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author | Randall Spangler <rspangler@chromium.org> | 2013-10-08 12:31:05 -0700 |
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committer | chrome-internal-fetch <chrome-internal-fetch@google.com> | 2013-10-11 03:58:05 +0000 |
commit | a1191b92d2f5784e2f4e1c5f40d4af1a41e55fda (patch) | |
tree | 1d37faaa2c4636eb414c7b1a382f30cf866d63ec /include | |
parent | 27e063ea100086a913ed655b611c88e077de5b00 (diff) | |
download | chrome-ec-a1191b92d2f5784e2f4e1c5f40d4af1a41e55fda.tar.gz |
rambi: Keyboard output column 2 must be inverted
The Silego chip used on Rambi inverts column 2. So the EC should pull the signal low when NOT scanning column 2, and release it at all other times.
BUG=chrome-os-partner:23198
BRANCH=none
TEST=not yet; need to probe on scope
Change-Id: If6a784493533f11ae54d18f27591697e69aa2282
Signed-off-by: Randall Spangler <rspangler@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/172674
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Diffstat (limited to 'include')
-rw-r--r-- | include/config.h | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/include/config.h b/include/config.h index 09478a1557..21821100a7 100644 --- a/include/config.h +++ b/include/config.h @@ -426,6 +426,14 @@ /*****************************************************************************/ /* Keyboard config */ +/* + * The Silego reset chip sits in between the EC and the physical keyboard on + * column 2. To save power in low-power modes, some Silego variants require + * the signal to be inverted so that the open-drain output from the EC isn't + * costing power due to the pull-up resistor in the Silego. + */ +#undef CONFIG_KEYBOARD_COL2_INVERTED + /* Enable extra debugging output from keyboard modules */ #undef CONFIG_KEYBOARD_DEBUG |