int dma_alloc_descriptor_ring(DMA_DescriptorRing_t *ring, /* */
int numDescriptors /* */
) {
size_t bytesToAlloc = dmacHw_descriptorLen(numDescriptors);
if ((ring == NULL) || (numDescriptors <= 0)) {
return -EINVAL;
}
ring->physAddr = 0;
ring->descriptorsAllocated = 0;
ring->bytesAllocated = 0;
ring->virtAddr = dma_alloc_writecombine(NULL,
bytesToAlloc,
&ring->physAddr,
GFP_KERNEL);
if (ring->virtAddr == NULL) {
return -ENOMEM;
}
ring->bytesAllocated = bytesToAlloc;
ring->descriptorsAllocated = numDescriptors;
return dma_init_descriptor_ring(ring, numDescriptors);
}
int dmacHw_initDescriptor(void *pDescriptorVirt, /* [ IN ] Virtual address of uncahced buffer allocated to form descriptor ring */
uint32_t descriptorPhyAddr, /* [ IN ] Physical address of pDescriptorVirt (descriptor buffer) */
uint32_t len, /* [ IN ] Size of the pBuf */
uint32_t num /* [ IN ] Number of descriptor in the ring */
) {
uint32_t i;
dmacHw_DESC_RING_t *pRing;
dmacHw_DESC_t *pDesc;
/* Check the alignment of the descriptor */
if ((uint32_t) pDescriptorVirt & 0x00000003) {
dmacHw_ASSERT(0);
return -1;
}
/* Check if enough space has been allocated for descriptor ring */
if (len < dmacHw_descriptorLen(num)) {
return -1;
}
pRing = dmacHw_GET_DESC_RING(pDescriptorVirt);
pRing->pHead =
(dmacHw_DESC_t *) ((uint32_t) pRing + sizeof(dmacHw_DESC_RING_t));
pRing->pFree = pRing->pTail = pRing->pEnd = pRing->pHead;
pRing->pProg = dmacHw_DESC_INIT;
/* Initialize link item chain, starting from the head */
pDesc = pRing->pHead;
/* Find the offset between virtual to physical address */
pRing->virt2PhyOffset = (uint32_t) pDescriptorVirt - descriptorPhyAddr;
/* Form the descriptor ring */
for (i = 0; i < num - 1; i++) {
/* Clear link list item */
memset((void *)pDesc, 0, sizeof(dmacHw_DESC_t));
/* Point to the next item in the physical address */
pDesc->llpPhy = (uint32_t) (pDesc + 1) - pRing->virt2PhyOffset;
/* Point to the next item in the virtual address */
pDesc->llp = (uint32_t) (pDesc + 1);
/* Mark descriptor is ready to use */
pDesc->ctl.hi = dmacHw_DESC_FREE;
/* Look into next link list item */
pDesc++;
}
/* Clear last link list item */
memset((void *)pDesc, 0, sizeof(dmacHw_DESC_t));
/* Last item pointing to the first item in the
physical address to complete the ring */
pDesc->llpPhy = (uint32_t) pRing->pHead - pRing->virt2PhyOffset;
/* Last item pointing to the first item in the
virtual address to complete the ring
*/
pDesc->llp = (uint32_t) pRing->pHead;
/* Mark descriptor is ready to use */
pDesc->ctl.hi = dmacHw_DESC_FREE;
/* Set the number of descriptors in the ring */
pRing->num = num;
return 0;
}
int dmacHw_initDescriptor(void *pDescriptorVirt,
uint32_t descriptorPhyAddr,
uint32_t len,
uint32_t num
) {
uint32_t i;
dmacHw_DESC_RING_t *pRing;
dmacHw_DESC_t *pDesc;
if ((uint32_t) pDescriptorVirt & 0x00000003) {
dmacHw_ASSERT(0);
return -1;
}
if (len < dmacHw_descriptorLen(num)) {
return -1;
}
pRing = dmacHw_GET_DESC_RING(pDescriptorVirt);
pRing->pHead =
(dmacHw_DESC_t *) ((uint32_t) pRing + sizeof(dmacHw_DESC_RING_t));
pRing->pFree = pRing->pTail = pRing->pEnd = pRing->pHead;
pRing->pProg = dmacHw_DESC_INIT;
pDesc = pRing->pHead;
pRing->virt2PhyOffset = (uint32_t) pDescriptorVirt - descriptorPhyAddr;
for (i = 0; i < num - 1; i++) {
memset((void *)pDesc, 0, sizeof(dmacHw_DESC_t));
pDesc->llpPhy = (uint32_t) (pDesc + 1) - pRing->virt2PhyOffset;
pDesc->llp = (uint32_t) (pDesc + 1);
pDesc->ctl.hi = dmacHw_DESC_FREE;
