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Maintain state for i2c_ev_handler() for each i2c bus (#14268)

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Steve Evans 2025-02-22 16:17:48 +00:00 • committed by GitHub
parent c91e3d1050
commit 1359b40ee7
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1 changed files with 41 additions and 34 deletions
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75
src/platform/STM32/bus_i2c_stm32f4xx.c
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@ -116,6 +116,14 @@ const i2cHardware_t i2cHardware[I2CDEV_COUNT] = {
i2cDevice_t i2cDevice[I2CDEV_COUNT]; i2cDevice_t i2cDevice[I2CDEV_COUNT];
// State used by event handler ISR
typedef struct {
uint8_t subaddress_sent; // flag to indicate if subaddess sent
uint8_t final_stop; // flag to indicate final bus condition
int8_t index; // index is signed -1 == send the subaddress
} i2cEvState_t;
static i2cEvState_t i2c_ev_state[I2CDEV_COUNT];
static volatile uint16_t i2cErrorCount = 0; static volatile uint16_t i2cErrorCount = 0;
void I2C1_ER_IRQHandler(void) void I2C1_ER_IRQHandler(void)
@ -316,18 +324,17 @@ void i2c_ev_handler(I2CDevice device)
{ {
I2C_TypeDef *I2Cx = i2cDevice[device].hardware->reg; I2C_TypeDef *I2Cx = i2cDevice[device].hardware->reg;
i2cEvState_t *ev_state = &i2c_ev_state[device];
i2cState_t *state = &i2cDevice[device].state; i2cState_t *state = &i2cDevice[device].state;
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 uint8_t SReg_1 = I2Cx->SR1; // read the status register here
if (SReg_1 & I2C_SR1_SB) { // we just sent a start - EV5 in ref manual if (SReg_1 & I2C_SR1_SB) { // we just sent a start - EV5 in ref manual
I2Cx->CR1 &= ~I2C_CR1_POS; // reset the POS bit so ACK/NACK applied to the current byte I2Cx->CR1 &= ~I2C_CR1_POS; // reset the POS bit so ACK/NACK applied to the current byte
I2C_AcknowledgeConfig(I2Cx, ENABLE); // make sure ACK is on I2C_AcknowledgeConfig(I2Cx, ENABLE); // make sure ACK is on
index = 0; // reset the index ev_state->index = 0; // reset the index
if (state->reading && (subaddress_sent || 0xFF == state->reg)) { // we have sent the subaddr if (state->reading && (ev_state->subaddress_sent || 0xFF == state->reg)) { // we have sent the subaddr
subaddress_sent = 1; // make sure this is set in case of no subaddress, so following code runs correctly ev_state->subaddress_sent = 1; // make sure this is set in case of no subaddress, so following code runs correctly
if (state->bytes == 2) if (state->bytes == 2)
I2Cx->CR1 |= I2C_CR1_POS; // set the POS bit so NACK applied to the final byte in the two byte read I2Cx->CR1 |= I2C_CR1_POS; // set the POS bit so NACK applied to the final byte in the two byte read
I2C_Send7bitAddress(I2Cx, state->addr, I2C_Direction_Receiver); // send the address and set hardware mode I2C_Send7bitAddress(I2Cx, state->addr, I2C_Direction_Receiver); // send the address and set hardware mode
@ -335,93 +342,93 @@ void i2c_ev_handler(I2CDevice device)
else { // direction is Tx, or we havent sent the sub and rep start else { // direction is Tx, or we havent sent the sub and rep start
I2C_Send7bitAddress(I2Cx, state->addr, I2C_Direction_Transmitter); // send the address and set hardware mode I2C_Send7bitAddress(I2Cx, state->addr, I2C_Direction_Transmitter); // send the address and set hardware mode
if (state->reg != 0xFF) // 0xFF as subaddress means it will be ignored, in Tx or Rx mode if (state->reg != 0xFF) // 0xFF as subaddress means it will be ignored, in Tx or Rx mode
index = -1; // send a subaddress ev_state->index = -1; // send a subaddress
} }
} }
