linux-kernel - [PATCH v2] gpiolib: Show correct direction from the beginning

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Date:   Fri, 21 Sep 2018 12:36:04 +0200
From:   Ricardo Ribalda Delgado <ricardo.ribalda@...il.com>
To:     Linus Walleij <linus.walleij@...aro.org>,
        Timur Tabi <timur@...eaurora.org>, swboyd@...omium.org,
        linux-gpio@...r.kernel.org, LKML <linux-kernel@...r.kernel.org>
Cc:     Ricardo Ribalda Delgado <ricardo.ribalda@...il.com>
Subject: [PATCH v2] gpiolib: Show correct direction from the beginning

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: Ricardo Ribalda Delgado <ricardo.ribalda@...il.com>
---
 drivers/gpio/gpiolib.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 4b45de883ada..00c17f64d9ff 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1352,7 +1352,12 @@ int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data,
 		 * 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;
+		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;
 	}
 
 #ifdef CONFIG_PINCTRL
-- 
2.18.0