linux-kernel - [PATCH v2] gpio: gpio-mockup: Fix usage of new GPIO_LINE

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Date:   Wed, 11 Dec 2019 08:46:31 +0800
From:   Kent Gibson <warthog618@...il.com>
To:     linux-kernel@...r.kernel.org, linux-gpio@...r.kernel.org,
        bgolaszewski@...libre.com, linus.walleij@...aro.org,
        bamv2005@...il.com
Cc:     Kent Gibson <warthog618@...il.com>
Subject: [PATCH v2] gpio: gpio-mockup: Fix usage of new GPIO_LINE_DIRECTION

Restore the external behavior of gpio-mockup to what it was prior to the
change to using GPIO_LINE_DIRECTION.

Fixes: e42615ec233b ("gpio: Use new GPIO_LINE_DIRECTION")
Signed-off-by: Kent Gibson <warthog618@...il.com>
---

Changes v1 -> v2:
 - add Fixes tag.
 
Fix a regression introduced in v5.5-rc1.

The change to GPIO_LINE_DIRECTION reversed the polarity of the
dir field within gpio-mockup.c, but overlooked inverting the value on
initialization and when returned by gpio_mockup_get_direction.
The latter is a bug.
The former is a problem for tests which assume initial conditions,
specifically the mockup used to initialize chips with all lines as inputs.
That superficially appeared to be the case after the previous patch due
to the bug in gpio_mockup_get_direction.

 drivers/gpio/gpio-mockup.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/gpio/gpio-mockup.c b/drivers/gpio/gpio-mockup.c
index 56d647a30e3e..c4fdc192ea4e 100644
--- a/drivers/gpio/gpio-mockup.c
+++ b/drivers/gpio/gpio-mockup.c
@@ -226,7 +226,7 @@ static int gpio_mockup_get_direction(struct gpio_chip *gc, unsigned int offset)
 	int direction;
 
 	mutex_lock(&chip->lock);
-	direction = !chip->lines[offset].dir;
+	direction = chip->lines[offset].dir;
 	mutex_unlock(&chip->lock);
 
 	return direction;
@@ -395,7 +395,7 @@ static int gpio_mockup_probe(struct platform_device *pdev)
 	struct gpio_chip *gc;
 	struct device *dev;
 	const char *name;
-	int rv, base;
+	int rv, base, i;
 	u16 ngpio;
 
 	dev = &pdev->dev;
@@ -447,6 +447,9 @@ static int gpio_mockup_probe(struct platform_device *pdev)
 	if (!chip->lines)
 		return -ENOMEM;
 
+	for (i = 0; i < gc->ngpio; i++)
+		chip->lines[i].dir = GPIO_LINE_DIRECTION_IN;
+
 	if (device_property_read_bool(dev, "named-gpio-lines")) {
 		rv = gpio_mockup_name_lines(dev, chip);
 		if (rv)
-- 
2.24.0