1 files changed, 246 insertions, 0 deletions

diff --git a/lib/chibios-contrib/os/hal/ports/MSP430X/hal_dma_lld.c b/lib/chibios-contrib/os/hal/ports/MSP430X/hal_dma_lld.c
new file mode 100644
index 000000000..fa68b0578
--- /dev/null
+++ b/lib/chibios-contrib/os/hal/ports/MSP430X/hal_dma_lld.c
@@ -0,0 +1,246 @@
+/*
+    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.                                         */
+/*===========================================================================*/
+
+static msp430x_dma_ch_reg_t * const dma_channels =
+    (msp430x_dma_ch_reg_t *)&DMA0CTL;
+
+static msp430x_dma_cb_t callbacks[MSP430X_DMA_CHANNELS];
+static threads_queue_t dma_queue;
+static unsigned int queue_length;
+
+/*===========================================================================*/
+/* Driver local functions.                                                   */
+/*===========================================================================*/
+
+/**
+ * @brief     Set a DMA trigger using an index.
+ *
+ * @param[in] index   The index of the DMA channel whose trigger is set.
+ * @param[in] trigger The trigger to use.
+ * @note  This is all to get around weird MSP behavior when writing to memory-
+ *        mapped registers using bytewise instructions.
+ */
+static void dma_trigger_set(uint8_t index, uint8_t trigger) {
+  uint16_t * ctl = ((uint16_t *)((uintptr_t)(&DMACTL0)) + (index / 2));
+  *ctl &= 0xFF00 >> (8 * (index % 2));
+  *ctl |= trigger << (8 * (index % 2));
+}
+static void init_request(const msp430x_dma_req_t * request, uint8_t index) {
+
+  dma_trigger_set(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) {
+    osalSysLockFromISR();
+    osalThreadDequeueNextI(&dma_queue, MSG_OK);
+    osalSysUnlockFromISR();
+
+    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) {
+  osalThreadQueueObjectInit(&dma_queue);
+}
+
+/**
+ * @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.
+ *          
+ *  @sclass
+ */
+int dmaRequestS(msp430x_dma_req_t * request, systime_t timeout) {
+  
+  osalDbgCheckClassS();
+  
+  /* Check if a DMA channel is available */
+  if (queue_length >= MSP430X_DMA_CHANNELS) {
+    msg_t queueresult = osalThreadEnqueueTimeoutS(&dma_queue, timeout);
+    if (queueresult != MSG_OK)
+      return -1;
+  }
+
+  /* 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;
+    }
+  }
+
+  /* Make the request */
+  init_request(request, i);
+  
+  return i;
+}
+
+/**
+ * @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.
+ * 
+ * @iclass
+ */
+bool dmaAcquireI(msp430x_dma_ch_t * channel, uint8_t index) {
+  
+  osalDbgCheckClassI();
+
+  /* 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 */
+  queue_length++;
+
+  while (dma_channels[index].ctl & DMAEN)
+    ;
+
+  /* Acquire the channel in an idle mode */
+  dma_trigger_set(index, DMA_TRIGGER_MNEM(DMAREQ));
+  dma_channels[index].sz  = 0;
+  dma_channels[index].ctl = DMAEN | DMAABORT | DMADT_4;
+
+  channel->registers = dma_channels + index;
+  channel->index     = 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) {
+
+  dma_trigger_set(channel->index, request->trigger);
+  /**(channel->ctl) = request->trigger;*/
+
+  channel->cb->callback = request->callback.callback;
+  channel->cb->args     = request->callback.args;
+
+  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 */
+}
+
+/**
+ * @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) {
+  syssts_t sts;
+
+  sts = osalSysGetStatusAndLockX();
+  osalDbgCheck(channel != NULL);
+
+  /* Release the channel in an idle mode */
+  channel->registers->ctl = DMAABORT;
+
+  /* release the DMA counter */
+  osalThreadDequeueAllI(&dma_queue, MSG_RESET);
+  queue_length = 0;
+  osalSysRestoreStatusX(sts);
+}
+
+#endif /* HAL_USE_DMA == TRUE */
+
+/** @} */