Files

358 lines
8.7 KiB
C++

//
// I/O wrapper functions for the C6/P4 RISC-V ULP
//
#ifndef __ULP_IO__
#define __ULP_IO__
#define INPUT 0
#define INPUT_PULLUP 1
#define OUTPUT 2
#define DISABLED 3
#define PROGMEM
#define HIGH 1
#define LOW 0
#define PIN_SDA 6
#define PIN_SCL 7
#define PIN_SCK 4
#define PIN_MOSI 6
// CPU cycles per bit
#define I2C_DELAY 40
void digitalWrite(int iPin, int iState) {
ulp_lp_core_gpio_set_level(iPin, iState);
}
void pinMode(int iPin, int iMode)
{
ulp_lp_core_gpio_init(iPin);
if (iMode == INPUT || iMode == INPUT_PULLUP) {
ulp_lp_core_gpio_output_disable(iPin);
ulp_lp_core_gpio_input_enable(iPin);
if (iMode == INPUT_PULLUP) {
ulp_lp_core_gpio_pullup_enable(iPin);
}
} else if (iMode == DISABLED) {
ulp_lp_core_gpio_input_disable(iPin);
ulp_lp_core_gpio_output_disable(iPin);
} else { // OUTPUT
ulp_lp_core_gpio_input_disable(iPin);
ulp_lp_core_gpio_output_enable(iPin);
}
} /* pinMode() */
int digitalRead(int iPin)
{
return (int)ulp_lp_core_gpio_get_level(iPin);
} /* digitalRead() */
void delayMicroseconds(long l)
{
l *= 40;
while (l) {
__asm__ __volatile__ ("nop");
l--;
}
}
void _delay(long l)
{
delayMicroseconds(l*1000);
}
void mymemcpy(void *d, void *s, size_t iLen)
{
uint8_t *d8 = (uint8_t *)d;
uint8_t *s8 = (uint8_t *)s;
while (iLen) {
*d8++ = *s8++;
iLen--;
}
} /* mymemcpy() */
void mymemset(void *d, uint8_t u8, int len)
{
uint8_t *d8;
if (((intptr_t)d & 3) == 0) { // dword aligned
uint32_t u32, *d32 = (uint32_t *)d;
u32 = u8 | (u8 << 8);
u32 |= (u32 << 16);
while (len >= 4) {
*d32++ = u32;
len -= 4;
}
d = d32;
}
d8 = (uint8_t *)d;
while (len) {
*d8++ = u8;
len--;
}
} /* mymemset() */
//
// Convert a number into a fixed length, zero-terminated string
//
void i2strf(char *pDest, int iVal, int iDigits)
{
char *d = pDest;
int i;
pDest[iDigits] = 0;
while (iDigits) {
iDigits--;
i = iVal % 10;
d[iDigits] = '0' + (char)i;
iVal /= 10;
}
} /* i2strf() */
//
// Convert a number into a zero-terminated string
//
int i2str(char *pDest, int iVal)
{
char *d = pDest;
int i, iPlaceVal = 10000;
int iDigits = 0;
if (iVal < 0) {
iDigits++;
*d++ = '-';
iVal = -iVal;
}
while (iPlaceVal) {
if (iVal >= iPlaceVal) {
i = iVal / iPlaceVal;
*d++ = '0' + (char)i;
iVal -= (i*iPlaceVal);
iDigits++;
} else if (iDigits != 0) {
*d++ = '0'; // non-zeros were already displayed
}
iPlaceVal /= 10;
}
if (d == pDest) // must be zero
*d++ = '0';
*d++ = 0; // terminator
return (int)(d - pDest - 1); // string length
} /* i2str() */
//
// Bit Bang SPI
//
void SPIWriteByte(uint8_t uc)
{
if (uc == 0 || uc == 0xff) { // special case
ulp_lp_core_gpio_set_level(PIN_MOSI, (uc & 1));
for (int i=0; i<8; i++) {
ulp_lp_core_gpio_set_level(PIN_SCK, 1); // no delays needed since it runs at a slow clock
ulp_lp_core_gpio_set_level(PIN_SCK, 0);
}
} else {
for (int i=0; i<8; i++) {
ulp_lp_core_gpio_set_level(PIN_MOSI, (uc & 0x80)); // msb first
ulp_lp_core_gpio_set_level(PIN_SCK, 1); // no delays needed since it runs at a slow clock
uc <<= 1;
ulp_lp_core_gpio_set_level(PIN_SCK, 0);
}
}
} /* SPIWriteByte() */
//
// Need to bit-bang I2C
//
uint8_t SDA_READ(void)
{
return ulp_lp_core_gpio_get_level(PIN_SDA);
}
void SDA_HIGH(void)
{
ulp_lp_core_gpio_output_disable(PIN_SDA);
ulp_lp_core_gpio_input_enable(PIN_SDA);
}
void SDA_LOW(void)
{
ulp_lp_core_gpio_input_disable(PIN_SDA);
ulp_lp_core_gpio_output_enable(PIN_SDA);
ulp_lp_core_gpio_set_level(PIN_SDA, 0);
}
void SCL_HIGH(void)
{
ulp_lp_core_gpio_output_disable(PIN_SCL);
ulp_lp_core_gpio_input_enable(PIN_SCL);
}
void SCL_LOW(void)
{
ulp_lp_core_gpio_input_disable(PIN_SCL);
ulp_lp_core_gpio_output_enable(PIN_SCL);
ulp_lp_core_gpio_set_level(PIN_SCL, 0);
}
// Transmit a byte and read the ack bit
// if we get a NACK (negative acknowledge) return 0
// otherwise return 1 for success
//
int i2cByteOut(uint8_t b)
{
uint8_t i, ack;
for (i=0; i<8; i++) {
