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authorYangbo Lu <yangbo.lu@nxp.com>2020-05-19 11:06:44 +0800
committerPeng Fan <peng.fan@nxp.com>2020-06-15 09:45:22 +0800
commitc927d65873c7706f436ab59a78d44a0eb80fe939 (patch)
treed3842f37f3043195eae78172d2458cde39fdc690 /drivers/mmc/Kconfig
parent9abf648436b49553e6cb4a7f03a021720616d75b (diff)
mmc: fsl_esdhc: workaround for hardware 3.3v IO reliability issue
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. If you do not want the workaround for better user experience, of course you can choose to not select it running eSDHC in unsafe mode. Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com> Acked-by: Peng Fan <peng.fan@nxp.com>
Diffstat (limited to 'drivers/mmc/Kconfig')
-rw-r--r--drivers/mmc/Kconfig15
1 files changed, 15 insertions, 0 deletions
diff --git a/drivers/mmc/Kconfig b/drivers/mmc/Kconfig
index 3c4f057373..8f56572c39 100644
--- 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