SPI read problem on iMX6.UL (no MISO data)

colinhelliwell — Sat, 25 Aug 2018 15:14:44 GMT

Has anyone had (and ideally solved!) problems with SPI master on the UL?

I’m using a 4.4.40 kernel, and trying a simple loopback test (MOSI shorted to MISO) with the spi_imx driver module and “spidev_test” utility.

I also have a bus analyser hooked up and this sees the data on MISO as well as MOSI, but the utility just gets zeroes back.

My board uses an SOM and I can swap the UL for a iMX6.S and it works – so I know there isn’t a wiring fault on the board. I don't think there's any significant difference in kernel config (though obviously the device trees are quite different).

I feel the device tree is probably correct, because Clk/SS/MOSI are all working; just not MISO. I have my own top-level dts for my board, but it includes the imx6ul-tx6ul.dtsi and imx6ul.dtsi from the kernel source.

Any thoughts please as to where the problem could be? Thanks.

Re: SPI read problem on iMX6.UL (no MISO data)

igorpadykov — Sun, 26 Aug 2018 23:06:24 GMT

Hi colinhelliwell

4.4.40 kernel is not supported by nxp, one can try with official nxp releases described on

i.MX Software|NXP

below example dts from L4.1.15 kernel, linux/arch/arm/boot/dts/imx6ul-14x14-evk.dts

imx6ul-14x14-evk.dts\dts\boot\arm\arch - linux-imx - i.MX Linux kernel

Best regards
igor
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i.MX ProcessorsのトピックRe: SPI read problem on iMX6.UL (no MISO data)

SPI read problem on iMX6.UL (no MISO data)

Re: SPI read problem on iMX6.UL (no MISO data)