Merge pull request #68 from awygle/msp430x

MSP430X DMA Support, EXP430FR6989 Demo + Makefile Updates

1 files changed, 244 insertions, 0 deletions

diff --git a/os/hal/ports/MSP430X/hal_dma_lld.c b/os/hal/ports/MSP430X/hal_dma_lld.c
new file mode 100644
index 0000000..58293ca
--- /dev/null
+++ b/os/hal/ports/MSP430X/hal_dma_lld.c
@@ -0,0 +1,244 @@
+/*

+    ChibiOS - Copyright (C) 2016 Andrew Wygle aka awygle

+

+    Licensed under the Apache License, Version 2.0 (the "License");

+    you may not use this file except in compliance with the License.

+    You may obtain a copy of the License at

+

+        http://www.apache.org/licenses/LICENSE-2.0

+

+    Unless required by applicable law or agreed to in writing, software

+    distributed under the License is distributed on an "AS IS" BASIS,

+    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

+    See the License for the specific language governing permissions and

+    limitations under the License.

+*/

+

+/**

+ * @file    MSP430X hal_dma_lld.c

+ * @brief   MSP430X DMA subsystem low level driver source.

+ *

+ * @addtogroup MSP430X_DMA

+ * @{

+ */

+

+#include "hal.h"

+#include "ch.h"

+#include "hal_dma_lld.h"

+

+#if (HAL_USE_DMA == TRUE) || defined(__DOXYGEN__)

+

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

+/* Driver local definitions.                                                 */

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

+

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

+/* Driver exported variables.                                                */

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

+

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

+/* Driver local variables and types.                                         */

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

+

+/* TODO make sure this is right... */

+static msp430x_dma_ch_reg_t * const dma_channels = (msp430x_dma_ch_reg_t *)&DMA0CTL;

+static uint8_t * const dma_ctls = (uint8_t *)&DMACTL0;

+

+static msp430x_dma_cb_t callbacks[MSP430X_DMA_CHANNELS];

+#if CH_CFG_USE_SEMAPHORES

+static semaphore_t dma_lock;

+#endif

+

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

+/* Driver local functions.                                                   */

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

+

+static void init_request(const msp430x_dma_req_t * request, uint8_t index) {

+  

+    dma_ctls[index] = request->trigger;

+    callbacks[index] = request->callback;

+    msp430x_dma_ch_reg_t * ch = &dma_channels[index];

+    ch->sa = (uintptr_t)request->source_addr;

+    ch->da = (uintptr_t)request->dest_addr;

+    ch->sz = request->size;

+    ch->ctl = DMAREQ | DMAIE | DMAEN | request->data_mode | request->addr_mode

+      | request->transfer_mode; 

+}

+

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

+/* Driver interrupt handlers.                                                */

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

+

+PORT_IRQ_HANDLER(DMA_VECTOR) {

+  uint8_t index;

+  OSAL_IRQ_PROLOGUE();

+  

+  index = (DMAIV >> 1) - 1;

+  

+  if (index < MSP430X_DMA_CHANNELS) {

+    msp430x_dma_cb_t * cb = &callbacks[index];

+    

+    /* WARNING: CALLBACKS ARE CALLED IN AN ISR CONTEXT! */

+    if (cb->callback != NULL) {

+      cb->callback(cb->args);

+    }

+  

+  } 

+  

+  OSAL_IRQ_EPILOGUE();

+}

+

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

+/* Driver exported functions.                                                */

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

+

+/**

+ * @brief Initialize the DMA engine.

+ * 

+ * @init

+ */

+void dmaInit(void) {

+#if CH_CFG_USE_SEMAPHORES

+  chSemObjectInit(&dma_lock, MSP430X_DMA_CHANNELS);

+#endif

+}

+

+/**

+ * @brief   Requests a DMA transfer operation from the DMA engine.

+ * @note    The DMA engine uses unclaimed DMA channels to provide DMA services

+ *          for one-off or infrequent uses. If all channels are busy, and

+ *          semaphores are enabled, the calling thread will sleep until a

+ *          channel is available or the request times out. If semaphores are

+ *          disabled, the calling thread will busy-wait instead of sleeping.

