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authorMarc Zyngier <maz@misterjones.org>2010-05-26 14:42:21 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-05-27 09:12:41 -0700
commita13c1868aa60ae7a2516b8d00ee8873dea587581 (patch)
treea90f714d48a3e076ef9093d5eb584e5655fbd5bd
parent5535cb681c38bda94af02ef4b043a25b52303e65 (diff)
downloadlinux-a13c1868aa60ae7a2516b8d00ee8873dea587581.tar.bz2
gpio: max732x: fix input configuration for open-drain pins
Fix a bug I noticed while hacking on the max732x driver for interrupt support. According to the datasheets, open-drain pins have to be configured as output-high (which in that case is actually high impedance) to be used as input. Signed-off-by: Marc Zyngier <maz@misterjones.org> Acked-by: Eric Miao <eric.y.miao@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--drivers/gpio/max732x.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/gpio/max732x.c b/drivers/gpio/max732x.c
index 26ff40110d9f..9cad60f9e962 100644
--- a/drivers/gpio/max732x.c
+++ b/drivers/gpio/max732x.c
@@ -232,6 +232,13 @@ static int max732x_gpio_direction_input(struct gpio_chip *gc, unsigned off)
return -EACCES;
}
+ /*
+ * Open-drain pins must be set to high impedance (which is
+ * equivalent to output-high) to be turned into an input.
+ */
+ if ((mask & chip->dir_output))
+ max732x_gpio_set_value(gc, off, 1);
+
return 0;
}