gpiolib: Show correct direction from the beginning

mainline inclusion
from mainline-v4.20-rc1
commit 3edfb7bd76bd1cba6b917736943dffd799deed8a
category: bugfix
bugzilla: 14225
CVE: NA

-------------------------------------------------

Current code assumes that the direction is input if direction_input
function is set.
This might not be the case on GPIOs with programmable direction.
Signed-off-by: NRicardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Tested-by: NJeffrey Hugo <jhugo@codeaurora.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
Reviewed-by: NHanjun Guo <guohanjun@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

drivers/gpio/gpiolib.c

@@ -1361,20 +1361,6 @@ int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data,
 
 	spin_unlock_irqrestore(&gpio_lock, flags);
 
-	for (i = 0; i < chip->ngpio; i++) {
-		struct gpio_desc *desc = &gdev->descs[i];
-
-		desc->gdev = gdev;
-
-		/* REVISIT: most hardware initializes GPIOs as inputs (often
-		 * with pullups enabled) so power usage is minimized. Linux
-		 * code should set the gpio direction first thing; but until
-		 * it does, and in case chip->get_direction is not set, we may
-		 * expose the wrong direction in sysfs.
-		 */
-		desc->flags = !chip->direction_input ? (1 << FLAG_IS_OUT) : 0;
-	}
-
 #ifdef CONFIG_PINCTRL
 	INIT_LIST_HEAD(&gdev->pin_ranges);
 #endif
@@ -1403,6 +1389,19 @@ int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data,
 	if (status)
 		goto err_remove_chip;
 
+	for (i = 0; i < chip->ngpio; i++) {
+		struct gpio_desc *desc = &gdev->descs[i];
+
+		desc->gdev = gdev;
+
+		if (chip->get_direction && gpiochip_line_is_valid(chip, i))
+			desc->flags = !chip->get_direction(chip, i) ?
+					(1 << FLAG_IS_OUT) : 0;
+		else
+			desc->flags = !chip->direction_input ?
+					(1 << FLAG_IS_OUT) : 0;
+	}
+
 	acpi_gpiochip_add(chip);
 
 	machine_gpiochip_add(chip);