+ */

+bool dmaRequest(msp430x_dma_req_t * request, systime_t timeout) {

+  /* Check if a DMA channel is available */

+#if CH_CFG_USE_SEMAPHORES

+  msg_t semresult = chSemWaitTimeout(&dma_lock, timeout);

+  if (semresult != MSG_OK)

+    return true;

+#endif

+  

+#if !(CH_CFG_USE_SEMAPHORES)

+  systime_t start = chVTGetSystemTimeX();

+  

+  do {

+#endif

+  /* Grab the correct DMA channel to use */

+  int i = 0;

+  for (i = 0; i < MSP430X_DMA_CHANNELS; i++) {

+    if (!(dma_channels[i].ctl & DMAEN)) {

+      break;

+    }

+  }

+#if !(CH_CFG_USE_SEMAPHORES)

+  while (chVTTimeElapsedSinceX(start) < timeout);

+#endif

+  

+#if !(CH_CFG_USE_SEMAPHORES)

+  if (i == MSP430X_DMA_CHANNELS) {

+    return true;

+  }

+#endif

+  

+  /* Make the request */

+  init_request(request, i);

+  

+#if CH_CFG_USE_SEMAPHORES

+  chSemSignal(&dma_lock);

+#endif

+  

+  return false;

+}

+

+/**

+ * @brief   Acquires exclusive control of a DMA channel.

+ * @pre     The channel must not be already acquired or an error is returned.

+ * @note    If the channel is in use by the DMA engine, blocks until acquired.

+ * @post    This channel must be interacted with using only the functions 

+ *          defined in this module.

+ *          

+ * @param[out] channel    The channel handle. Must be pre-allocated.

+ * @param[in]  index      The index of the channel (< MSP430X_DMA_CHANNELS).

+ * @return                The operation status.

+ * @retval false          no error, channel acquired.

+ * @retval true           error, channel already acquired.

+ */

+bool dmaAcquire(msp430x_dma_ch_t * channel, uint8_t index) {

+  /* Acquire the channel in an idle mode */

+  

+  /* Is the channel already acquired? */

+  osalDbgAssert(index < MSP430X_DMA_CHANNELS, "invalid channel index");

+  if (dma_channels[index].ctl & DMADT_4) {

+    return true;

+  }

+  

+  /* Increment the DMA counter */

+#if CH_CFG_USE_SEMAPHORES

+  msg_t semresult = chSemWait(&dma_lock);

+  if (semresult != MSG_OK)

+    return true;

+#endif

+  

+  while (dma_channels[index].ctl & DMAEN) ;

+  

+  dma_ctls[index] = DMA_TRIGGER_MNEM(DMAREQ);

+  dma_channels[index].sz = 0;

+  dma_channels[index].ctl = DMAEN | DMAABORT | DMADT_4;

+  

+  channel->registers = dma_channels + index;

+  channel->ctl = dma_ctls + index;

+  channel->cb = callbacks + index;

+  

+  return false;

+}

+

+/**

+ * @brief   Initiates a DMA transfer operation using an acquired channel.

+ * @pre     The channel must have been acquired using @p dmaAcquire().

+ * 

+ * @param[in] channel   pointer to a DMA channel from @p dmaAcquire().

+ * @param[in] request   pointer to a DMA request object.

+ */

+void dmaTransfer(msp430x_dma_ch_t * channel, msp430x_dma_req_t * request) {

+  

+    *(channel->ctl) = request->trigger;

+    

+    channel->cb->callback = request->callback.callback;

+    channel->cb->args = request->callback.args;

+    

+    chSysLock();

+    channel->registers->ctl &= (~DMAEN);

+    channel->registers->sa = (uintptr_t)request->source_addr;

+    channel->registers->da = (uintptr_t)request->dest_addr;

+    channel->registers->sz = request->size;

+    channel->registers->ctl = DMAIE | request->data_mode | request->addr_mode

+      | request->transfer_mode | DMADT_4 | DMAEN | DMAREQ; /* repeated transfers */

+    chSysUnlock();

+}

+

+/**

+ * @brief   Releases exclusive control of a DMA channel.

+ * @details The channel is released from control and returned to the DMA engine

+ *          pool. Trying to release an unallocated channel is an illegal

+ *          operation and is trapped if assertions are enabled.

+ * @pre     The channel must have been acquired using @p dmaAcquire().

+ * @post    The channel is returned to the DMA engine pool.

+ */

+void dmaRelease(msp430x_dma_ch_t * channel) {

+  

+  osalDbgCheck(channel != NULL);

+  osalDbgAssert(channel->registers->ctl & DMADT_4, "not acquired");

+  

+  /* Release the channel in an idle mode */

+  channel->registers->ctl = DMAABORT;

+  

+  /* release the DMA counter */

+#if CH_CFG_USE_SEMAPHORES

+  chSemSignal(&dma_lock);

+#endif

+}

+

+#endif /* HAL_USE_DMA == TRUE */

+

+/** @} */