[SOLVED] need spi slave in up board

peterzhang

hi everyone,
I am going to play up board for yocto. I need use spi as slave mode.
I want to know :
1.how to enable spi slave mode in device tree (DTB)?
2. is there a linux driver for spi slave mode?

Thank you very much for your reply.

ccalde

Hi @peterzhang ,

Unfortunately, SPI slave mode is not supported for UP boards.

peterzhang

@ccalde said:
Hi @peterzhang ,

Unfortunately, SPI slave mode is not supported for UP boards.

hi @ccalde
thank you very much for your reply so soon.

you mean I absolutely can not use spi slave mode in upboards?
I mean can I write a linux spi slave driver to make it work?

or the microprocessor can not support the spi slave mode at all?
or there is no connections in upboards?

anyway, if upboards can not use spi slave mode. do you have any board to support spi slave mode in linux yocto? my project need spi slave in linux.

Thank you very much for your reply.

ccalde

Hi @peterzhang ,

SPI slave is not included for UP board kernel.
The microprocessor supports the slave mode. Please check here the datasheet:
https://wiki.up-community.org/Hardware_Specification#Processor

Also, for the pin configuration, please visit the pinout Wiki page for UP board:
https://wiki.up-community.org/Pinout

peterzhang

@caldera said:
Hi @peterzhang ,

SPI slave is not included for UP board kernel.
The microprocessor supports the slave mode. Please check here the datasheet:
https://wiki.up-community.org/Hardware_Specification#Processor

Also, for the pin configuration, please visit the pinout Wiki page for UP board:
https://wiki.up-community.org/Pinout

hi @caldera
Thank you very much for your reply so soon.
yes, I find 1.the microprocessor supports the slave mode. and 2. there are two spi (cs0 and cs1) in UPboard., the PINs(connections) are there. normally the current UP board kernel support only spi master mode.

so is it possible for me to write a spi slave driver to make it as spi slave? of course,it's hard to write a spi slave driver from scratch ,

but I have no choice. I tried nxp Imx6,imx7 boards.but spi slave is not working properly in imx6,imx7. only raspberry pi works well.but raspberry pi only for demo. we can not apply it for productions.

so I am going to try use Upboards.

do you know some other boards can work well for spi slave? I am looking for more boards.

Thank you for your reply.

peterzhang

@caldera
one more questions: if I change spi to slave mode. do I need change bios ? or do need change dtb(device tree). It seems there is no dtb for intel microprocessor, only bios ?
Thanks

ccalde

Hi,

No, you can not switch to slave mode via BIOS as that was developed for master mode only.

peterzhang

@ccalde said:
Hi,

No, you can not switch to slave mode via BIOS as that was developed for master mode only.

thanks. I got it.so I have to change a different board.