// my_sleep_us(iDelay);
if (b & 0x80)
SDA_HIGH(); // set data line to 1
else
SDA_LOW(); // set data line to 0
b <<= 1;
// my_sleep_us(iDelay);
SCL_HIGH(); // clock high (slave latches data)
ulp_lp_core_delay_cycles(I2C_DELAY);
SCL_LOW(); // clock low
ulp_lp_core_delay_cycles(I2C_DELAY);
} // for i
//my_sleep_us(iDelay);
// read ack bit
SDA_HIGH(); // set data line for reading
//my_sleep_us(iDelay);
SCL_HIGH(); // clock line high
ulp_lp_core_delay_cycles(I2C_DELAY); // DEBUG - delay/2
ack = SDA_READ();
//my_sleep_us(iDelay);
SCL_LOW(); // clock low
ulp_lp_core_delay_cycles(I2C_DELAY); // DEBUG - delay/2
SDA_LOW(); // data low
return (ack == 0); // a low ACK bit means success
} /* i2cByteOut() */
//
// Receive a byte and read the ack bit
// if we get a NACK (negative acknowledge) return 0
// otherwise return 1 for success
//
uint8_t i2cByteIn(uint8_t bLast)
{
uint8_t i;
uint8_t b = 0;
SDA_HIGH(); // set data line as input
for (i=0; i<8; i++)
{
ulp_lp_core_delay_cycles(I2C_DELAY); // wait for data to settle
SCL_HIGH(); // clock high (slave latches data)
ulp_lp_core_delay_cycles(I2C_DELAY);
b <<= 1;
if (SDA_READ() != 0) // read the data bit
b |= 1; // set data bit
SCL_LOW(); // clock low
} // for i
if (bLast)
SDA_HIGH(); // last byte sends a NACK
else
SDA_LOW();
// my_sleep_us(iDelay);
SCL_HIGH(); // clock high
ulp_lp_core_delay_cycles(I2C_DELAY);
SCL_LOW(); // clock low to send ack
ulp_lp_core_delay_cycles(I2C_DELAY);
// SDA_HIGH();
SDA_LOW(); // data low
return b;
} /* i2cByteIn() */
//
// Send I2C STOP condition
//
void i2cEnd(void)
{
SDA_LOW(); // data line low
ulp_lp_core_delay_cycles(I2C_DELAY);
SCL_HIGH(); // clock high
ulp_lp_core_delay_cycles(I2C_DELAY);
SDA_HIGH(); // data high
ulp_lp_core_delay_cycles(I2C_DELAY);
} /* i2cEnd() */
int i2cBegin(uint8_t addr, uint8_t bRead)
{
int rc;
// SCL_HIGH();
// my_sleep_us(iDelay);
SDA_LOW(); // data line low first
ulp_lp_core_delay_cycles(I2C_DELAY);
SCL_LOW(); // then clock line low is a START signal
addr <<= 1;
if (bRead)
addr++; // set read bit
rc = i2cByteOut(addr); // send the slave address and R/W bit
return rc;
} /* i2cBegin() */
void I2CWrite(uint8_t addr, uint8_t *pData, int iLen)
{
uint8_t b;
int rc;
i2cBegin(addr, 0);
rc = 1;
while (iLen && rc == 1)
{
b = *pData++;
rc = i2cByteOut(b);
if (rc == 1) // success
{
iLen--;
}
} // for each byte
i2cEnd();
//return (rc == 1) ? (iOldLen - iLen) : 0; // 0 indicates bad ack from sending a byte
} /* I2CWrite() */
int I2CRead(uint8_t addr, uint8_t *pData, int iLen)
{
i2cBegin(addr, 1);
while (iLen--)
{
*pData++ = i2cByteIn(iLen == 0);
} // for each byte
i2cEnd();
return 1;
} /* I2CRead() */
int I2CTest(uint8_t addr)
{
int response = 0;
if (i2cBegin(addr, 0)) // try to write to the given address
{
response = 1;
}
i2cEnd();
return response;
} /* I2CTest() */
void I2CInit(void)
{
ulp_lp_core_gpio_init(PIN_SDA);
ulp_lp_core_gpio_output_disable(PIN_SDA);
ulp_lp_core_gpio_input_enable(PIN_SDA);
ulp_lp_core_gpio_pullup_enable(PIN_SDA);
ulp_lp_core_gpio_init(PIN_SCL);
ulp_lp_core_gpio_output_disable(PIN_SCL);
ulp_lp_core_gpio_input_enable(PIN_SCL);
ulp_lp_core_gpio_pullup_enable(PIN_SCL);
}
void I2CDeInit(void)
{
ulp_lp_core_gpio_output_disable(PIN_SDA);
ulp_lp_core_gpio_input_disable(PIN_SDA);
ulp_lp_core_gpio_output_disable(PIN_SCL);
ulp_lp_core_gpio_input_disable(PIN_SCL);
}
//
// Read N bytes starting at a specific I2C internal register
// returns 1 for success, 0 for error
//
void I2CReadRegister(uint8_t iAddr, uint8_t u8Register, uint8_t *pData, int iLen)
{
I2CWrite(iAddr, &u8Register, 1);
I2CRead(iAddr, pData, iLen);
} /* I2CReadRegister() */
// Init the GPIO pin for output mode
void init_gpio(uint8_t pin)
{
ulp_lp_core_gpio_init(pin);
ulp_lp_core_gpio_set_output_mode(pin, GPIO_MODE_OUTPUT);
ulp_lp_core_gpio_output_enable(pin);
} /* init_gpio() */
#endif // __ULP_IO__