[PATCH 1/2] gpiolib: of: Improve gpiolib-of support pull up/down on expanders

From: Adam Ford
Date: Sat Apr 11 2020 - 21:34:03 EST


When using GPIO expanders attached to I2C ports, their set_config function
needs to be passed a config setting which contains options to enable pull
up or pull down bias feature. In order to set this config properly,
the gpio parser needs to handle GPIO_PULL_UP and GPIO_PULL_DOWN.

This patch enables the flags corresponding to GPIO_PULL_UP and
GPIO_PULL_DOWN.

Signed-off-by: Adam Ford <aford173@xxxxxxxxx>

diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
index c6d30f73df07..bf17afb1f66d 100644
--- a/drivers/gpio/gpiolib-of.c
+++ b/drivers/gpio/gpiolib-of.c
@@ -344,6 +344,12 @@ struct gpio_desc *gpiod_get_from_of_node(struct device_node *node,
if (transitory)
lflags |= GPIO_TRANSITORY;

+ if (flags & OF_GPIO_PULL_UP)
+ lflags |= GPIO_PULL_UP;
+
+ if (flags & OF_GPIO_PULL_DOWN)
+ lflags |= GPIO_PULL_DOWN;
+
ret = gpiod_configure_flags(desc, propname, lflags, dflags);
if (ret < 0) {
gpiod_put(desc);
@@ -585,6 +591,10 @@ static struct gpio_desc *of_parse_own_gpio(struct device_node *np,
*lflags |= GPIO_ACTIVE_LOW;
if (xlate_flags & OF_GPIO_TRANSITORY)
*lflags |= GPIO_TRANSITORY;
+ if (xlate_flags & OF_GPIO_PULL_UP)
+ *lflags |= GPIO_PULL_UP;
+ if (xlate_flags & OF_GPIO_PULL_DOWN)
+ *lflags |= GPIO_PULL_DOWN;

if (of_property_read_bool(np, "input"))
*dflags |= GPIOD_IN;
--
2.25.1