Support optional SoftI2C pullups on MSP430 (f6a842b1) · Commits · derf / multipass

Makefile

+4 −0

Original line number	Diff line number	Diff line
		@@ -32,6 +32,10 @@ ifneq ($(findstring softi2c,${drivers}), )
		COMMON_FLAGS += -DDRIVER_SOFTI2C
		endif

		ifeq (${softi2c_pullup}, 1)
		COMMON_FLAGS += -DSOFTI2C_PULLUP
		endif

		ifeq (${timer_cycles}, 1)
		COMMON_FLAGS += -DTIMER_CYCLES
		endif

include/arch/msp430fr5969lp/driver/gpio.h

+41 −0

Original line number	Diff line number	Diff line
		@@ -63,6 +63,29 @@ class GPIO {
		PJDIR &= ~(1 << (pin - pj_0));
		}
		}
		inline void input(unsigned char const pin, unsigned char const pull) {
		if (pin < p2_0) {
		P1DIR &= ~(1 << pin);
		P1OUT = pull ? (P1OUT \| (1 << pin)) : (P1OUT & ~(1 << pin));
		P1REN \|= (1 << pin);
		} else if (pin < p3_0) {
		P2DIR &= ~(1 << (pin - p2_0));
		P2OUT = pull ? (P2OUT \| (1 << (pin - p2_0))) : (P2OUT & ~(1 << (pin - p2_0)));
		P2REN \|= (1 << (pin - p2_0));
		} else if (pin < p4_0) {
		P3DIR &= ~(1 << (pin - p3_0));
		P3OUT = pull ? (P3OUT \| (1 << (pin - p3_0))) : (P3OUT & ~(1 << (pin - p3_0)));
		P3REN \|= (1 << (pin - p3_0));
		} else if (pin < pj_0) {
		P4DIR &= ~(1 << (pin - p4_0));
		P4OUT = pull ? (P4OUT \| (1 << (pin - p4_0))) : (P4OUT & ~(1 << (pin - p4_0)));
		P4REN \|= (1 << (pin - p4_0));
		} else if (pin < PIN_INVALID) {
		PJDIR &= ~(1 << (pin - pj_0));
		PJOUT = pull ? (PJOUT \| (1 << (pin - pj_0))) : (PJOUT & ~(1 << (pin - pj_0)));
		PJREN \|= (1 << (pin - pj_0));
		}
		}
		inline void output(unsigned char const pin) {
		if (pin < p2_0) {
		P1DIR \|= (1 << pin);
		@@ -76,6 +99,24 @@ class GPIO {
		PJDIR \|= (1 << (pin - pj_0));
		}
		}
		inline void output(unsigned char const pin, unsigned char const value) {
		if (pin < p2_0) {
		P1OUT = value ? (P1OUT \| (1 << pin)) : (P1OUT & ~(1 << pin));
		P1DIR \|= (1 << pin);
		} else if (pin < p3_0) {
		P2OUT = value ? (P2OUT \| (1 << (pin - p2_0))) : (P2OUT & ~(1 << (pin - p2_0)));
		P2DIR \|= (1 << (pin - p2_0));
		} else if (pin < p4_0) {
		P3OUT = value ? (P3OUT \| (1 << (pin - p3_0))) : (P3OUT & ~(1 << (pin - p3_0)));
		P3DIR \|= (1 << (pin - p3_0));
		} else if (pin < pj_0) {
		P4OUT = value ? (P4OUT \| (1 << (pin - p4_0))) : (P4OUT & ~(1 << (pin - p4_0)));
		P4DIR \|= (1 << (pin - p4_0));
		} else if (pin < PIN_INVALID) {
		PJOUT = value ? (PJOUT \| (1 << (pin - pj_0))) : (PJOUT & ~(1 << (pin - pj_0)));
		PJDIR \|= (1 << (pin - pj_0));
		}
		}
		inline unsigned char read(unsigned char const pin) {
		if (pin < p2_0) {
		return P1IN & (1 << pin);

