lib: utils/gpio: respect flag GPIO_FLAG_ACTIVE_LOW

"gpio-poweroff" and "gpio-restart" always set gpio to high to
active the function, but some chips need a low signal to active.
Fortunately, it can be achieved by setting GPIO_FLAG_ACTIVE_LOW
for the gpio. Implement this flag support for the gpio library
so the gpio reset can function well.

Signed-off-by: Inochi Amaoto <inochiama@outlook.com>
Reviewed-by: Anup Patel <anup@brainfault.org>

diff --git a/lib/utils/gpio/gpio.c b/lib/utils/gpio/gpio.c
index 3a3a6b24a7b20b28f111e191a729ab970274f6d0..6ffe929087891ac596aeb055abfacbd87e9f464a 100644 (file)
--- a/lib/utils/gpio/gpio.c
+++ b/lib/utils/gpio/gpio.c
@@ -73,17 +73,26 @@ int gpio_direction_output(struct gpio_pin *gp, int value)
        if (!gp->chip->direction_output)
                return SBI_ENOSYS;
 
+       if (gp->flags & GPIO_FLAG_ACTIVE_LOW)
+               value = value == 0 ? 1 : 0;
+
        return gp->chip->direction_output(gp, value);
 }
 
 int gpio_get(struct gpio_pin *gp)
 {
+       int value;
+
        if (!gp || !gp->chip || (gp->chip->ngpio <= gp->offset))
                return SBI_EINVAL;
        if (!gp->chip->get)
                return SBI_ENOSYS;
 
-       return gp->chip->get(gp);
+       value = gp->chip->get(gp);
+
+       if (gp->flags & GPIO_FLAG_ACTIVE_LOW)
+               value = value == 0 ? 1 : 0;
+       return value;
 }
 
 int gpio_set(struct gpio_pin *gp, int value)
@@ -93,6 +102,9 @@ int gpio_set(struct gpio_pin *gp, int value)
        if (!gp->chip->set)
                return SBI_ENOSYS;
 
+       if (gp->flags & GPIO_FLAG_ACTIVE_LOW)
+               value = value == 0 ? 1 : 0;
+
        gp->chip->set(gp, value);
        return 0;
 }