/*
ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010,
2011,2012 Giovanni Di Sirio.
This file is part of ChibiOS/RT.
ChibiOS/RT is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
ChibiOS/RT is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see .
*/
/*
Concepts and parts of this file have been contributed by Uladzimir Pylinsky
aka barthess.
*/
/**
* @file STM32/i2c_lld.c
* @brief STM32 I2C subsystem low level driver source.
*
* @addtogroup I2C
* @{
*/
#include "ch.h"
#include "hal.h"
#if HAL_USE_I2C || defined(__DOXYGEN__)
/*===========================================================================*/
/* Driver local definitions. */
/*===========================================================================*/
#define I2C1_RX_DMA_CHANNEL \
STM32_DMA_GETCHANNEL(STM32_I2C_I2C1_RX_DMA_STREAM, \
STM32_I2C1_RX_DMA_CHN)
#define I2C1_TX_DMA_CHANNEL \
STM32_DMA_GETCHANNEL(STM32_I2C_I2C1_TX_DMA_STREAM, \
STM32_I2C1_TX_DMA_CHN)
#define I2C2_RX_DMA_CHANNEL \
STM32_DMA_GETCHANNEL(STM32_I2C_I2C2_RX_DMA_STREAM, \
STM32_I2C2_RX_DMA_CHN)
#define I2C2_TX_DMA_CHANNEL \
STM32_DMA_GETCHANNEL(STM32_I2C_I2C2_TX_DMA_STREAM, \
STM32_I2C2_TX_DMA_CHN)
#define I2C3_RX_DMA_CHANNEL \
STM32_DMA_GETCHANNEL(STM32_I2C_I2C3_RX_DMA_STREAM, \
STM32_I2C3_RX_DMA_CHN)
#define I2C3_TX_DMA_CHANNEL \
STM32_DMA_GETCHANNEL(STM32_I2C_I2C3_TX_DMA_STREAM, \
STM32_I2C3_TX_DMA_CHN)
/*===========================================================================*/
/* Driver constants. */
/*===========================================================================*/
#define I2C_EV5_MASTER_MODE_SELECT \
((uint32_t)(((I2C_SR2_MSL | I2C_SR2_BUSY) << 16) | I2C_SR1_SB))
#define I2C_EV6_MASTER_TRA_MODE_SELECTED \
((uint32_t)(((I2C_SR2_MSL|I2C_SR2_BUSY|I2C_SR2_TRA) << 16) | \
I2C_SR1_ADDR|I2C_SR1_TXE))
#define I2C_EV6_MASTER_REC_MODE_SELECTED \
((uint32_t)(((I2C_SR2_MSL|I2C_SR2_BUSY)<< 16) | I2C_SR1_ADDR))
#define I2C_EV8_2_MASTER_BYTE_TRANSMITTED \
((uint32_t)(((I2C_SR2_MSL | I2C_SR2_BUSY | I2C_SR2_TRA) << 16) | \
I2C_SR1_BTF | I2C_SR1_TXE))
#define I2C_EV_MASK 0x00FFFFFF
/*===========================================================================*/
/* Driver exported variables. */
/*===========================================================================*/
/** @brief I2C1 driver identifier.*/
#if STM32_I2C_USE_I2C1 || defined(__DOXYGEN__)
I2CDriver I2CD1;
#endif
/** @brief I2C2 driver identifier.*/
#if STM32_I2C_USE_I2C2 || defined(__DOXYGEN__)
I2CDriver I2CD2;
#endif
/** @brief I2C3 driver identifier.*/
#if STM32_I2C_USE_I2C3 || defined(__DOXYGEN__)
I2CDriver I2CD3;
#endif
/*===========================================================================*/
/* Driver local variables. */
/*===========================================================================*/
/* The following variables have debugging purpose only and are included when
the option CH_DBG_ENABLE_ASSERTS is enabled.*/
#if CH_DBG_ENABLE_ASSERTS
static volatile uint16_t dbgSR1;
static volatile uint16_t dbgSR2;
static volatile uint16_t dbgCR1;
static volatile uint16_t dbgCR2;
#endif /* CH_DBG_ENABLE_ASSERTS */
/*===========================================================================*/
/* Driver local functions. */
/*===========================================================================*/
/**
* @brief Wakes up the waiting thread.
