Commit f6c24bc8 authored by Birte Kristina Friesel's avatar Birte Kristina Friesel
Browse files

I2C: Add support for manual / always-on gpio pullups

parent 7dac0ccc

Makefile

+14 −2
Original line number Diff line number Diff line
@@ -71,8 +71,20 @@ ifneq (${timer_freq}, ) 
	COMMON_FLAGS += -DF_TIMER=${timer_freq}

endif



ifeq (${softi2c_pullup}, 1)

	COMMON_FLAGS += -DSOFTI2C_PULLUP

ifeq (${softi2c_pullup}, internal)

	COMMON_FLAGS += -DSOFTI2C_PULLUP_INTERNAL

endif



ifeq (${softi2c_pullup}, external)

	COMMON_FLAGS += -DSOFTI2C_PULLUP_EXTERNAL

endif



ifeq (${softi2c_pullup}, gpio)

	COMMON_FLAGS += -DSOFTI2C_PULLUP_FIXED_GPIO

endif



ifeq (${i2c_pullup}, gpio)

	COMMON_FLAGS += -DI2C_PULLUP_FIXED_GPIO

endif



ifeq (${softi2c_timer}, 1)

include/driver/soft_i2c.h

+9 −0
Original line number Diff line number Diff line
@@ -6,6 +6,9 @@ class SoftI2C { 
		SoftI2C(const SoftI2C &copy);



		unsigned char sda, scl;

#if SOFTI2C_PULLUP_EXTERNAL || SOFTI2C_PULLUP_FIXED_GPIO

		unsigned char sda_pull, scl_pull;

#endif



		void start();

		void stop();
@@ -13,7 +16,13 @@ class SoftI2C { 
		unsigned char rx(bool send_ack);



	public:

#if SOFTI2C_PULLUP_EXTERNAL || SOFTI2C_PULLUP_FIXED_GPIO

		SoftI2C(unsigned char sda, unsigned char scl,

				unsigned char sda_pull, unsigned char scl_pull) :

			sda(sda), scl(scl), sda_pull(sda_pull), scl_pull(scl_pull) {}

#else

		SoftI2C(unsigned char sda, unsigned char scl) : sda(sda), scl(scl) {}

#endif

		signed char setup();

		void scan(unsigned int *results);

		signed char xmit(unsigned char address,

src/arch/msp430fr5969lp/driver/i2c.cc

+4 −0
Original line number Diff line number Diff line
@@ -10,6 +10,10 @@ volatile unsigned short old_ifg = 0; 


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;

src/driver/soft_i2c.cc

+34 −5
Original line number Diff line number Diff line
@@ -13,17 +13,22 @@ 
#include "driver/timer.h"

#endif



#ifdef SOFTI2C_PULLUP

#ifdef SOFTI2C_PULLUP_INTERNAL

#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

#elif SOFTI2C_PULLUP_EXTERNAL

#define SDA_HIGH do { gpio.input(sda); gpio.write(sda_pull, 1); } while (0)

#define SDA_LOW do { gpio.write(sda_pull, 0); gpio.output(sda); } while (0)

#define SCL_HIGH do { gpio.input(scl); gpio.write(scl_pull, 1); } while (0)

#define SCL_LOW do { gpio.write(scl_pull, 0); gpio.output(scl); } while (0)

#else /* !SOFTI2C_PULLUP_{INTERNAL,EXTERNAL} */

#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

#endif /* SOFTI2C_PULLUP */



#ifndef SOFTI2C_TIMER
@@ -31,10 +36,24 @@ 
#define I2C_WAIT arch.delay_us((500000UL / F_I2C) - 10)

#else

#define I2C_WAIT

#endif

#endif /* !SOFTI2C_TIMER */



signed char SoftI2C::setup()

{

#ifdef SOFTI2C_PULLUP_EXTERNAL

	gpio.output(sda_pull);

	gpio.output(scl_pull);

#endif

#ifdef SOFTI2C_PULLUP_FIXED_GPIO

#if MULTIPASS_ARCH_msp430fr5969lp

	gpio.output(GPIO::p1_4);

	gpio.output(GPIO::p1_5);

	gpio.write(GPIO::p1_4, 1);

	gpio.write(GPIO::p1_5, 1);

#else

#error "softi2c_pullup=gpio not supported on this architecture"

#endif /* MULTIPASS_ARCH_* */

#endif /* SOFTI2C_PULLUP_FIXED_GPIO */

	SDA_HIGH;

	SCL_HIGH;

	return 0;
@@ -303,6 +322,13 @@ ON_TIMER_INTERRUPT_tail 


#endif



#if SOFTI2C_PULLUP_EXTERNAL

#ifdef MULTIPASS_ARCH_msp430fr5969lp

SoftI2C i2c(GPIO::p1_6, GPIO::p1_7, GPIO::p1_4, GPIO::p1_5);

#else

#error "softi2c_pullup = external not supported on this architecture"

#endif /* MULTIPASS_ARCH_* */

#else

#ifdef MULTIPASS_ARCH_esp8266

SoftI2C i2c(GPIO::d6, GPIO::d7);

#elif MULTIPASS_ARCH_arduino_nano
@@ -311,4 +337,7 @@ SoftI2C i2c(GPIO::pc4, GPIO::pc5); 
SoftI2C i2c(GPIO::pc4, GPIO::pc5);

#elif MULTIPASS_ARCH_msp430fr5969lp

SoftI2C i2c(GPIO::p1_6, GPIO::p1_7);

#endif
 
#elif MULTIPASS_ARCH_posix

SoftI2C i2c(GPIO::px00, GPIO::px01);

#endif /* MULTIPASS_ARCH_* */

#endif /* !SOFTI2C_PULLUP_EXTERNAL */