SPI on Xavier NX #1223
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Hi! I'm trying to use the SPI pins on the 40 pin header on a Xavier NX carrierboard (the pinout is the same as a devkit), I'm using the emmc versions of the NX modules. I have added
in /dev. I have put a strap from pin 19 to 21 and run spidev-test but I get no data:
I have these lines in my dtsi
What do I need to do to make spi work? Edit: I have also seen the issues regarding jetson nano to get spi to work but those seem specific to jetson nano? And I'm not sure how or if to add similar patches for xavier nx? |
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Replies: 2 comments · 4 replies
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Which branch and L4T version are you based off of, and have you checked that the pinmux configuration is correctly connecting those pins to the SPI controlller? |
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I'm on dunfell and L4T 32.7.3. I'm not quite sure how to check that? Would that be in tegra194-p3668-all-p3509-0000-hdr40.dts? |
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Or do you mean how they are physically connected? If so yes, it's identical to the devkit in that regard. |
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I decompiled the device tree (I think) with
|
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You can examine the pin assignments by looking at the files under
to verify that the pins have been assigned to the SPI controller. If you don't see the above, then the pins need to be configured. And, it turns out, the pins are not configured for the 40-pin header with the default pin configuration (which I didn't know until I saw this JetsonHacks page). If you add
to your |
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Thank you so much! This solves the problem, I saw the tegra194-p3668-all-p3509-0000-hdr40 file before and saw it had the right settings but I did not know it was not being applied. |
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You can examine the pin assignments by looking at the files under
/sys/kernel/debug/pinctrl
. Specifically for these pins, you can do:to verify that t…