pinctrl: as3722: fix handling of GPIO invert bit

The AS3722_GPIO_INV bit will always be blindly overwritten by
as3722_pinctrl_gpio_set_direction() and will be ignored when
setting the value of the GPIO in as3722_gpio_set() since the
enable_gpio_invert flag is never set.  This will cause an
initially inverted GPIO to toggle when requested as an output,
which could be problematic if, for example, the GPIO controls
a critical regulator.

Instead of setting up the enable_gpio_invert flag, just leave
the invert bit alone and check it before setting the GPIO value.

Cc: <stable@vger.kernel.org> # v3.14+
Signed-off-by: Andrew Bresticker <abrestic@chromium.org>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 11 insertions, 6 deletions

diff --git a/drivers/pinctrl/pinctrl-as3722.c b/drivers/pinctrl/pinctrl-as3722.c
index 92ed4b2e3c07..c862f9c0e9ce 100644
--- a/drivers/pinctrl/pinctrl-as3722.c
+++ b/drivers/pinctrl/pinctrl-as3722.c
@@ -64,7 +64,6 @@ struct as3722_pin_function {
 };
 
 struct as3722_gpio_pin_control {
-        bool enable_gpio_invert;
         unsigned mode_prop;
         int io_function;
 };
@@ -320,10 +319,8 @@ static int as3722_pinctrl_gpio_set_direction(struct pinctrl_dev *pctldev,
                 return mode;
         }
 
-        if (as_pci->gpio_control[offset].enable_gpio_invert)
-                mode |= AS3722_GPIO_INV;
-
-        return as3722_write(as3722, AS3722_GPIOn_CONTROL_REG(offset), mode);
+        return as3722_update_bits(as3722, AS3722_GPIOn_CONTROL_REG(offset),
+                                AS3722_GPIO_MODE_MASK, mode);
 }
 
 static const struct pinmux_ops as3722_pinmux_ops = {
@@ -496,10 +493,18 @@ static void as3722_gpio_set(struct gpio_chip *chip, unsigned offset,
 {
         struct as3722_pctrl_info *as_pci = to_as_pci(chip);
         struct as3722 *as3722 = as_pci->as3722;
-        int en_invert = as_pci->gpio_control[offset].enable_gpio_invert;
+        int en_invert;
         u32 val;
         int ret;
 
+        ret = as3722_read(as3722, AS3722_GPIOn_CONTROL_REG(offset), &val);
+        if (ret < 0) {
+                dev_err(as_pci->dev,
+                        "GPIO_CONTROL%d_REG read failed: %d\n", offset, ret);
+                return;
+        }
+        en_invert = !!(val & AS3722_GPIO_INV);
+
         if (value)
                 val = (en_invert) ? 0 : AS3722_GPIOn_SIGNAL(offset);
         else