The DMA controller can be used to transfer data to and from the SPI
controller without involving the CPU for each word of a SPI transfer.
Add support for DMA mode, and do some other cleanups while touching the
same code.
The dts changes in this series depend on the DMA series [1].
[1]: https://lore.kernel.org/lkml/20260105114445.878262-1-cosmin-gabriel.tanislav.xa@renesas.com/#t
V3:
* impose proper maxItems for each device
* impose maxItems for dmas property
V2:
* drop patches picked up by Mark
* add new dt-bindings patch to allow multiple DMAs
* wire up all DMA controllers for every SPI controller
Cosmin Tanislav (3):
dt-bindings: spi: renesas,rzv2h-rspi: allow multiple DMAs
arm64: dts: renesas: r9a09g077: wire up DMA support for SPI
arm64: dts: renesas: r9a09g087: wire up DMA support for SPI
.../bindings/spi/renesas,rzv2h-rspi.yaml | 16 +++++++++++++---
arch/arm64/boot/dts/renesas/r9a09g077.dtsi | 16 ++++++++++++++++
arch/arm64/boot/dts/renesas/r9a09g087.dtsi | 16 ++++++++++++++++
3 files changed, 45 insertions(+), 3 deletions(-)
--
2.52.0