Hello, Support for the RZN1 DMA engine allows us adapt a little bit the 8250 DW UART driver with to bring DMA support for this SoC. This short series applies on top of the series bringing RZN1 DMA support, currently on its v4, see [1]. Technically speaking, only the DT patch needs to be applied after [1]. The other patches can come in at any moment, because if no "dmas" property is provided in the DT, DMA support will simply be ignored. [1] https://lore.kernel.org/dmaengine/20220310155755.287294-1-miquel.raynal@xxxxxxxxxxx/T/#mce6fec36e16dca560ab18935c273fcaf794a1cc4 Thanks, Miquèl Miquel Raynal (2): serial: 8250_dw: Provide the RZN1 CPR register value ARM: dts: r9a06g032: Fill the UART DMA properties Phil Edworthy (5): serial: 8250_dma: Use ->tx_dma function pointer to start next DMA serial: 8250_dw: Move the per-device structure serial: 8250_dw: Use a fallback CPR value if not synthesized serial: 8250_dw: Add a dma_capable bit to the platform data serial: 8250_dw: Add support for RZ/N1 DMA arch/arm/boot/dts/r9a06g032.dtsi | 15 ++++ drivers/tty/serial/8250/8250_dma.c | 4 +- drivers/tty/serial/8250/8250_dw.c | 119 +++++++++++++++++++++++---- drivers/tty/serial/8250/8250_dwlib.c | 17 +++- drivers/tty/serial/8250/8250_dwlib.h | 22 +++++ 5 files changed, 155 insertions(+), 22 deletions(-) -- 2.27.0