SK-AM69: MCU_SPI1 failed to RX.

Minsoo Sun

Part Number: SK-AM69

Tool/software:

Hello, Ti.

I set the MCU_SPI1_* pins as SPI Master and connected to SPI sensors to test out SPI functions.

I used spidev_test command to read sensor(ADXL345) ID (which should be 0xE0).
I checked MISO line with oscilloscope and the sensor replied with 0xE0.
But the result shows it received 0x00.

Here is device tree I use for testing (only partial)

&wkup_pmx2 {
    bootph-all;
    fpga_card_spi_pins: fpga-card-spi-pins {
	    bootph-all;
        pinctrl-single,pins = <
            J784S4_WKUP_IOPAD(0x058, PIN_INPUT, 0) /* (H38) WKUP_GPIO0_0.MCU_SPI1_CLK */	/* CARD_SPI_CLK */
            J784S4_WKUP_IOPAD(0x064, PIN_INPUT, 0) /* (J36) WKUP_GPIO0_3.MCU_SPI1_CS0 */	/* CARD_SPI_CS0 */
            J784S4_WKUP_IOPAD(0x094, PIN_INPUT, 1) /* (K37) WKUP_GPIO0_15.MCU_SPI1_CS2 */	/* CARD_SPI_CS1 */
            J784S4_WKUP_IOPAD(0x05c, PIN_INPUT, 0) /* (J34) WKUP_GPIO0_1.MCU_SPI1_D0 */	/* CARD_SPI_AP_OUT */
            J784S4_WKUP_IOPAD(0x060, PIN_INPUT, 0) /* (J35) WKUP_GPIO0_2.MCU_SPI1_D1 */	/* CARD_SPI_AP_IN */
        >;
    };
};

&mcu_spi1 {
	status = "okay";

	pinctrl-names = "default";
	pinctrl-0 = <&fpga_card_spi_pins>;

	spi-max-frequency = <50000000>;
	ti,pindir-d0-out-d1-in;

	test@0 {
		compatible = "rohm,dh2228fv";
		reg = <0>;
		spi-max-frequency = <50000000>;
		status = "okay";
		spi-cpha;
		spi-cpol;
	};
};

As I could decode the signal from both MOSI and MISO line on oscilloscope, the HW is not the issue.

I also found a record that there is similar problem on the TDA4VM board.
Referring to the mentioned record and the following information found in the TRM, it appears that MCU_MCSPI1 is internally connected to MCSPI3.
From what I understand, to connect MCU_MCSPI1 to I/O, the MCU_SPI_CTRL[SPI_LINKDIS] register needs to be configured.