X-Git-Url: http://cloudbase.mooo.com/gitweb/z180-stamp.git/blobdiff_plain/4bc81323e51ac138e733c14eeb6f283ae706e904..2c60e1dc26e1f424d9673541aebe778601070838:/avr/serial.c

diff --git a/avr/serial.c b/avr/serial.c
index b2fea51..d3aeb4e 100644
--- a/avr/serial.c
+++ b/avr/serial.c
@@ -1,4 +1,7 @@
 /*
+ * (C) Copyright 2014 Leo C. <erbl259-lmu@yahoo.de>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
  */
 
 #include <avr/io.h>
@@ -12,19 +15,19 @@
 
 
 static int _write(char c, FILE *stream);
-static FILE mystdout = FDEV_SETUP_STREAM(_write, 
+static FILE mystdout = FDEV_SETUP_STREAM(_write,
 		NULL, _FDEV_SETUP_WRITE);
 
 
 
-#define BUFFER_SIZE 64
+#define BUFFER_SIZE 128
 
 #if ((BUFFER_SIZE-1) & BUFFER_SIZE)
 # error: BUFFER_SIZE not power of 2
 #endif
 
 #if ((BUFFER_SIZE) > 256)
-# error: BUFFER_SIZE 
+# error: BUFFER_SIZE
 #endif
 
 struct ring rx_ring;
@@ -36,21 +39,20 @@ uint8_t tx_ring_buffer[BUFFER_SIZE];
 
 /* Initialize UART */
 
-void usart0_setup(void) {
+void usart0_setup(unsigned long baud) {
 
 	ATOMIC_BLOCK(ATOMIC_RESTORESTATE) {
 
 		PRR0 &= ~_BV(PRUSART0);
 		UCSR0B = 0;
+		UCSR0A = 0;
+		UBRR0  = (F_CPU + (baud/2) + 8) / baud / 16 - 1;
+		UCSR0B = _BV(RXCIE0) | _BV(RXEN0) | _BV(TXEN0);
+		UCSR0C = 3 << UCSZ00;
 
 		/* Initialize ring buffers. */
 		ring_init(&rx_ring, rx_ring_buffer, BUFFER_SIZE);
 		ring_init(&tx_ring, tx_ring_buffer, BUFFER_SIZE);
-
-		UCSR0A = 0;
-		UBRR0  = F_CPU / BAUD / 16 - 1;
-		UCSR0B = _BV(RXCIE0) | _BV(RXEN0) | _BV(TXEN0);
-		UCSR0C = 3 << UCSZ00;
 	};
 }
 
@@ -82,10 +84,10 @@ ISR(USART0_UDRE_vect)
 
 /*--------------------------------------------------------------------------*/
 
-void serial_setup(void)
+void serial_setup(unsigned long baud)
 {
 	stdout = &mystdout;
-	usart0_setup();
+	usart0_setup(baud);
 }
 
 /*--------------------------------------------------------------------------*/
@@ -119,5 +121,3 @@ uint_fast8_t serial_tstc(void)
 {
 	return !ring_is_empty(&rx_ring);
 }
-
-