src/arch/msp430fr5969lp/arch.cc

+7 −0

Original line number	Diff line number	Diff line
		@@ -72,6 +72,13 @@ extern void loop();
		volatile char run_loop = 0;
		#endif

		void Arch::delay_us(unsigned char const us)
		{
		for (int i = 0; i < us/10; i++) {
		__delay_cycles(160);
		}
		}

		void Arch::idle_loop(void)
		{
		while (1) {

src/arch/msp430fr5969lp/driver/i2c.cc

+1 −1

Original line number	Diff line number	Diff line
		@@ -16,7 +16,7 @@ signed char I2C::setup()
		UCB0CTL1 &= ~UCSWRST;
		UCB0I2CSA = 0;

		__delay_cycles(1600);
		arch.delay_us(100);

		if (UCB0STAT & UCBBUSY)
		return -1;

src/driver/soft_i2c.cc

+32 −19

Original line number	Diff line number	Diff line
		#include "driver/soft_i2c.h"
		#include "driver/gpio.h"
		#include "arch.h"

		#ifdef SOFTI2C_PULLUP
		#define SDA_HIGH gpio.input(sda, 1)
		#define SDA_LOW gpio.output(sda, 0)
		#define SCL_HIGH gpio.input(scl, 1)
		#define SCL_LOW gpio.output(scl, 0)
		#else
		#define SDA_HIGH gpio.input(sda)
		#define SDA_LOW gpio.output(sda)
		#define SCL_HIGH gpio.input(scl)
		#define SCL_LOW gpio.output(scl)
		#endif

		signed char SoftI2C::setup()
		{
		gpio.write(sda, 0);
		gpio.write(scl, 0);
		SDA_HIGH;
		SCL_HIGH;
		return 0;
		}

		void SoftI2C::start()
		{
		gpio.input(sda);
		gpio.input(scl);
		SDA_HIGH;
		SCL_HIGH;
		//
		gpio.output(sda);
		SDA_LOW;
		//
		gpio.output(scl);
		SCL_LOW;
		}

		void SoftI2C::stop()
		{
		gpio.output(scl);
		SCL_LOW;
		//
		gpio.output(sda);
		SDA_LOW;
		//
		gpio.input(scl);
		SCL_HIGH;
		//
		gpio.input(sda);
		SDA_HIGH;
		}

		bool SoftI2C::tx(unsigned char byte)
		@@ -34,20 +47,20 @@ bool SoftI2C::tx(unsigned char byte)
		unsigned char got_ack = 0;
		for (unsigned char i = 0; i <= 8; i++) {
		if ((byte & 0x80) \|\| (i == 8)) {
		gpio.input(sda);
		SDA_HIGH;
		} else {
		gpio.output(sda);
		SDA_LOW;
		}
		byte <<= 1;
		//
		gpio.input(scl);
		SCL_HIGH;
		//
		if (i == 8) {
		if (!gpio.read(sda)) {
		got_ack = 1;
		}
		}
		gpio.output(scl);
		SCL_LOW;
		//
		}
		return got_ack;
		@@ -56,21 +69,21 @@ bool SoftI2C::tx(unsigned char byte)
		unsigned char SoftI2C::rx(bool send_ack)
		{
		unsigned char byte = 0;
		gpio.input(sda);
		SDA_HIGH;
		for (unsigned char i = 0; i <= 8; i++) {
		//
		gpio.input(scl);
		SCL_HIGH;
		//
		if ((i < 8) && gpio.read(sda)) {
		byte \|= 1 << (7 - i);
		}
		//
		gpio.output(scl);
		SCL_LOW;
		//
		if ((i == 7) && send_ack) {
		gpio.output(sda);
		SDA_LOW;
		} else if ((i == 8) && send_ack) {
		gpio.input(sda);
		SDA_HIGH;
		}
		}
		return byte;

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