Device tree modification for iMX7 for using M4

Technical Support
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Hi,
We are developing a custom board for our product. Initially, we planned to go with iMX6 and we have completed the schematics upto 90% for iMX6 but now we are moving to iMX7 for better data acquistion using M4 controller. Our plan is, we are going to use only the SPI from M4 side and we will be sending the data to A7 using RpMSG. We are going to use only the four SPI pins.I know iMX6 and iMX7 are pin compatable. So, for using the SPI pins with M4, I need to disable the SPI bus in the device tree and make sure that the four SPI pins are not used by any other drivers from the Linux side. Is this enough or do I need to disable the whole gpio bank 4 as four of its pins are muxed with SPI pins ? I am not going to use any gpio pin from M4.

Thanks for your time,
Regards,
Nishanth

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Hi @nishanth1829!

Thanks for contacting us!

Disabling the SPI bus in the device tree and making sure the pins are unused on the Linux side should be enough. You’d only need to disable the GPIO bank if you were going to use those pins as GPIOs.

Best regards,

Gustavo

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Hi @gustavo.tx ,
Thank you.
Regards, Nishanth

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You are welcome.

Best regards,
Jaski