| Message ID | 20200505084318.15307-2-narmstrong@baylibre.com |
|---|---|
| State | Accepted |
| Commit | 47bd533e9dd0f967ff7b62f3edfd6c97131e1501 |
| Headers | show |
| Series | gpio: add gpio open-drain & open-source emulation | expand |
Hi Neil, +Tom Rini On Tue, 5 May 2020 at 02:43, Neil Armstrong <narmstrong at baylibre.com> wrote: > > Handle the GPIOD_OPEN_DRAIN & GPIOD_OPEN_SOURCE flags to emulate open drain > and open source by setting the GPIO line as input depending on the > requested value. > > The behaviour is taken from the Linux gpiolib. > > Signed-off-by: Neil Armstrong <narmstrong at baylibre.com> > --- > drivers/gpio/gpio-uclass.c | 15 +++++++++++++++ > 1 file changed, 15 insertions(+) > Reviewed-by: Simon Glass <sjg at chromium.org> I wonder how we should handle small increases in functionality, like this. If a board doesn't want the code-stize hit in SPL, should we have it behind a Kconfig, like CONFIG_GPIO_EXTRA? Regards, Simon
On Wed, May 06, 2020 at 08:47:20AM -0600, Simon Glass wrote: > Hi Neil, > > +Tom Rini > > On Tue, 5 May 2020 at 02:43, Neil Armstrong <narmstrong at baylibre.com> wrote: > > > > Handle the GPIOD_OPEN_DRAIN & GPIOD_OPEN_SOURCE flags to emulate open drain > > and open source by setting the GPIO line as input depending on the > > requested value. > > > > The behaviour is taken from the Linux gpiolib. > > > > Signed-off-by: Neil Armstrong <narmstrong at baylibre.com> > > --- > > drivers/gpio/gpio-uclass.c | 15 +++++++++++++++ > > 1 file changed, 15 insertions(+) > > > > Reviewed-by: Simon Glass <sjg at chromium.org> > > I wonder how we should handle small increases in functionality, like > this. If a board doesn't want the code-stize hit in SPL, should we > have it behind a Kconfig, like CONFIG_GPIO_EXTRA? I suppose it'll come down to how much growth and where.
diff --git a/drivers/gpio/gpio-uclass.c b/drivers/gpio/gpio-uclass.c index 757ab7106e..d3cea11f76 100644 --- a/drivers/gpio/gpio-uclass.c +++ b/drivers/gpio/gpio-uclass.c @@ -526,6 +526,21 @@ int dm_gpio_set_value(const struct gpio_desc *desc, int value) if (desc->flags & GPIOD_ACTIVE_LOW) value = !value; + + /* + * Emulate open drain by not actively driving the line high or + * Emulate open source by not actively driving the line low + */ + if ((desc->flags & GPIOD_OPEN_DRAIN && value) || + (desc->flags & GPIOD_OPEN_SOURCE && !value)) + return gpio_get_ops(desc->dev)->direction_input(desc->dev, + desc->offset); + else if (desc->flags & GPIOD_OPEN_DRAIN || + desc->flags & GPIOD_OPEN_SOURCE) + return gpio_get_ops(desc->dev)->direction_output(desc->dev, + desc->offset, + value); + gpio_get_ops(desc->dev)->set_value(desc->dev, desc->offset, value); return 0; }
Handle the GPIOD_OPEN_DRAIN & GPIOD_OPEN_SOURCE flags to emulate open drain and open source by setting the GPIO line as input depending on the requested value. The behaviour is taken from the Linux gpiolib. Signed-off-by: Neil Armstrong <narmstrong at baylibre.com> --- drivers/gpio/gpio-uclass.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+)