Hi everyone, As part of Google Summer of Code, I've tasked myself with implementing DMA support for the earlier Allwinner platforms. This first round of patches is the result of said effort. The first patch is the actual driver to support these platforms. Patches four and five add the corresponding DMA node to the device trees. Patches two and three are two patches I created to test the driver with some memory to device / device to memory transfers. The former lets the 8250_dw driver, used for the sunxi UARTs, use DMA transfers. After testing for a while, it seems there is an issue with DMA transfers on the UARTs - for normal user-interactive operation it seems to work okay, but pasting some chunk of text to it seems to hang the UART and some messages about "too much work for IRQ" show up with the UART IRQ number. I was not able to investigate further because I'm interacting with the device via the UART. The latter patch for the SPI driver lets me use DMA for SPI transfers of <=64 bytes. Anything larger than the FIFO size seems to stall; is this expected behaviour? Patches six and seven add the DMA properties to SPI so you can test with the third patch. Patch eight does the same for the UARTs. The last two patches add a dummy SPIdev device to both cubieboard and cubietruck to facilitate testing with spidev_test. My main testing procedure for SPI has been spidev_test from the kernel tree, with and without shorting MISO and MOSI. For memory to memory transfers, I have used dmatest.ko with various configurations. I have done testing on a cubieboard (A10, sun4i) and cubietruck (A20, sun7i) and while I expect no issues to show up, I will be repeating my tests on an A10S olinuxino as well. You will find some extra remarks on individual patches after their descriptions. All comments are welcome. Thanks! Emilio Emilio López (10): dma: sun4i: Add support for the DMA engine on sun[457]i SoCs serial: 8250_dw: support DMA on the OF case spi: sun4i: add DMA support ARM: sun7i: Add node to represent the DMA controller ARM: sun4i: Add node to represent the DMA controller ARM: sun7i: enable DMA on SPI ARM: sun4i: enable DMA on SPI ARM: sun7i: add DMA properties to UARTs ARM: sun4i: cubieboard: add an SPIdev device for testing ARM: sun7i: cubietruck: add an SPIdev device for testing .../devicetree/bindings/dma/sun4i-dma.txt | 45 + arch/arm/boot/dts/sun4i-a10-cubieboard.dts | 12 + arch/arm/boot/dts/sun4i-a10.dtsi | 23 + arch/arm/boot/dts/sun7i-a20-cubietruck.dts | 12 + arch/arm/boot/dts/sun7i-a20.dtsi | 32 + drivers/dma/Kconfig | 10 + drivers/dma/Makefile | 1 + drivers/dma/sun4i-dma.c | 1065 ++++++++++++++++++++ drivers/spi/spi-sun4i.c | 146 ++- drivers/tty/serial/8250/8250_dw.c | 7 +- 10 files changed, 1345 insertions(+), 8 deletions(-) create mode 100644 Documentation/devicetree/bindings/dma/sun4i-dma.txt create mode 100644 drivers/dma/sun4i-dma.c -- 2.0.0 -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
