Commit 044ff708 authored by Birte Kristina Friesel's avatar Birte Kristina Friesel
Browse files

add (untested!) MSP430 SPI driver

parent 6493f6ee

include/msp430fr5969lp/driver/spi.h

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#ifndef SPI_H

#define SPI_H



class SPI {

	private:

		SPI(const SPI &copy);



	public:

		SPI () {}

		signed char setup();

		signed char xmit(

				unsigned char tx_len, unsigned char *tx_buf,

				unsigned char rx_len, unsigned char *rx_buf);

};



extern SPI spi;



#endif

include/msp430fr5969lp/driver/spi_b.h

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#ifndef SPI_H

#define SPI_H



class SPI {

	private:

		SPI(const SPI &copy);



	public:

		SPI () {}

		signed char setup();

		signed char xmit(

				unsigned char tx_len, unsigned char *tx_buf,

				unsigned char rx_len, unsigned char *rx_buf);

};



extern SPI spi;



#endif

src/arch/msp430fr5969lp/driver/spi.cc

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#include "driver/spi.h"

#include <msp430.h>



signed char SPI::setup()

{

	/* UCA1CLK Pin 2.4 */

	P2SEL0 &= ~BIT4;

	P2SEL1 |= BIT4;

	P2DIR |= BIT4;



	/* UCA1SIMO Pin 2.5 */

	P2SEL0 &= ~BIT5;

	P2SEL1 |= BIT5;

	P2DIR |= BIT5;



	/* UCA1SOMI Pin 2.6 */

	P2SEL0 &= ~BIT6;

	P2SEL1 |= BIT6;

	P2DIR &= ~BIT6;

	//P2REN |= BIT6;



	UCA1CTLW0 |= UCSWRST;

	UCA1MCTLW = 0; // no modulation



	UCA1CTLW0 = UCCKPH | UCMSB | UCMST | UCSYNC | UCMODE_0 | UCSSEL__SMCLK | UCSWRST;

	UCA1BRW = 15; // /16 -> 1MHz

	UCA1CTLW0 &= ~UCSWRST;

}



signed char SPI::xmit(unsigned char tx_len, unsigned char *tx_buf,

		unsigned char rx_len, unsigned char *rx_buf)

{

	volatile char rxbuf_cache;

	if (tx_len < 1) {

		return -1;

	}



	UCA1IE &= ~(UCTXIE | UCRXIE);



	while (UCA1STATW & UCBUSY) ;



	rxbuf_cache = UCA1RXBUF;

	UCA1TXBUF = tx_buf[0];



	unsigned char tx_pos = 1;

	unsigned char rx_pos = 0;



	while (tx_pos < tx_len || rx_pos < rx_len) {

		if ((tx_pos < tx_len) && (UCA1IF & UCTXIFG)) {

			UCBA1TXBUF = tx_buf[tx_pos++];

		}

		if (UCA1IFG & UCRXIFG) {

			if (rx_pos < rx_len) {

				rx_buf[rx_pos] = UCA1RXBUF;

			} else {

				rxbuf_cache = UCA1RXBUF;

			}

		}

		rx_pos++;

	}

}

src/arch/msp430fr5969lp/driver/spi_b.cc

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#include "driver/spi.h"

#include <msp430.h>



signed char SPI::setup()

{

	/* UCB0CLK Pin 2.2 */

	P2SEL0 &= ~BIT2;

	P2SEL1 |= BIT2;

	P2DIR |= BIT2;



	/* UCB0SIMO Pin 1.6 */

	P1SEL0 &= ~BIT6;

	P1SEL1 |= BIT6;

	P1DIR |= BIT6;



	/* UCB0SOMI Pin 1.7 */

	P1SEL0 &= ~BIT7;

	P1SEL1 |= BIT7;

	P1DIR &= ~BIT7;

	//P1REN |= BIT6;



	UCB0CTLW0 = UCCKPH | UCMSB | UCMST | UCSYNC | UCMODE_0 | UCSSEL__SMCLK | UCSWRST;

	UCB0BRW = 15; // /16 -> 1MHz

	UCB0CTLW0 &= ~UCSWRST;

}



signed char SPI::xmit(unsigned char tx_len, unsigned char *tx_buf,

		unsigned char rx_len, unsigned char *rx_buf)

{

	volatile char rxbuf_cache;

	if (tx_len < 1) {

		return -1;

	}



	UCB0IE &= ~(UCTXIE | UCRXIE);



	while (UCB0STATW & UCBUSY) ;



	rxbuf_cache = UCB0RXBUF;

	UCB0TXBUF = tx_buf[0];



	unsigned char tx_pos = 1;

	unsigned char rx_pos = 0;



	while (tx_pos < tx_len || rx_pos < rx_len) {

		if ((tx_pos < tx_len) && (UCB0IFG & UCTXIFG)) {

			UCB0TXBUF = tx_buf[tx_pos++];

		}

		if (UCB0IFG & UCRXIFG) {

			if (rx_pos < rx_len) {

				rx_buf[rx_pos] = UCB0RXBUF;

			} else {

				rxbuf_cache = UCB0RXBUF;

			}

			rx_pos++;

		}

	}

}