[RFC v2 1/2] sdhci: Add device tree property broken-highspeed
From: Zach Brown
Date: Wed Oct 12 2016 - 14:41:29 EST
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
The broken-highspeed property will let the sdhci driver know that
highspeed will not work.
Signed-off-by: Zach Brown <zach.brown@xxxxxx>
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
@@ -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"