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#include "gfx.h"
#if GFX_COMPAT_V2 && GFX_COMPAT_OLDCOLORS
#undef Red
#undef Green
#undef Blue
#endif
#include "stm32f7_i2c.h"
/*
* The CR2 register needs atomic access. Hence always use this function to setup a transfer configuration.
*/
static void _i2cConfigTransfer(I2C_TypeDef* i2c, uint16_t slaveAddr, uint8_t numBytes, uint32_t mode, uint32_t request)
{
uint32_t tmpreg = 0;
// Get the current CR2 register value
tmpreg = i2c->CR2;
// Clear tmpreg specific bits
tmpreg &= (uint32_t) ~((uint32_t) (I2C_CR2_SADD | I2C_CR2_NBYTES | I2C_CR2_RELOAD | I2C_CR2_AUTOEND | I2C_CR2_RD_WRN | I2C_CR2_START | I2C_CR2_STOP));
// update tmpreg
tmpreg |= (uint32_t) (((uint32_t) slaveAddr & I2C_CR2_SADD) | (((uint32_t) numBytes << 16) & I2C_CR2_NBYTES) | (uint32_t) mode | (uint32_t) request);
// Update the actual CR2 contents
i2c->CR2 = tmpreg;
}
/*
* According to the STM32Cube HAL the CR2 register needs to be reset after each transaction.
*/
static void _i2cResetCr2(I2C_TypeDef* i2c)
{
i2c->CR2 &= (uint32_t) ~((uint32_t) (I2C_CR2_SADD | I2C_CR2_HEAD10R | I2C_CR2_NBYTES | I2C_CR2_RELOAD | I2C_CR2_RD_WRN));
}
bool_t i2cInit(I2C_TypeDef* i2c)
{
// Enable I2Cx peripheral clock.
// Select APB1 as clock source
if (i2c == I2C1) {
RCC->DCKCFGR2 &= ~RCC_DCKCFGR2_I2C1SEL;
RCC->APB1ENR |= RCC_APB1ENR_I2C1EN;
} else if (i2c == I2C2) {
RCC->DCKCFGR2 &= ~RCC_DCKCFGR2_I2C2SEL;
RCC->APB1ENR |= RCC_APB1ENR_I2C2EN;
} else if (i2c == I2C3) {
RCC->DCKCFGR2 &= ~RCC_DCKCFGR2_I2C3SEL;
RCC->APB1ENR |= RCC_APB1ENR_I2C3EN;
} else if (i2c == I2C4) {
RCC->DCKCFGR2 &= ~RCC_DCKCFGR2_I2C4SEL;
RCC->APB1ENR |= RCC_APB1ENR_I2C4EN;
} else {
return FALSE;
}
// Disable the I2Cx peripheral
i2c->CR1 &= ~I2C_CR1_PE;
while (i2c->CR1 & I2C_CR1_PE);
// Set timings. Asuming I2CCLK is 50 MHz (APB1 clock source)
i2c->TIMINGR = 0x40912732; // Discovery BSP code from ST examples
// Use 7-bit addresses
i2c->CR2 &=~ I2C_CR2_ADD10;
// Enable auto-end mode
i2c->CR2 |= I2C_CR2_AUTOEND;
// Disable the analog filter
i2c->CR1 |= I2C_CR1_ANFOFF;
// Disable NOSTRETCH
i2c->CR1 |= I2C_CR1_NOSTRETCH;
// Enable the I2Cx peripheral
i2c->CR1 |= I2C_CR1_PE;
return TRUE;
}
void i2cSend(I2C_TypeDef* i2c, uint8_t slaveAddr, uint8_t* data, uint16_t length)
{
// We are currently not able to send more than 255 bytes at once
if (length > 255) {
return;
}
// Setup the configuration
_i2cConfigTransfer(i2c, slaveAddr, length, (!I2C_CR2_RD_WRN) | I2C_CR2_AUTOEND, I2C_CR2_START);
// Transmit the whole buffer
while (length > 0) {
while (!(i2c->ISR & I2C_ISR_TXIS));
i2c->TXDR = *data++;
length--;
}
// Wait until the transfer is complete
while (!(i2c->ISR & I2C_ISR_TXE));
// Wait until the stop condition was automagically sent
while (!(i2c->ISR & I2C_ISR_STOPF));
// Reset the STOP bit
i2c->ISR &= ~I2C_ISR_STOPF;
// Reset the CR2 register
_i2cResetCr2(i2c);
}
void i2cSendByte(I2C_TypeDef* i2c, uint8_t slaveAddr, uint8_t data)
{
i2cSend(i2c, slaveAddr, &data, 1);
}
void i2cWriteReg(I2C_TypeDef* i2c, uint8_t slaveAddr, uint8_t regAddr, uint8_t value)
{
uint8_t txbuf[2];
txbuf[0] = regAddr;
txbuf[1] = value;
i2cSend(i2c, slaveAddr, txbuf, 2);
}
void i2cRead(I2C_TypeDef* i2c, uint8_t slaveAddr, uint8_t* data, uint16_t length)
{
int i;
// We are currently not able to read more than 255 bytes at once
if (length > 255) {
return;
}
// Setup the configuration
_i2cConfigTransfer(i2c, slaveAddr, length, I2C_CR2_RD_WRN | I2C_CR2_AUTOEND, I2C_CR2_START);
// Transmit the whole buffer
for (i = 0; i < length; i++) {
while (!(i2c->ISR & I2C_ISR_RXNE));
data[i] = i2c->RXDR;
}
// Wait until the stop condition was automagically sent
while (!(i2c->ISR & I2C_ISR_STOPF));
// Reset the STOP bit
i2c->ISR &= ~I2C_ISR_STOPF;
// Reset the CR2 register
_i2cResetCr2(i2c);
}
uint8_t i2cReadByte(I2C_TypeDef* i2c, uint8_t slaveAddr, uint8_t regAddr)
{
uint8_t ret = 0xAA;
i2cSend(i2c, slaveAddr, ®Addr, 1);
i2cRead(i2c, slaveAddr, &ret, 1);
return ret;
}
uint16_t i2cReadWord(I2C_TypeDef* i2c, uint8_t slaveAddr, uint8_t regAddr)
{
uint8_t ret[2] = { 0xAA, 0xAA };
i2cSend(i2c, slaveAddr, ®Addr, 1);
i2cRead(i2c, slaveAddr, ret, 2);
return (uint16_t)((ret[0] << 8) | (ret[1] & 0x00FF));
}
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