void DRV_USART_BufferAddRead
(
DRV_HANDLE hClient,
DRV_USART_BUFFER_HANDLE * bufferHandle,
void * destination,
size_t nBytes
)
{
DRV_USART_CLIENT_OBJ * clientObj;
DRV_USART_OBJ * hDriver;
bool interruptWasEnabled = false;
DRV_USART_BUFFER_OBJ * bufferObj = NULL;
DRV_USART_BUFFER_OBJ * iterator;
unsigned int i;
/* This function adds a buffer to the read queue */
/* We first check the arguments and initialize the
buffer handle */
if(bufferHandle == NULL)
{
return;
}
*bufferHandle = DRV_USART_BUFFER_HANDLE_INVALID;
clientObj = _DRV_USART_DriverHandleValidate(hClient);
if(clientObj == NULL)
{
SYS_ASSERT(false, "Invalid driver handle");
return;
}
if((nBytes == 0) || (NULL == destination))
{
/* We either got an invalid client handle,
invalid destination pointer or 0 bytes to
transfer */
SYS_ASSERT(false, "Invalid parameters");
return;
}
hDriver = clientObj->hDriver;
if(hDriver->queueSizeCurrentRead >= hDriver->queueSizeRead)
{
/* This means the queue is full. We cannot add
* this request */
//SYS_ASSERT(false, "Receive Queue is full");
return;
}
/* We will allow buffers to be added in the interrupt
* context of this USART driver. But we must make
* sure that if we are in interrupt, then we should
* not modify mutexes. */
if(hDriver->interruptNestingCount == 0)
{
/* Grab a mutex. This is okay because we are not in an
* interrupt context */
if(OSAL_MUTEX_Lock(&(hDriver->mutexDriverInstance), OSAL_WAIT_FOREVER) == OSAL_RESULT_TRUE)
{
/* We will disable interrupts so that the queue
* status does not get updated asynchronously.
* This code will always execute. */
interruptWasEnabled = _DRV_USART_InterruptSourceDisable(hDriver->rxInterruptSource);
}
else
{
/* The mutex acquisition timed out. Return with an
* invalid handle. This code will not execute
* if there is no RTOS. */
return;
}
}
/* Search the buffer pool for a free buffer object */
for(i = 0 ; i < DRV_USART_QUEUE_DEPTH_COMBINED; i ++)
{
if(!gDrvUSARTBufferObj[i].inUse)
{
/* This means this object is free.
* Configure the object and then
* break */
bufferObj = &gDrvUSARTBufferObj[i];
bufferObj->size = nBytes;
bufferObj->inUse = true;
bufferObj->buffer = (uint8_t*)destination;
bufferObj->hClient = clientObj;
bufferObj->next = NULL;
bufferObj->previous = NULL;
bufferObj->nCurrentBytes = 0;
bufferObj->flags = (0 | DRV_USART_BUFFER_OBJ_FLAG_BUFFER_ADD);
/* Assign a handle to this buffer. The buffer handle must be unique.