*
* @param[in] i2cp pointer to the @p I2CDriver object
* @param[in] msg wakeup message
*
* @notapi
*/
#define wakeup_isr(i2cp, msg) { \
chSysLockFromIsr(); \
if ((i2cp)->thread != NULL) { \
Thread *tp = (i2cp)->thread; \
(i2cp)->thread = NULL; \
tp->p_u.rdymsg = (msg); \
chSchReadyI(tp); \
} \
chSysUnlockFromIsr(); \
}
/**
* @brief Aborts an I2C transaction.
*
* @param[in] i2cp pointer to the @p I2CDriver object
*
* @notapi
*/
static void i2c_lld_abort_operation(I2CDriver *i2cp) {
I2C_TypeDef *dp = i2cp->i2c;
/* Stops the I2C peripheral.*/
dp->CR1 = I2C_CR1_SWRST;
dp->CR1 = 0;
dp->CR2 = 0;
dp->SR1 = 0;
/* Stops the associated DMA streams.*/
dmaStreamDisable(i2cp->dmatx);
dmaStreamDisable(i2cp->dmarx);
}
/**
* @brief Handling of stalled I2C transactions.
*
* @param[in] i2cp pointer to the @p I2CDriver object
*
* @notapi
*/
static void i2c_lld_safety_timeout(void *p) {
I2CDriver *i2cp = (I2CDriver *)p;
chSysLockFromIsr();
if (i2cp->thread) {
Thread *tp = i2cp->thread;
i2c_lld_abort_operation(i2cp);
i2cp->thread = NULL;
tp->p_u.rdymsg = RDY_TIMEOUT;
chSchReadyI(tp);
}
chSysUnlockFromIsr();
}
/**
* @brief Set clock speed.
*
* @param[in] i2cp pointer to the @p I2CDriver object
*
* @notapi
*/
static void i2c_lld_set_clock(I2CDriver *i2cp) {
I2C_TypeDef *dp = i2cp->i2c;
uint16_t regCCR, clock_div;
int32_t clock_speed = i2cp->config->clock_speed;
i2cdutycycle_t duty = i2cp->config->duty_cycle;
chDbgCheck((i2cp != NULL) && (clock_speed > 0) && (clock_speed <= 4000000),
"i2c_lld_set_clock");
/* CR2 Configuration.*/
dp->CR2 &= (uint16_t)~I2C_CR2_FREQ;
dp->CR2 |= (uint16_t)I2C_CLK_FREQ;
/* CCR Configuration.*/
regCCR = 0;
clock_div = I2C_CCR_CCR;
if (clock_speed <= 100000) {
/* Configure clock_div in standard mode.*/
chDbgAssert(duty == STD_DUTY_CYCLE,
"i2c_lld_set_clock(), #1",
"Invalid standard mode duty cycle");
/* Standard mode clock_div calculate: Tlow/Thigh = 1/1.*/
chDbgAssert((STM32_PCLK1 % (clock_speed * 2)) == 0,
"i2c_lld_set_clock(), #2",
"PCLK1 must be divided without remainder");
clock_div = (uint16_t)(STM32_PCLK1 / (clock_speed * 2));
chDbgAssert(clock_div >= 0x04,
"i2c_lld_set_clock(), #3",
"Clock divider less then 0x04 not allowed");
regCCR |= (clock_div & I2C_CCR_CCR);
/* Sets the Maximum Rise Time for standard mode.*/
dp->TRISE = I2C_CLK_FREQ + 1;
}
else if (clock_speed <= 400000) {
/* Configure clock_div in fast mode.*/
chDbgAssert((duty == FAST_DUTY_CYCLE_2) || (duty == FAST_DUTY_CYCLE_16_9),
"i2c_lld_set_clock(), #4",
"Invalid fast mode duty cycle");
if (duty == FAST_DUTY_CYCLE_2) {
/* Fast mode clock_div calculate: Tlow/Thigh = 2/1.*/
chDbgAssert((STM32_PCLK1 % (clock_speed * 3)) == 0,
"i2c_lld_set_clock(), #5",
"PCLK1 must be divided without remainder");
clock_div = (uint16_t)(STM32_PCLK1 / (clock_speed * 3));
}
else if (duty == FAST_DUTY_CYCLE_16_9) {
/* Fast mode clock_div calculate: Tlow/Thigh = 16/9.*/
chDbgAssert((STM32_PCLK1 % (clock_speed * 25)) == 0,
"i2c_lld_set_clock(), #6",
"PCLK1 must be divided without remainder");
clock_div = (uint16_t)(STM32_PCLK1 / (clock_speed * 25));
regCCR |= I2C_CCR_DUTY;
}
chDbgAssert(clock_div >= 0x01,
"i2c_lld_set_clock(), #7",
"Clock divider less then 0x04 not allowed");
regCCR |= (I2C_CCR_FS | (clock_div & I2C_CCR_CCR));
/* Sets the Maximum Rise Time for fast mode.*/
dp->TRISE = (I2C_CLK_FREQ * 300 / 1000) + 1;
}
chDbgAssert((clock_div <= I2C_CCR_CCR),
"i2c_lld_set_clock(), #8", "the selected clock is too low");
dp->CCR = regCCR;
}
/**
* @brief Set operation mode of I2C hardware.
