[PATCH] gpio: sunxi: Don't clear pull settings when setting input

[James Hilliard]

sunxi_gpio_set_flags() always programs the pull register when
switching a pin to input. When neither GPIOD_PULL_UP nor
GPIOD_PULL_DOWN is requested, this writes 0 (pull disabled)
and can clobber an existing bias configuration applied via pinctrl.

Only update the pull configuration when a pull-up or pull-down is
explicitly requested, leaving existing pull settings unchanged.

Fixes: 35ae126c16a6 ("gpio: sunxi: Implement .set_flags")
Signed-off-by: James Hilliard <james.hilliard1 at gmail.com>
---
 drivers/gpio/sunxi_gpio.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpio/sunxi_gpio.c b/drivers/gpio/sunxi_gpio.c
index 094c45a6927..ad891da3a97 100644
--- a/drivers/gpio/sunxi_gpio.c
+++ b/drivers/gpio/sunxi_gpio.c
@@ -301,7 +301,8 @@ static int sunxi_gpio_set_flags(struct udevice *dev, unsigned int offset,
 			pull = 1;
 		else if (flags & GPIOD_PULL_DOWN)
 			pull = 2;
-		sunxi_gpio_set_pull_bank(plat->regs, offset, pull);
+		if (pull)
+			sunxi_gpio_set_pull_bank(plat->regs, offset, pull);
 		sunxi_gpio_set_cfgbank(plat->regs, offset, SUNXI_GPIO_INPUT);
 	}
 
-- 
2.43.0