* To do this, we construct the buffer handle out of the
* gDrvUSARTTokenCount and allocated buffer index. Note that
* gDrvUSARTTokenCount is incremented and wrapped around when the
* value reaches OxFFFF. We do avoid a case where the token value
* becomes 0xFFFF and the buffer index also becomes 0xFFFF */
bufferObj->bufferHandle = _DRV_USART_MAKE_HANDLE(gDrvUSARTTokenCount, i);
*bufferHandle = bufferObj->bufferHandle;
/* Update the token number. */
_DRV_USART_UPDATE_BUFFER_TOKEN(gDrvUSARTTokenCount);
break;
}
}
if(i == DRV_USART_QUEUE_DEPTH_COMBINED)
{
/* This means we could not find a buffer. This
will happen if the the DRV_USART_QUEUE_DEPTH_COMBINED
parameter is configured to be less */
SYS_ASSERT(false, "Insufficient Combined Queue Depth");
/* Enable the interrupt if it was enabled */
if(interruptWasEnabled)
{
_DRV_USART_InterruptSourceEnable(hDriver->rxInterruptSource);
}
if(hDriver->interruptNestingCount == 0)
{
/* Release mutex */
OSAL_MUTEX_Unlock(&(hDriver->mutexDriverInstance));
}
return;
}
/* Increment the current queue size*/
hDriver->queueSizeCurrentRead ++;
/* Check if the queue is empty */
if(hDriver->queueRead == NULL)
{
/* This is the first buffer in the
queue */
hDriver->queueRead = bufferObj;
/* This is the first item in the queue. Enable
RX interrupt. */
_DRV_USART_InterruptSourceEnable(hDriver->rxInterruptSource);
}
else
{
/* This means the read queue is not empty. We must add
the buffer object to the end of the queue */
iterator = hDriver->queueRead;
while(iterator->next != NULL)
{
/* Get the next buffer object */
iterator = iterator->next;
}
/* At this point, iterator will point to the
last object in the queue. We add the buffer
object to the linked list. Note that we
need to set up the previous pointer as well
because buffer should be deleted when the
client closes the driver */
iterator->next = bufferObj;
bufferObj->previous = iterator;
/* We are done. Restore the interrupt enable status
and return. */
if(interruptWasEnabled)
{
_DRV_USART_InterruptSourceEnable(hDriver->rxInterruptSource);
}
}
if(hDriver->interruptNestingCount == 0)
{
/* Release mutex */
OSAL_MUTEX_Unlock(&(hDriver->mutexDriverInstance));
}
return;
}
void DRV_USART_BufferAddRead
(
DRV_HANDLE hClient,
DRV_USART_BUFFER_HANDLE * bufferHandle,
void * destination,
size_t nBytes
)
{
DRV_USART_CLIENT_OBJ * clientObj;
DRV_USART_OBJ * hDriver;
bool interruptWasEnabled=false;
DRV_USART_BUFFER_OBJ * bufferObj, * iterator;
DRV_USART_BUFFER_OBJECT_INDEX usartBufIndex;
/* This function adds a buffer to the read queue */
/* We first check the arguments and initialize the
buffer handle */
if(bufferHandle == NULL)
{
return;
}
*bufferHandle = DRV_USART_BUFFER_HANDLE_INVALID;
clientObj = _DRV_USART_DriverHandleValidate(hClient);
if(clientObj == NULL)
{
SYS_ASSERT(false, "Invalid driver handle");
return;
}
if((nBytes == 0) || (NULL == destination))
{
/* We either got an invalid client handle,
invalid destination pointer or 0 bytes to
transfer */
SYS_DEBUG(0, "Invalid parameters");
return;
}
hDriver = clientObj->hDriver;
if(hDriver->queueSizeCurrentRead >= hDriver->queueSizeRead)
{
/* This means the queue is full. We cannot add
* this request */
SYS_DEBUG(0, "Receive Queue is full");
return;
}
/* We will allow buffers to be added in the interrupt
* context of this USART driver. But we must make
* sure that if we are in interrupt, then we should
* not modify mutexes. */
if(hDriver->interruptNestingCount == 0)
{
/* Grab a mutex. This is okay because we are not in an
* interrupt context */
if(OSAL_MUTEX_Lock(&(hDriver->mutexDriverInstance), OSAL_WAIT_FOREVER) == OSAL_RESULT_TRUE)
{
/* We will disable interrupts so that the queue
* status does not get updated asynchronously.
