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authorDavid Hendricks <dhendrix@chromium.org>2015-01-14 20:41:30 -0800
committerPatrick Georgi <pgeorgi@google.com>2015-04-17 09:21:03 +0200
commitf9b49e8782efb7628984e1f3c3abc1ef7a58b84b (patch)
tree40f9537f47a506e831e44c1bc10b467f48b45d26 /src/lib/gpio.c
parent92da778d32993b819b3a94e7b73046734647d661 (diff)
downloadcoreboot-f9b49e8782efb7628984e1f3c3abc1ef7a58b84b.tar.xz
Add delay before reading GPIOs in gpio_base2_value()
This adds a 10us delay in between (re-)configuring and reading GPIOs in gpio_base2_value() to give the values stored some time to update. As far as I know this hasn't bitten us since the function was added, but adding a short delay here seems like the right thing to do. BUG=none BRANCH=none TEST=built and booted on Brain Change-Id: I869cf375680435ad87729f93d29a623bdf09dfbc Signed-off-by: Patrick Georgi <pgeorgi@chromium.org> Original-Commit-Id: 2484900fc9ceba87220a293de8ef20c3b9b20cfd Original-Signed-off-by: David Hendricks <dhendrix@chromium.org> Original-Change-Id: I79616a09d8d2ce4e416ffc94e35798dd25a6250d Original-Reviewed-on: https://chromium-review.googlesource.com/240854 Original-Reviewed-by: Julius Werner <jwerner@chromium.org> Reviewed-on: http://review.coreboot.org/9725 Tested-by: build bot (Jenkins) Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Diffstat (limited to 'src/lib/gpio.c')
-rw-r--r--src/lib/gpio.c8
1 files changed, 6 insertions, 2 deletions
diff --git a/src/lib/gpio.c b/src/lib/gpio.c
index 0875538bae..633eabb4f5 100644
--- a/src/lib/gpio.c
+++ b/src/lib/gpio.c
@@ -26,10 +26,14 @@ int gpio_base2_value(gpio_t gpio[], int num_gpio)
{
int i, result = 0;
- for (i = 0; i < num_gpio; i++) {
+ for (i = 0; i < num_gpio; i++)
gpio_input(gpio[i]);
+
+ /* Wait until signals become stable */
+ udelay(10);
+
+ for (i = 0; i < num_gpio; i++)
result |= gpio_get(gpio[i]) << i;
- }
return result;
}