Certain board configurations can make highspeed malfuction due to timing issues. In these cases a way is needed to force the controller and card into standard speed even if they otherwise appear to be capable of highspeed.
The broken-highspeed property will let the sdhci driver know that highspeed will not work. Signed-off-by: Zach Brown <zach.br...@ni.com> --- Documentation/devicetree/bindings/mmc/mmc.txt | 2 ++ 1 file changed, 2 insertions(+) diff --git a/Documentation/devicetree/bindings/mmc/mmc.txt b/Documentation/devicetree/bindings/mmc/mmc.txt index 8a37782..a2b298c 100644 --- a/Documentation/devicetree/bindings/mmc/mmc.txt +++ b/Documentation/devicetree/bindings/mmc/mmc.txt @@ -52,6 +52,8 @@ Optional properties: - no-sdio: controller is limited to send sdio cmd during initialization - no-sd: controller is limited to send sd cmd during initialization - no-mmc: controller is limited to send mmc cmd during initialization +- broken-highspeed: Highspeed is broken, even if the controller and card + themselves claim they support highspeed. *NOTE* on CD and WP polarity. To use common for all SD/MMC host controllers line polarity properties, we have to fix the meaning of the "normal" and "inverted" -- 2.7.4