* This code will always execute. */
if(SYS_DMA_CHANNEL_HANDLE_INVALID != hDriver->dmaChannelHandleRead)
{
interruptWasEnabled = _DRV_USART_InterruptSourceDisable(hDriver->dmaInterruptReceive);
}
else
{
interruptWasEnabled = _DRV_USART_InterruptSourceDisable(hDriver->rxInterruptSource);
}
}
else
{
/* The mutex acquisition timed out. Return with an
* invalid handle. This code will not execute
* if there is no RTOS. */
return;
}
}
usartBufIndex = _DRV_USART_QueueObjectIndexGet();
if (usartBufIndex != DRV_USART_BUFFER_OBJECT_INDEX_INVALID)
{
bufferObj = &gDrvUSARTBufferObj[usartBufIndex];
bufferObj->bufferHandle = _DRV_USART_DMA_MAKE_HANDLE(gDrvUSARTDMATokenCount, usartBufIndex);
*bufferHandle = bufferObj->bufferHandle;
_DRV_USART_DMA_UPDATE_BUFFER_TOKEN(gDrvUSARTDMATokenCount);
bufferObj->size = nBytes;
bufferObj->inUse = true;
bufferObj->buffer = (uint8_t*)destination;
bufferObj->hClient = clientObj;
bufferObj->next = NULL;
bufferObj->previous = NULL;
bufferObj->nCurrentBytes = 0;
bufferObj->flags = (0 | DRV_USART_BUFFER_OBJ_FLAG_BUFFER_ADD);
}
else
{
/* This means we could not find a buffer. This
will happen if the the DRV_USART_QUEUE_DEPTH_COMBINED
parameter is configured to be less */
SYS_ASSERT(false, "Insufficient Combined Queue Depth");
/* Enable the interrupt if it was enabled */
if(interruptWasEnabled)
{
if(SYS_DMA_CHANNEL_HANDLE_INVALID != hDriver->dmaChannelHandleRead)
{
_DRV_USART_InterruptSourceEnable(hDriver->dmaInterruptReceive);
}
else
{
_DRV_USART_InterruptSourceEnable(hDriver->rxInterruptSource);
}
}
/* Release mutex */
OSAL_MUTEX_Unlock(&(hDriver->mutexDriverInstance));
return;
}
/* Increment the current queue size*/
hDriver->queueSizeCurrentRead ++;
/* Check if the queue is empty */
if(hDriver->queueRead == NULL)
{
/* This is the first buffer in the queue */
hDriver->queueRead = bufferObj;
/* This is the first item in the queue. Enable RX interrupt. */
if(SYS_DMA_CHANNEL_HANDLE_INVALID != hDriver->dmaChannelHandleRead)
{
/* Since this is the first buffer in the queue Add it immediately
to DMA for processing */
size_t srcSize, cellSize;
srcSize = 1;
cellSize = 1;
SYS_DMA_ChannelTransferAdd(hDriver->dmaChannelHandleRead,
PLIB_USART_ReceiverAddressGet(hDriver->moduleId),
srcSize,bufferObj->buffer, bufferObj->size,
cellSize);
_SYS_DMA_ChannelForceStart(hDriver->dmaChannelHandleRead);
_DRV_USART_InterruptSourceEnable(hDriver->dmaInterruptReceive);
}
else
{
_DRV_USART_InterruptSourceEnable(hDriver->rxInterruptSource);
}
}
else
{
/* This means the read queue is not empty. We must add
the buffer object to the end of the queue */
iterator = hDriver->queueRead;
while(iterator->next != NULL)
{
/* Get the next buffer object */
iterator = iterator->next;
}
/* At this point, iterator will point to the
last object in the queue. We add the buffer
object to the linked list. Note that we
need to set up the previous pointer as well
because buffer should be deleted when the
client closes the driver */
iterator->next = bufferObj;
bufferObj->previous = iterator;
/* We are done. Restore the interrupt enable status
and return. */
if(interruptWasEnabled)
{
if(SYS_DMA_CHANNEL_HANDLE_INVALID != hDriver->dmaChannelHandleRead)
{
/* There is already a buffer under processing in the queue.
This buffer will be added to DMA for processing immediately
after the processing of the buffer prior to this buffer completes.
