files changed, 189 insertions, 0 deletions

diff --git a/src/usart.c b/src/usart.c
new file mode 100644
index 0000000..9187bc6
--- /dev/null
+++ b/src/usart.c
@@ -0,0 +1,177 @@
+#include "../usart.h"
+
+#ifdef MCUSUPPORT_USART
+
+volatile int8_t _usart_busy;
+
+inline void usart_init_uart(void) {
+    usart_init_async(USART_BAUDRATE_115200, USART_PARITY_NONE,
+                     USART_STOPBIT_SINGLE, USART_DATABITS_8);
+}
+
+void usart_init_async(enum usartBaudrate baudrate,
+                      enum usartParity parity, enum usartStopBit stopbit,
+                      enum usartDataBits databits) {
+    _usart_busy = 0;
+    switch (baudrate) {
+    case USART_BAUDRATE_2400:
+#define BAUD 2400
+#include "usart_baundrate_helper.h"
+        break;
+    case USART_BAUDRATE_4800:
+#define BAUD 4800
+#include "usart_baundrate_helper.h"
+        break;
+    case USART_BAUDRATE_9600:
+#define BAUD 9600
+#include "usart_baundrate_helper.h"
+        break;
+    case USART_BAUDRATE_19200:
+#define BAUD 19200
+#include "usart_baundrate_helper.h"
+        break;
+    case USART_BAUDRATE_38400:
+#define BAUD 38400
+#include "usart_baundrate_helper.h"
+        break;
+    case USART_BAUDRATE_57600:
+#define BAUD 57600
+#include "usart_baundrate_helper.h"
+        break;
+    case USART_BAUDRATE_115200:
+#define BAUD 115200
+#include "usart_baundrate_helper.h"
+        break;
+    }
+    switch (parity) {
+    case USART_PARITY_NONE:
+        UCSR0C &= ~(_BV(UPM00) | _BV(UPM01));
+        break;
+    case USART_PARITY_ODD:
+        UCSR0C &= ~_BV(UPM00);
+        UCSR0C |= _BV(UPM01);
+        break;
+    case USART_PARITY_EVEN:
+        UCSR0C |= _BV(UPM00) | _BV(UPM01);
+        break;
+    }
+    switch (stopbit) {
+    case USART_STOPBIT_SINGLE:
+        UCSR0C &= ~_BV(USBS0);
+        break;
+    case USART_STOPBIT_DOUBLE:
+        UCSR0C |= _BV(USBS0);
+        break;
+    }
+    switch (databits) {
+    case USART_DATABITS_5:
+        UCSR0C &= ~(_BV(UCSZ00) | _BV(UCSZ01));
+        break;
+    case USART_DATABITS_6:
+        UCSR0C &= ~_BV(UCSZ01);
+        UCSR0C |= _BV(UCSZ00);
+        break;
+    case USART_DATABITS_7:
+        UCSR0C &= ~_BV(UCSZ00);
+        UCSR0C |= _BV(UCSZ01);
+        break;
+    case USART_DATABITS_8:
+        UCSR0C |= _BV(UCSZ00) | _BV(UCSZ01);
+        break;
+    }
+    // Enable receiver, transmitter and RX complete,
+    // Data register empty interrupts
+    UCSR0B = _BV(RXEN0) | _BV(TXEN0) | _BV(RXCIE0) | _BV(UDRIE0);
+#ifdef _IOE_USART_INBUFFER
+    IOEBUFFER_INIT(_ioe_usart_inbuffer, CONFIG_IOE_USART_INBUFFER_SIZE);
+#endif
+#ifdef _IOE_USART_OUTBUFFER
+    IOEBUFFER_INIT(_ioe_usart_outbuffer, CONFIG_IOE_USART_OUTBUFFER_SIZE);
+#endif
+}
+
+inline void usart_send(uint8_t data) {
+#ifdef _IOE_USART_OUTBUFFER
+    if (!_usart_busy) {
+        _usart_busy = 1;
+        UDR0 = data;
+    } else {
+        IOEBUFFER_PUT(_ioe_usart_outbuffer, CONFIG_IOE_USART_OUTBUFFER_SIZE,
+                data, CONFIG_IOE_USART_OUTBUFFER_MODE);
+    }
+#else
+    _usart_busy = 1;
+    UDR0 = data;
+#endif /* _IOE_USART_OUTBUFFER */
+}
+
+#ifdef _IOE_USART_OUTBUFFER
+void usart_send_str(char *str) {
+    while(*str != '\0') {
+        usart_send((uint8_t) *str);
+        str++;
+    }
+}
+#endif /* _IOE_USART_OUTBUFFER */
+
+#ifdef _IOE_USART_INBUFFER
+uint8_t usart_get(void) {
+    uint8_t rtn = 0;
+    IOEBUFFER_GET(_ioe_usart_inbuffer, CONFIG_IOE_USART_INBUFFER_SIZE, rtn);
+    return rtn;
+}
+#endif
+
+inline uint8_t usart_queryerror(void) {
+    return UCSR0A & (_BV(FE0) | _BV(DOR0) | _BV(UPE0));
+}
+
+inline int8_t usart_busy(void) {
+    return _usart_busy;
+}
+
+#ifdef _IOE_USART_INBUFFER
+uint8_t usart_inbuffered(void) {
+    uint8_t rtn;
+    IOEBUFFER_CNT(_ioe_usart_inbuffer, CONFIG_IOE_USART_INBUFFER_SIZE, rtn);
+    return rtn;
+}
+#endif
+
+#ifdef _IOE_USART_OUTBUFFER
+uint8_t usart_outbuffered(void) {
+    uint8_t rtn;
+    IOEBUFFER_CNT(_ioe_usart_outbuffer, CONFIG_IOE_USART_OUTBUFFER_SIZE, rtn);
+    return rtn;
+}
+#endif
+
+////// Interrupts ////////////////////////////////
+void (*usart_receive) (uint8_t data) = 0;
+void (*usart_sent) (void) = 0;
+
+SIGNAL(USART_RX_vect) {
+#ifdef _IOE_USART_INBUFFER
+    IOEBUFFER_PUT(_ioe_usart_inbuffer, CONFIG_IOE_USART_INBUFFER_SIZE,
+            UDR0, CONFIG_IOE_USART_INBUFFER_MODE);
+#endif /* _IOE_USART_INBUFFER */
+    if (usart_receive)
+        usart_receive(UDR0);
+}
+
+SIGNAL(USART_UDRE_vect) {
+#ifdef _IOE_USART_OUTBUFFER
+    uint8_t val;
+    IOEBUFFER_GET(_ioe_usart_outbuffer, CONFIG_IOE_USART_OUTBUFFER_SIZE, val);
+    if (val)
+        UDR0 = val;
+    else
+        _usart_busy = 0;
+#else
+    _usart_busy = 0;
+#endif /* _IOE_USART_OUTBUFFER */
+    if (usart_sent)
+        usart_sent();
+}
+
+#endif
diff --git a/src/usart_baundrate_helper.h b/src/usart_baundrate_helper.h
new file mode 100644
index 0000000..0271bdd
--- /dev/null
+++ b/src/usart_baundrate_helper.h
@@ -0,0 +1,12 @@
+#include <util/setbaud.h>
+UBRR0H = UBRRH_VALUE;
+UBRR0L = UBRRL_VALUE;
+#if USE_2X
+UCSR0A |= _BV(U2X0);
+#else
+UCSR0A &= ~_BV(U2X0);
+#endif
+#undef BAUD
+#undef UBRRH_VALUE
+#undef UBRRL_VALUE
+#undef USE_2X