struct dma_slave_caps documentation omitted the correct kernel-doc
opening comment mark.

Document byte granularity and interpretation of the src/dst_addr_widths
bit flag fields used by struct dma_slave_caps and struct dma_device.

Add punctuation to their "directions" member documentations, and cleanup
wording of the description.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Commit 93c6ee94c140 ("dma: Support for 3 bytes word size") and
commit 534a729866f9 ("dmaengine: Add 16 bytes, 32 bytes and 64 bytes
bus widths") added additional values for the allowed word size, but
omitted these from the struct dma_slave_config documentation.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Some of the DMA controllers are capable of issuing the commands
to peripheral by the DMA. These commands can be list of register
reads/writes and its different from normal data reads/writes.
This patch adds new flag DMA_PREP_CMD in DMA API which tells
the driver that the data passed to DMA API is command data
and DMA controller driver will form descriptor in the required
format.

This flag can be used by any DMA controller driver which requires
the descriptor in different format for non-Data descriptors.

Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

There are no in kernel consumers for DMA_SG op. Removing operation,
dead code, and test code in dmatest.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Gary Hook <gary.hook@amd.com>
Cc: Ludovic Desroches <ludovic.desroches@microchip.com>
Cc: Kedareswara rao Appana <appana.durga.rao@xilinx.com>
Cc: Li Yang <leoyang.li@nxp.com>
Cc: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Almost all ->device_prep_dma_xx() methods have a wrapper defined in
dmaengine.h. Add one for  ->device_prep_dma_memcpy().

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Some slave devices uses address window instead of single register for read
and/or write of data. With the src/dst_port_window_size the address window
can be specified and the DMAengine driver should use this information to
correctly set up the transfer to loop within the provided window.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Adding a new callback that will provide the error result for a transaction.
The result is allocated on the stack and the callback should create a copy
if it wishes to retain the information after exiting. The result parameter
is now defined and takes over the dummy void pointer we placed in the
helper functions previously. dmaengine drivers should start converting
to the new "callback_result" callback in order to receive transaction
results.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

dmaengine has various device callbacks and exposes helper
functions to invoke these. These helpers should check if channel,
device and callback is valid or not before invoking them.

Reported-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>