*
* @param[in] i2cp pointer to the @p I2CDriver object
*
* @notapi
*/
static void i2c_lld_set_opmode(I2CDriver *i2cp) {
I2C_TypeDef *dp = i2cp->i2c;
i2copmode_t opmode = i2cp->config->op_mode;
uint16_t regCR1;
regCR1 = dp->CR1;
switch (opmode) {
case OPMODE_I2C:
regCR1 &= (uint16_t)~(I2C_CR1_SMBUS|I2C_CR1_SMBTYPE);
break;
case OPMODE_SMBUS_DEVICE:
regCR1 |= I2C_CR1_SMBUS;
regCR1 &= (uint16_t)~(I2C_CR1_SMBTYPE);
break;
case OPMODE_SMBUS_HOST:
regCR1 |= (I2C_CR1_SMBUS|I2C_CR1_SMBTYPE);
break;
}
dp->CR1 = regCR1;
}
/**
* @brief Return the last event value from I2C status registers.
* @details Important but implicit destination of this function is
* clearing interrupts flags.
* @note Internal use only.
* @note Function reads SR2 before SR1. This is workaround, not a bug.
* ADDR was not cleared and it was possible to clear ADDR after
* transfer is properly setup (enabled DMA stream).
*
* @param[in] i2cp pointer to the @p I2CDriver object
*
* @notapi
*/
static uint32_t i2c_get_event(I2CDriver *i2cp) {
I2C_TypeDef *dp = i2cp->i2c;
uint16_t regSR2 = dp->SR2;
uint16_t regSR1 = dp->SR1;
#if CH_DBG_ENABLE_ASSERTS
dbgSR1 = regSR1;
dbgSR2 = regSR2;
dbgCR1 = dp->CR1;
dbgCR2 = dp->CR2;
#endif /* CH_DBG_ENABLE_ASSERTS */
return (I2C_EV_MASK & (regSR1 | (regSR2 << 16)));
}
/**
* @brief I2C shared ISR code.
*
* @param[in] i2cp pointer to the @p I2CDriver object
*
* @notapi
*/
static void i2c_lld_serve_event_interrupt(I2CDriver *i2cp) {
I2C_TypeDef *dp = i2cp->i2c;
uint32_t event = i2c_get_event(i2cp);
uint32_t rxlen = dmaStreamGetTransactionSize(i2cp->dmarx);
/* Interrupts are disabled just before dmaStreamEnable() because there
is no need of interrupts until next transaction begin. All the work is
done by the DMA.*/
switch (event) {
case I2C_EV5_MASTER_MODE_SELECT:
dp->DR = i2cp->addr;
break;
case I2C_EV6_MASTER_REC_MODE_SELECTED:
if (rxlen <= 2)
dp->CR1 &= ~I2C_CR1_ACK;
if (rxlen == 2)
dp->CR1 |= I2C_CR1_POS;
dp->CR2 &= ~I2C_CR2_ITEVTEN;
dmaStreamEnable(i2cp->dmarx);
dp->CR2 |= I2C_CR2_LAST; /* Needed in receiver mode. */
break;
case I2C_EV6_MASTER_TRA_MODE_SELECTED:
dp->CR2 &= ~I2C_CR2_ITEVTEN;
dmaStreamEnable(i2cp->dmatx);
break;
case I2C_EV8_2_MASTER_BYTE_TRANSMITTED:
/* Catches BTF event after the end of transmission.*/
if (rxlen > 0) {
/* Starts "read after write" operation, LSB = 1 -> receive.*/
i2cp->addr |= 0x01;
dp->CR1 |= I2C_CR1_START | I2C_CR1_ACK;
return;
}
dp->CR2 &= ~I2C_CR2_ITEVTEN;
dp->CR1 |= I2C_CR1_STOP;
wakeup_isr(i2cp, RDY_OK);
break;
default:
break;
}
/* Clear ADDR flag. Last part of workaround
(see comments to i2c_get_event() function). */
if (event & (I2C_SR1_ADDR | I2C_SR1_ADD10))
if (dp->SR2){;}
}
/**
* @brief DMA RX end IRQ handler.
