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Code Issues Releases Activity

I2C: Some more fixes. I2C test passes at 400KBit and 200KBit but needs to be investigated further

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git-svn-id: svn://svn.openpilot.org/OpenPilot/trunk@280 ebee16cc-31ac-478f-84a7-5cbb03baadba
This commit is contained in:
FredericG 2010-03-10 21:11:19 +00:00 committed by FredericG
parent ac93d532b7
commit dbde2b1bac
1 changed files with 52 additions and 23 deletions
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75
flight/PiOS/STM32F10x/pios_i2c.c
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@ -30,14 +30,12 @@
/* Project Includes */
#include "pios.h"
// FIXME: temp assert
#define assert(exp) {if (!(exp)) while(1);}
#if !defined(PIOS_DONT_USE_I2C)
/* Options */
#define USE_DEBUG_PINS
// #define USE_DEBUG_PINS
/* Global Variables */
volatile uint32_t PIOS_I2C_UnexpectedEvent;
@ -84,6 +82,7 @@ static I2CRecTypeDef I2CRec;
#ifdef USE_DEBUG_PINS
#define DEBUG_PIN_ISR 0
#define DEBUG_PIN_BUSY 1
#define DEBUG_PIN_ASSERT 7
#define DebugPinHigh(x) PIOS_DEBUG_PinHigh(x)
#define DebugPinLow(x) PIOS_DEBUG_PinLow(x)
#else
@ -91,6 +90,10 @@ static I2CRecTypeDef I2CRec;
#define DebugPinLow(x)
#endif
// FIXME: temp assert
#define assert(exp) {if (!(exp)) while(1){DebugPinHigh(DEBUG_PIN_ASSERT);DebugPinLow(DEBUG_PIN_ASSERT);};};
/**
* Initializes IIC driver
* \param[in] mode currently only mode 0 supported
@ -128,6 +131,8 @@ int32_t PIOS_I2C_Init(void)
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = PIOS_I2C_IRQ_ER_PRIORITY;
NVIC_Init(&NVIC_InitStructure);
DebugPinLow(2);
/* No error */
return 0;
}
@ -298,6 +303,9 @@ int32_t PIOS_I2C_TransferWait(void)
uint32_t repeat_ctr = PIOS_I2C_TIMEOUT_VALUE;
uint16_t last_buffer_ix = i2cx->buffer_ix;
DebugPinHigh(3);
//while(i2cx->transfer_state.BUSY);
while(--repeat_ctr > 0) {
/* Check if buffer index has changed - if so, reload repeat counter */
if(i2cx->buffer_ix != last_buffer_ix) {
@ -314,6 +322,7 @@ int32_t PIOS_I2C_TransferWait(void)
/* Release semaphore for easier programming at user level */
i2cx->i2c_semaphore = 0;
}
DebugPinLow(3);
return check_state;
}
}
@ -329,6 +338,8 @@ int32_t PIOS_I2C_TransferWait(void)
/* Release semaphore (!) */
i2cx->i2c_semaphore = 0;
DebugPinLow(3);
return (i2cx->last_transfer_error = I2C_ERROR_TIMEOUT);
}
@ -357,6 +368,7 @@ int32_t PIOS_I2C_Transfer(I2CTransferTypeDef transfer, uint8_t address, uint8_t
I2CRecTypeDef *i2cx = &I2CRec;
int32_t error;
/* Wait until previous transfer finished */
if((error = PIOS_I2C_TransferWait())) {
/* Transmission error during previous transfer */
@ -374,6 +386,7 @@ int32_t PIOS_I2C_Transfer(I2CTransferTypeDef transfer, uint8_t address, uint8_t
i2cx->transfer_state.ALL = 0;
i2cx->transfer_error = 0;
/* Set buffer length and start index */
i2cx->buffer_len = len;
i2cx->buffer_ix = 0;
@ -404,8 +417,10 @@ int32_t PIOS_I2C_Transfer(I2CTransferTypeDef transfer, uint8_t address, uint8_t
}
// Start the transfer
TransferStart(i2cx);
