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betaflight/drv_i2c.c
timecop 57b289466d added featureClearAll to fix pwm/ppm switching due to erased eeprom being FF's 
switched nop to __NOP from cm3 headers
got rid of __GNUC__ DMB stuff as well, since its all properly defined in cm3 headers
added mpu lowpass filter config and defaulted to 42hz. seems to fly smoother.
features are in eeprom, removed default setting from main.c

git-svn-id: https://afrodevices.googlecode.com/svn/trunk/baseflight@98 7c89a4a9-59b9-e629-4cfe-3a2d53b20e61
2012-02-28 12:30:21 +00:00

336 lines
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#include "board.h"
// I2C2
// SCL PB10
// SDA PB11
static I2C_TypeDef *I2Cx;
static void i2c_er_handler(void);
static void i2c_ev_handler(void);
static void i2cUnstick(void);
void I2C1_ER_IRQHandler(void)
{
i2c_er_handler();
}
void I2C1_EV_IRQHandler(void)
{
i2c_ev_handler();
}
void I2C2_ER_IRQHandler(void)
{
i2c_er_handler();
}
void I2C2_EV_IRQHandler(void)
{
i2c_ev_handler();
}
#define I2C_DEFAULT_TIMEOUT 30000
static volatile uint16_t i2cErrorCount = 0;
static volatile bool error = false;
static volatile bool busy;
static volatile uint8_t addr;
static volatile uint8_t reg;
static volatile uint8_t bytes;
static volatile uint8_t writing;
static volatile uint8_t reading;
static volatile uint8_t* write_p;
static volatile uint8_t* read_p;
static void i2c_er_handler(void)
{
volatile uint32_t SR1Register, SR2Register;
/* Read the I2C1 status register */
SR1Register = I2Cx->SR1;
if (SR1Register & 0x0F00) { //an error
// I2C1error.error = ((SR1Register & 0x0F00) >> 8); //save error
// I2C1error.job = job; //the task
}
/* If AF, BERR or ARLO, abandon the current job and commence new if there are jobs */
if (SR1Register & 0x0700) {
SR2Register = I2Cx->SR2; //read second status register to clear ADDR if it is set (note that BTF will not be set after a NACK)
I2C_ITConfig(I2Cx, I2C_IT_BUF, DISABLE); //disable the RXNE/TXE interrupt - prevent the ISR tailchaining onto the ER (hopefully)
if (!(SR1Register & 0x0200) && !(I2Cx->CR1 & 0x0200)) { //if we dont have an ARLO error, ensure sending of a stop
if (I2Cx->CR1 & 0x0100) { //We are currently trying to send a start, this is very bad as start,stop will hang the peripheral
while (I2Cx->CR1 & 0x0100); //wait for any start to finish sending
I2C_GenerateSTOP(I2Cx, ENABLE); //send stop to finalise bus transaction
while (I2Cx->CR1 & 0x0200); //wait for stop to finish sending
i2cInit(I2Cx); //reset and configure the hardware
} else {
I2C_GenerateSTOP(I2Cx, ENABLE); //stop to free up the bus
I2C_ITConfig(I2Cx, I2C_IT_EVT | I2C_IT_ERR, DISABLE); //Disable EVT and ERR interrupts while bus inactive
}
}
}
I2Cx->SR1 &= ~0x0F00; //reset all the error bits to clear the interrupt
busy = 0;
}
bool i2cWrite(uint8_t addr_, uint8_t reg_, uint8_t data)
{
uint8_t my_data[1];
uint32_t timeout = I2C_DEFAULT_TIMEOUT;
addr = addr_ << 1;
reg = reg_;
writing = 1;
reading = 0;
my_data[0] = data;
write_p = my_data;
read_p = my_data;
bytes = 1;
busy = 1;
if (!(I2Cx->CR2 & I2C_IT_EVT)) { //if we are restarting the driver
if (!(I2Cx->CR1 & 0x0100)) { // ensure sending a start
while (I2Cx->CR1 & 0x0200) { ; } //wait for any stop to finish sending
I2C_GenerateSTART(I2Cx, ENABLE); //send the start for the new job
}
I2C_ITConfig(I2Cx, I2C_IT_EVT | I2C_IT_ERR, ENABLE); //allow the interrupts to fire off again
}
while (busy && --timeout > 0);
if (timeout == 0) {
i2cErrorCount++;
// reinit peripheral + clock out garbage
i2cInit(I2Cx);
return false;
}
return true;
}
bool i2cRead(uint8_t addr_, uint8_t reg_, uint8_t len, uint8_t* buf)
{
uint32_t timeout = I2C_DEFAULT_TIMEOUT;
addr = addr_ << 1;
reg = reg_;
writing = 0;
reading = 1;
read_p = buf;
write_p = buf;
bytes = len;
busy = 1;
if (!(I2Cx->CR2 & I2C_IT_EVT)) { //if we are restarting the driver
if (!(I2Cx->CR1 & 0x0100)) { // ensure sending a start
