[PATCH] pinctrl: at91-pio4: fix pull-up/down logic

From: Ludovic Desroches
Date: Tue Apr 19 2016 - 10:03:24 EST


The default configuration of a pin is often with a value in the
pull-up/down field at chip reset. So, even if the internal logic of the
controller prevents writing a configuration with pull-up and pull-down at
the same time, we must ensure explicitly this condition before writing the
register.

This was leading to a pull-down condition not taken into account for
instance.

Signed-off-by: Ludovic Desroches <ludovic.desroches@xxxxxxxxx>
Fixes: 776180848b57 ("pinctrl: introduce driver for Atmel PIO4 controller")
Cc: stable@xxxxxxxxxxxxxxx #v4.4 and later
---
drivers/pinctrl/pinctrl-at91-pio4.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/pinctrl/pinctrl-at91-pio4.c b/drivers/pinctrl/pinctrl-at91-pio4.c
index 629b6fe..75093d7 100644
--- a/drivers/pinctrl/pinctrl-at91-pio4.c
+++ b/drivers/pinctrl/pinctrl-at91-pio4.c
@@ -722,9 +722,11 @@ static int atmel_conf_pin_config_group_set(struct pinctrl_dev *pctldev,
break;
case PIN_CONFIG_BIAS_PULL_UP:
conf |= ATMEL_PIO_PUEN_MASK;
+ conf &= (~ATMEL_PIO_PDEN_MASK);
break;
case PIN_CONFIG_BIAS_PULL_DOWN:
conf |= ATMEL_PIO_PDEN_MASK;
+ conf &= (~ATMEL_PIO_PUEN_MASK);
break;
case PIN_CONFIG_DRIVE_OPEN_DRAIN:
if (arg == 0)
--
2.5.0