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Add STM32 boards support through stm32duino #34

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108 changes: 108 additions & 0 deletions SoftwareWire.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -61,43 +61,111 @@

#include "SoftwareWire.h"

#if defined(ARDUINO_ARCH_STM32)
#if defined(STM32F1xx)
#define GPIO_MODE_INPUT_CLEAR_BIT (GPIO_CRL_MODE0_0 | GPIO_CRL_MODE0_1 | GPIO_CRL_CNF0_0)
#define GPIO_MODE_INPUT_SET_BIT GPIO_CRL_CNF0_1
#define GPIO_MODE_OUTPUT_CLEAR_BIT (GPIO_CRL_CNF0_0 | GPIO_CRL_CNF0_1)
#define GPIO_MODE_OUTPUT_SET_BIT (GPIO_CRL_MODE0_0 | GPIO_CRL_MODE0_1)
#define I2C_SET_MODE_LOW(_reg, _shift) \
MODIFY_REG(*_reg, GPIO_MODE_OUTPUT_CLEAR_BIT << (2 * _shift) % 32, \
GPIO_MODE_OUTPUT_SET_BIT << (2 * _shift) % 32 );
#define I2C_SET_MODE_HIGH(_reg, _shift) \
MODIFY_REG(*_reg, GPIO_MODE_INPUT_CLEAR_BIT << (2 * _shift) % 32, \
GPIO_MODE_INPUT_SET_BIT << (2 * _shift) % 32 );

#else
#if defined(GPIO_MODER_MODE0_0)
#define GPIO_MODE_INPUT_CLEAR_BIT (GPIO_MODER_MODE0_0 | GPIO_MODER_MODE0_1)
#define GPIO_MODE_INPUT_SET_BIT 0
#define GPIO_MODE_OUTPUT_CLEAR_BIT GPIO_MODER_MODE0_1
#define GPIO_MODE_OUTPUT_SET_BIT GPIO_MODER_MODE0_0

#elif defined(GPIO_MODER_MODER0_0)
#define GPIO_MODE_INPUT_CLEAR_BIT (GPIO_MODER_MODER0_0 | GPIO_MODER_MODER0_1)
#define GPIO_MODE_INPUT_SET_BIT 0
#define GPIO_MODE_OUTPUT_CLEAR_BIT GPIO_MODER_MODER0_1
#define GPIO_MODE_OUTPUT_SET_BIT GPIO_MODER_MODE0R_0

#else
#error GPIO Mode not implemented
#endif // GPIO_MODER_MODE0_0

#define I2C_SET_MODE_LOW(_reg, _shift) \
MODIFY_REG(*_reg, GPIO_MODE_OUTPUT_CLEAR_BIT << _shift, \
GPIO_MODE_OUTPUT_SET_BIT << _shift);
#define I2C_SET_MODE_HIGH(_reg, _shift) \
MODIFY_REG(*_reg, GPIO_MODE_INPUT_CLEAR_BIT << _shift, \
GPIO_MODE_INPUT_SET_BIT << _shift);

#endif // STM32F1xx
#endif // ARDUINO_ARCH_STM32

// Sets SDA low and drives output.
// The SDA may not be HIGH output, so first the output register is cleared
// (clearing internal pullup resistor), after that the SDA is set as output.
#if defined(ARDUINO_ARCH_STM32)
#define i2c_sda_lo() \
*_sdaPortReg &= ~_sdaBitMask; \
I2C_SET_MODE_LOW(_sdaDirReg, _sdaModeShift);
#else
#define i2c_sda_lo() \
*_sdaPortReg &= ~_sdaBitMask; \
*_sdaDirReg |= _sdaBitMask;
#endif


// sets SCL low and drives output.
// The SCL may not be HIGH output, so first the output register is cleared
// (clearing internal pullup resistor), after that the SCL is set as output.
#if defined(ARDUINO_ARCH_STM32)
#define i2c_scl_lo() \
*_sclPortReg &= ~_sclBitMask; \
I2C_SET_MODE_LOW(_sclDirReg, _sclModeShift);
#else
#define i2c_scl_lo() \
*_sclPortReg &= ~_sclBitMask; \
*_sclDirReg |= _sclBitMask;
#endif


// Set SDA high and to input (releases pin) (i.e. change to input, turn on pullup).
// The SDA may not become HIGH output. Therefore the pin is first set to input,
// after that, a pullup resistor is switched on if needed.
#if defined(ARDUINO_ARCH_STM32)
#define i2c_sda_hi() \
I2C_SET_MODE_HIGH(_sdaDirReg, _sdaModeShift); \
if(_pullups) { *_sdaPortReg |= _sdaBitMask; }
#else
#define i2c_sda_hi() \
*_sdaDirReg &= ~_sdaBitMask; \
if(_pullups) { *_sdaPortReg |= _sdaBitMask; }
#endif // ARDUINO_ARCH_STM32


// set SCL high and to input (releases pin) (i.e. change to input, turn on pullup)
// The SCL may not become HIGH output. Therefore the pin is first set to input,
// after that, a pullup resistor is switched on if needed.
#if defined(ARDUINO_ARCH_STM32)
#define i2c_scl_hi() \
I2C_SET_MODE_HIGH(_sclDirReg, _sclModeShift); \
if(_pullups) { *_sclPortReg |= _sclBitMask; }
#else
#define i2c_scl_hi() \
*_sclDirReg &= ~_sclBitMask; \
if(_pullups) { *_sclPortReg |= _sclBitMask; }
#endif // ARDUINO_ARCH_STM32