else if (SReg_1 & I2C_SR1_ADDR) { // we just sent the address - EV6 in ref manual else if (SReg_1 & I2C_SR1_ADDR) { // we just sent the address - EV6 in ref manual
// Read SR1,2 to clear ADDR // Read SR1,2 to clear ADDR
__DMB(); // memory fence to control hardware __DMB(); // memory fence to control hardware
if (state->bytes == 1 && state->reading && subaddress_sent) { // we are receiving 1 byte - EV6_3 if (state->bytes == 1 && state->reading && ev_state->subaddress_sent) { // we are receiving 1 byte - EV6_3
I2C_AcknowledgeConfig(I2Cx, DISABLE); // turn off ACK I2C_AcknowledgeConfig(I2Cx, DISABLE); // turn off ACK
__DMB(); __DMB();
(void)I2Cx->SR2; // clear ADDR after ACK is turned off (void)I2Cx->SR2; // clear ADDR after ACK is turned off
I2C_GenerateSTOP(I2Cx, ENABLE); // program the stop I2C_GenerateSTOP(I2Cx, ENABLE); // program the stop
final_stop = 1; ev_state->final_stop = 1;
I2C_ITConfig(I2Cx, I2C_IT_BUF, ENABLE); // allow us to have an EV7 I2C_ITConfig(I2Cx, I2C_IT_BUF, ENABLE); // allow us to have an EV7
} }
else { // EV6 and EV6_1 else { // EV6 and EV6_1
(void)I2Cx->SR2; // clear the ADDR here (void)I2Cx->SR2; // clear the ADDR here
__DMB(); __DMB();
if (state->bytes == 2 && state->reading && subaddress_sent) { // rx 2 bytes - EV6_1 if (state->bytes == 2 && state->reading && ev_state->subaddress_sent) { // rx 2 bytes - EV6_1
I2C_AcknowledgeConfig(I2Cx, DISABLE); // turn off ACK I2C_AcknowledgeConfig(I2Cx, DISABLE); // turn off ACK
I2C_ITConfig(I2Cx, I2C_IT_BUF, DISABLE); // disable TXE to allow the buffer to fill I2C_ITConfig(I2Cx, I2C_IT_BUF, DISABLE); // disable TXE to allow the buffer to fill
} }
else if (state->bytes == 3 && state->reading && subaddress_sent) // rx 3 bytes else if (state->bytes == 3 && state->reading && ev_state->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 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 else // receiving greater than three bytes, sending subaddress, or transmitting
I2C_ITConfig(I2Cx, I2C_IT_BUF, ENABLE); I2C_ITConfig(I2Cx, I2C_IT_BUF, ENABLE);
} }
} }
else if (SReg_1 & I2C_SR1_BTF) { // Byte transfer finished - EV7_2, EV7_3 or EV8_2 else if (SReg_1 & I2C_SR1_BTF) { // Byte transfer finished - EV7_2, EV7_3 or EV8_2
final_stop = 1; ev_state->final_stop = 1;
if (state->reading && subaddress_sent) { // EV7_2, EV7_3 if (state->reading && ev_state->subaddress_sent) { // EV7_2, EV7_3
if (state->bytes > 2) { // EV7_2 if (state->bytes > 2) { // EV7_2
I2C_AcknowledgeConfig(I2Cx, DISABLE); // turn off ACK I2C_AcknowledgeConfig(I2Cx, DISABLE); // turn off ACK
state->read_p[index++] = (uint8_t)I2Cx->DR; // read data N-2 state->read_p[ev_state->index++] = (uint8_t)I2Cx->DR; // read data N-2
I2C_GenerateSTOP(I2Cx, ENABLE); // program the Stop I2C_GenerateSTOP(I2Cx, ENABLE); // program the Stop
final_stop = 1; // required to fix hardware ev_state->final_stop = 1; // required to fix hardware
state->read_p[index++] = (uint8_t)I2Cx->DR; // read data N - 1 state->read_p[ev_state->index++] = (uint8_t)I2Cx->DR; // read data N - 1
I2C_ITConfig(I2Cx, I2C_IT_BUF, ENABLE); // enable TXE to allow the final EV7 I2C_ITConfig(I2Cx, I2C_IT_BUF, ENABLE); // enable TXE to allow the final EV7
} }
else { // EV7_3 else { // EV7_3
if (final_stop) if (ev_state->final_stop)
I2C_GenerateSTOP(I2Cx, ENABLE); // program the Stop I2C_GenerateSTOP(I2Cx, ENABLE); // program the Stop
else else
I2C_GenerateSTART(I2Cx, ENABLE); // program a rep start I2C_GenerateSTART(I2Cx, ENABLE); // program a rep start
state->read_p[index++] = (uint8_t)I2Cx->DR; // read data N - 1 state->read_p[ev_state->index++] = (uint8_t)I2Cx->DR; // read data N - 1
