dm: gpio: Add methods for open drain setting
Certain GPIO devices have the capability to switch their GPIOs into
open-drain mode, that is, instead of actively driving the output
(Push-pull output), the pin is connected to the collector (for a NPN
transistor) or the drain (for a MOSFET) of a transistor, respectively.
The pin then either forms an open circuit or a connection to ground,
depending on the state of the transistor.
This patch adds functions to the GPIO uclass to switch GPIOs to
open-drain mode on devices that support it.
Signed-off-by: Mario Six <mario.six@gdsys.cc>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: York Sun <york.sun@nxp.com>
diff --git a/drivers/gpio/gpio-uclass.c b/drivers/gpio/gpio-uclass.c
index 732b6c2..4559739 100644
--- a/drivers/gpio/gpio-uclass.c
+++ b/drivers/gpio/gpio-uclass.c
@@ -367,6 +367,38 @@
return 0;
}
+int dm_gpio_get_open_drain(struct gpio_desc *desc)
+{
+ struct dm_gpio_ops *ops = gpio_get_ops(desc->dev);
+ int ret;
+
+ ret = check_reserved(desc, "get_open_drain");
+ if (ret)
+ return ret;
+
+ if (ops->set_open_drain)
+ return ops->get_open_drain(desc->dev, desc->offset);
+ else
+ return -ENOSYS;
+}
+
+int dm_gpio_set_open_drain(struct gpio_desc *desc, int value)
+{
+ struct dm_gpio_ops *ops = gpio_get_ops(desc->dev);
+ int ret;
+
+ ret = check_reserved(desc, "set_open_drain");
+ if (ret)
+ return ret;
+
+ if (ops->set_open_drain)
+ ret = ops->set_open_drain(desc->dev, desc->offset, value);
+ else
+ return 0; /* feature not supported -> ignore setting */
+
+ return ret;
+}
+
int dm_gpio_set_dir_flags(struct gpio_desc *desc, ulong flags)
{
struct udevice *dev = desc->dev;