*
* @param[in] i2cp pointer to the @p I2CDriver object
* @param[in] flags pre-shifted content of the ISR register
*
* @notapi
*/
static void i2c_lld_serve_rx_end_irq(I2CDriver *i2cp, uint32_t flags) {
I2C_TypeDef *dp = i2cp->i2c;
/* DMA errors handling.*/
#if defined(STM32_I2C_DMA_ERROR_HOOK)
if ((flags & (STM32_DMA_ISR_TEIF | STM32_DMA_ISR_DMEIF)) != 0) {
STM32_I2C_DMA_ERROR_HOOK(i2cp);
}
#else
(void)flags;
#endif
dmaStreamDisable(i2cp->dmarx);
dp->CR2 &= ~I2C_CR2_LAST;
dp->CR1 &= ~I2C_CR1_ACK;
dp->CR1 |= I2C_CR1_STOP;
wakeup_isr(i2cp, RDY_OK);
}
/**
* @brief DMA TX end IRQ handler.
*
* @param[in] i2cp pointer to the @p I2CDriver object
*
* @notapi
*/
static void i2c_lld_serve_tx_end_irq(I2CDriver *i2cp, uint32_t flags) {
I2C_TypeDef *dp = i2cp->i2c;
/* DMA errors handling.*/
#if defined(STM32_I2C_DMA_ERROR_HOOK)
if ((flags & (STM32_DMA_ISR_TEIF | STM32_DMA_ISR_DMEIF)) != 0) {
STM32_I2C_DMA_ERROR_HOOK(i2cp);
}
#else
(void)flags;
#endif
dmaStreamDisable(i2cp->dmatx);
/* Enables interrupts to catch BTF event meaning transmission part complete.
Interrupt handler will decide to generate STOP or to begin receiving part
of R/W transaction itself.*/
dp->CR2 |= I2C_CR2_ITEVTEN;
}
/**
* @brief I2C error handler.
*
* @param[in] i2cp pointer to the @p I2CDriver object
*
* @notapi
*/
static void i2c_lld_serve_error_interrupt(I2CDriver *i2cp) {
I2C_TypeDef *dp = i2cp->i2c;
i2cflags_t errors;
/* Clears interrupt flags just to be safe.*/
chSysLockFromIsr();
dmaStreamDisable(i2cp->dmatx);
dmaStreamDisable(i2cp->dmarx);
chSysUnlockFromIsr();
errors = I2CD_NO_ERROR;
if (dp->SR1 & I2C_SR1_BERR) { /* Bus error. */
dp->SR1 &= ~I2C_SR1_BERR;
errors |= I2CD_BUS_ERROR;
}
if (dp->SR1 & I2C_SR1_ARLO) { /* Arbitration lost. */
dp->SR1 &= ~I2C_SR1_ARLO;
errors |= I2CD_ARBITRATION_LOST;
}
if (dp->SR1 & I2C_SR1_AF) { /* Acknowledge fail. */
dp->SR1 &= ~I2C_SR1_AF;
dp->CR2 &= ~I2C_CR2_ITEVTEN;
dp->CR1 |= I2C_CR1_STOP; /* Setting stop bit. */
errors |= I2CD_ACK_FAILURE;
}
if (dp->SR1 & I2C_SR1_OVR) { /* Overrun. */
dp->SR1 &= ~I2C_SR1_OVR;
errors |= I2CD_OVERRUN;
}
if (dp->SR1 & I2C_SR1_PECERR) { /* PEC error. */
dp->SR1 &= ~I2C_SR1_PECERR;
errors |= I2CD_PEC_ERROR;
}
if (dp->SR1 & I2C_SR1_TIMEOUT) { /* SMBus Timeout. */
dp->SR1 &= ~I2C_SR1_TIMEOUT;
errors |= I2CD_TIMEOUT;
}
if (dp->SR1 & I2C_SR1_SMBALERT) { /* SMBus alert. */
dp->SR1 &= ~I2C_SR1_SMBALERT;
errors |= I2CD_SMB_ALERT;
}
/* If some error has been identified then sends wakes the waiting thread.*/
if (errors != I2CD_NO_ERROR) {
i2cp->errors = errors;
wakeup_isr(i2cp, RDY_RESET);
}
}
/*===========================================================================*/
/* Driver interrupt handlers. */
/*===========================================================================*/
#if STM32_I2C_USE_I2C1 || defined(__DOXYGEN__)
/**
* @brief I2C1 event interrupt handler.
