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 v5, 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/20220315191255.221473-1-miquel.raynal@xxxxxxxxxxx/T/#m0ef3323abce3eec961e142bf2fb35e95b9045fc5 Thanks, Miquèl Changes in v2: * Rebased on top of Emil's patches. Added platform data structures instead of raw quirk integers in order to provide a CPR value. * Added includes in dwlib.h even though it's not particularly useful, it may help preventing a build error later on if we ever decide to include this file from another location. * Dropped the call to ->tx_dma and instead implemented a callback that can be called from serial8250_tx/rx_dma. * Used the device API instead of the of API. * Changed the logic about DMA capabilities to avoid breaking existing designs. * Introduced a new quirk related to the flow-control feature of the RZ/N1 version of the UART controller when used with DMA. * Re-arranged the entire series as advised by Andy and Geert. * Added several preparation patches to ease the review of various functional changes. Miquel Raynal (6): serial: 8250: dw: Use the device API serial: 8250: dw: Create a more generic platform data structure serial: 8250: dw: Check when possible if DMA is effectively supported serial: 8250: dma: Allow driver operations before starting DMA transfers serial: 8250: dw: Introduce an rx_timeout variable in the IRQ path ARM: dts: r9a06g032: Fill the UART DMA properties Phil Edworthy (4): serial: 8250: dw: Move the per-device structure serial: 8250: dw: Allow to use a fallback CPR value if not synthesized serial: 8250: dw: Add support for DMA flow controlling devices serial: 8250: dw: Improve RZN1 support arch/arm/boot/dts/r9a06g032.dtsi | 15 ++++ drivers/tty/serial/8250/8250.h | 18 +++++ drivers/tty/serial/8250/8250_dma.c | 4 + drivers/tty/serial/8250/8250_dw.c | 116 +++++++++++++++++++++------ drivers/tty/serial/8250/8250_dwlib.c | 11 ++- drivers/tty/serial/8250/8250_dwlib.h | 26 ++++++ 6 files changed, 163 insertions(+), 27 deletions(-) -- 2.27.0
