Enable SPI on TX2 with Jetpack4.2/R32.1

Robotics & Edge Computing Jetson & Embedded Systems Jetson TX2
1

Hello,

I want to enable SPI1(SOM Connector)->SPI4(Customer usage)->/dev/spidev3.0(Software name),and do as this topic:TX2_SPI

1).tegra186-soc-spi.dtsi:
spi3: spi@3240000 {

    compatible = "nvidia,tegra186-spi";

    reg = <0x0 0x03240000 0x0 0x10000>;

    interrupts = <0 39 0x04>;

    #address-cells = <1>;

    #size-cells = <0>;

    iommus = <&smmu TEGRA_SID_GPCDMA_0>;

    dmas = <&gpcdma 18>, <&gpcdma 18>;

    dma-names = "rx", "tx";

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

    clocks = <&tegra_car TEGRA186_CLK_SPI4>,

        <&tegra_car TEGRA186_CLK_PLLP_OUT0>,

        <&tegra_car TEGRA186_CLK_CLK_M>;

    clock-names = "spi", "pll_p", "clk_m";

    resets = <&tegra_car TEGRA186_RESET_SPI4>;

    reset-names = "spi";

    status = "okay";

#add below
spi@0 {

        compatible = "spidev";

        reg = <0x0>;

        spi-max-frequency = <0x1312D00>;

        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>;

    };

};

2).kernel config:
CONFIG_SPI=y
CONFIG_SPI_TEGRA114=y
CONFIG_SPI_SPIDEV=m
CONFIG_QSPI_TEGRA186=y

3).Pinmux config:
bootloader/t186ref/BCT/tegra186-mb1-bct-pinmux-quill-p3310-1000-c03.cfg
#default
pinmux.0x02430038 = 0x00000000; # GPIO gpio_cam4_pn3
pinmux.0x02430040 = 0x00000000; # GPIO gpio_cam5_pn4
pinmux.0x02430048 = 0x00000000; # GPIO gpio_cam6_pn5
pinmux.0x02430050 = 0x00000000; # GPIO gpio_cam7_pn6
#chang to
pinmux.0x02430038 = 0x00000401; # gpio_cam4_pn3: spi4, tristate-disable, input-disable
pinmux.0x02430040 = 0x00000455; # gpio_cam5_pn4: spi4, pull-down, tristate-enable, input-enable
pinmux.0x02430048 = 0x00000401; # gpio_cam6_pn5: spi4, tristate-disable, input-disable
pinmux.0x02430050 = 0x00000409; # gpio_cam7_pn6: spi4, pull-up, tristate-disable, input-disable

4).rebuild and reflash kernerl and dtb,reboot.

MOSI and MISO loopback test cmd:

sudo ./spidev_test -D /dev/spidev3.0

I think my spidev_test result is failed because RX data is all “00”.

What did I miss? and how to debug this issue?

Thanks!

1 Like
3

Hi,
I figured it out, modify tegra186-mb1-bct-pinmux-quill-p3310-1000-c03.cfg and reflash tx2 to set pinmux config have no effective,only manual devmem2 to chenge pinmux REG can make spi work in my test.

4

You need totally reflash whole system image to apply new cfg.

5

A little change need totally relfash whole system image,looks like unreasonable.
devmem2 is better for me.