From 8ed765aac31b473e1881986d9fe2b6386f49f933 Mon Sep 17 00:00:00 2001 From: Daniel Drake Date: Sun, 25 Nov 2012 13:02:54 -0500 Subject: mmc: dt: add no-1-8-v device tree flag The OLPC XO-1.75 laptop includes a SDHCI controller which is 1.8v capable, and it truthfully reports so in its capabilities. This alternate voltage is used for driving new "UHS-I" SD cards at their full speed. However, what the controller doesn't know is that the motherboard physically doesn't have a 1.8v supply available, so attempting to switch to the 1.8v level will result in a situation that cannot be recovered from without physically replugging the SD card. Add a device tree flag that can be used on systems like these, and hook it up to the equivalent SDHCI quirk. Signed-off-by: Daniel Drake Reviewed-by: Philip Rakity Signed-off-by: Chris Ball --- Documentation/devicetree/bindings/mmc/mmc.txt | 2 ++ 1 file changed, 2 insertions(+) (limited to 'Documentation/devicetree/bindings') diff --git a/Documentation/devicetree/bindings/mmc/mmc.txt b/Documentation/devicetree/bindings/mmc/mmc.txt index b96e510979b..a591c6741d7 100644 --- a/Documentation/devicetree/bindings/mmc/mmc.txt +++ b/Documentation/devicetree/bindings/mmc/mmc.txt @@ -21,6 +21,8 @@ Optional properties: - cd-inverted: when present, polarity on the cd gpio line is inverted - wp-inverted: when present, polarity on the wp gpio line is inverted - max-frequency: maximum operating clock frequency +- no-1-8-v: when present, denotes that 1.8v card voltage is not supported on + this system, even if the controller claims it is. Optional SDIO properties: - keep-power-in-suspend: Preserves card power during a suspend/resume cycle -- cgit v1.2.3-70-g09d2