diff options
author | mario.six@gdsys.cc <mario.six@gdsys.cc> | 2016-05-25 13:15:21 (GMT) |
---|---|---|
committer | York Sun <york.sun@nxp.com> | 2016-06-04 05:13:52 (GMT) |
commit | 53ecdfb92034ce836ec94ba33ba0d8d27ea3c16c (patch) | |
tree | 22547ebd91bd1284d0a966d62743d08f307e87d8 /drivers | |
parent | 07d31f8f98fb350776c78a681ef27fd8ee288acd (diff) | |
download | u-boot-fsl-qoriq-53ecdfb92034ce836ec94ba33ba0d8d27ea3c16c.tar.xz |
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>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/gpio/gpio-uclass.c | 32 |
1 files changed, 32 insertions, 0 deletions
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 @@ 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; |