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| author | Felix Ekblom <felixe@chromium.org> | 2019-11-15 11:44:46 +0100 |
|---|---|---|
| committer | Commit Bot <commit-bot@chromium.org> | 2019-11-27 11:25:15 +0000 |
| commit | 93805b9b52f7f8daf616b0d1f90f01bba4a545f8 (patch) | |
| tree | b633bcc2baa6ef68cc8fc7d31555cc892661e467 | |
| parent | 9496abb082a4ec60ab740e093fe09f56ceec7cd2 (diff) | |
| download | chrome-ec-93805b9b52f7f8daf616b0d1f90f01bba4a545f8.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>
(cherry picked from commit e73c807595eba1bc1a1b575fb12f252522cffca3)
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/1930553
| -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 a11fe42645..f625c1d699 100644 --- a/chip/npcx/cec.c +++ b/chip/npcx/cec.c @@ -1160,6 +1160,9 @@ 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); |