pDesc++;
}
memset((void *)pDesc, 0, sizeof(dmacHw_DESC_t));
pDesc->llpPhy = (uint32_t) pRing->pHead - pRing->virt2PhyOffset;
pDesc->llp = (uint32_t) pRing->pHead;
pDesc->ctl.hi = dmacHw_DESC_FREE;
pRing->num = num;
return 0;
}
int dma_alloc_double_dst_descriptors(DMA_Handle_t handle, /* */
dma_addr_t srcData, /* */
dma_addr_t dstData1, /* */
dma_addr_t dstData2, /* */
size_t numBytes /* */
) {
DMA_Channel_t *channel;
DMA_DeviceAttribute_t *devAttr;
int numDst1Descriptors;
int numDst2Descriptors;
int numDescriptors;
size_t ringBytesRequired;
int rc = 0;
channel = HandleToChannel(handle);
if (channel == NULL) {
return -ENODEV;
}
devAttr = &DMA_gDeviceAttribute[channel->devType];
/* */
/* */
/* */
numDst1Descriptors =
dmacHw_calculateDescriptorCount(&devAttr->config, (void *)srcData,
(void *)dstData1, numBytes);
if (numDst1Descriptors < 0) {
return -EINVAL;
}
numDst2Descriptors =
dmacHw_calculateDescriptorCount(&devAttr->config, (void *)srcData,
(void *)dstData2, numBytes);
if (numDst2Descriptors < 0) {
return -EINVAL;
}
numDescriptors = numDst1Descriptors + numDst2Descriptors;
/* */
/* */
/* */
ringBytesRequired = dmacHw_descriptorLen(numDescriptors);
/* */
if (ringBytesRequired > devAttr->ring.bytesAllocated) {
/* */
/* */
/* */
might_sleep();
/* */
dma_free_descriptor_ring(&devAttr->ring);
/* */
rc =
dma_alloc_descriptor_ring(&devAttr->ring,
numDescriptors);
if (rc < 0) {
printk(KERN_ERR
"%s: dma_alloc_descriptor_ring(%d) failed\n",
__func__, ringBytesRequired);
return rc;
}
}
/* */
/* */
/* */
if (dmacHw_initDescriptor(devAttr->ring.virtAddr,
devAttr->ring.physAddr,
devAttr->ring.bytesAllocated,
numDescriptors) < 0) {
printk(KERN_ERR "%s: dmacHw_initDescriptor failed\n", __func__);
return -EINVAL;
}
/* */
/* */
if (dmacHw_setDataDescriptor(&devAttr->config,
devAttr->ring.virtAddr,
(void *)srcData,
(void *)dstData1, numBytes) < 0) {
printk(KERN_ERR "%s: dmacHw_setDataDescriptor 1 failed\n",
__func__);
return -EINVAL;
}
if (dmacHw_setDataDescriptor(&devAttr->config,
devAttr->ring.virtAddr,
(void *)srcData,
(void *)dstData2, numBytes) < 0) {
printk(KERN_ERR "%s: dmacHw_setDataDescriptor 2 failed\n",
__func__);
return -EINVAL;
}
/* */
/* */
devAttr->prevSrcData = 0;
devAttr->prevDstData = 0;
devAttr->prevNumBytes = 0;
return numDescriptors;
}
int dma_alloc_descriptors(DMA_Handle_t handle, /* */
dmacHw_TRANSFER_TYPE_e transferType, /* */
dma_addr_t srcData, /* */
dma_addr_t dstData, /* */
size_t numBytes /* */
) {
DMA_Channel_t *channel;
DMA_DeviceAttribute_t *devAttr;
int numDescriptors;
size_t ringBytesRequired;
int rc = 0;
channel = HandleToChannel(handle);
if (channel == NULL) {
return -ENODEV;
}
devAttr = &DMA_gDeviceAttribute[channel->devType];
if (devAttr->config.transferType != transferType) {
return -EINVAL;
}
/* */
/* */
/* */
numDescriptors = dmacHw_calculateDescriptorCount(&devAttr->config,
(void *)srcData,
(void *)dstData,
numBytes);
if (numDescriptors < 0) {
printk(KERN_ERR "%s: dmacHw_calculateDescriptorCount failed\n",
__func__);
return -EINVAL;
}
/* */
/* */
ringBytesRequired = dmacHw_descriptorLen(numDescriptors);
/* */
if (ringBytesRequired > devAttr->ring.bytesAllocated) {
/* */
/* */
/* */
might_sleep();
/* */
dma_free_descriptor_ring(&devAttr->ring);
/* */
rc =
dma_alloc_descriptor_ring(&devAttr->ring,
numDescriptors);
if (rc < 0) {
printk(KERN_ERR
"%s: dma_alloc_descriptor_ring(%d) failed\n",
__func__, numDescriptors);
return rc;
}
/* */
