Using SRAM on SPI interface on IMX6UL

[justinwave]

Hello,

I have a custom board designed off the IMX6UL EVK board and what to access SRAM loacted on the SPI interface. The SRAM chip is the 23LC1024 and am using the 4.9.11_1.0.0_ga kernel. I was unable to find a driver for the SRAM and am unsure of how to configure it in the device tree and then how to read and write to it from user space.

In the device tree, what should I set the the compatible field to? Should it be "mtd-ram", "spidev" or "mmio-ram"?

Also, how then would I access the SRAM from a user space application?

Any help is greatly appreciated, thank you.

[igorpadykov · Accepted solution]

Hi justinwave

one can look at general linux guidelines

F-RAM Support under Linux – KBA223028 | Cypress Developer Community 

[PATCH] mtd: mchp23k256: Add driver for this SPI SRAM device 

and NXP spi-nor driver description found in linux documentation on

https://www.nxp.com/support/developer-resources/run-time-software/i.mx-developer-resources/i.mx-6ser...

Best regards
igor
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[justinwave]

Igor, thank you for the links. The patch for the mchp23k256 has been accepted and add to the mainline kernel. I was able to use this as a reference for a driver on the fsl 4.9 kernel.

Thank you.