(This functionality is implemented in _DRV_USART_BufferQueueRxTasks)*/
_SYS_DMA_ChannelForceStart(hDriver->dmaChannelHandleRead);
_DRV_USART_InterruptSourceEnable(hDriver->dmaInterruptReceive);
}
else
{
_DRV_USART_InterruptSourceEnable(hDriver->rxInterruptSource);
}
}
}
/* Release mutex */
OSAL_MUTEX_Unlock(&(hDriver->mutexDriverInstance));
return;
}
size_t DRV_USART_Read(const DRV_HANDLE hClient, void * destination, size_t nBytes)
{
DRV_USART_CLIENT_OBJ * clientObj;
DRV_USART_OBJ * hDriver;
USART_MODULE_ID plibID;
DRV_USART_BUFFER_OBJ * iterator, * bufferObj;
size_t count = 0;
uint8_t * data;
bool status;
/* Validate the driver handle */
clientObj = _DRV_USART_DriverHandleValidate(hClient);
if(clientObj == NULL)
{
SYS_DEBUG(0, "Invalid driver handle");
return 0;
}
hDriver = (DRV_USART_OBJ *)clientObj->hDriver;
plibID = hDriver->moduleId;
if(!(clientObj->ioIntent & DRV_IO_INTENT_READ))
{
/* This client did not open the driver for
reading */
SYS_DEBUG(0, "Driver not opened for read");
return 0;
}
if((destination == NULL) || (nBytes == 0))
{
/* We have a NULL pointer or dont have
any data to write. */
SYS_DEBUG(0, "NULL data pointer or no data to write");
return 0;
}
data = (uint8_t *)destination;
/* Grab he hardware instance mutex */
if(OSAL_MUTEX_Lock(hDriver->mutexDriverInstance, OSAL_WAIT_FOREVER) == OSAL_RESULT_TRUE)
{
if(!(clientObj->ioIntent & DRV_IO_INTENT_NONBLOCKING))
{
/* This is a blocking implementation. We populate the client buffer
object and add it to the queue. We then wait till the buffer is
completely processed. */
/* Because we are modifying the queue, we should disable the
interrupt */
status = _DRV_USART_InterruptSourceDisable(hDriver->rxInterruptSource);
/* Get the queue head */
iterator = hDriver->queueRead;
/* If the queue is not empty, get to the end of the queue */
if(iterator != NULL)
{
while(iterator->next != NULL)
{
iterator = iterator->next;
}
}
/* We should be at the end of the queue now. Populate the client
buffer object */
bufferObj = &clientObj->bufferObject;
bufferObj->buffer = destination;
bufferObj->nCurrentBytes = 0;
bufferObj->size = nBytes;
bufferObj->inUse = true;
bufferObj->hClient = clientObj;
bufferObj->flags = (0 | DRV_USART_BUFFER_OBJ_FLAG_READ_WRITE);
/* Add this object to the queue and enable the RX interrupt */
bufferObj->previous = iterator;
bufferObj->next = NULL;
/* If we are not at the start of the queue, then update the next
pointer of the last object else set the queue head to point to
this object */
if(hDriver->queueRead == NULL)
{
hDriver->queueRead = bufferObj;
}
else
{
iterator->next = bufferObj;
bufferObj->previous = iterator;
}
/* Now enable the interrupt and release the mutex so that the system
can proceed */
_DRV_USART_InterruptSourceEnable(hDriver->rxInterruptSource);
OSAL_ASSERT((OSAL_MUTEX_Unlock(hDriver->mutexDriverInstance)),
"Unable to unlock hardware instance mutex");
/* If we are in a bare metal configuration, then wait till the
buffer is processed. If we are in RTOS configuration then pend on
the client semaphore. */
if(OSAL_SEM_Pend(clientObj->semReadDone, OSAL_WAIT_FOREVER) == OSAL_RESULT_TRUE)
{
/* This is the implementation of the blocking behavior. In a
RTOS configuration, if the code reaches here, it means then
that buffer has been processed. */
while(bufferObj->inUse);
if(bufferObj->nCurrentBytes != nBytes)
{
/* This means this buffer was terminated because of an
error. */
return(DRV_USART_READ_ERROR);
}
count = nBytes;
}
}
else if(clientObj->ioIntent & DRV_IO_INTENT_NONBLOCKING)
{
/* This is a non blocking implementation*/
if(hDriver->queueRead != NULL)
{
/* This means queue is not empty. We cannot read
data now. */
count = 0;
}
else
{
while((PLIB_USART_ReceiverDataIsAvailable(plibID)) &&
(count < nBytes))
{
/* This is not a blocking implementation. We read
the hardware till the FIFO is empty. */
data[count] = PLIB_USART_ReceiverByteReceive(plibID);
count ++;
/* We need to check for errors. Store the error
in the client error field. */
clientObj->error = PLIB_USART_ErrorsGet(plibID);
if(clientObj->error != DRV_USART_ERROR_NONE)
{
/* This means we have an error. Release the mutex and
exit */
OSAL_ASSERT((OSAL_MUTEX_Unlock(hDriver->mutexDriverInstance)),
"Unable to unlock hardware instance mutex");
return(DRV_USART_READ_ERROR);
}
}
}
}
}
else
{
/* Timed out while waiting for read mutex.
