[PATCH 1/4] gpiolib: implement gpiod_set_value

[Ahmad Fatoum]

Linux gpiod_set_value is silent if the GPIO descriptor is NULL, but
barebox warns about it. Also having gpio_set_value not respect active
low/high, while Linux gpiod_set_value respects it is error-prone.

Add a new gpiod_set_value function that covers this. gpio == -ENOENT is
taken as the dummy value for optional GPIOs.

Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
---
 include/gpiod.h | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/include/gpiod.h b/include/gpiod.h
index c8b2cd47a3cb..adac50b4c36d 100644
--- a/include/gpiod.h
+++ b/include/gpiod.h
@@ -14,7 +14,7 @@ enum gpiod_flags {
 	GPIOD_IN	= GPIOF_IN,
 	/*
 	 * To change this later to a different logic level (i.e. taking
-	 * active low into account), use gpio_direction_active()
+	 * active low into account), use gpiod_set_value()
 	 */
 	GPIOD_OUT_LOW	= GPIOF_OUT_INIT_INACTIVE,
 	GPIOD_OUT_HIGH	= GPIOF_OUT_INIT_ACTIVE,
@@ -23,4 +23,10 @@ enum gpiod_flags {
 /* returned gpio descriptor can be passed to any normal gpio_* function */
 int gpiod_get(struct device_d *dev, const char *_con_id, enum gpiod_flags flags);
 
+static inline void gpiod_set_value(unsigned gpio, bool value)
+{
+	if (gpio != -ENOENT)
+		gpio_direction_active(gpio, value);
+}
+
 #endif
-- 
2.30.2