Jetson TX1 J21 SPI1

Robotics & Edge Computing Jetson & Embedded Systems Jetson TX1
1

Hi,

Is Jestson J21 SPI1 spidev0 or spidev1?
From pinmux data, Jestson SPI1 connects J21 SPI1 ( pin 24, 26, 19, 21, 23),
however we found J21 SPI1 is spidev0 not spidev1 on Tx1 after we enabled SPI.
a. Is this a name discrepancy or our patch issue? (See the patch below)
b. What Jetson TX1 pin SPI2 or SPI0 refers to? (Jetson Tx1 pin SPI2–> spidev1, Jetson Tx1 pin SPI0 – spidev2)

diff --git a/arch/arm64/boot/dts/tegra210-jetson-cv-base-p2597-2180-a00.dts b/arch/arm64/boot/dts/tegra210-jetson-cv-base-p2597-2180-a00.dts
index 2a8f8f38…604b1bc 100644
— a/arch/arm64/boot/dts/tegra210-jetson-cv-base-p2597-2180-a00.dts
+++ b/arch/arm64/boot/dts/tegra210-jetson-cv-base-p2597-2180-a00.dts
@@ -270,14 +270,94 @@
status = “okay”;
};

  • spi@7000da00 {
  •   status = "ok";

  • gpio@6000d000 {

  •   gpio_default: default {

  •   	gpio-to-sfio = <16 17 18 19 20>;

  •   };

    };

  • spi@7000d400 {

  •   compatible = "nvidia,tegra210-spi";

  •   reg = <0x0 0x7000d400 0x0 0x200>;

  •   interrupts = <0 59 0x04>;

  •   nvidia,dma-request-selector = <&apbdma 15>;

  •   iommus = <&smmu TEGRA_SWGROUP_PPCS>;

  •   #address-cells = <1>;

  •   #size-cells = <0>;

  •   clocks = <&tegra_car 41>;
  status = "okay";

  •   dmas = <&apbdma 15>, <&apbdma 15>;

  •   dma-names = "rx", "tx";

  •   nvidia,clk-parents = "pll_p", "clk_m";

  •   spi-spidev@0 {

  •   	status = "okay";

  •   	#address-cells = <0x1>;

  •   	#size-cells = <0x0>;

  •   	compatible = "linux,spidev", "spidev";

  •   	reg = <0>;

  •   	spi-max-frequency = <16000000>;

  •   	spi-cpha;

  •   	controller-data {

  •   		nvidia,enable-hw-based-cs;

  •   		nvidia,cs-setup-clk-count = <0x1e>;

  •   		nvidia,cs-hold-clk-count =  <0x1e>;

  •   		nvidia,rx-clk-tap-delay = <0x1f>;

  •   		nvidia,tx-clk-tap-delay = <0x0>;

  •   		nvidia,default-chipselect;

  •   		nvidia,chipselect-gpio = <&gpio 19 0>;

  •   	};

  •   };

  • };

  • spi@7000d600 {

  •   compatible = "nvidia,tegra210-spi";

  •   reg = <0x0 0x7000d600 0x0 0x200>;

  •   interrupts = <0 82 0x04>;

  •   nvidia,dma-request-selector = <&apbdma 16>;

  •   iommus = <&smmu TEGRA_SWGROUP_PPCS>;

  •   #address-cells = <1>;

  •   #size-cells = <0>;

  •   clocks = <&tegra_car 44>;

  •   status = "okay";

  •   dmas = <&apbdma 16>, <&apbdma 16>;

  •   dma-names = "rx", "tx";

  •   nvidia,clk-parents = "pll_p", "clk_m";

  •       spi1_0 {

  •   	#address-cells = <0x1>;

  •   	#size-cells = <0x0>;

  •   	compatible = "spidev";

  •   	reg = <0x0>;

  •   	spi-max-frequency = <0x17d7840>;

  •   	nvidia,enable-hw-based-cs;

  •   	nvidia,cs-setup-clk-count = <0x1e>;

  •   	nvidia,cs-hold-clk-count = <0x1e>;

  •   	nvidia,rx-clk-tap-delay = <0x1f>;

  •   	nvidia,tx-clk-tap-delay = <0x0>;

  •       };

  • };

pinmux_spi.png
pinmux_spi.png1280×1024 158 KB

2

Hi linuxsky, I guess the device node is decided by driver probing sequence but not sure if we can adjust it by device tree. Maybe you can have a try.

3

Dear Vickyy,

Thank you for your help.
We just want to make sure our patch works correctly or not.

Plus, do you mean to adjust tegra210-soc-base.dtsi?

Thank you,

4

Since you just want to test you may find it faster to reverse compile the existing dtb file in “/boot” to dts and edit that followed by compiling it back from dts to dtb.

dtc -I dtb -O dts -o /tmp/extracted.dts /boot/the_firmware_in_extlinux.dtb
# ...edit...
dtc -I dts -O dtb -o /tmp/modified.dtb /tmp/extracted.dts
5

linuxsky,

in ./kernel/arch/arm64/boot/dts/tegra210-soc-base.dtsi, below bold define the spi alias.

    [b]spi0[/b]: spi@7000d400 {

…
spi1: spi@7000d600 {
…
spi2: spi@7000d800 {
…
spi3: spi@7000da00 {
…

You can try to define your own.

6

Hi Linuxdev and Vickky,

Thank you for your support.
I can define it by modify /boot/the_firmware_in_extlinux.dtb or tegra210-soc-base.dtsi

Thanks