* We simply return 0 */
count = 0;
}
return(count);
}
void DRV_USART_BufferAddWrite
(
DRV_HANDLE hClient,
DRV_USART_BUFFER_HANDLE * bufferHandle,
void * source,
size_t nBytes
)
{
DRV_USART_CLIENT_OBJ * clientObj;
DRV_USART_OBJ * hDriver;
bool interruptWasEnabled = false;
DRV_USART_BUFFER_OBJ * bufferObj, * iterator;
unsigned int i;
/* This function adds a buffer to the write queue */
/* We first check the arguments and initialize the
buffer handle */
if(bufferHandle != NULL)
{
*bufferHandle = DRV_USART_BUFFER_HANDLE_INVALID;
}
/* Validate the driver handle */
clientObj = _DRV_USART_DriverHandleValidate(hClient);
if(clientObj == NULL)
{
SYS_DEBUG(0, "Invalid Driver Handle");
return;
}
if((nBytes == 0) || (NULL == source) || (bufferHandle == NULL))
{
/* We either got an invalid client handle,
invalid source pointer or 0 bytes to
transfer */
SYS_DEBUG(0, "Invalid parameters");
return;
}
hDriver = clientObj->hDriver;
if(hDriver->queueSizeCurrentWrite >= hDriver->queueSizeWrite)
{
/* This means the queue is full. We cannot add
this request */
SYS_DEBUG(0, "Transmit Queue is full");
return;
}
/* We will allow buffers to be added in the interrupt
context of this USART driver. But we must make
sure that if we are in interrupt, then we should
not modify mutexes. */
if(hDriver->interruptNestingCount == 0)
{
/* Grab a mutex. This is okay because we are not in an
interrupt context */
if(OSAL_MUTEX_Lock(hDriver->mutexDriverInstance, OSAL_WAIT_FOREVER) == OSAL_RESULT_TRUE)
{
/* We will disable interrupts so that the queue
status does not get updated asynchronously.
This code will always execute. */
interruptWasEnabled = _DRV_USART_InterruptSourceDisable(hDriver->txInterruptSource);
}
else
{
/* The mutex acquisition timed out. Return with an
invalid handle. This code will not execute
if there is no RTOS. */
return;
}
}
/* Search the buffer pool for a free buffer object */
for(i = 0 ; i < DRV_USART_QUEUE_DEPTH_COMBINED; i ++)
{
if(!gDrvUSARTBufferObj[i].inUse)
{
/* This means this object is free.
* Configure the object and then
* break */
bufferObj = &gDrvUSARTBufferObj[i];
bufferObj->size = nBytes;
bufferObj->inUse = true;
bufferObj->buffer = (uint8_t*)source;
bufferObj->hClient = clientObj;
bufferObj->nCurrentBytes = 0;
bufferObj->next = NULL;
bufferObj->previous = NULL;
bufferObj->flags = (0 | DRV_USART_BUFFER_OBJ_FLAG_BUFFER_ADD);
/* Assign a handle to this buffer */
*bufferHandle = (DRV_USART_BUFFER_HANDLE)bufferObj;
break;
}
}
if(i == DRV_USART_QUEUE_DEPTH_COMBINED)
{
/* This means we could not find a buffer. This
will happen if the the DRV_USART_QUEUE_DEPTH_COMBINED
parameter is configured to be less */
SYS_DEBUG(0, "Insufficient Combined Queue Depth");
/* Enable the interrupt if it was enabled */
if(interruptWasEnabled)
{
_DRV_USART_InterruptSourceEnable(hDriver->txInterruptSource);
}
/* Release mutex */
OSAL_ASSERT((OSAL_MUTEX_Unlock(hDriver->mutexDriverInstance)),
"Unable to unlock buffer add write mutex");
return;
}
/* Increment the current queue size*/
hDriver->queueSizeCurrentWrite ++;
/* Check if the queue is empty */
if(hDriver->queueWrite == NULL)
{
/* This is the first buffer in the
queue */
hDriver->queueWrite = bufferObj;
/* Enabling the interrupt here will cause the task
routine to start processing this buffer. If this
function is being called in an ISR, then this
statement will not have any effect. */
_DRV_USART_InterruptSourceEnable(hDriver->txInterruptSource);
}
else
{
/* This means the write queue is not empty. We must add
