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betaflight/src/drivers/bus_i2c_stm32f10x.c
dongie 0e80dbf025 reformat I2C driver and align comments. add timeout checking and move hardware reinit common code into separate function.
moved nvic priority group init into drv_system, where it belongs

Conflicts:
	src/drivers/system_common.c
	src/drv_i2c.c
2014-05-30 09:38:03 +01:00

352 lines
16 KiB
C
Executable file

#include <stdbool.h>
#include <stdint.h>
#include <platform.h>
#include "build_config.h"
#include "gpio_common.h"
#include "system_common.h"
#include "bus_i2c.h"
#ifndef SOFT_I2C
// 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 bool i2cHandleHardwareFailure(void)
{
i2cErrorCount++;
// reinit peripheral + clock out garbage
i2cInit(I2Cx);
return false;
}
bool i2cWriteBuffer(uint8_t addr_, uint8_t reg_, uint8_t len_, uint8_t *data)
{
uint32_t timeout = I2C_DEFAULT_TIMEOUT;
addr = addr_ << 1;
reg = reg_;
writing = 1;
reading = 0;
write_p = data;
read_p = data;
bytes = len_;
busy = 1;
error = false;
if (!(I2Cx->CR2 & I2C_IT_EVT)) { // if we are restarting the driver
if (!(I2Cx->CR1 & 0x0100)) { // ensure sending a start
while (I2Cx->CR1 & 0x0200 && --timeout > 0) { ; } // wait for any stop to finish sending
if (timeout == 0)
return i2cHandleHardwareFailure();
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
}
timeout = I2C_DEFAULT_TIMEOUT;
while (busy && --timeout > 0) { ; }
if (timeout == 0)
return i2cHandleHardwareFailure();
return !error;
}
bool i2cWrite(uint8_t addr_, uint8_t reg_, uint8_t data)
{
return i2cWriteBuffer(addr_, reg_, 1, &data);
}
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;
error = false;
if (!(I2Cx->CR2 & I2C_IT_EVT)) { // if we are restarting the driver
if (!(I2Cx->CR1 & 0x0100)) { // ensure sending a start
while (I2Cx->CR1 & 0x0200 && --timeout > 0) { ; } // wait for any stop to finish sending
if (timeout == 0)
return i2cHandleHardwareFailure();
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
}
timeout = I2C_DEFAULT_TIMEOUT;
while (busy && --timeout > 0) { ; }
if (timeout == 0)
return i2cHandleHardwareFailure();
return !error;
}
static void i2c_er_handler(void)
{
// Read the I2C1 status register
volatile uint32_t SR1Register = I2Cx->SR1;
if (SR1Register & 0x0F00) // an error
error = true;
// If AF, BERR or ARLO, abandon the current job and commence new if there are jobs
if (SR1Register & 0x0700) {
(void)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;
}
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
__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();
(void)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
(void)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++] = (uint8_t)I2Cx->DR; // read data N-2
I2C_GenerateSTOP(I2Cx, ENABLE); // program the Stop
final_stop = 1; // required to fix hardware
read_p[index++] = (uint8_t)I2Cx->DR; // 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++] = (uint8_t)I2Cx->DR; // read data N - 1
read_p[index++] = (uint8_t)I2Cx->DR; // 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++] = (uint8_t)I2Cx->DR;
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
I2Cx->DR = 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++;
I2Cx->DR = 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
subaddress_sent = 0; // reset this here
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;
I2C_InitTypeDef i2c;
gpio_config_t gpio;
// Init pins
gpio.pin = Pin_10 | Pin_11;
gpio.speed = Speed_2MHz;
gpio.mode = Mode_AF_OD;
gpioInit(GPIOB, &gpio);
I2Cx = I2C;
// clock out stuff to make sure slaves arent stuck
i2cUnstick();
// Init I2C
I2C_DeInit(I2Cx);
I2C_StructInit(&i2c);
I2C_ITConfig(I2Cx, I2C_IT_EVT | I2C_IT_ERR, DISABLE); // Enable EVT and ERR interrupts - they are enabled by the first request
i2c.I2C_Mode = I2C_Mode_I2C;
i2c.I2C_DutyCycle = I2C_DutyCycle_2;
i2c.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit;
i2c.I2C_ClockSpeed = 400000;
I2C_Cmd(I2Cx, ENABLE);
I2C_Init(I2Cx, &i2c);
// I2C ER Interrupt
nvic.NVIC_IRQChannel = I2C2_ER_IRQn;
nvic.NVIC_IRQChannelPreemptionPriority = 0;
nvic.NVIC_IRQChannelSubPriority = 0;
nvic.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&nvic);
// I2C EV Interrupt
nvic.NVIC_IRQChannel = I2C2_EV_IRQn;
nvic.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_Init(&nvic);
}
uint16_t i2cGetErrorCounter(void)
{
return i2cErrorCount;
}
static void i2cUnstick(void)
{
gpio_config_t gpio;
uint8_t i;
gpio.pin = Pin_10 | Pin_11;
gpio.speed = Speed_2MHz;
gpio.mode = Mode_Out_OD;
gpioInit(GPIOB, &gpio);
digitalHi(GPIOB, Pin_10 | Pin_11);
for (i = 0; i < 8; i++) {
// Wait for any clock stretching to finish
while (!digitalIn(GPIOB, Pin_10))
delayMicroseconds(10);
// Pull low
digitalLo(GPIOB, Pin_10); // Set bus low
delayMicroseconds(10);
// Release high again
digitalHi(GPIOB, Pin_10); // Set bus high
delayMicroseconds(10);
}
// Generate a start then stop condition
// SCL PB10
// SDA PB11
digitalLo(GPIOB, Pin_11); // Set bus data low
delayMicroseconds(10);
digitalLo(GPIOB, Pin_10); // Set bus scl low
delayMicroseconds(10);
digitalHi(GPIOB, Pin_10); // Set bus scl high
delayMicroseconds(10);
digitalHi(GPIOB, Pin_11); // Set bus sda high
// Init pins
gpio.pin = Pin_10 | Pin_11;
gpio.speed = Speed_2MHz;
gpio.mode = Mode_AF_OD;
gpioInit(GPIOB, &gpio);
}
#endif