mmc: fsl_esdhc: workaround for hardware 3.3v IO reliability issue

[oweals/u-boot.git] / drivers / mmc / Kconfig

diff --git a/drivers/mmc/Kconfig b/drivers/mmc/Kconfig
index 3c4f057373fce6d4f89c9809c5012f55bd7d7fb9..8f56572c39a00c46be9861bfbfab23124f2157f0 100644 (file)
--- a/drivers/mmc/Kconfig
+++ b/drivers/mmc/Kconfig
@@ -727,6 +727,21 @@ config FSL_ESDHC
          This selects support for the eSDHC (Enhanced Secure Digital Host
          Controller) found on numerous Freescale/NXP SoCs.
 
+config FSL_ESDHC_33V_IO_RELIABILITY_WORKAROUND
+       bool "enable eSDHC workaround for 3.3v IO reliability issue"
+       depends on FSL_ESDHC && DM_MMC
+       default n
+       help
+         When eSDHC operates at 3.3v, damage can accumulate in an internal
+         level shifter at a higher than expected rate. The faster the interface
+         runs, the more damage accumulates. This issue now is found on LX2160A
+         eSDHC1 for only SD card. The hardware workaround is recommended to use
+         an on-board level shifter that is 1.8v on SoC side and 3.3v on SD card
+         side. For boards without hardware workaround, this option could be
+         enabled, ensuring 1.8v IO voltage and disabling eSDHC if no card.
+         This option assumes no hotplug, and u-boot has to make all the way to
+         to linux to use 1.8v UHS-I speed mode if has card.
+
 config FSL_ESDHC_IMX
        bool "Freescale/NXP i.MX eSDHC controller support"
        help