mmc: tegra: allow disabling external clock loopback
Introduce CONFIG_TEGRA124_MMC_DISABLE_EXT_LOOPBACK to disable the external clock
loopback and use the internal one on SDMMC3 as per the SDMMC_VENDOR_MISC_CNTRL_0
register's SDMMC_SPARE1 bits being set to 0xfffd according to the TRM.
Signed-off-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Acked-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Marcel Ziswiler <marcel@ziswiler.com>
Signed-off-by: Tom Warren <twarren@nvidia.com>
diff --git a/drivers/mmc/Kconfig b/drivers/mmc/Kconfig
index 05e0b10..560391f 100644
--- a/drivers/mmc/Kconfig
+++ b/drivers/mmc/Kconfig
@@ -367,6 +367,17 @@
endif
+config TEGRA124_MMC_DISABLE_EXT_LOOPBACK
+ bool "Disable external clock loopback"
+ depends on MMC_SDHCI_TEGRA && TEGRA124
+ help
+ Disable the external clock loopback and use the internal one on SDMMC3
+ as per the SDMMC_VENDOR_MISC_CNTRL_0 register's SDMMC_SPARE1 bits
+ being set to 0xfffd according to the TRM.
+
+ TODO(marcel.ziswiler@toradex.com): Move to device tree controlled
+ approach once proper kernel integration made it mainline.
+
endmenu
config SYS_FSL_ERRATUM_ESDHC111