linux-toradex.git/drivers/dma/dw-axi-dmac, branch master

dmaengine: dw-axi-dmac: Add support for CV1800B DMA

2026-02-26T15:30:01+00:00

As the DMA controller on Sophgo CV1800 series SoC only has 8 channels,
the SoC provides a dma multiplexer to reuse the DMA channel. However,
the dma multiplexer also controls the DMA interrupt multiplexer, which
means that the dma multiplexer needs to know the channel number.

Allow the driver to use DMA phandle args as the channel number, so the
DMA multiplexer can route the DMA interrupt correctly.

Signed-off-by: Inochi Amaoto 
Reviewed-by: Frank Li 
Link: https://patch.msgid.link/20260120013706.436742-3-inochiama@gmail.com
Signed-off-by: Vinod Koul

dmaengine: dw-axi-dmac: Remove unnecessary return statement from void function

2026-02-26T15:30:00+00:00

checkpatch.pl --strict reports a WARNING in dw-axi-dmac-platform.c:

  WARNING: void function return statements are not generally useful
  FILE: drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c

According to Linux kernel coding style [Documentation/process/
coding-style.rst], explicit "return;" statements at the end of void
functions are redundant and should be omitted. The function will
automatically return upon reaching the closing brace, so the extra
statement adds unnecessary clutter without functional benefit.

This patch removes the superfluous "return;" statement in
dw_axi_dma_set_hw_channel() to comply with kernel coding standards and
eliminate the checkpatch warning.

Fixes: 32286e279385 ("dmaengine: dw-axi-dmac: Remove free slot check algorithm in dw_axi_dma_set_hw_channel")
Signed-off-by: Khairul Anuar Romli 
Link: https://patch.msgid.link/20260202060224.12616-4-karom.9560@gmail.com
Signed-off-by: Vinod Koul

dmaengine: dw-axi-dmac: Add blank line after function

2026-02-26T15:29:22+00:00

checkpatch.pl reports a CHECK warning in dw-axi-dmac-platform.c:

  CHECK: Please use a blank line after function/struct/union/enum
  declarations
  drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c:

The Linux kernel coding style [Documentation/process/coding-style.rst]
requires a blank line after function definitions to provide visual
separation between distinct code elements.

This patch inserts the required blank line after the closing brace of the
function definition after dw_axi_dma_set_byte_halfword(), placing it
before the contextual comment that describes the locking requirements.

Signed-off-by: Khairul Anuar Romli 
Link: https://patch.msgid.link/20260202060224.12616-3-karom.9560@gmail.com
Signed-off-by: Vinod Koul

dmaengine: dw-axi-dmac: fix Alignment should match open parenthesis

2026-02-25T10:03:38+00:00

checkpatch.pl --strict reports a CHECK warning in dw-axi-dmac-platform.c:

  CHECK: Alignment should match open parenthesis

This warning occurs when multi-line function calls or expressions have
continuation lines that don't properly align with the opening parenthesis
position.

This patch fixes all instances in dw-axi-dmac-platform.c where continuation
lines were indented with an inconsistent number of spaces/tabs that neither
matched the parenthesis column nor followed a standard indent pattern.
Proper alignment improves code readability and maintainability by making
parameter lists visually consistent across the kernel codebase.

Fixes: 1fe20f1b8454 ("dmaengine: Introduce DW AXI DMAC driver")
Fixes: e32634f466a9 ("dma: dw-axi-dmac: support per channel interrupt")
Signed-off-by: Khairul Anuar Romli 
Link: https://patch.msgid.link/20260202060224.12616-2-karom.9560@gmail.com
Signed-off-by: Vinod Koul

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:

Single allocations:	kmalloc(sizeof(TYPE), ...)
are replaced with:	kmalloc_obj(TYPE, ...)

Array allocations:	kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with:	kmalloc_objs(TYPE, COUNT, ...)

Flex array allocations:	kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with:	kmalloc_flex(*PTR, FAM, COUNT, ...)

(where TYPE may also be *VAR)

The resulting allocations no longer return "void *", instead returning
"TYPE *".

Signed-off-by: Kees Cook

dmaengine: dw-axi-dmac: use sg_nents_for_dma() helper

2026-01-09T03:06:00+00:00

Instead of open coded variant let's use recently introduced helper.

Reviewed-by: Bjorn Andersson 
Signed-off-by: Andy Shevchenko 
Link: https://patch.msgid.link/20260108105619.3513561-6-andriy.shevchenko@linux.intel.com
Signed-off-by: Vinod Koul

dmaengine: Switch back to struct platform_driver::remove()

2024-10-14T18:20:34+00:00

After commit 0edb555a65d1 ("platform: Make platform_driver::remove()
return void") .remove() is (again) the right callback to implement for
platform drivers.

Convert all platform drivers below drivers/dma after the previous
conversion commits apart from the wireless drivers to use .remove(),
with the eventual goal to drop struct platform_driver::remove_new(). As
.remove() and .remove_new() have the same prototypes, conversion is done
by just changing the structure member name in the driver initializer.

Signed-off-by: Uwe Kleine-König 
Link: https://lore.kernel.org/r/20241004062227.187726-2-u.kleine-koenig@baylibre.com
Signed-off-by: Vinod Koul

dma: dw-axi-dmac: support per channel interrupt

2024-04-07T11:48:14+00:00

Hardware might not support a single combined interrupt that covers all
channels. In that case we have to deal with interrupt per channel. Add
support for that configuration.

Signed-off-by: Baruch Siach 
Link: https://lore.kernel.org/r/ebab52e886ef1adc3c40e636aeb1ba3adfe2e578.1711453387.git.baruchs-c@neureality.ai
Signed-off-by: Vinod Koul

Avoid hw_desc array overrun in dw-axi-dmac

2024-04-07T11:45:24+00:00

I have a use case where nr_buffers = 3 and in which each descriptor is composed by 3
segments, resulting in the DMA channel descs_allocated to be 9. Since axi_desc_put()
handles the hw_desc considering the descs_allocated, this scenario would result in a
kernel panic (hw_desc array will be overrun).

To fix this, the proposal is to add a new member to the axi_dma_desc structure,
where we keep the number of allocated hw_descs (axi_desc_alloc()) and use it in
axi_desc_put() to handle the hw_desc array correctly.

Additionally I propose to remove the axi_chan_start_first_queued() call after completing
the transfer, since it was identified that unbalance can occur (started descriptors can
be interrupted and transfer ignored due to DMA channel not being enabled).

Signed-off-by: Joao Pinto 
Link: https://lore.kernel.org/r/1711536564-12919-1-git-send-email-jpinto@synopsys.com
Signed-off-by: Vinod Koul

dmaengine: dw-axi-dmac: Add support for StarFive JH8100 DMA

2024-04-07T11:41:12+00:00

JH8100 requires reset operation only in device probe.

Signed-off-by: Tan Chun Hau 
Link: https://lore.kernel.org/r/20240327025126.229475-3-chunhau.tan@starfivetech.com
Signed-off-by: Vinod Koul