[RFC 1/2] mmc: sdhci: dt: Add device tree properties sdhci-caps and sdhci-caps-mask

[Zach Brown <zach.brown@ni.com>]

On some systems the sdhci capabilty registers are incorrect for one
reason or another.

The sdhci-caps-mask property specifies which bits in the registers
are incorrect and should be turned off before using sdhci-caps to turn
on bits.

The sdhci-caps property specifies which bits should be turned on.

Signed-off-by: Zach Brown <zach.brown@ni.com>
---
 Documentation/devicetree/bindings/mmc/mmc.txt | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/Documentation/devicetree/bindings/mmc/mmc.txt b/Documentation/devicetree/bindings/mmc/mmc.txt
index 8a37782..1415aa0 100644
--- a/Documentation/devicetree/bindings/mmc/mmc.txt
+++ b/Documentation/devicetree/bindings/mmc/mmc.txt
@@ -52,6 +52,13 @@ 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
+- sdhci-caps-mask: The sdhci capabilities registers are incorrect. This 64bit
+  property corresponds to the bits in the sdhci capabilty registers. If the bit
+  is on in the mask then the bit is incorrect in the registers and should be
+  turned off.
+- sdhci-caps: The sdhci capabilities registers are incorrect. This 64bit
+  property corresponds to the bits in the sdhci capability registers. If the
+  bit is on in the property then the bit should be on in the reigsters.
 
 *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