[PATCH 4.4 54/73] pinctrl: at91-pio4: fix pull-up/down logic

Greg Kroah-Hartman
2016-05-17T01:20:16Z

From: Ludovic Desroches <ludovic.desroches@atmel.com>

commit 5305a7b7e860bb40ab226bc7d58019416073948a upstream.

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@atmel.com>
Fixes: 776180848b57 ("pinctrl: introduce driver for Atmel PIO4 controller")
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/pinctrl/pinctrl-at91-pio4.c | 2 ++
1 file changed, 2 insertions(+)

--- a/drivers/pinctrl/pinctrl-at91-pio4.c
+++ b/drivers/pinctrl/pinctrl-at91-pio4.c
@@ -717,9 +717,11 @@ static int atmel_conf_pin_config_group_s
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)