gpio: palmas: Fix misreported GPIO out value

It seems that the value read back from the PALMAS_GPIO_DATA_IN register
isn't valid if the GPIO direction is out.  When that's the case, we can
read back the PALMAS_GPIO_DATA_OUT register to get the proper output value.

Signed-off-by: Andrew Chew <achew@nvidia.com>
Acked-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

diff --git a/drivers/gpio/gpio-palmas.c b/drivers/gpio/gpio-palmas.c
index 09360c4..8588af0 100644 (file)
--- a/drivers/gpio/gpio-palmas.c
+++ b/drivers/gpio/gpio-palmas.c
@@ -43,9 +43,22 @@ static int palmas_gpio_get(struct gpio_chip *gc, unsigned offset)
        unsigned int val;
        int ret;
 
-       ret = palmas_read(palmas, PALMAS_GPIO_BASE, PALMAS_GPIO_DATA_IN, &val);
+       ret = palmas_read(palmas, PALMAS_GPIO_BASE, PALMAS_GPIO_DATA_DIR, &val);
        if (ret < 0) {
-               dev_err(gc->dev, "GPIO_DATA_IN read failed, err = %d\n", ret);
+               dev_err(gc->dev, "GPIO_DATA_DIR read failed, err = %d\n", ret);
+               return ret;
+       }
+
+       if (val & (1 << offset)) {
+               ret = palmas_read(palmas, PALMAS_GPIO_BASE,
+                                 PALMAS_GPIO_DATA_OUT, &val);
+       } else {
+               ret = palmas_read(palmas, PALMAS_GPIO_BASE,
+                                 PALMAS_GPIO_DATA_IN, &val);
+       }
+       if (ret < 0) {
+               dev_err(gc->dev, "GPIO_DATA_IN/OUT read failed, err = %d\n",
+                       ret);
                return ret;
        }
        return !!(val & BIT(offset));