New drivers should use dma_request_chan() instead
dma_request_slave_channel()

dma_request_slave_channel() is a simple wrapper for dma_request_chan()
eating up the error code for channel request failure and makes deferred
probing impossible.

Move the dma_request_slave_channel() into the header as inline function,
mark it as deprecated.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20200828110507.22407-1-peter.ujfalusi@ti.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

No users left in the kernel, it can be removed.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Link: https://lore.kernel.org/r/20200828084141.14902-1-peter.ujfalusi@ti.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

Pull dmaengine updates from Vinod Koul:
 "Core:
   - Support out of order dma completion
   - Support for repeating transaction

  New controllers:
   - Support for Actions S700 DMA engine
   - Renesas R8A774E1, r8a7742 controller binding
   - New driver for Xilinx DPDMA controller

  Other:
   - Support of out of order dma completion in idxd driver
   - W=1 warning cleanup of subsystem
   - Updates to ti-k3-dma, dw, idxd drivers"

* tag 'dmaengine-5.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vkoul/dmaengine: (68 commits)
  dmaengine: dw: Don't include unneeded header to platform data header
  dmaengine: Actions: Add support for S700 DMA engine
  dmaengine: Actions: get rid of bit fields from dma descriptor
  dt-bindings: dmaengine: convert Actions Semi Owl SoCs bindings to yaml
  dmaengine: idxd: add missing invalid flags field to completion
  dmaengine: dw: Initialize max_sg_burst capability
  dmaengine: dw: Introduce max burst length hw config
  dmaengine: dw: Initialize min and max burst DMA device capability
  dmaengine: dw: Set DMA device max segment size parameter
  dmaengine: dw: Take HC_LLP flag into account for noLLP auto-config
  dmaengine: Introduce DMA-device device_caps callback
  dmaengine: Introduce max SG burst capability
  dmaengine: Introduce min burst length capability
  dt-bindings: dma: dw: Add max burst transaction length property
  dt-bindings: dma: dw: Convert DW DMAC to DT binding
  dmaengine: ti: k3-udma: Query throughput level information from hardware
  dmaengine: ti: k3-udma: Use defines for capabilities register parsing
  dmaengine: xilinx: dpdma: Fix kerneldoc warning
  dmaengine: xilinx: dpdma: add missing kernel doc
  dmaengine: xilinx: dpdma: remove comparison of unsigned expression
  ...

 Conflicts:
	Documentation/driver-api/dmaengine/provider.rst
	include/linux/dmaengine.h

There are DMA devices (like ours version of Synopsys DW DMAC) which have
DMA capabilities non-uniformly redistributed between the device channels.
In order to provide a way of exposing the channel-specific parameters to
the DMA engine consumers, we introduce a new DMA-device callback. In case
if provided it gets called from the dma_get_slave_caps() method and is
able to override the generic DMA-device capabilities.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20200723005848.31907-6-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Vinod Koul <vkoul@kernel.org>

Some devices may lack the support of the hardware accelerated SG list
entries automatic walking through and execution. In this case a burden of
the SG list traversal and DMA engine re-initialization lies on the
DMA engine driver (normally implemented by using a DMA transfer completion
IRQ to recharge the DMA device with a next SG list entry). But such
solution may not be suitable for some DMA consumers. In particular SPI
devices need both Tx and Rx DMA channels work synchronously in order
to avoid the Rx FIFO overflow. In case if Rx DMA channel is paused for
some time while the Tx DMA channel works implicitly pulling data into the
Rx FIFO, the later will be eventually overflown, which will cause the data
loss. So if SG list entries aren't automatically fetched by the DMA
engine, but are one-by-one manually selected for execution in the
ISRs/deferred work/etc., such problem will eventually happen due to the
non-deterministic latencies of the service execution.

In order to let the DMA consumer know about the DMA device capabilities
regarding the hardware accelerated SG list traversal we introduce the
max_sg_burst capability. It is supposed to be initialized by the DMA engine
driver with 0 if there is no limitation of the number of SG entries
atomically executed and with non-zero value if there is such constraints,
so the upper limit is determined by the number set to the property.

Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20200723005848.31907-5-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Vinod Koul <vkoul@kernel.org>

Some hardware aside from default 0/1 may have greater minimum burst
transactions length constraints. Here we introduce the DMA device
and slave capability, which if required can be initialized by the DMA
engine driver with the device-specific value.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20200723005848.31907-4-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Vinod Koul <vkoul@kernel.org>

Xilinx ZynqMP DisplayPort Subsystem driver

Signed-off-by: Dave Airlie <airlied@redhat.com>

From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200718001755.GA5962@pendragon.ideasonboard.com

Drop the doubled word "has" in a comment.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Vinod Koul <vkoul@kernel.org>
Cc: dmaengine@vger.kernel.org
Link: https://lore.kernel.org/r/06e64046-ebf1-15db-dbaf-73698de3b493@infradead.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>

DMA engines used with displays perform 2D interleaved transfers to read
framebuffers from memory and feed the data to the display engine. As the
same framebuffer can be displayed for multiple frames, the DMA
transactions need to be repeated until a new framebuffer replaces the
current one. This feature is implemented natively by some DMA engines
that have the ability to repeat transactions and switch to a new
transaction at the end of a transfer without any race condition or frame
loss.

This patch implements support for this feature in the DMA engine API. A
new DMA_PREP_REPEAT transaction flag allows DMA clients to instruct the
DMA channel to repeat the transaction automatically until one or more
new transactions are issued on the channel (or until all active DMA
transfers are explicitly terminated with the dmaengine_terminate_*()
functions). A new DMA_REPEAT transaction type is also added for DMA
engine drivers to report their support of the DMA_PREP_REPEAT flag.

A new DMA_PREP_LOAD_EOT transaction flag is also introduced (with a
corresponding DMA_LOAD_EOT capability bit), as requested during the
review of v4. The flag instructs the DMA channel that the transaction
being queued should replace the active repeated transaction when the
latter terminates (at End Of Transaction). Not setting the flag will
result in the active repeated transaction to continue being repeated,
and the new transaction being silently ignored.

The DMA_PREP_REPEAT flag is currently supported for interleaved
transactions only. Its usage can easily be extended to cover more
transaction types simply by adding an appropriate check in the
corresponding dmaengine_prep_*() function.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Link: https://lore.kernel.org/r/20200717013337.24122-3-laurent.pinchart@ideasonboard.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>