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From: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
To: Linus Walleij <linus.walleij@linaro.org>,
	Timur Tabi <timur@kernel.org>,
	swboyd@chromium.org, linux-gpio@vger.kernel.org,
	LKML <linux-kernel@vger.kernel.org>,
	Jeffrey Hugo <jhugo@codeaurora.org>
Cc: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Subject: [PATCH v4 3/3] gpiolib: Show correct direction from the beginning
Date: Tue,  2 Oct 2018 16:08:58 +0200	[thread overview]
Message-ID: <20181002140858.16833-1-ricardo.ribalda@gmail.com> (raw)

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@gmail.com>
---
Changelog v4:

timur@kernel.org:
Remove REVISIT comment

 drivers/gpio/gpiolib.c | 27 +++++++++++++--------------
 1 file changed, 13 insertions(+), 14 deletions(-)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 6925196136ce..cad859fece65 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1344,20 +1344,6 @@ 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
@@ -1374,6 +1360,19 @@ int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data,
 	if (status)
 		goto err_remove_irqchip_mask;
 
+	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;
+	}
+
 	status = gpiochip_add_irqchip(chip, lock_key, request_key);
 	if (status)
 		goto err_remove_chip;
-- 
2.19.0

             reply	other threads:[~2018-10-02 14:08 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-10-02 14:08 Ricardo Ribalda Delgado [this message]
2018-10-02 15:21 ` [PATCH v4 3/3] gpiolib: Show correct direction from the beginning Jeffrey Hugo
2018-10-04 22:26   ` Jeffrey Hugo
2018-10-05  6:52     ` Ricardo Ribalda Delgado
2018-10-05 14:18       ` Jeffrey Hugo

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