* the buffer object to the end of the queue */
iterator = hDriver->queueWrite;
while(iterator->next != NULL)
{
/* Get the next buffer object */
iterator = iterator->next;
}
/* At this point, iterator will point to the
last object in the queue. We add the buffer
object to the linked list. Note that we
need to set up the previous pointer as well
because buffer should be deleted when the
client closes the driver */
iterator->next = bufferObj;
bufferObj->previous = iterator;
/* We are done. Restore the interrupt enable status
and return. */
if(interruptWasEnabled)
{
_DRV_USART_InterruptSourceEnable(hDriver->txInterruptSource);
}
}
/* Release mutex */
OSAL_ASSERT((OSAL_MUTEX_Unlock(hDriver->mutexDriverInstance)),
"Unable to unlock buffer add write mutex");
return;
}
bool _DRV_USART_ClientBufferQueueObjectsRemove(DRV_USART_CLIENT_OBJ * clientObj)
{
DRV_USART_OBJ * dObj = clientObj->hDriver;
bool interruptWasEnabled = false;
DRV_USART_BUFFER_OBJ * iterator = NULL;
if(OSAL_MUTEX_Lock(dObj->mutexDriverInstance, OSAL_WAIT_FOREVER) == OSAL_RESULT_TRUE)
{
/* Disable the transmit interrupt */
interruptWasEnabled = _DRV_USART_InterruptSourceDisable(dObj->txInterruptSource);
iterator = dObj->queueWrite;
while(iterator != NULL)
{
if(clientObj == (DRV_USART_CLIENT_OBJ *)iterator->hClient)
{
/* That means this buffer object is owned
by this client. This buffer object should
be removed. The following code removes
the object from a doubly linked list queue. */
iterator->inUse = false;
if(iterator->previous != NULL)
{
iterator->previous->next = iterator->next;
}
if(iterator->next != NULL)
{
iterator->next->previous = iterator->previous;
}
}
iterator = iterator->next;
}
/* Re-enable the interrupt if it was enabled */
if(interruptWasEnabled)
{
_DRV_USART_InterruptSourceEnable(dObj->txInterruptSource);
}
/* Now check the receive buffer queue. Start by disabling the
receive interrupt */
interruptWasEnabled = _DRV_USART_InterruptSourceDisable(dObj->rxInterruptSource);
iterator = dObj->queueRead;
while(iterator != NULL)
{
if(clientObj == (DRV_USART_CLIENT_OBJ *)iterator->hClient)
{
/* That means this buffer object is owned
by this client. This buffer object should
be removed. The following code removed
the object from a doubly linked list queue. */
iterator->inUse = false;
if(iterator->previous != NULL)
{
iterator->previous->next = iterator->next;
}
if(iterator->next != NULL)
{
iterator->next->previous = iterator->previous;
}
}
iterator = iterator->next;
}
if(interruptWasEnabled)
{
_DRV_USART_InterruptSourceEnable(dObj->rxInterruptSource);
}
/* Unlock the mutex */
OSAL_ASSERT((OSAL_MUTEX_Unlock(dObj->mutexDriverInstance)),
"Unable to unlock Driver instance mutex");
}
else
{
/* The case where the mutex lock timed out and the
client buffer objects could not be removed from
the driver queue, the close function should fail. */
return false;
}
return true;
}
void DRV_USART_Deinitialize(SYS_MODULE_OBJ object)
{
DRV_USART_OBJ * dObj;
DRV_USART_BUFFER_OBJ * iterator;
bool status;
/* Check that the object is valid */
if(object == SYS_MODULE_OBJ_INVALID)
{
SYS_DEBUG(0, "Invalid system object handle" );
return;
}
if(object >= DRV_USART_INSTANCES_NUMBER)
{
SYS_DEBUG(0, "Invalid system object handle" );
return;
}
dObj = (DRV_USART_OBJ*) &gDrvUSARTObj[object];
if(!dObj->inUse)
{
SYS_DEBUG(0, "Invalid system object handle");
return;
}
/* The driver will not have clients when it is
being de-initialized. So the order in which
