pinctrl: baytrail: show output gpio state correctly on Intel Baytrail

commit d90c3381 upstream.

Even if a gpio pin is set to output, we still need to set INPUT_EN
functionality (by clearing INPUT_EN bit) to be able to read the pin's
level.

E.g. without this change, we'll always read low level state from sysfs.

Cc: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: David Cohen <david.a.cohen@linux.intel.com>
Reviewed-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
[ luis: backported to 3.16: adjusted context ]
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

drivers/pinctrl/pinctrl-baytrail.c

@@ -310,7 +310,7 @@ static int byt_gpio_direction_output(struct gpio_chip *chip,
 	spin_lock_irqsave(&vg->lock, flags);
 
 	reg_val = readl(reg) | BYT_DIR_MASK;
-	reg_val &= ~BYT_OUTPUT_EN;
+	reg_val &= ~(BYT_OUTPUT_EN | BYT_INPUT_EN);
 
 	if (value)
 		writel(reg_val | BYT_LEVEL, reg);