/**
* @brief RX DMA common service routine.
*
* @param[in] uartp pointer to the @p UARTDriver object
* @param[in] flags pre-shifted content of the ISR register
*/
static void uart_lld_serve_rx_end_irq(UARTDriver *uartp, uint32_t flags) {
/* DMA errors handling.*/
#if defined(STM32_UART_DMA_ERROR_HOOK)
if ((flags & (STM32_DMA_ISR_TEIF | STM32_DMA_ISR_DMEIF)) != 0) {
STM32_UART_DMA_ERROR_HOOK(uartp);
}
#else
(void)flags;
#endif
if (uartp->rxstate == UART_RX_IDLE) {
/* Receiver in idle state, a callback is generated, if enabled, for each
received character and then the driver stays in the same state.*/
if (uartp->config->rxchar_cb != NULL)
uartp->config->rxchar_cb(uartp, uartp->rxbuf);
}
else {
/* Receiver in active state, a callback is generated, if enabled, after
a completed transfer.*/
dmaStreamDisable(uartp->dmarx);
uartp->rxstate = UART_RX_COMPLETE;
if (uartp->config->rxend_cb != NULL)
uartp->config->rxend_cb(uartp);
/* If the callback didn't explicitly change state then the receiver
automatically returns to the idle state.*/
if (uartp->rxstate == UART_RX_COMPLETE) {
uartp->rxstate = UART_RX_IDLE;
set_rx_idle_loop(uartp);
}
}
}
/**
* @brief USART initialization.
* @details This function must be invoked with interrupts disabled.
*
* @param[in] uartp pointer to the @p UARTDriver object
*/
static void usart_start(UARTDriver *uartp) {
uint32_t cr1;
USART_TypeDef *u = uartp->usart;
/* Defensive programming, starting from a clean state.*/
usart_stop(uartp);
/* Baud rate setting.*/
u->BRR = (uint32_t)(uartp->clock / uartp->config->speed);
/* Resetting eventual pending status flags.*/
u->ICR = 0xFFFFFFFFU;
/* Note that some bits are enforced because required for correct driver
operations.*/
u->CR2 = uartp->config->cr2 | USART_CR2_LBDIE;
u->CR3 = uartp->config->cr3 | USART_CR3_DMAT | USART_CR3_DMAR |
USART_CR3_EIE;
/* Mustn't ever set TCIE here - if done, it causes an immediate
interrupt.*/
cr1 = USART_CR1_UE | USART_CR1_PEIE | USART_CR1_TE | USART_CR1_RE;
u->CR1 = uartp->config->cr1 | cr1;
/* Starting the receiver idle loop.*/
set_rx_idle_loop(uartp);
}
/**
* @brief USART initialization.
* @details This function must be invoked with interrupts disabled.
*
* @param[in] uartp pointer to the @p UARTDriver object
*/
static void usart_start(UARTDriver *uartp) {
uint16_t cr1;
USART_TypeDef *u = uartp->usart;
/* Defensive programming, starting from a clean state.*/
usart_stop(uartp);
/* Baud rate setting.*/
if (uartp->usart == USART1)
u->BRR = STM32_PCLK2 / uartp->config->speed;
else
u->BRR = STM32_PCLK1 / uartp->config->speed;
/* Resetting eventual pending status flags.*/
(void)u->SR; /* SR reset step 1.*/
(void)u->DR; /* SR reset step 2.*/
u->SR = 0;
/* Note that some bits are enforced because required for correct driver
operations.*/
if (uartp->config->txend2_cb == NULL)
cr1 = USART_CR1_UE | USART_CR1_PEIE | USART_CR1_TE | USART_CR1_RE;
else
cr1 = USART_CR1_UE | USART_CR1_PEIE | USART_CR1_TE | USART_CR1_RE |
USART_CR1_TCIE;
u->CR1 = uartp->config->cr1 | cr1;
u->CR2 = uartp->config->cr2 | USART_CR2_LBDIE;
u->CR3 = uartp->config->cr3 | USART_CR3_DMAT | USART_CR3_DMAR |
USART_CR3_EIE;
/* Starting the receiver idle loop.*/
set_rx_idle_loop(uartp);
}
/**
* @brief Stops any ongoing receive operation.
* @note Stopping a receive operation also suppresses the receive callbacks.
*
* @param[in] uartp pointer to the @p UARTDriver object
*
* @return The number of data frames not received by the
* stopped receive operation.
*
* @notapi
*/
size_t uart_lld_stop_receive(UARTDriver *uartp) {
size_t n;
dmaStreamDisable(uartp->dmarx);
n = dmaStreamGetTransactionSize(uartp->dmarx);
set_rx_idle_loop(uartp);
return n;
}
/**
* @brief USART initialization.
* @details This function must be invoked with interrupts disabled.
*
* @param[in] uartp pointer to the @p UARTDriver object
*/
static void usart_start(UARTDriver *uartp) {
uint16_t cr1;
USART_TypeDef *u = uartp->usart;
/* Defensive programming, starting from a clean state.*/
usart_stop(uartp);
/* Baud rate setting.*/
#if STM32_HAS_USART6
if ((uartp->usart == USART1) || (uartp->usart == USART6))
#else
if (uartp->usart == USART1)
#endif
u->BRR = STM32_PCLK2 / uartp->config->speed;
else
u->BRR = STM32_PCLK1 / uartp->config->speed;
/* Resetting eventual pending status flags.*/
(void)u->SR; /* SR reset step 1.*/
(void)u->DR; /* SR reset step 2.*/
u->SR = 0;
/* Note that some bits are enforced because required for correct driver
operations.*/
u->CR2 = uartp->config->cr2 | USART_CR2_LBDIE;
u->CR3 = uartp->config->cr3 | USART_CR3_DMAT | USART_CR3_DMAR |
USART_CR3_EIE;
/* Mustn't ever set TCIE here - if done, it causes an immediate
interrupt.*/
cr1 = USART_CR1_UE | USART_CR1_PEIE | USART_CR1_TE | USART_CR1_RE;
u->CR1 = uartp->config->cr1 | cr1;
/* Starting the receiver idle loop.*/
set_rx_idle_loop(uartp);
}