if (dmacHw_initDescriptor(devAttr->ring.virtAddr,
devAttr->ring.physAddr,
devAttr->ring.bytesAllocated,
numDescriptors) < 0) {
printk(KERN_ERR "%s: dmacHw_initDescriptor failed\n",
__func__);
return -EINVAL;
}
} else {
/* */
/* */
dmacHw_resetDescriptorControl(devAttr->ring.virtAddr);
}
/* */
/* */
if (dmacHw_setDataDescriptor(&devAttr->config,
devAttr->ring.virtAddr,
(void *)srcData,
(void *)dstData, numBytes) < 0) {
printk(KERN_ERR "%s: dmacHw_setDataDescriptor failed\n",
__func__);
return -EINVAL;
}
/* */
/* */
devAttr->prevSrcData = srcData;
devAttr->prevDstData = dstData;
devAttr->prevNumBytes = numBytes;
return 0;
}
int dma_alloc_double_dst_descriptors(DMA_Handle_t handle, /* DMA Handle */
dma_addr_t srcData, /* Physical address of source data */
dma_addr_t dstData1, /* Physical address of first destination buffer */
dma_addr_t dstData2, /* Physical address of second destination buffer */
size_t numBytes /* Number of bytes in each destination buffer */
) {
DMA_Channel_t *channel;
DMA_DeviceAttribute_t *devAttr;
int numDst1Descriptors;
int numDst2Descriptors;
int numDescriptors;
size_t ringBytesRequired;
int rc = 0;
channel = HandleToChannel(handle);
if (channel == NULL) {
return -ENODEV;
}
devAttr = &DMA_gDeviceAttribute[channel->devType];
/* Figure out how many descriptors we need. */
/* printk("srcData: 0x%08x dstData: 0x%08x, numBytes: %d\n", */
/* srcData, dstData, numBytes); */
numDst1Descriptors =
dmacHw_calculateDescriptorCount(&devAttr->config, (void *)srcData,
(void *)dstData1, numBytes);
if (numDst1Descriptors < 0) {
return -EINVAL;
}
numDst2Descriptors =
dmacHw_calculateDescriptorCount(&devAttr->config, (void *)srcData,
(void *)dstData2, numBytes);
if (numDst2Descriptors < 0) {
return -EINVAL;
}
numDescriptors = numDst1Descriptors + numDst2Descriptors;
/* printk("numDescriptors: %d\n", numDescriptors); */
/* Check to see if we can reuse the existing descriptor ring, or if we need to allocate */
/* a new one. */
ringBytesRequired = dmacHw_descriptorLen(numDescriptors);
/* printk("ringBytesRequired: %d\n", ringBytesRequired); */
if (ringBytesRequired > devAttr->ring.bytesAllocated) {
/* Make sure that this code path is never taken from interrupt context. */
/* It's OK for an interrupt to initiate a DMA transfer, but the descriptor */
/* allocation needs to have already been done. */
might_sleep();
/* Free the old descriptor ring and allocate a new one. */
dma_free_descriptor_ring(&devAttr->ring);
/* And allocate a new one. */
rc =
dma_alloc_descriptor_ring(&devAttr->ring,
numDescriptors);
if (rc < 0) {
printk(KERN_ERR
"%s: dma_alloc_descriptor_ring(%d) failed\n",
__func__, ringBytesRequired);
return rc;
}
}
/* Setup the descriptor for this transfer. Since this function is used with */
/* CONTINUOUS DMA operations, we need to reinitialize every time, otherwise */
/* setDataDescriptor will keep trying to append onto the end. */
if (dmacHw_initDescriptor(devAttr->ring.virtAddr,
devAttr->ring.physAddr,
devAttr->ring.bytesAllocated,
numDescriptors) < 0) {
printk(KERN_ERR "%s: dmacHw_initDescriptor failed\n", __func__);
return -EINVAL;
}
/* dma_alloc/free both set the prevSrc/DstData to 0. If they happen to be the same */
/* as last time, then we don't need to call setDataDescriptor again. */
if (dmacHw_setDataDescriptor(&devAttr->config,
devAttr->ring.virtAddr,
(void *)srcData,
(void *)dstData1, numBytes) < 0) {
printk(KERN_ERR "%s: dmacHw_setDataDescriptor 1 failed\n",
