How to use SPI? Can you tell me brief steps?

[ShaneCCC]

Have a reference to below link.

Spidev read failed on xavier devkit

I want to use spi to read some device, so I enable spidev0.0, spidev1.0, spidev2.0. But there is no any signal on spi port when I test these port. my device tree: spi@3210000 { compatible = "nvidia,tegra186-spi"; reg = <0x0 0x3210000 0x0 0x10000>; interrupts = <0x0 0x24 0x4>; #address-cells = <0x1>; #size-cells = <0x0>; iommus = <0x2 0x20>; dma-coherent; dmas = <0x1e 0xf 0x1e 0xf>; dma-names = "rx", "tx"; spi-max-frequency = <0x3dfd240>; nvidia,clk-parents = "pll_p", "cl…

SPI1 not work on Xavier

I enable the spi1 and add spidev device node in dts. I can find the /dev/spidev0.0, but I can’t detect the signal with Logical Analysis. So, I want to know that the SPI1 is spidev0.0, right ?

SPI works with JetPack 3.3 but not JetPack 4.2

Hello, I have modified the device tree using JetPack 3.3 and managed to get SPI working, including talking to an actual SPI slave device from the TX2. However, I wish to use the latest JetPack 4.2 (to be up-to-date and because other features work in 4.2 that I do not have working in 3.3), but when I make the same changes to the device tree for supporting SPI with JetPack 4.2, the SPI no longer works. I see my changes to the device tree, the /dev/spidevM.N devices show up, and I can open/read/wr…