state->read_p[index++] = (uint8_t)I2Cx->DR; // read data N state->read_p[ev_state->index++] = (uint8_t)I2Cx->DR; // read data N
index++; // to show job completed ev_state->index++; // to show job completed
} }
} }
else { // EV8_2, which may be due to a subaddress sent or a write completion else { // EV8_2, which may be due to a subaddress sent or a write completion
if (subaddress_sent || (state->writing)) { if (ev_state->subaddress_sent || (state->writing)) {
if (final_stop) if (ev_state->final_stop)
I2C_GenerateSTOP(I2Cx, ENABLE); // program the Stop I2C_GenerateSTOP(I2Cx, ENABLE); // program the Stop
else else
I2C_GenerateSTART(I2Cx, ENABLE); // program a rep start I2C_GenerateSTART(I2Cx, ENABLE); // program a rep start
index++; // to show that the job is complete ev_state->index++; // to show that the job is complete
} }
else { // We need to send a subaddress else { // We need to send a subaddress
I2C_GenerateSTART(I2Cx, ENABLE); // program the repeated Start I2C_GenerateSTART(I2Cx, ENABLE); // program the repeated Start
subaddress_sent = 1; // this is set back to zero upon completion of the current task ev_state->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 // we must wait for the start to clear, otherwise we get constant BTF
while (I2Cx->CR1 & I2C_CR1_START) {; } while (I2Cx->CR1 & I2C_CR1_START) {; }
} }
else if (SReg_1 & I2C_SR1_RXNE) { // Byte received - EV7 else if (SReg_1 & I2C_SR1_RXNE) { // Byte received - EV7
state->read_p[index++] = (uint8_t)I2Cx->DR; state->read_p[ev_state->index++] = (uint8_t)I2Cx->DR;
if (state->bytes == (index + 3)) if (state->bytes == (ev_state->index + 3))
I2C_ITConfig(I2Cx, I2C_IT_BUF, DISABLE); // disable TXE to allow the buffer to flush so we can get an EV7_2 I2C_ITConfig(I2Cx, I2C_IT_BUF, DISABLE); // disable TXE to allow the buffer to flush so we can get an EV7_2
if (state->bytes == index) // We have completed a final EV7 if (state->bytes == ev_state->index) // We have completed a final EV7
index++; // to show job is complete ev_state->index++; // to show job is complete
} }
else if (SReg_1 & I2C_SR1_TXE) { // Byte transmitted EV8 / EV8_1 else if (SReg_1 & I2C_SR1_TXE) { // Byte transmitted EV8 / EV8_1
if (index != -1) { // we dont have a subaddress to send if (ev_state->index != -1) { // we dont have a subaddress to send
I2Cx->DR = state->write_p[index++]; I2Cx->DR = state->write_p[ev_state->index++];
if (state->bytes == index) // we have sent all the data if (state->bytes == ev_state->index) // we have sent all the data
I2C_ITConfig(I2Cx, I2C_IT_BUF, DISABLE); // disable TXE to allow the buffer to flush I2C_ITConfig(I2Cx, I2C_IT_BUF, DISABLE); // disable TXE to allow the buffer to flush
} }
else { else {
index++; ev_state->index++;
I2Cx->DR = state->reg; // send the subaddress I2Cx->DR = state->reg; // send the subaddress
if (state->reading || !(state->bytes)) // if receiving or sending 0 bytes, flush now if (state->reading || !(state->bytes)) // if receiving or sending 0 bytes, flush now
I2C_ITConfig(I2Cx, I2C_IT_BUF, DISABLE); // disable TXE to allow the buffer to flush I2C_ITConfig(I2Cx, I2C_IT_BUF, DISABLE); // disable TXE to allow the buffer to flush
} }
} }
if (index == state->bytes + 1) { // we have completed the current job if (ev_state->index == state->bytes + 1) { // we have completed the current job
subaddress_sent = 0; // reset this here ev_state->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 if (ev_state->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 I2C_ITConfig(I2Cx, I2C_IT_EVT | I2C_IT_ERR, DISABLE); // Disable EVT and ERR interrupts while bus inactive
state->busy = 0; state->busy = 0;
} }