Input: adp5588-keys - get value from data out when dir is out

As discussed here: http://ez.analog.com/message/35852, the 5587 revC and
5588 revB spec sheets contain a mistake in the GPIO_DAT_STATx register
description.

According to R.Shnell at ADI, as well as my own observations, it should
read: "GPIO data status (shows GPIO state when read for inputs)".

This commit changes the get value function accordingly.
Signed-off-by: Jean-Francois Dagenais <jeff.dagenais@gmail.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/keyboard/adp5588-keys.c

@@ -76,8 +76,18 @@ static int adp5588_gpio_get_value(struct gpio_chip *chip, unsigned off)
 	struct adp5588_kpad *kpad = container_of(chip, struct adp5588_kpad, gc);
 	unsigned int bank = ADP5588_BANK(kpad->gpiomap[off]);
 	unsigned int bit = ADP5588_BIT(kpad->gpiomap[off]);
+	int val;
 
-	return !!(adp5588_read(kpad->client, GPIO_DAT_STAT1 + bank) & bit);
+	mutex_lock(&kpad->gpio_lock);
+
+	if (kpad->dir[bank] & bit)
+		val = kpad->dat_out[bank];
+	else
+		val = adp5588_read(kpad->client, GPIO_DAT_STAT1 + bank);
+
+	mutex_unlock(&kpad->gpio_lock);
+
+	return !!(val & bit);
 }
 
 static void adp5588_gpio_set_value(struct gpio_chip *chip,