*
* @notapi
*/
CH_IRQ_HANDLER(I2C1_EV_IRQHandler) {
CH_IRQ_PROLOGUE();
i2c_lld_serve_event_interrupt(&I2CD1);
CH_IRQ_EPILOGUE();
}
/**
* @brief I2C1 error interrupt handler.
*/
CH_IRQ_HANDLER(I2C1_ER_IRQHandler) {
CH_IRQ_PROLOGUE();
i2c_lld_serve_error_interrupt(&I2CD1);
CH_IRQ_EPILOGUE();
}
#endif /* STM32_I2C_USE_I2C1 */
#if STM32_I2C_USE_I2C2 || defined(__DOXYGEN__)
/**
* @brief I2C2 event interrupt handler.
*
* @notapi
*/
CH_IRQ_HANDLER(I2C2_EV_IRQHandler) {
CH_IRQ_PROLOGUE();
i2c_lld_serve_event_interrupt(&I2CD2);
CH_IRQ_EPILOGUE();
}
/**
* @brief I2C2 error interrupt handler.
*
* @notapi
*/
CH_IRQ_HANDLER(I2C2_ER_IRQHandler) {
CH_IRQ_PROLOGUE();
i2c_lld_serve_error_interrupt(&I2CD2);
CH_IRQ_EPILOGUE();
}
#endif /* STM32_I2C_USE_I2C2 */
#if STM32_I2C_USE_I2C3 || defined(__DOXYGEN__)
/**
* @brief I2C3 event interrupt handler.
*
* @notapi
*/
CH_IRQ_HANDLER(I2C3_EV_IRQHandler) {
CH_IRQ_PROLOGUE();
i2c_lld_serve_event_interrupt(&I2CD3);
CH_IRQ_EPILOGUE();
}
/**
* @brief I2C3 error interrupt handler.
*
* @notapi
*/
CH_IRQ_HANDLER(I2C3_ER_IRQHandler) {
CH_IRQ_PROLOGUE();
i2c_lld_serve_error_interrupt(&I2CD3);
CH_IRQ_EPILOGUE();
}
#endif /* STM32_I2C_USE_I2C3 */
/*===========================================================================*/
/* Driver exported functions. */
/*===========================================================================*/
/**
* @brief Low level I2C driver initialization.
*
* @notapi
*/
void i2c_lld_init(void) {
#if STM32_I2C_USE_I2C1
i2cObjectInit(&I2CD1);
I2CD1.thread = NULL;
I2CD1.i2c = I2C1;
I2CD1.dmarx = STM32_DMA_STREAM(STM32_I2C_I2C1_RX_DMA_STREAM);
I2CD1.dmatx = STM32_DMA_STREAM(STM32_I2C_I2C1_TX_DMA_STREAM);
#endif /* STM32_I2C_USE_I2C1 */
#if STM32_I2C_USE_I2C2
i2cObjectInit(&I2CD2);
I2CD2.thread = NULL;
I2CD2.i2c = I2C2;
I2CD2.dmarx = STM32_DMA_STREAM(STM32_I2C_I2C2_RX_DMA_STREAM);
I2CD2.dmatx = STM32_DMA_STREAM(STM32_I2C_I2C2_TX_DMA_STREAM);
#endif /* STM32_I2C_USE_I2C2 */
#if STM32_I2C_USE_I2C3
i2cObjectInit(&I2CD3);
I2CD3.thread = NULL;
I2CD3.i2c = I2C3;
I2CD3.dmarx = STM32_DMA_STREAM(STM32_I2C_I2C3_RX_DMA_STREAM);
I2CD3.dmatx = STM32_DMA_STREAM(STM32_I2C_I2C3_TX_DMA_STREAM);
#endif /* STM32_I2C_USE_I2C3 */
}
/**
* @brief Configures and activates the I2C peripheral.
