1 files changed, 128 insertions, 0 deletions
diff --git a/src/arch/msp430fr5994lp/driver/i2c.cc b/src/arch/msp430fr5994lp/driver/i2c.cc
new file mode 100644
index 0000000..fe5b37b
--- /dev/null
+++ b/src/arch/msp430fr5994lp/driver/i2c.cc
@@ -0,0 +1,128 @@
+#include "driver/i2c.h"
+#include "arch.h"
+#include <msp430.h>
+
+#ifndef F_I2C
+#define F_I2C 100000
+#endif
+
+volatile unsigned short old_ifg = 0;
+
+#if (F_CPU / F_I2C) < 45
+inline void await_i2c_int(unsigned int ie_flags, unsigned int ifg_flags) {
+	while (!(UCB0IFG & ifg_flags)) ;
+	if (UCB0IFG & (UCNACKIFG | UCCLTOIFG)) {
+		UCB0IFG &= ~(UCNACKIFG | UCCLTOIFG);
+	}
+}
+#else
+inline void await_i2c_int(unsigned int ie_flags, unsigned int ifg_flags)
+{
+	UCB0IFG = 0;
+	old_ifg = 0;
+	UCB0IE = ie_flags;
+	do {
+		arch.idle();
+	} while (!(old_ifg & ifg_flags));
+	UCB0IE = 0;
+}
+#endif
+
+signed char I2C::setup()
+{
+#ifdef I2C_PULLUP_FIXED_GPIO
+	P1DIR |= BIT4 | BIT5;
+	P1OUT |= BIT4 | BIT5;
+#endif
+	UCB0CTL1 = UCSWRST;
+	UCB0CTLW0 = UCMODE_3 | UCMST | UCSYNC | UCSSEL_2 | UCSWRST | UCCLTO_1;
+	UCB0BRW = (F_CPU / F_I2C) - 1;
+	P1DIR &= ~(BIT6 | BIT7);
+	P1SEL0 &= ~(BIT6 | BIT7);
+	P1SEL1 |= BIT6 | BIT7;
+
+	UCB0CTL1 &= ~UCSWRST;
+	UCB0I2CSA = 0;
+
+	arch.delay_us(100);
+
+	if (UCB0STAT & UCBBUSY)
+		return -1;
+
+	return 0;
+}
+
+void I2C::scan(unsigned int *results)
+{
+	for (unsigned char address = 0; address < 128; address++) {
+		UCB0I2CSA = address;
+		UCB0CTL1 |= UCTR | UCTXSTT | UCTXSTP;
+
+		while (UCB0CTL1 & UCTXSTP);
+
+		if (UCB0IFG & UCNACKIFG) {
+			UCB0IFG &= ~UCNACKIFG;
+		} else {
+			results[address / (8 * sizeof(unsigned int))] |= 1 << (address % (8 * sizeof(unsigned int)));
+		}
+	}
+	UCB0IFG = 0;
+}
+
+signed char I2C::xmit(unsigned char address,
+		unsigned char tx_len, unsigned char *tx_buf,
+		unsigned char rx_len, unsigned char *rx_buf)
+{
+	unsigned char i;
+	UCB0I2CSA = address;
+	if (tx_len) {
+		UCB0CTL1 |= UCTR | UCTXSTT;
+		for (i = 0; i < tx_len; i++) {
+			await_i2c_int(UCTXIE0 | UCNACKIE | UCCLTOIE, UCTXIFG0 | UCNACKIFG | UCCLTOIFG);
+			if (old_ifg & (UCNACKIFG | UCCLTOIFG)) {
+				UCB0CTL1 |= UCTXSTP;
+				return -1;
+			}
+			old_ifg = 0;
+			UCB0TXBUF = tx_buf[i];
+		}
+		await_i2c_int(UCTXIE0 | UCNACKIE | UCCLTOIE, UCTXIFG0 | UCNACKIFG | UCCLTOIFG);
+		//if (UCB0IFG & (UCNACKIFG | UCCLTOIFG)) {
+		//	UCB0IFG &= ~UCNACKIFG;
+		//	UCB0IFG &= ~UCCLTOIFG;
+		//	UCB0CTL1 |= UCTXSTP;
+		//	return -1;
+		//}
+	}
+	if (rx_len) {
+		UCB0I2CSA = address;
+		UCB0IFG = 0;
+		UCB0CTL1 &= ~UCTR;
+		UCB0CTL1 |= UCTXSTT;
+
+		while (UCB0CTL1 & UCTXSTT);
+		UCB0IFG &= ~UCTXIFG0;
+
+		for (i = 0; i < rx_len; i++) {
+			if (i == rx_len - 1)
+				UCB0CTL1 |= UCTXSTP;
+			await_i2c_int(UCRXIE | UCNACKIE | UCCLTOIE, UCRXIFG0 | UCNACKIFG | UCCLTOIFG);
+			rx_buf[i] = UCB0RXBUF;
+			UCB0IFG &= ~UCRXIFG0;
+		}
+		UCB0IFG &= ~UCRXIFG0;
+	}
+
+	UCB0CTL1 |= UCTXSTP;
+
+	while (UCB0CTL1 & UCTXSTP);
+	return 0;
+}
+
+__attribute__((interrupt(USCI_B0_VECTOR))) __attribute__((wakeup)) void handle_usci_b0()
+{
+	old_ifg = UCB0IFG;
+	UCB0IFG = 0;
+}
+
+I2C i2c;