[PATCH 4.14 19/21] net: rfkill: gpio: set GPIO direction

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

4.14-stable review patch.  If anyone has any objections, please let me know.

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

From: Rouven Czerwinski <r.czerwinski@pengutronix.de>

commit 23484d817082c3005252d8edfc8292c8a1006b5b upstream.

Fix the undefined usage of the GPIO consumer API after retrieving the
GPIO description with GPIO_ASIS. The API documentation mentions that
GPIO_ASIS won't set a GPIO direction and requires the user to set a
direction before using the GPIO.

This can be confirmed on i.MX6 hardware, where rfkill-gpio is no longer
able to enabled/disable a device, presumably because the GPIO controller
was never configured for the output direction.

Fixes: b2f750c3a80b ("net: rfkill: gpio: prevent value glitch during probe")
Cc: stable@vger.kernel.org
Signed-off-by: Rouven Czerwinski <r.czerwinski@pengutronix.de>
Link: https://msgid.link/20231207075835.3091694-1-r.czerwinski@pengutronix.de
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/rfkill/rfkill-gpio.c |    8 ++++++++
 1 file changed, 8 insertions(+)

--- a/net/rfkill/rfkill-gpio.c
+++ b/net/rfkill/rfkill-gpio.c
@@ -129,6 +129,14 @@ static int rfkill_gpio_probe(struct plat
 		return -EINVAL;
 	}
 
+	ret = gpiod_direction_output(rfkill->reset_gpio, true);
+	if (ret)
+		return ret;
+
+	ret = gpiod_direction_output(rfkill->shutdown_gpio, true);
+	if (ret)
+		return ret;
+
 	rfkill->rfkill_dev = rfkill_alloc(rfkill->name, &pdev->dev,
 					  rfkill->type, &rfkill_gpio_ops,
 					  rfkill);