we do the following steps is not that important */
/* Indicate that this object is not is use */
dObj->inUse = false;
/* Deinitialize the USART status */
dObj->status = SYS_STATUS_UNINITIALIZED ;
/* Disable the interrupt */
status = _DRV_USART_InterruptSourceDisable(dObj->txInterruptSource) ;
status = _DRV_USART_InterruptSourceDisable(dObj->rxInterruptSource) ;
status = _DRV_USART_InterruptSourceDisable(dObj->errorInterruptSource);
/* Disable USART module */
PLIB_USART_Disable (dObj->moduleId);
/* Deallocate all mutexes */
OSAL_ASSERT( (OSAL_MUTEX_Delete(&(dObj->mutexDriverInstance)) == OSAL_RESULT_TRUE),
"Unable to delete client handle mutex" );
/* TODO: Disable all DMA interrupts */
/* Remove all objects from the read and write queue */
iterator = dObj->queueWrite;
while(iterator != NULL)
{
/* Return the buffer object to the pool */
iterator->inUse = false;
iterator = iterator->next;
}
iterator = dObj->queueRead;
while(iterator != NULL)
{
/* Return the buffer object to the pool */
iterator->inUse = false;
iterator = iterator->next;
}
}
void _DRV_USART_BufferQueueTxTasks(DRV_USART_OBJ * hDriver)
{
/* Start by getting the buffer at the head of queue. */
DRV_USART_BUFFER_OBJ * bufferObj;
DRV_USART_CLIENT_OBJ * client;
USART_MODULE_ID plibID;
bool status;
bufferObj = hDriver->queueWrite;
plibID = hDriver->moduleId;
/* If this driver is configured for polled mode in an RTOS, the tasks
routine would be called from another thread. We need to get the driver
instance mutex before updating the queue. If the driver is configured for
interrupt mode, then _DRV_USART_TAKE_MUTEX will compile to true */
if(DRV_USART_INTERRUPT_MODE == false)
{
if(OSAL_MUTEX_Lock(hDriver->mutexDriverInstance, OSAL_WAIT_FOREVER))
{
/* We were able to take the mutex */
}
else
{
/* The mutex acquisition timed out. Return with an
invalid handle. This code will not execute
if there is no RTOS. */
return;
}
}
if(bufferObj != NULL)
{
/* This means the queue is not empty. Check if this buffer is done */
if(bufferObj->nCurrentBytes >= bufferObj->size)
{
/* This means the buffer is completed. If there
is a callback registered with client, then
call it */
client = (DRV_USART_CLIENT_OBJ *)bufferObj->hClient;
if((client->eventHandler != NULL) && (bufferObj->flags & DRV_USART_BUFFER_OBJ_FLAG_BUFFER_ADD))
{
/* Before calling the event handler, the interrupt nesting
counter is incremented. This will allow driver routine that
are called from the event handler to know the interrupt
nesting level. Events are only generated for buffers that
were submitted using the buffer add routine */
hDriver->interruptNestingCount ++;
client->eventHandler(DRV_USART_BUFFER_EVENT_COMPLETE,
(DRV_USART_BUFFER_HANDLE)bufferObj,
client->context);
/* Decrement the nesting count */
hDriver->interruptNestingCount -- ;
}
/* Get the next buffer in the queue and deallocate
* this buffer */
hDriver->queueWrite = bufferObj->next;
bufferObj->inUse = false;
hDriver->queueSizeCurrentWrite --;
if(bufferObj->flags & DRV_USART_BUFFER_OBJ_FLAG_READ_WRITE)
{
/* This means we should post the semaphore */
OSAL_ASSERT(_DRV_USART_SEM_POST(client->semWriteDone) == OSAL_RESULT_TRUE,
"Unable to post write buffer queue empty semaphore");
}
}
}
/* Check if the queue is still not empty and process
the buffer */
if(hDriver->queueWrite != NULL)
{
bufferObj = hDriver->queueWrite;
/* Fill up the FIFO with data till the FIFO is full
and we have data to send */
while((!PLIB_USART_TransmitterBufferIsFull(plibID))