while (I2Cx->CR1 & 0x0200) { ; } //wait for any stop to finish sending
I2C_GenerateSTART(I2Cx, ENABLE); //send the start for the new job
}
I2C_ITConfig(I2Cx, I2C_IT_EVT | I2C_IT_ERR, ENABLE); //allow the interrupts to fire off again
}
while (busy && --timeout > 0);
if (timeout == 0) {
i2cErrorCount++;
// reinit peripheral + clock out garbage
i2cInit(I2Cx);
return false;
}
return true;
}
void i2c_ev_handler(void)
{
static uint8_t subaddress_sent, final_stop; //flag to indicate if subaddess sent, flag to indicate final bus condition
static int8_t index; //index is signed -1==send the subaddress
uint8_t SReg_1 = I2Cx->SR1; //read the status register here
if (SReg_1 & 0x0001) { //we just sent a start - EV5 in ref manual
I2Cx->CR1 &= ~0x0800; //reset the POS bit so ACK/NACK applied to the current byte
I2C_AcknowledgeConfig(I2Cx, ENABLE); //make sure ACK is on
index = 0; //reset the index
if (reading && (subaddress_sent || 0xFF == reg)) { //we have sent the subaddr
subaddress_sent = 1; //make sure this is set in case of no subaddress, so following code runs correctly
if (bytes == 2)
I2Cx->CR1 |= 0x0800; //set the POS bit so NACK applied to the final byte in the two byte read
I2C_Send7bitAddress(I2Cx, addr, I2C_Direction_Receiver); //send the address and set hardware mode
} else { //direction is Tx, or we havent sent the sub and rep start
I2C_Send7bitAddress(I2Cx, addr, I2C_Direction_Transmitter); //send the address and set hardware mode
if (reg != 0xFF) //0xFF as subaddress means it will be ignored, in Tx or Rx mode
index = -1; //send a subaddress
}
} else if (SReg_1 & 0x0002) { //we just sent the address - EV6 in ref manual
//Read SR1,2 to clear ADDR
volatile uint8_t a;
__DMB(); // memory fence to control hardware
if (bytes == 1 && reading && subaddress_sent) { //we are receiving 1 byte - EV6_3
I2C_AcknowledgeConfig(I2Cx, DISABLE); //turn off ACK
__DMB();
a = I2Cx->SR2; //clear ADDR after ACK is turned off
I2C_GenerateSTOP(I2Cx, ENABLE); //program the stop
final_stop = 1;
I2C_ITConfig(I2Cx, I2C_IT_BUF, ENABLE); //allow us to have an EV7
} else { //EV6 and EV6_1
a = I2Cx->SR2; //clear the ADDR here
__DMB();
if (bytes == 2 && reading && subaddress_sent) { //rx 2 bytes - EV6_1
I2C_AcknowledgeConfig(I2Cx, DISABLE); //turn off ACK
I2C_ITConfig(I2Cx, I2C_IT_BUF, DISABLE); //disable TXE to allow the buffer to fill
} else if (bytes == 3 && reading && subaddress_sent) //rx 3 bytes
I2C_ITConfig(I2Cx, I2C_IT_BUF, DISABLE); //make sure RXNE disabled so we get a BTF in two bytes time
else //receiving greater than three bytes, sending subaddress, or transmitting
I2C_ITConfig(I2Cx, I2C_IT_BUF, ENABLE);
}
} else if (SReg_1 & 0x004) { //Byte transfer finished - EV7_2, EV7_3 or EV8_2
final_stop = 1;
if (reading && subaddress_sent) { //EV7_2, EV7_3
if (bytes > 2) { //EV7_2
I2C_AcknowledgeConfig(I2Cx, DISABLE); //turn off ACK
read_p[index++] = I2C_ReceiveData(I2Cx); //read data N-2
I2C_GenerateSTOP(I2Cx, ENABLE); //program the Stop
final_stop = 1; //reuired to fix hardware
read_p[index++] = I2C_ReceiveData(I2Cx); //read data N-1
I2C_ITConfig(I2Cx, I2C_IT_BUF, ENABLE); //enable TXE to allow the final EV7
} else { //EV7_3
if (final_stop)
I2C_GenerateSTOP(I2Cx, ENABLE); //program the Stop
else
I2C_GenerateSTART(I2Cx, ENABLE); //program a rep start
read_p[index++] = I2C_ReceiveData(I2Cx); //read data N-1
read_p[index++] = I2C_ReceiveData(I2Cx); //read data N
index++; //to show job completed
}
} else { //EV8_2, which may be due to a subaddress sent or a write completion
if (subaddress_sent || (writing)) {
if (final_stop)
I2C_GenerateSTOP(I2Cx, ENABLE); //program the Stop
else
I2C_GenerateSTART(I2Cx, ENABLE); //program a rep start
index++; //to show that the job is complete
} else { //We need to send a subaddress
I2C_GenerateSTART(I2Cx, ENABLE); //program the repeated Start
