Merge branch 'topic/xilinx' into fixes

Conflicts:
	Documentation/driver-api/dmaengine/provider.rst
	include/linux/dmaengine.h
This commit is contained in:
Vinod Koul
2020-08-07 11:13:37 +05:30
9 changed files with 1708 additions and 1 deletions

View File

@@ -86,7 +86,9 @@ The details of these operations are:
- interleaved_dma: This is common to Slave as well as M2M clients. For slave
address of devices' fifo could be already known to the driver.
Various types of operations could be expressed by setting
appropriate values to the 'dma_interleaved_template' members.
appropriate values to the 'dma_interleaved_template' members. Cyclic
interleaved DMA transfers are also possible if supported by the channel by
setting the DMA_PREP_REPEAT transfer flag.
A non-NULL return of this transfer API represents a "descriptor" for
the given transaction.

View File

@@ -255,6 +255,27 @@ Currently, the types available are:
identifier for each descriptor sent to the DMA device in order to
properly track the completion.
- DMA_REPEAT
- The device supports repeated transfers. A repeated transfer, indicated by
the DMA_PREP_REPEAT transfer flag, is similar to a cyclic transfer in that
it gets automatically repeated when it ends, but can additionally be
replaced by the client.
- This feature is limited to interleaved transfers, this flag should thus not
be set if the DMA_INTERLEAVE flag isn't set. This limitation is based on
the current needs of DMA clients, support for additional transfer types
should be added in the future if and when the need arises.
- DMA_LOAD_EOT
- The device supports replacing repeated transfers at end of transfer (EOT)
by queuing a new transfer with the DMA_PREP_LOAD_EOT flag set.
- Support for replacing a currently running transfer at another point (such
as end of burst instead of end of transfer) will be added in the future
based on DMA clients needs, if and when the need arises.
These various types will also affect how the source and destination
addresses change over time.
@@ -550,6 +571,34 @@ DMA_CTRL_REUSE
writes for which the descriptor should be in different format from
normal data descriptors.
- DMA_PREP_REPEAT
- If set, the transfer will be automatically repeated when it ends until a
new transfer is queued on the same channel with the DMA_PREP_LOAD_EOT flag.
If the next transfer to be queued on the channel does not have the
DMA_PREP_LOAD_EOT flag set, the current transfer will be repeated until the
client terminates all transfers.
- This flag is only supported if the channel reports the DMA_REPEAT
capability.
- DMA_PREP_LOAD_EOT
- If set, the transfer will replace the transfer currently being executed at
the end of the transfer.
- This is the default behaviour for non-repeated transfers, specifying
DMA_PREP_LOAD_EOT for non-repeated transfers will thus make no difference.
- When using repeated transfers, DMA clients will usually need to set the
DMA_PREP_LOAD_EOT flag on all transfers, otherwise the channel will keep
repeating the last repeated transfer and ignore the new transfers being
queued. Failure to set DMA_PREP_LOAD_EOT will appear as if the channel was
stuck on the previous transfer.
- This flag is only supported if the channel reports the DMA_LOAD_EOT
capability.
General Design Notes
====================