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| author | Felix Ekblom <felixe@chromium.org> | 2019-11-15 11:44:46 +0100 |
|---|---|---|
| committer | Commit Bot <commit-bot@chromium.org> | 2019-11-22 09:50:07 +0000 |
| commit | e73c807595eba1bc1a1b575fb12f252522cffca3 (patch) | |
| tree | 9463ec627dce349fe01c36ee7d95d30c83340f22 | |
| parent | 1503fa64670763133409d7b3fd59a91a7a28171d (diff) | |
| download | chrome-ec-e73c807595eba1bc1a1b575fb12f252522cffca3.tar.gz | |
Ensure CEC bus pin is not driven low
We have seen cases where after a cold EC reboot the pin is low until the
first CEC message is sent by AP (after which the bus is left in a well
defined state again)
This is a follow up to https://crrev.com/c/1346990 which initializes
the pull up in case not done by the RO FW.
BRANCH=none
BUG=b:144548408
TEST=CEC pin only goes low for ~40ms instead of 30s.
Signed-off-by: Felix Ekblom <felixe@chromium.org>
Change-Id: I3c98f8858f407279ad1bd086210969d69df2230b
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/1928993
Reviewed-by: Daisuke Nojiri <dnojiri@chromium.org>
| -rw-r--r-- | chip/npcx/cec.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/chip/npcx/cec.c b/chip/npcx/cec.c index effbf6bd46..b41e36e127 100644 --- a/chip/npcx/cec.c +++ b/chip/npcx/cec.c @@ -1006,6 +1006,9 @@ static void cec_init(void) /* If RO doesn't set it, RW needs to set it explicitly. */ gpio_set_level(CEC_GPIO_PULL_UP, 1); + /* Ensure the CEC bus is not pulled low by default on startup. */ + gpio_set_level(CEC_GPIO_OUT, 1); + CPRINTS("CEC initialized"); } DECLARE_HOOK(HOOK_INIT, cec_init, HOOK_PRIO_LAST); |