In the document:
i.MX Linux® Reference Manual, Rev. 0, 07/2016 on page 237 it says:
esdhc_execute_tuning() handles the preparation for tuning. It's only used for SD3.0
UHS-I mode.
But esdhc_execute_tuning is not compiled in the kernel on the SD card that comes with the MCIMX6ULL-EVK board.
In /proc/config.gz:
# CONFIG_MMC_SDHCI_OF_ESDHC is not set
This causes the tuning code to not be compiled.
What is the reason for this? CONFIG_MMC_SDHCI_OF_ESDHC is not mentioned in:
i.MX Linux® Reference Manual, Rev. 0, 07/2016
So does this parameter not make sense for the i.MX6ULL SDIO interface?
I see that there is also the function "sdhci_execute_tuning()" in drivers/mmc/host/sdhci.c. So maybe the release notes from the Linux Reference Manual are not applicable to the i.MX6ULL which is using the driver found in "sdhci-esdhc-imx.c"?
Here is an excerpt from the Linux Reference Manual:
• The init function esdhc_pltfm_init() initializes the platform hardware and set platform
dependant flags or values to sdhci_host structure.
• The exit function esdhc_pltfm_exit() deinitializes the platform hardware and frees the
memory allocated.
• The function esdhc_pltfm_get_max_clock() gets the maximum SD bus clock frequency
supported by the platform.
• The function esdhc_pltfm_get_min_clock() gets the minimum SD bus clock frequency
supported by the platform.
• esdhc_pltfm_get_ro() gets the card read only status.
• esdhc_execute_tuning() handles the preparation for tuning. It's only used for SD3.0
UHS-I mode.
• esdhc_set_clock() handles the clock change request.
Figure below shows how the MMC-related drivers are lay
Hello,
The board is not supported but if you are playing with your own board you can add it to the kernel.
Regards