From 51a00f59ea9ecb49471b30921f36821fdfa75bc4 Mon Sep 17 00:00:00 2001
From: Daniel Friesel <derf@finalrewind.org>
Date: Thu, 14 Dec 2017 15:51:11 +0100
Subject: Add I2C and LM75 drivers

---
 src/arch/msp430fr5969lp/Makefile.inc  |  7 ++-
 src/arch/msp430fr5969lp/driver/i2c.cc | 92 +++++++++++++++++++++++++++++++++++
 2 files changed, 97 insertions(+), 2 deletions(-)
 create mode 100644 src/arch/msp430fr5969lp/driver/i2c.cc

(limited to 'src/arch')

diff --git a/src/arch/msp430fr5969lp/Makefile.inc b/src/arch/msp430fr5969lp/Makefile.inc
index 36d19c6..6d2ae6a 100644
--- a/src/arch/msp430fr5969lp/Makefile.inc
+++ b/src/arch/msp430fr5969lp/Makefile.inc
@@ -10,8 +10,11 @@ CC = /opt/msp430/ti/gcc/bin/msp430-elf-gcc
 CXX = /opt/msp430/ti/gcc/bin/msp430-elf-g++
 OBJCOPY = /opt/msp430/ti/gcc/bin/msp430-elf-objcopy
 
-TARGETS += src/arch/msp430fr5969lp/arch.cc src/arch/msp430fr5969lp/driver/gpio.cc
-TARGETS += src/arch/msp430fr5969lp/driver/stdout.cc src/arch/msp430fr5969lp/driver/uptime.cc
+TARGETS += src/arch/msp430fr5969lp/arch.cc
+TARGETS += src/arch/msp430fr5969lp/driver/gpio.cc
+TARGETS += src/arch/msp430fr5969lp/driver/stdout.cc
+TARGETS += src/arch/msp430fr5969lp/driver/uptime.cc
+TARGETS += src/arch/msp430fr5969lp/driver/i2c.cc
 
 OBJECTS = ${TARGETS:.cc=.o}
 
diff --git a/src/arch/msp430fr5969lp/driver/i2c.cc b/src/arch/msp430fr5969lp/driver/i2c.cc
new file mode 100644
index 0000000..80f33b0
--- /dev/null
+++ b/src/arch/msp430fr5969lp/driver/i2c.cc
@@ -0,0 +1,92 @@
+#include "driver/i2c.h"
+#include <msp430.h>
+
+signed char I2C::setup()
+{
+	UCB0CTL1 = UCSWRST;
+	UCB0CTLW0 = UCMODE_3 | UCMST | UCSYNC | UCSSEL_2 | UCSWRST | UCCLTO_1;
+	UCB0BRW = 0xf00;
+	P1DIR &= ~(BIT6 | BIT7);
+	P1SEL0 &= ~(BIT6 | BIT7);
+	P1SEL1 |= BIT6 | BIT7;
+
+	UCB0CTL1 &= ~UCSWRST;
+	UCB0I2CSA = 0;
+
+	__delay_cycles(1600);
+
+	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++) {
+			while (!(UCB0IFG & (UCTXIFG0 | UCNACKIFG | UCCLTOIFG)));
+			if (UCB0IFG & (UCNACKIFG | UCCLTOIFG)) {
+				UCB0IFG &= ~UCNACKIFG;
+				UCB0IFG &= ~UCCLTOIFG;
+				UCB0CTL1 |= UCTXSTP;
+				return -1;
+			}
+			UCB0TXBUF = tx_buf[i];
+		}
+		while (!(UCB0IFG & (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;
+			while (!(UCB0IFG & (UCRXIFG0 | UCNACKIFG | UCCLTOIFG)));
+			rx_buf[i] = UCB0RXBUF;
+			UCB0IFG &= ~UCRXIFG0;
+		}
+		UCB0IFG &= ~UCRXIFG0;
+	}
+
+	UCB0CTL1 |= UCTXSTP;
+
+	while (UCB0CTL1 & UCTXSTP);
+	return 0;
+}
+
+I2C i2c;
-- 
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