atusb/fw2: moved board-specific functions (SPI, RF reset) out of main()

- Makefile (OBJS): added spi.o
- spi.h, spi.c, atusb.c: moved SPI functions to new file
- spi.h (spi), spi.c (spi), atusb.c (main): renamed function "spi" to
  "spi_io"
- atusb.c (reset_rf, main): moved transceiver reset to separate function

atusb/fw2/Makefile

@@ -16,7 +16,7 @@ USB_OBJS = $(FreakUSB)/usb/usb.o $(FreakUSB)/usb/ctrl.o \
   $(FreakUSB)/usb/usb_buf.o \
   $(FreakUSB)/hw/at90usbxx2/ep.o $(FreakUSB)/hw/at90usbxx2/hw.o \
   $(FreakUSB)/hw/at90usbxx2/isr.o
-OBJS = atusb.o descr.o $(USB_OBJS)
+OBJS = atusb.o spi.o descr.o $(USB_OBJS)
 
 CFLAGS += -I../fw/include \
 	  -I$(FreakUSB)/usb -I$(FreakUSB)/hw/at90usbxx2 \

atusb/fw2/atusb.c

@@ -7,29 +7,25 @@
 
 #include "freakusb.h"
 
-#include "io.h"
 #include "at86rf230.h"
+#include "io.h"
+#include "spi.h"
 
 
-static void spi_begin(void)
+void reset_rf(void);
+
+
+void reset_rf(void)
 {
-	CLR(nSS);
-}
+	/* AT86RF231 data sheet, 12.4.13, reset pulse width: 625 ns (min) */
 
+	CLR(nRST_RF);
+	_delay_us(1);
+	SET(nRST_RF);
 
-static uint8_t spi(uint8_t v)
-{
-//	while (!(UCSR1A & 1 << UDRE1));
-	UDR1 = v;
-	while (!(UCSR1A & 1 << RXC1));
-	return UDR1;
-}
+	/* 12.4.14: SPI access latency after reset: 625 ns (min) */
 
-
-static void spi_end(void)
-{
-//	while (!(UCSR1A & 1 << TXC1));
-	SET(nSS);
+	_delay_us(1);
 }
 
 
@@ -43,32 +39,12 @@ int main(void)
 	/* set up all the outputs; default port value is 0 */
 
 	OUT(LED);
-	OUT(nRST_RF);	/* reset the transceiver */
+	OUT(nRST_RF);	/* resets the transceiver */
 	OUT(SLP_TR);
-	OUT(SCLK);
-	OUT(MOSI);
-	OUT(nSS);
 
-	/* set up UART-SPI */
+	spi_init();
 
-	UCSR1C = 1 << UMSEL11 | 1 << UMSEL10;
-				/* set MSPI, MSB first, SPI data mode 0 */
-	UCSR1B = 1 << RXEN1 | 1 << TXEN1;
-				/* enable receiver and transmitter */
-	UBRR1 = 0;		/* reconfirm the bit rate */
-
-	/* bring the transceiver out of reset */
-
-	/*
-	 * AT86RF231 data sheet, 12.4.13, reset pulse with: 625 ns (min).
-	 * We spend a lot more time getting here, so no extra wait is needed.
-	 */
-	SET(nRST_RF);
-
-	/*
-	 * 12.4.14: SPI access latency after reset: 625 ns
-	 */
-	_delay_us(1);
+	reset_rf();
 
 	/* switch CLKM to 8 MHz */
 
@@ -81,8 +57,8 @@ int main(void)
 	 */
 
 	spi_begin();
-	spi(AT86RF230_REG_WRITE | REG_TRX_CTRL_0);
-	spi(CLKM_CTRL_8MHz);
+	spi_send(AT86RF230_REG_WRITE | REG_TRX_CTRL_0);
+	spi_send(CLKM_CTRL_8MHz);
 	spi_end();
 
 	/* now we should be at 8 MHz */

atusb/fw2/spi.c

@@ -0,0 +1,44 @@
+#include <stdint.h>
+
+#include <avr/io.h>
+
+#include "io.h"
+#include "spi.h"
+
+
+void spi_begin(void)
+{
+	CLR(nSS);
+}
+
+
+uint8_t spi_io(uint8_t v)
+{
+//      while (!(UCSR1A & 1 << UDRE1));
+        UDR1 = v;
+        while (!(UCSR1A & 1 << RXC1));
+        return UDR1;
+}
+
+
+void spi_end(void)
+{
+//      while (!(UCSR1A & 1 << TXC1));
+	SET(nSS);
+}
+
+
+void spi_init(void)
+{
+	OUT(SCLK);
+	OUT(MOSI);
+	OUT(nSS);
+	IN(MISO);
+
+	UBRR1 = 0;	/* set bit rate to zero to begin */
+	UCSR1C = 1 << UMSEL11 | 1 << UMSEL10;
+			/* set MSPI, MSB first, SPI data mode 0 */
+	UCSR1B = 1 << RXEN1 | 1 << TXEN1;
+			/* enable receiver and transmitter */
+	UBRR1 = 0;	/* reconfirm the bit rate */
+}

atusb/fw2/spi.h

@@ -0,0 +1,14 @@
+#ifndef SPI_H
+#define	SPI_H
+
+#include <stdint.h>
+
+void spi_begin(void);
+uint8_t spi_io(uint8_t v);
+void spi_end(void);
+void spi_init(void);
+
+#define	spi_send(v)	(void) spi_io(v)
+#define	spi_recv(v)	spi_io(0)
+
+#endif /* !SPI_H */