I2C_GenerateSTART(i2cx->base, ENABLE);
TransferStart(i2cx);
// All is fine
return 0;
@ -420,6 +435,7 @@ static void EV_IRQHandler(I2CRecTypeDef *i2cx)
DebugPinHigh(DEBUG_PIN_ISR);
/* Read SR1 and SR2 at the beginning (if not done so, flags may get lost) */
uint32_t event = I2C_GetLastEvent(i2cx->base);
@ -440,6 +456,7 @@ static void EV_IRQHandler(I2CRecTypeDef *i2cx)
i2cx->rx_buffer_ptr[i2cx->buffer_ix++] = b;
}
/* Last byte received, disable interrupts and return. */
if(i2cx->transfer_state.STOP_REQUESTED) {
TransferEnd(i2cx);
@ -491,13 +508,14 @@ static void EV_IRQHandler(I2CRecTypeDef *i2cx)
/* Peripheral is transfering last byte, request stop condition / */
/* On write-without-stop transfer-type, request start condition instead */
if(!i2cx->transfer_state.WRITE_WITHOUT_STOP) {
DebugPinHigh(2);
i2cx->transfer_state.STOP_REQUESTED = 1;
if(!i2cx->transfer_state.WRITE_WITHOUT_STOP)
{
I2C_GenerateSTOP(i2cx->base, ENABLE);
i2cx->transfer_state.STOP_REQUESTED = 1;
DebugPinLow(2);
} else {
TransferEnd(i2cx);
}
else
{
DebugPinHigh(2);
}
if(i2cx->buffer_len == 0) {
@ -511,6 +529,7 @@ static void EV_IRQHandler(I2CRecTypeDef *i2cx)
goto isr_return;
}
// Send address
/* SB set, cleared by reading SR1 (done by I2C_GetLastEvent) followed by writing DR register */
if(event & I2C_FLAG_SB) {
/* Don't send address if stop was requested (WRITE_WITHOUT_STOP - mode, start condition was sent) */
@ -528,21 +547,31 @@ static void EV_IRQHandler(I2CRecTypeDef *i2cx)
: I2C_Direction_Transmitter);
goto isr_return;
}
/* This code is only reached if something got wrong, e.g. interrupt handler is called too late, */
/* The device reset itself (while testing, it was always event 0x00000000). we have to stop the transfer, */
/* Else read/write of corrupt data may be the result. */
/* Notify error */
PIOS_I2C_UnexpectedEvent = event;
i2cx->transfer_error = I2C_ERROR_UNEXPECTED_EVENT;
TransferEnd(i2cx);
DebugPinHigh(DEBUG_PIN_ASSERT);DebugPinLow(DEBUG_PIN_ASSERT);
/* Do dummy read to send NAK + STOP condition */
I2C_AcknowledgeConfig(i2cx->base, DISABLE);
b = I2C_ReceiveData(i2cx->base);
I2C_GenerateSTOP(i2cx->base, ENABLE);
//
// FredericG: Despite the comments below, it seems to me that this situation can happen and can
// be ignored without ill effects...
// For now this condition does not stop the transfer, but further investigation in needed
//
// assert(0);
//
// /* This code is only reached if something got wrong, e.g. interrupt handler is called too late, */
// /* The device reset itself (while testing, it was always event 0x00000000). we have to stop the transfer, */
// /* Else read/write of corrupt data may be the result. */
//
// /* Notify error */
// PIOS_I2C_UnexpectedEvent = event;
// i2cx->transfer_error = I2C_ERROR_UNEXPECTED_EVENT;
//
// TransferEnd(i2cx);
//
// /* Do dummy read to send NAK + STOP condition */
// I2C_AcknowledgeConfig(i2cx->base, DISABLE);
// b = I2C_ReceiveData(i2cx->base);
// I2C_GenerateSTOP(i2cx->base, ENABLE);
isr_return:
DebugPinLow(DEBUG_PIN_ISR);