path: root/Documentation
diff options
authorDoug Anderson <dianders@chromium.org>2013-01-11 17:03:50 +0000
committerChris Ball <cjb@laptop.org>2013-02-24 14:36:52 -0500
commita70aaa64da2205d32d1c9362d8f5d4be619cd58f (patch)
treea1744e9c87a2437863c707bb9ec043b5a4cebe5a /Documentation
parentmmc: correct the EXCEPTION_EVENTS_STATUS value in comment (diff)
mmc: dw_mmc: Add "disable-wp" device tree property
The "disable-wp" property is used to specify that a given SD card slot doesn't have a concept of write protect. This eliminates the need for special case code for SD slots that should never be write protected (like a micro SD slot or a dev board). The dw_mmc driver is special in needing to specify "disable-wp" because the lack of a "wp-gpios" property means to use the special purpose write protect line. On some other mmc devices the lack of "wp-gpios" means that write protect should be disabled. Signed-off-by: Doug Anderson <dianders@chromium.org> Acked-by: Seungwon Jeon <tgih.jun@samsung.com> Acked-by: Will Newton <will.newton@imgtec.com> Acked-by: Olof Johansson <olof@lixom.net> Signed-off-by: Chris Ball <cjb@laptop.org>
Diffstat (limited to 'Documentation')
1 files changed, 10 insertions, 2 deletions
diff --git a/Documentation/devicetree/bindings/mmc/synopsis-dw-mshc.txt b/Documentation/devicetree/bindings/mmc/synopsis-dw-mshc.txt
index 06cd32d08052..726fd2122a13 100644
--- a/Documentation/devicetree/bindings/mmc/synopsis-dw-mshc.txt
+++ b/Documentation/devicetree/bindings/mmc/synopsis-dw-mshc.txt
@@ -26,8 +26,16 @@ Required Properties:
* bus-width: as documented in mmc core bindings.
* wp-gpios: specifies the write protect gpio line. The format of the
- gpio specifier depends on the gpio controller. If the write-protect
- line is not available, this property is optional.
+ gpio specifier depends on the gpio controller. If a GPIO is not used
+ for write-protect, this property is optional.
+ * disable-wp: If the wp-gpios property isn't present then (by default)
+ we'd assume that the write protect is hooked up directly to the
+ controller's special purpose write protect line (accessible via
+ the WRTPRT register). However, it's possible that we simply don't
+ want write protect. In that case specify 'disable-wp'.
+ NOTE: This property is not required for slots known to always
+ connect to eMMC or SDIO cards.
Optional properties: