From 53ecdfb92034ce836ec94ba33ba0d8d27ea3c16c Mon Sep 17 00:00:00 2001 From: "mario.six@gdsys.cc" Date: Wed, 25 May 2016 15:15:21 +0200 Subject: 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 Reviewed-by: Simon Glass Reviewed-by: York Sun --- drivers/gpio/gpio-uclass.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) (limited to 'drivers') diff --git a/drivers/gpio/gpio-uclass.c b/drivers/gpio/gpio-uclass.c index 732b6c2afa..4559739d61 100644 --- a/drivers/gpio/gpio-uclass.c +++ b/drivers/gpio/gpio-uclass.c @@ -367,6 +367,38 @@ int dm_gpio_set_value(const struct gpio_desc *desc, int value) 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; -- cgit v1.2.1