__func__);
return -EINVAL;
}
if (dmacHw_setDataDescriptor(&devAttr->config,
devAttr->ring.virtAddr,
(void *)srcData,
(void *)dstData2, numBytes) < 0) {
printk(KERN_ERR "%s: dmacHw_setDataDescriptor 2 failed\n",
__func__);
return -EINVAL;
}
/* You should use dma_start_transfer rather than dma_transfer_xxx so we don't */
/* try to make the 'prev' variables right. */
devAttr->prevSrcData = 0;
devAttr->prevDstData = 0;
devAttr->prevNumBytes = 0;
return numDescriptors;
}
int dma_alloc_descriptors(DMA_Handle_t handle, /* DMA Handle */
dmacHw_TRANSFER_TYPE_e transferType, /* Type of transfer being performed */
dma_addr_t srcData, /* Place to get data to write to device */
dma_addr_t dstData, /* Pointer to device data address */
size_t numBytes /* Number of bytes to transfer to the device */
) {
DMA_Channel_t *channel;
DMA_DeviceAttribute_t *devAttr;
int numDescriptors;
size_t ringBytesRequired;
int rc = 0;
channel = HandleToChannel(handle);
if (channel == NULL) {
return -ENODEV;
}
devAttr = &DMA_gDeviceAttribute[channel->devType];
if (devAttr->config.transferType != transferType) {
return -EINVAL;
}
/* Figure out how many descriptors we need. */
/* printk("srcData: 0x%08x dstData: 0x%08x, numBytes: %d\n", */
/* srcData, dstData, numBytes); */
numDescriptors = dmacHw_calculateDescriptorCount(&devAttr->config,
(void *)srcData,
(void *)dstData,
numBytes);
if (numDescriptors < 0) {
printk(KERN_ERR "%s: dmacHw_calculateDescriptorCount failed\n",
__func__);
return -EINVAL;
}
/* Check to see if we can reuse the existing descriptor ring, or if we need to allocate */
/* a new one. */
ringBytesRequired = dmacHw_descriptorLen(numDescriptors);
/* printk("ringBytesRequired: %d\n", ringBytesRequired); */
if (ringBytesRequired > devAttr->ring.bytesAllocated) {
/* Make sure that this code path is never taken from interrupt context. */
/* It's OK for an interrupt to initiate a DMA transfer, but the descriptor */
/* allocation needs to have already been done. */
might_sleep();
/* Free the old descriptor ring and allocate a new one. */
dma_free_descriptor_ring(&devAttr->ring);
/* And allocate a new one. */
rc =
dma_alloc_descriptor_ring(&devAttr->ring,
numDescriptors);
if (rc < 0) {
printk(KERN_ERR
"%s: dma_alloc_descriptor_ring(%d) failed\n",
__func__, numDescriptors);
return rc;
}
/* Setup the descriptor for this transfer */
if (dmacHw_initDescriptor(devAttr->ring.virtAddr,
devAttr->ring.physAddr,
devAttr->ring.bytesAllocated,
numDescriptors) < 0) {
printk(KERN_ERR "%s: dmacHw_initDescriptor failed\n",
__func__);
return -EINVAL;
}
} else {
/* We've already got enough ring buffer allocated. All we need to do is reset */
/* any control information, just in case the previous DMA was stopped. */
dmacHw_resetDescriptorControl(devAttr->ring.virtAddr);
}
/* dma_alloc/free both set the prevSrc/DstData to 0. If they happen to be the same */
/* as last time, then we don't need to call setDataDescriptor again. */
if (dmacHw_setDataDescriptor(&devAttr->config,
devAttr->ring.virtAddr,
(void *)srcData,
(void *)dstData, numBytes) < 0) {
printk(KERN_ERR "%s: dmacHw_setDataDescriptor failed\n",
__func__);
return -EINVAL;
}
/* Remember the critical information for this transfer so that we can eliminate */
/* another call to dma_alloc_descriptors if the caller reuses the same buffers */
devAttr->prevSrcData = srcData;
devAttr->prevDstData = dstData;
devAttr->prevNumBytes = numBytes;
return 0;
}