*
* @param[in] i2cp pointer to the @p I2CDriver object
*
* @notapi
*/
void i2c_lld_start(I2CDriver *i2cp) {
I2C_TypeDef *dp = i2cp->i2c;
i2cp->dmamode = STM32_DMA_CR_PSIZE_BYTE | STM32_DMA_CR_MSIZE_BYTE |
STM32_DMA_CR_MINC | STM32_DMA_CR_DMEIE | STM32_DMA_CR_TEIE |
STM32_DMA_CR_TCIE;
/* If in stopped state then enables the I2C and DMA clocks.*/
if (i2cp->state == I2C_STOP) {
#if STM32_I2C_USE_I2C1
if (&I2CD1 == i2cp) {
bool_t b;
rccResetI2C1();
b = dmaStreamAllocate(i2cp->dmarx,
STM32_I2C_I2C1_IRQ_PRIORITY,
(stm32_dmaisr_t)i2c_lld_serve_rx_end_irq,
(void *)i2cp);
chDbgAssert(!b, "i2c_lld_start(), #1", "stream already allocated");
b = dmaStreamAllocate(i2cp->dmatx,
STM32_I2C_I2C1_IRQ_PRIORITY,
(stm32_dmaisr_t)i2c_lld_serve_tx_end_irq,
(void *)i2cp);
chDbgAssert(!b, "i2c_lld_start(), #2", "stream already allocated");
rccEnableI2C1(FALSE);
nvicEnableVector(I2C1_EV_IRQn,
CORTEX_PRIORITY_MASK(STM32_I2C_I2C1_IRQ_PRIORITY));
nvicEnableVector(I2C1_ER_IRQn,
CORTEX_PRIORITY_MASK(STM32_I2C_I2C1_IRQ_PRIORITY));
i2cp->dmamode |= STM32_DMA_CR_CHSEL(I2C1_RX_DMA_CHANNEL) |
STM32_DMA_CR_PL(STM32_I2C_I2C1_DMA_PRIORITY);
}
#endif /* STM32_I2C_USE_I2C1 */
#if STM32_I2C_USE_I2C2
if (&I2CD2 == i2cp) {
bool_t b;
rccResetI2C2();
b = dmaStreamAllocate(i2cp->dmarx,
STM32_I2C_I2C2_IRQ_PRIORITY,
(stm32_dmaisr_t)i2c_lld_serve_rx_end_irq,
(void *)i2cp);
chDbgAssert(!b, "i2c_lld_start(), #3", "stream already allocated");
b = dmaStreamAllocate(i2cp->dmatx,
STM32_I2C_I2C2_IRQ_PRIORITY,
(stm32_dmaisr_t)i2c_lld_serve_tx_end_irq,
(void *)i2cp);
chDbgAssert(!b, "i2c_lld_start(), #4", "stream already allocated");
rccEnableI2C2(FALSE);
nvicEnableVector(I2C2_EV_IRQn,
CORTEX_PRIORITY_MASK(STM32_I2C_I2C2_IRQ_PRIORITY));
nvicEnableVector(I2C2_ER_IRQn,
CORTEX_PRIORITY_MASK(STM32_I2C_I2C2_IRQ_PRIORITY));
i2cp->dmamode |= STM32_DMA_CR_CHSEL(I2C2_RX_DMA_CHANNEL) |
STM32_DMA_CR_PL(STM32_I2C_I2C2_DMA_PRIORITY);
}
#endif /* STM32_I2C_USE_I2C2 */
#if STM32_I2C_USE_I2C3
if (&I2CD3 == i2cp) {
bool_t b;
rccResetI2C3();
b = dmaStreamAllocate(i2cp->dmarx,
STM32_I2C_I2C3_IRQ_PRIORITY,
(stm32_dmaisr_t)i2c_lld_serve_rx_end_irq,
(void *)i2cp);
chDbgAssert(!b, "i2c_lld_start(), #5", "stream already allocated");
b = dmaStreamAllocate(i2cp->dmatx,
STM32_I2C_I2C3_IRQ_PRIORITY,
(stm32_dmaisr_t)i2c_lld_serve_tx_end_irq,
(void *)i2cp);
chDbgAssert(!b, "i2c_lld_start(), #6", "stream already allocated");
rccEnableI2C3(FALSE);
nvicEnableVector(I2C3_EV_IRQn,
CORTEX_PRIORITY_MASK(STM32_I2C_I2C3_IRQ_PRIORITY));
nvicEnableVector(I2C3_ER_IRQn,
CORTEX_PRIORITY_MASK(STM32_I2C_I2C3_IRQ_PRIORITY));
i2cp->dmamode |= STM32_DMA_CR_CHSEL(I2C3_RX_DMA_CHANNEL) |
STM32_DMA_CR_PL(STM32_I2C_I2C3_DMA_PRIORITY);
}
#endif /* STM32_I2C_USE_I2C3 */
}
/* DMA streams mode preparation in advance.*/
dmaStreamSetMode(i2cp->dmatx, i2cp->dmamode | STM32_DMA_CR_DIR_M2P);
dmaStreamSetMode(i2cp->dmarx, i2cp->dmamode | STM32_DMA_CR_DIR_P2M);
/* I2C registers pointed by the DMA.*/
dmaStreamSetPeripheral(i2cp->dmarx, &dp->DR);
dmaStreamSetPeripheral(i2cp->dmatx, &dp->DR);
/* Reset i2c peripheral.*/
dp->CR1 = I2C_CR1_SWRST;
dp->CR1 = 0;
dp->CR2 = I2C_CR2_ITERREN | I2C_CR2_DMAEN;
/* Setup I2C parameters.*/
i2c_lld_set_clock(i2cp);
i2c_lld_set_opmode(i2cp);
/* Ready to go.*/
dp->CR1 |= I2C_CR1_PE;
}
/**
* @brief Deactivates the I2C peripheral.
