git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@2090 35acf78f-673a-0410-8e92-d51de3d6d3f4

1 files changed, 248 insertions, 0 deletions

diff --git a/os/hal/platforms/STM32/uart_lld.c b/os/hal/platforms/STM32/uart_lld.c
new file mode 100644
index 000000000..4967bb06f
--- /dev/null
+++ b/os/hal/platforms/STM32/uart_lld.c
@@ -0,0 +1,248 @@
+/*

+    ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010 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 <http://www.gnu.org/licenses/>.

+*/

+

+/**

+ * @file    STM32/uart_lld.c

+ * @brief   STM32 low level UART driver code.

+ *

+ * @addtogroup STM32_UART

+ * @{

+ */

+

+#include "ch.h"

+#include "hal.h"

+

+#if CH_HAL_USE_UART || defined(__DOXYGEN__)

+

+/*===========================================================================*/

+/* Driver exported variables.                                                */

+/*===========================================================================*/

+

+/** @brief USART1 UART driver identifier.*/

+#if STM32_UART_USE_USART1 || defined(__DOXYGEN__)

+UARTDriver UARTD1;

+#endif

+

+/*===========================================================================*/

+/* Driver local variables.                                                   */

+/*===========================================================================*/

+

+/*===========================================================================*/

+/* Driver local functions.                                                   */

+/*===========================================================================*/

+

+#define dma_setup(dmap, cndtr, cmar, ccr) {                                 \

+  (dmap)->CNDTR             = (uint32_t)(cndtr);                            \

+  (dmap)->CMAR              = (uint32_t)(cmar);                             \

+  (dmap)->CCR               = (uint32_t)(ccr);                              \

+}

+

+#define dma_disable(dmap) {                                                 \

+  (dmap)->CCR   = 0;                                                        \

+}

+

+#define dma_rx_setup(uartp, cndtr, cmar, ccr)                               \

+  dma_setup((uartp)->ud_dmarx, (cndtr), (cmar), (uartp)->ud_dmaccr|(ccr))

+

+#define dma_tx_setup(uartp, cndtr, cmar, ccr) {                             \

+  dma_setup((uartp)->ud_dmatx, (cndtr), (cmar), (uartp)->ud_dmaccr|(ccr))

+

+/**

+ * @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) {

+  USART_TypeDef *u = uartp->ud_usart;

+

+  /* Baud rate setting.*/

+  if (uartp->ud_usart == USART1)

+    u->BRR = STM32_PCLK2 / uartp->ud_config->uc_speed;

+  else

+    u->BRR = STM32_PCLK1 / uartp->ud_config->uc_speed;

+

+  /* Note that some bits are enforced because required for correct driver

+     operations.*/

+  u->CR1 = uartp->ud_config->uc_cr1 | USART_CR1_UE | USART_CR1_PEIE |

+                                      USART_CR1_TE | USART_CR1_RE;

+  u->CR2 = uartp->ud_config->uc_cr2 | USART_CR2_LBDIE;

+  u->CR3 = uartp->ud_config->uc_cr3 | USART_CR3_EIE;

+  (void)u->SR;  /* SR reset step 1.*/

+  (void)u->DR;  /* SR reset step 2.*/

+

+  /* RX DMA channel preparation, circular 1 frame transfers, an interrupt is

+     generated for each received character.*/

+  dma_rx_setup(uartp, 1, &uartp->ud_rxbuf,

+               DMA_CCR1_TCIE | DMA_CCR1_TEIE | DMA_CCR1_CIRC | DMA_CCR1_EN);

+  

+  /* TX DMA channel preparation, simply disabled.*/

+  dma_disable(uartp->ud_dmatx);

+}

+

+/**

+ * @brief   USART de-initialization.

+ * @details This function must be invoked with interrupts disabled.

+ *

+ * @param[in] u         pointer to an USART I/O block

+ */

+static void usart_stop(UARTDriver *uartp) {

+

+  /* Stops RX and TX DMA channels.*/

+  dma_disable(uartp->ud_dmarx);

+  dma_disable(uartp->ud_dmatx);

+  

+  /* Stops USART operations.*/

+  uartp->ud_usart->CR1 = 0;

+  uartp->ud_usart->CR2 = 0;

+  uartp->ud_usart->CR3 = 0;

+}

+

+/*===========================================================================*/

+/* Driver interrupt handlers.                                                */

+/*===========================================================================*/

+

+/*===========================================================================*/

+/* Driver exported functions.                                                */

+/*===========================================================================*/

+

+/**

+ * @brief   Low level UART driver initialization.

