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>
This commit is contained in:
Marc Zyngier 2010-05-26 14:42:21 -07:00 committed by Linus Torvalds
parent 5535cb681c
commit a13c1868aa

View File

@ -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;
}