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[0/2] Apple SIO driver

Message ID 20230712133806.4450-1-povik+lin@cutebit.org
Headers show
Series Apple SIO driver | expand

Message

Martin Povišer July 12, 2023, 1:38 p.m. UTC 
Hi all,

see attached a driver for the SIO coprocessor found on recent Apple
SoCs. This coprocessor provides general DMA services, it can feed
many peripherals but so far it seems it will only be useful for
audio output over HDMI/DisplayPort. So the driver here only supports
the DMA_CYCLIC mode of transactions with the focus being on audio.
There's a downstream prototype ALSA driver the DMA driver is being
tested against.

Some of the boilerplate code in implementing the dmaengine interface
was lifted from apple-admac.c. Among other things these two drivers
have in common that they implement the DMA_CYCLIC regime on top of
hardware/coprocessor layer supporting linear transactions only.

The binding schema saw two RFC rounds before and has a reviewed-by
from Rob.
https://lore.kernel.org/asahi/167693643966.613996.10372170526471864080.robh@kernel.org

Best regards,
Martin

Martin Povišer (2):
  dt-bindings: dma: apple,sio: Add schema
  dmaengine: apple-sio: Add Apple SIO driver

 .../devicetree/bindings/dma/apple,sio.yaml    | 111 ++
 MAINTAINERS                                   |   2 +
 drivers/dma/Kconfig                           |  10 +
 drivers/dma/Makefile                          |   1 +
 drivers/dma/apple-sio.c                       | 956 ++++++++++++++++++
 5 files changed, 1080 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/dma/apple,sio.yaml
 create mode 100644 drivers/dma/apple-sio.c

Comments

Krzysztof Kozlowski July 12, 2023, 7:42 p.m. UTC | #1 
On 12/07/2023 15:38, Martin Povišer wrote:
> Hi all,
> 
> see attached a driver for the SIO coprocessor found on recent Apple
> SoCs. This coprocessor provides general DMA services, it can feed
> many peripherals but so far it seems it will only be useful for
> audio output over HDMI/DisplayPort. So the driver here only supports
> the DMA_CYCLIC mode of transactions with the focus being on audio.
> There's a downstream prototype ALSA driver the DMA driver is being
> tested against.
> 
> Some of the boilerplate code in implementing the dmaengine interface
> was lifted from apple-admac.c. Among other things these two drivers
> have in common that they implement the DMA_CYCLIC regime on top of
> hardware/coprocessor layer supporting linear transactions only.
> 
> The binding schema saw two RFC rounds before and has a reviewed-by
> from Rob.
> https://lore.kernel.org/asahi/167693643966.613996.10372170526471864080.robh@kernel.org

Thank you for explanation. Then this is v3, not v1.

No need for resending, but if it happens, consider naming it v4. :)

Best regards,
Krzysztof