diff options
| author | Doug Anderson <dianders@chromium.org> | 2013-01-11 18:03:50 +0100 |
|---|---|---|
| committer | Chris Ball <cjb@laptop.org> | 2013-02-24 20:36:52 +0100 |
| commit | a70aaa64da2205d32d1c9362d8f5d4be619cd58f (patch) | |
| tree | a1744e9c87a2437863c707bb9ec043b5a4cebe5a /Documentation | |
| parent | mmc: correct the EXCEPTION_EVENTS_STATUS value in comment (diff) | |
| download | linux-a70aaa64da2205d32d1c9362d8f5d4be619cd58f.tar.xz linux-a70aaa64da2205d32d1c9362d8f5d4be619cd58f.zip | |
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')
| -rw-r--r-- | Documentation/devicetree/bindings/mmc/synopsis-dw-mshc.txt | 12 |
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: |