*
* @param[in] i2cp pointer to the @p I2CDriver object
*
* @notapi
*/
void i2c_lld_stop(I2CDriver *i2cp) {
/* If not in stopped state then disables the I2C clock.*/
if (i2cp->state != I2C_STOP) {
/* I2C disable.*/
i2c_lld_abort_operation(i2cp);
dmaStreamRelease(i2cp->dmatx);
dmaStreamRelease(i2cp->dmarx);
#if STM32_I2C_USE_I2C1
if (&I2CD1 == i2cp) {
nvicDisableVector(I2C1_EV_IRQn);
nvicDisableVector(I2C1_ER_IRQn);
rccDisableI2C1(FALSE);
}
#endif
#if STM32_I2C_USE_I2C2
if (&I2CD2 == i2cp) {
nvicDisableVector(I2C2_EV_IRQn);
nvicDisableVector(I2C2_ER_IRQn);
rccDisableI2C2(FALSE);
}
#endif
#if STM32_I2C_USE_I2C3
if (&I2CD3 == i2cp) {
nvicDisableVector(I2C3_EV_IRQn);
nvicDisableVector(I2C3_ER_IRQn);
rccDisableI2C3(FALSE);
}
#endif
}
}
/**
* @brief Receives data via the I2C bus as master.
* @details Number of receiving bytes must be more than 1 because of stm32
* hardware restrictions.
*
* @param[in] i2cp pointer to the @p I2CDriver object
* @param[in] addr slave device address
* @param[out] rxbuf pointer to the receive buffer
* @param[in] rxbytes number of bytes to be received
* @param[in] timeout the number of ticks before the operation timeouts,
* the following special values are allowed:
* - @a TIME_INFINITE no timeout.
* .
* @return The operation status.
* @retval RDY_OK if the function succeeded.
* @retval RDY_RESET if one or more I2C errors occurred, the errors can
* be retrieved using @p i2cGetErrors().
* @retval RDY_TIMEOUT if a timeout occurred before operation end. After a
* timeout the driver must be stopped and restarted
* because the bus is in an uncertain state.
*
* @notapi
*/
msg_t i2c_lld_master_receive_timeout(I2CDriver *i2cp, i2caddr_t addr,
uint8_t *rxbuf, size_t rxbytes,
systime_t timeout) {
I2C_TypeDef *dp = i2cp->i2c;
VirtualTimer vt;
chDbgCheck((rxbytes > 1), "i2c_lld_master_receive_timeout");
/* Global timeout for the whole operation.*/
if (timeout != TIME_INFINITE)
chVTSetI(&vt, timeout, i2c_lld_safety_timeout, (void *)i2cp);
/* Releases the lock from high level driver.*/
chSysUnlock();
/* Initializes driver fields, LSB = 1 -> receive.*/
i2cp->addr = (addr << 1) | 0x01;
i2cp->errors = 0;
/* RX DMA setup.*/
dmaStreamSetMemory0(i2cp->dmarx, rxbuf);
dmaStreamSetTransactionSize(i2cp->dmarx, rxbytes);
/* Waits until BUSY flag is reset and the STOP from the previous operation
is completed, alternatively for a timeout condition.*/
while ((dp->SR2 & I2C_SR2_BUSY) || (dp->CR1 & I2C_CR1_STOP)) {
chSysLock();
if ((timeout != TIME_INFINITE) && !chVTIsArmedI(&vt))
return RDY_TIMEOUT;
chSysUnlock();
}
/* This lock will be released in high level driver.*/
chSysLock();
/* Atomic check on the timer in order to make sure that a timeout didn't
happen outside the critical zone.*/
if ((timeout != TIME_INFINITE) && !chVTIsArmedI(&vt))
return RDY_TIMEOUT;
/* Starts the operation.*/
dp->CR2 |= I2C_CR2_ITEVTEN;
dp->CR1 |= I2C_CR1_START | I2C_CR1_ACK;
/* Waits for the operation completion or a timeout.*/
i2cp->thread = chThdSelf();
chSchGoSleepS(THD_STATE_SUSPENDED);
if ((timeout != TIME_INFINITE) && chVTIsArmedI(&vt))
chVTResetI(&vt);
return chThdSelf()->p_u.rdymsg;
}
/**
* @brief Transmits data via the I2C bus as master.
