Hello Simon,
I did take a look into SPI driver for SAME70 a few months ago. The one thing that was a little bit weird to me was the lack of DMA flags passed to sam_ dmachannel() function (somewhere here https://github.com/apache/incubator- nuttx/blob/master/arch/arm/src/samv7/sam_spi.c#L2043) compared to the flags I needed to select for ADC DMA support to function correctly (https:// github.com/apache/incubator-nuttx/blob/master/arch/arm/src/samv7/sam_afec.c# L1125). I didn't invest more time into it as we had other priorities back then and I think we sticked with SPI without DMA. But it could be one of the problems. You can also take a look into sam_afec.c file, the DMA is working fine there. Hope this helps. Best regards, Michal Lenc ---------- Původní e-mail ---------- Od: Simon Filgis <si...@ingenieurbuero-filgis.de> Komu: dev@nuttx.apache.org Datum: 8. 2. 2022 11:52:38 Předmět: SPI with DMA on SAME70 "Dear all, I'm using ST7789.c in combination with lvgl-lib. The bottleneck to the display is the SPI communication. But even if I increase the SPI frequency to 24MHz, it does not get faster. This is because of constant delay between the bytes. I guessed that this can be improved using DMA. But that does not seem to work out of the box. In the SPI TX callback the result of the DMA transfer is -4. The transfer is not executed. Can anybody give me a hint on what to do? Best regards, Simon -- Hard- and Softwaredevelopment Consultant Ingenieurbüro-Filgis USt-IdNr.: DE305343278 "
