Use nrfx QSPI with Zephyr filesystem

Question

I'm using Zephyr on a nRF52840 and I'd like to use the QSPI with the Fat Filesystem. I added the following Config statements to prj.conf: 
 # Filesystem
CONFIG_FILE_SYSTEM=y
CONFIG_FAT_FILESYSTEM_ELM=y
CONFIG_NRFX_QSPI=y
CONFIG_DISK_ACCESS=y
CONFIG_DISK_ACCESS_SDHC=y
CONFIG_DISK_ACCESS_SPI_SDHC=y 
 The nrfx QSPI driver and file system code is then included in the build, but I'm unsure how to associate the QSPI with the filesystem. I don't see a "CONFIG_DISK_ACCESS_QSPI_SDHC" to replace the "CONFIG_DISK_ACCESS_SPI_SDHC". Or is there a different way to do this that I'm missing? 
 Thanks!

CktDesigner · Accepted Answer

After doing a lot of reading, I determined that it is not possible to control an SDcard using QSPI. While they are very similar, QSPI transmits command over the D0 signal while SDcard uses a separate CMD signal (for both command and response). I thought that perhaps there might be a way to connect D0 to CMD, but I don't see a way to retrieve the command response using the QSPI setup.

Simon · Answer

It does not seem like it's possible to use QSPI with an SD Card, after browsing through DevZone. I'll copy in another answer I found: 
 "Using SD card in any other modes than SPI would require a licence from the SD card association, link . Even if we had such an example, we wouldn't be allowed to publish it. Hence only SPI examples are shown for SD Cards." 
 Would using SPI be an option for you? 
 Best regards, 
 Simon

Use nrfx QSPI with Zephyr filesystem

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