+ */

+void uart_lld_init(void) {

+

+#if STM32_UART_USE_USART1

+  RCC->APB2RSTR     = RCC_APB2RSTR_USART1RST;

+  RCC->APB2RSTR     = 0;

+  uartObjectInit(&UARTD1);

+  UARTD1.ud_usart   = USART1;

+  UARTD1.ud_dmarx   = DMA1_Channel4;

+  UARTD1.ud_dmatx   = DMA1_Channel5;

+  UARTD1.ud_dmaccr  = 0;

+  UARTD1.ud_dmarmsk = 0xF << (4 - 1);

+  UARTD1.ud_dmatmsk = 0xF << (5 - 1);

+#endif

+}

+

+/**

+ * @brief   Configures and activates the UART peripheral.

+ *

+ * @param[in] uartp      pointer to the @p UARTDriver object

+ */

+void uart_lld_start(UARTDriver *uartp) {

+

+  if (uartp->ud_state == UART_STOP) {

+#if STM32_UART_USE_USART1

+    if (&UARTD1 == uartp) {

+      dmaEnable(DMA1_ID);   /* NOTE: Must be enabled before the IRQs.*/

+      NVICEnableVector(USART1_IRQn,

+                       CORTEX_PRIORITY_MASK(STM32_UART_USART1_IRQ_PRIORITY));

+      NVICEnableVector(DMA1_Channel4_IRQn,

+                       CORTEX_PRIORITY_MASK(STM32_UART_USART1_IRQ_PRIORITY));

+      NVICEnableVector(DMA1_Channel5_IRQn,

+                       CORTEX_PRIORITY_MASK(STM32_UART_USART1_IRQ_PRIORITY));

+      RCC->APB2ENR |= RCC_APB2ENR_USART1EN;

+    }

+#endif

+

+    /* Static DMA setup, the transfer size depends on the USART settings,

+       it is 16 bits if M=1 and PCE=0 else it is 8 bits.*/

+    uartp->ud_dmaccr      = STM32_UART_USART1_DMA_PRIORITY << 12;

+    if ((uartp->ud_config->uc_cr1 & (USART_CR1_M | USART_CR1_PCE)) == USART_CR1_M)

+      uartp->ud_dmaccr |= DMA_CCR1_MSIZE_0 | DMA_CCR1_PSIZE_0;

+    uartp->ud_dmarx->CPAR = (uint32_t)&uartp->ud_usart->DR;

+    uartp->ud_dmatx->CPAR = (uint32_t)&uartp->ud_usart->DR;

+  }

+  uartp->ud_txstate = UART_TX_IDLE;

+  uartp->ud_rxstate = UART_RX_IDLE;

+  usart_start(uartp);

+}

+

+/**

+ * @brief   Deactivates the UART peripheral.

+ *

+ * @param[in] uartp      pointer to the @p UARTDriver object

+ */

+void uart_lld_stop(UARTDriver *uartp) {

+

+  if (uartp->ud_state == SD_READY) {

+    usart_stop(uartp);

+

+#if STM32_UART_USE_USART1

+    if (&UARTD1 == uartp) {

+      NVICDisableVector(USART1_IRQn);

+      NVICDisableVector(DMA1_Channel4_IRQn);

+      NVICDisableVector(DMA1_Channel5_IRQn);

+      dmaDisable(DMA1_ID);

+      RCC->APB2ENR &= ~RCC_APB2ENR_USART1EN;

+      return;

+    }

+#endif

+  }

+}

+

+/**

+ * @brief   Starts a transmission on the UART peripheral.

+ * @note    The buffers are organized as uint8_t arrays for data sizes below

+ *          or equal to 8 bits else it is organized as uint16_t arrays.

+ *

+ * @param[in] uartp     pointer to the @p UARTDriver object

+ * @param[in] n         number of data frames to send

+ * @param[in] txbuf     the pointer to the transmit buffer

+ */

+void uart_lld_start_send(UARTDriver *uartp, size_t n, const void *txbuf) {

+

+}

+

+/**

+ * @brief   Stops any ongoing transmission.

+ * @note    Stopping a transmission also suppresses the transmission callbacks.

+ *

+ * @param[in] uartp      pointer to the @p UARTDriver object

+ */

+void uart_lld_stop_send(UARTDriver *uartp) {

+

+}

+

+/**

+ * @brief   Starts a receive operation on the UART peripheral.

+ * @note    The buffers are organized as uint8_t arrays for data sizes below

+ *          or equal to 8 bits else it is organized as uint16_t arrays.

+ *

+ * @param[in] uartp     pointer to the @p UARTDriver object

+ * @param[in] n         number of data frames to send

+ * @param[in] rxbuf     the pointer to the receive buffer

+ */

+void uart_lld_start_receive(UARTDriver *uartp, size_t n, void *rxbuf) {

+

+}

+

+/**

+ * @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

+ */

+void uart_lld_stop_receive(UARTDriver *uartp) {

+

+}

+

+#endif /* CH_HAL_USE_UART */

+

+/** @} */