* @details Number of receiving bytes must be 0 or more than 1 because of stm32
* hardware restrictions.
*
* @param[in] i2cp pointer to the @p I2CDriver object
* @param[in] addr slave device address
* @param[in] txbuf pointer to the transmit buffer
* @param[in] txbytes number of bytes to be transmitted
* @param[out] rxbuf pointer to the receive buffer
* @param[in] rxbytes number of bytes to be received
* @param[in] timeout the number of ticks before the operation timeouts,
* the following special values are allowed:
* - @a TIME_INFINITE no timeout.
* .
* @return The operation status.
* @retval RDY_OK if the function succeeded.
* @retval RDY_RESET if one or more I2C errors occurred, the errors can
* be retrieved using @p i2cGetErrors().
* @retval RDY_TIMEOUT if a timeout occurred before operation end. After a
* timeout the driver must be stopped and restarted
* because the bus is in an uncertain state.
*
* @notapi
*/
msg_t i2c_lld_master_transmit_timeout(I2CDriver *i2cp, i2caddr_t addr,
const uint8_t *txbuf, size_t txbytes,
uint8_t *rxbuf, size_t rxbytes,
systime_t timeout) {
I2C_TypeDef *dp = i2cp->i2c;
VirtualTimer vt;
chDbgCheck(((rxbytes == 0) || ((rxbytes > 1) && (rxbuf != NULL))),
"i2c_lld_master_transmit_timeout");
/* Global timeout for the whole operation.*/
if (timeout != TIME_INFINITE)
chVTSetI(&vt, timeout, i2c_lld_safety_timeout, (void *)i2cp);
/* Releases the lock from high level driver.*/
chSysUnlock();
/* Initializes driver fields, LSB = 0 -> write.*/
i2cp->addr = addr << 1;
i2cp->errors = 0;
/* TX DMA setup.*/
dmaStreamSetMemory0(i2cp->dmatx, txbuf);
dmaStreamSetTransactionSize(i2cp->dmatx, txbytes);
/* RX DMA setup.*/
dmaStreamSetMemory0(i2cp->dmarx, rxbuf);
dmaStreamSetTransactionSize(i2cp->dmarx, rxbytes);
/* Waits until BUSY flag is reset and the STOP from the previous operation
is completed, alternatively for a timeout condition.*/
while ((dp->SR2 & I2C_SR2_BUSY) || (dp->CR1 & I2C_CR1_STOP)) {
chSysLock();
if ((timeout != TIME_INFINITE) && !chVTIsArmedI(&vt))
return RDY_TIMEOUT;
chSysUnlock();
}
/* This lock will be released in high level driver.*/
chSysLock();
/* Atomic check on the timer in order to make sure that a timeout didn't
happen outside the critical zone.*/
if ((timeout != TIME_INFINITE) && !chVTIsArmedI(&vt))
return RDY_TIMEOUT;
/* Starts the operation.*/
dp->CR2 |= I2C_CR2_ITEVTEN;
dp->CR1 |= I2C_CR1_START;
/* Waits for the operation completion or a timeout.*/
i2cp->thread = chThdSelf();
chSchGoSleepS(THD_STATE_SUSPENDED);
if ((timeout != TIME_INFINITE) && chVTIsArmedI(&vt))
chVTResetI(&vt);
return chThdSelf()->p_u.rdymsg;
}
#endif /* HAL_USE_I2C */
/** @} */