&& (bufferObj->nCurrentBytes < bufferObj->size ))
{
PLIB_USART_TransmitterByteSend(plibID, bufferObj->buffer[bufferObj->nCurrentBytes]);
bufferObj->nCurrentBytes ++;
}
}
else
{
/* If the queue is empty, then disable the TX interrupt */
status = _DRV_USART_InterruptSourceDisable(hDriver->txInterruptSource);
}
/* Release the mutex */
OSAL_ASSERT(_DRV_USART_RELEASE_MUTEX(hDriver->mutexDriverInstance),
"Unable to release Hardware Instance Mutex");
}
void _DRV_USART_BufferQueueRxTasks(DRV_USART_OBJ * hDriver)
{
DRV_USART_BUFFER_OBJ * bufferObj;
DRV_USART_CLIENT_OBJ * client;
USART_MODULE_ID plibID;
bool status;
bufferObj = hDriver->queueWrite;
plibID = hDriver->moduleId;
/* If this driver is configured for polled mode in an RTOS, the tasks
routine would be called from another thread. We need to get the driver
instance mutex before updating the queue. If the driver is configured for
interrupt mode, then _DRV_USART_TAKE_MUTEX will compile to true */
if(DRV_USART_INTERRUPT_MODE == false)
{
if(OSAL_MUTEX_Lock(hDriver->mutexDriverInstance, OSAL_WAIT_FOREVER) == OSAL_RESULT_TRUE)
{
/* We were able to take the mutex */
}
else
{
/* The mutex acquisition timed out. Return with an
invalid handle. This code will not execute
if there is no RTOS. */
return;
}
}
/* In this function, the driver checks if there are any buffers in queue. If
so the buffer is serviced. A buffer that is serviced completely is
removed from the queue. Start by getting the buffer at the head of the
queue */
bufferObj = hDriver->queueRead;
if(bufferObj != NULL)
{
/* The USART driver is configured to generate an interrupt when the FIFO
is not empty. Additionally the queue is not empty. Which means there
is work to done in this routine. Read data from the FIFO till either
the FIFO is empty or till we have read the requested number of bytes.
*/
while((PLIB_USART_ReceiverDataIsAvailable(plibID))
&& (bufferObj->nCurrentBytes < bufferObj->size ))
{
bufferObj->buffer[bufferObj->nCurrentBytes] = PLIB_USART_ReceiverByteReceive(plibID);
bufferObj->nCurrentBytes ++;
}
/* Check if this buffer is done */
if(bufferObj->nCurrentBytes >= bufferObj->size)
{
/* This means the buffer is completed. If there
is a callback registered with client, then
call it */
client = (DRV_USART_CLIENT_OBJ *)bufferObj->hClient;
if((client->eventHandler != NULL) && (bufferObj->flags & DRV_USART_BUFFER_OBJ_FLAG_BUFFER_ADD))
{
/* Call the event handler. We additionally increment the
interrupt nesting count which lets the driver functions
that are called from the event handler know that an
interrupt context is active.
*/
hDriver->interruptNestingCount ++;
client->eventHandler(DRV_USART_BUFFER_EVENT_COMPLETE,
(DRV_USART_BUFFER_HANDLE)bufferObj,
client->context);
hDriver->interruptNestingCount --;
}
/* Get the next buffer in the queue and deallocate
this buffer */
hDriver->queueRead = bufferObj->next;
bufferObj->inUse = false;
hDriver->queueSizeCurrentRead --;
if(bufferObj->flags & DRV_USART_BUFFER_OBJ_FLAG_READ_WRITE)
{
/* This means we should post the semaphore */
OSAL_ASSERT(_DRV_USART_SEM_POST(client->semReadDone) == OSAL_RESULT_TRUE,
"Unable to post write buffer queue empty semaphore");
}
}
}
if(hDriver->queueRead == NULL)
{
/* The queue is empty. We can disable the interrupt */
status = _DRV_USART_InterruptSourceDisable(hDriver->rxInterruptSource);
}
/* Release the mutex */
OSAL_ASSERT(_DRV_USART_RELEASE_MUTEX(hDriver->mutexDriverInstance),
"Unable to release Hardware Instance Mutex");
}