subaddress_sent = 1; //this is set back to zero upon completion of the current task
}
}
//we must wait for the start to clear, otherwise we get constant BTF
while (I2Cx->CR1 & 0x0100) { ; }
} else if (SReg_1 & 0x0040) { //Byte received - EV7
read_p[index++] = I2C_ReceiveData(I2Cx);
if (bytes == (index + 3))
I2C_ITConfig(I2Cx, I2C_IT_BUF, DISABLE); //disable TXE to allow the buffer to flush so we can get an EV7_2
if (bytes == index) //We have completed a final EV7
index++; //to show job is complete
} else if (SReg_1 & 0x0080) { //Byte transmitted -EV8/EV8_1
if (index != -1) { //we dont have a subaddress to send
I2C_SendData(I2Cx, write_p[index++]);
if (bytes == index) //we have sent all the data
I2C_ITConfig(I2Cx, I2C_IT_BUF, DISABLE); //disable TXE to allow the buffer to flush
} else {
index++;
I2C_SendData(I2Cx, reg); //send the subaddress
if (reading || !bytes) //if receiving or sending 0 bytes, flush now
I2C_ITConfig(I2Cx, I2C_IT_BUF, DISABLE); //disable TXE to allow the buffer to flush
}
}
if (index == bytes + 1) { //we have completed the current job
//Completion Tasks go here
//End of completion tasks
subaddress_sent = 0; //reset this here
// I2Cx->CR1 &= ~0x0800; //reset the POS bit so NACK applied to the current byte
if (final_stop) //If there is a final stop and no more jobs, bus is inactive, disable interrupts to prevent BTF
I2C_ITConfig(I2Cx, I2C_IT_EVT | I2C_IT_ERR, DISABLE); //Disable EVT and ERR interrupts while bus inactive
busy = 0;
}
}
void i2cInit(I2C_TypeDef *I2C)
{
NVIC_InitTypeDef NVIC_InitStructure;
GPIO_InitTypeDef GPIO_InitStructure;
I2C_InitTypeDef I2C_InitStructure;
// Init pins
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10 | GPIO_Pin_11;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_OD;
GPIO_Init(GPIOB, &GPIO_InitStructure);
I2Cx = I2C;
// clock out stuff to make sure slaves arent stuck
i2cUnstick();
// Init I2C
I2C_DeInit(I2Cx);
I2C_StructInit(&I2C_InitStructure);
I2C_ITConfig(I2Cx, I2C_IT_EVT | I2C_IT_ERR, DISABLE); //Enable EVT and ERR interrupts - they are enabled by the first request
I2C_InitStructure.I2C_Mode = I2C_Mode_I2C;
I2C_InitStructure.I2C_DutyCycle = I2C_DutyCycle_2;
I2C_InitStructure.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit;
I2C_InitStructure.I2C_ClockSpeed = 400000;
I2C_Cmd(I2Cx, ENABLE);
I2C_Init(I2Cx, &I2C_InitStructure);
NVIC_PriorityGroupConfig(0x500);
// I2C ER Interrupt
NVIC_InitStructure.NVIC_IRQChannel = I2C2_ER_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
// I2C EV Interrupt
NVIC_InitStructure.NVIC_IRQChannel = I2C2_EV_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_Init(&NVIC_InitStructure);
}
uint16_t i2cGetErrorCounter(void)
{
return i2cErrorCount;
}
static void i2cUnstick(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
uint8_t i;
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10 | GPIO_Pin_11;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_OD;
GPIO_Init(GPIOB, &GPIO_InitStructure);
GPIO_SetBits(GPIOB, GPIO_Pin_10 | GPIO_Pin_11);
for (i = 0; i < 8; i++) {
// Wait for any clock stretching to finish
while (!GPIO_ReadInputDataBit(GPIOB, GPIO_Pin_10))
delayMicroseconds(10);
// Pull low
GPIO_ResetBits(GPIOB, GPIO_Pin_10); //Set bus low
delayMicroseconds(10);
// Release high again
GPIO_SetBits(GPIOB, GPIO_Pin_10); //Set bus high
delayMicroseconds(10);
}
// Generate a start then stop condition
// SCL PB10
// SDA PB11
GPIO_ResetBits(GPIOB, GPIO_Pin_11); // Set bus data low
delayMicroseconds(10);
GPIO_ResetBits(GPIOB, GPIO_Pin_10); // Set bus scl low
delayMicroseconds(10);
GPIO_SetBits(GPIOB, GPIO_Pin_10); // Set bus scl high
delayMicroseconds(10);
GPIO_SetBits(GPIOB, GPIO_Pin_11); // Set bus sda high
// Init pins
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10 | GPIO_Pin_11;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_OD;
GPIO_Init(GPIOB, &GPIO_InitStructure);
}
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