// Read the bit value of the pin
// Note that is the pin can also be read when it is an output.
#if defined(ARDUINO_ARCH_STM32)
#define i2c_sda_read() ((*_sdaPinReg & _sdaBitMask) ? 1 : 0)
#define i2c_scl_read() ((*_sclPinReg & _sclBitMask) ? 1 : 0)
#else
#define i2c_sda_read() ((uint8_t) (*_sdaPinReg & _sdaBitMask) ? 1 : 0)
#define i2c_scl_read() ((uint8_t) (*_sclPinReg & _sclBitMask) ? 1 : 0)
#endif


//
Expand All @@ -124,19 +192,44 @@ SoftwareWire::SoftwareWire(uint8_t sdaPin, uint8_t sclPin, boolean pullups, bool
setTimeout( 1000L);

// Turn Arduino pin numbers into PORTx, DDRx, and PINx
#if defined(ARDUINO_ARCH_STM32)
GPIO_TypeDef* port;
#else
uint8_t port;
#endif


port = digitalPinToPort(_sdaPin);
_sdaBitMask = digitalPinToBitMask(_sdaPin);
#if defined(ARDUINO_ARCH_STM32)
// By default, MODE/MODER bit field is 2 bytes wide
set_GPIO_Port_Clock(STM_PORT(digitalPinToPinName(_sdaPin)));
_sdaModeShift = 2 * __CLZ(__RBIT(_sdaBitMask));
#endif
_sdaPortReg = portOutputRegister(port);
_sdaDirReg = portModeRegister(port);
_sdaPinReg = portInputRegister(port); // PinReg is the input register, not the Arduino pin.

port = digitalPinToPort(_sclPin);
_sclBitMask = digitalPinToBitMask(_sclPin);
#if defined(ARDUINO_ARCH_STM32)
// By default, MODE/MODER bit field is 2 bytes wide
set_GPIO_Port_Clock(STM_PORT(digitalPinToPinName(_sclPin)));
_sclModeShift = 2 * __CLZ(__RBIT(_sclBitMask));
#endif
_sclPortReg = portOutputRegister(port);
_sclDirReg = portModeRegister(port);
_sclPinReg = portInputRegister(port);

#if defined(ARDUINO_ARCH_STM32) && defined(STM32F1xx)
// Manage GPIOx_CRL / GPIOx_CRH depending on pin [0..7] or pin [8..16]
if (__CLZ(__RBIT(_sdaBitMask)) > 7U) {
_sdaDirReg ++;
}
if (__CLZ(__RBIT(_sclBitMask)) > 7U) {
_sclDirReg ++;
}
#endif
}


Expand Down Expand Up @@ -520,6 +613,20 @@ void SoftwareWire::printStatus( Print& Ser)
Ser.print(F(" _sclBitMask = 0x"));
Ser.println(_sclBitMask, HEX);
Ser.print(F(" _sdaPortReg = "));

#if defined(ARDUINO_ARCH_STM32)
Ser.println( (uint32_t) _sdaPortReg, HEX);
Ser.print(F(" _sclPortReg = "));
Ser.println( (uint32_t) _sclPortReg, HEX);
Ser.print(F(" _sdaDirReg = "));
Ser.println( (uint32_t) _sdaDirReg, HEX);
Ser.print(F(" _sclDirReg = "));
Ser.println( (uint32_t) _sclDirReg, HEX);
Ser.print(F(" _sdaPinReg = "));
Ser.println( (uint32_t) _sdaPinReg, HEX);
Ser.print(F(" _sclPinReg = "));
Ser.println( (uint32_t) _sclPinReg, HEX);
#else
Ser.println( (uint16_t) _sdaPortReg, HEX);
Ser.print(F(" _sclPortReg = "));
Ser.println( (uint16_t) _sclPortReg, HEX);
Expand All @@ -531,6 +638,7 @@ void SoftwareWire::printStatus( Print& Ser)
Ser.println( (uint16_t) _sdaPinReg, HEX);
Ser.print(F(" _sclPinReg = "));
Ser.println( (uint16_t) _sclPinReg, HEX);
#endif

Ser.print(F(" line state sda = "));
Ser.println(i2c_sda_read());
Expand Down
18 changes: 18 additions & 0 deletions SoftwareWire.h
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Original file line number Diff line number Diff line change
Expand Up @@ -52,15 +52,33 @@ class SoftwareWire

uint8_t _sdaPin;
uint8_t _sclPin;
#if defined(ARDUINO_ARCH_STM32)
uint32_t _sdaBitMask;
uint32_t _sdaModeShift;
uint32_t _sclBitMask;
uint32_t _sclModeShift;
#else
uint8_t _sdaBitMask;
uint8_t _sclBitMask;
#endif



#if defined(ARDUINO_ARCH_STM32)
volatile uint32_t *_sdaPortReg;
volatile uint32_t *_sclPortReg;
volatile uint32_t *_sdaDirReg;
volatile uint32_t *_sclDirReg;
volatile uint32_t *_sdaPinReg;
volatile uint32_t *_sclPinReg;
#else
volatile uint8_t *_sdaPortReg;
volatile uint8_t *_sclPortReg;
volatile uint8_t *_sdaDirReg;
volatile uint8_t *_sclDirReg;
volatile uint8_t *_sdaPinReg;
volatile uint8_t *_sclPinReg;
#endif

uint8_t _transmission; // transmission status, returned by endTransmission(). 0 is no error.
uint16_t _i2cdelay; // delay in micro seconds for sda and scl bits.
Expand Down