Hi.
After long long study, finally I reach ‘change device tree’ step.
As @ShaneCCC suggest, I try to follow 3 post shown in below.
- Spidev read failed on xavier devkit
- SPI1 not work on Xavier
- SPI works with JetPack 3.3 but not JetPack 4.2
At first post, @bwp2012 wrote sample spi 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”, “clk_m”;
clocks = <0x4 0x87 0x4 0x66 0x4 0xe>;
clock-names = “spi”, “pll_p”, “clk_m”;
resets = <0x5 0x5b>;
reset-names = “spi”;
status = “okay”;
linux,phandle = <0x172>;
phandle = <0x172>;
spidev@0 {
compatible = "spidev";
reg = <0x0>;
spi-max-frequency = <0x1312d00>;
};
};
I only can understand SPI memory starting address 0x3210000 and the length is 0x10000.
And I don’t know about why ‘reg’ field has 4 arguments.(First and thrid arguments are for what]?
[reg = <0x0 0x3210000 0x0 0x10000>;]
and also at the end of my develope, I need to use interrupts for SPI.
but I can’t find why interrupt field has <0x0 0x24 0x4>.
[interrupts = <0x0 0x24 0x4>;]
Thus, Is there any documents for detail explain about jetson device tree contents?
Or can anyone make device-tree components if I explain detail of my SPI mode setting?
Thanks!