[PATCH v2025.09.y 13/58] gpio: Fix GPIOD_ASIS flag

[Ahmad Fatoum <a.fatoum@pengutronix.de>]

From: Sascha Hauer <s.hauer@pengutronix.de>

GPIOs can be requested with GPIOD_ASIS and with this the GPIO should be
kept in its current state. This doesn't work currently as GPIOD_ASIS is
defined as 0 and the flags are then interpreted as GPIOF_INIT_LOW (also
0).

To fix this set GPIOD_ASIS to a bit value which makes it a flag which
can be explicitly tested for.

Note this is different than in Linux. Linux defines GPIOD_ASIS to 0 just
like barebox did, but in Linux the other GPIOD_* flags have an explicit
"change this setting" flag which we don't have in barebox. Introducing
these flags in barebox would mean we have to add the "change this
setting" flags in various other places, like for example
gpiod_request_one().

Motivation for this patch is the only current user of GPIOD_ASIS, the
fixed regulator driver. Without this patch regulators will already be
enabled in the fixed regulator drivers probe function.

(cherry picked from commit 6436a1dc83dd98c38b119a7efbe8b0a999172749)

Link: https://lore.barebox.org/20260105-riotboard-v1-3-789b844d7e36@pengutronix.de
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 drivers/gpio/gpiolib.c        | 15 +++++++++------
 include/gpio.h                |  2 ++
 include/linux/gpio/consumer.h |  2 +-
 3 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index ec4d8e889bb1..e1493ffb6640 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -622,6 +622,7 @@ static int gpiodesc_request_one(struct gpio_desc *desc, unsigned long lflags,
 	const bool logical     = (dflags & GPIOF_LOGICAL) == GPIOF_LOGICAL;
 	const bool init_active = (dflags & GPIOF_INIT_ACTIVE) == GPIOF_INIT_ACTIVE;
 	const bool init_high   = (dflags & GPIOF_INIT_HIGH) == GPIOF_INIT_HIGH;
+	const bool set         = (dflags & GPIOF_ASIS) == GPIOF_ASIS;
 
 	err = gpiodesc_request(desc, label);
 	if (err)
@@ -631,12 +632,14 @@ static int gpiodesc_request_one(struct gpio_desc *desc, unsigned long lflags,
 	if (active_low)
 		desc->flags |= OF_GPIO_ACTIVE_LOW;
 
-	if (dir_in)
-		err = gpiod_direction_input(desc);
-	else if (logical)
-		err = gpiod_direction_output(desc, init_active);
-	else
-		err = gpiod_direction_output_raw(desc, init_high);
+	if (!set) {
+		if (dir_in)
+			err = gpiod_direction_input(desc);
+		else if (logical)
+			err = gpiod_direction_output(desc, init_active);
+		else
+			err = gpiod_direction_output_raw(desc, init_high);
+	}
 
 	if (err)
 		gpiodesc_free(desc);
diff --git a/include/gpio.h b/include/gpio.h
index 92fd27b2b996..2264d0c495a4 100644
--- a/include/gpio.h
+++ b/include/gpio.h
@@ -114,6 +114,8 @@ static inline int gpio_is_valid(int gpio)
 #define GPIOF_OUT_INIT_ACTIVE	(GPIOF_DIR_OUT | GPIOF_INIT_ACTIVE)
 #define GPIOF_OUT_INIT_INACTIVE	(GPIOF_DIR_OUT | GPIOF_INIT_INACTIVE)
 
+#define GPIOF_ASIS	BIT(4)
+
 /**
  * struct gpio - a structure describing a GPIO with configuration
  * @gpio:	the GPIO number
diff --git a/include/linux/gpio/consumer.h b/include/linux/gpio/consumer.h
index c461f3f3108b..a425145351b0 100644
--- a/include/linux/gpio/consumer.h
+++ b/include/linux/gpio/consumer.h
@@ -13,7 +13,7 @@
  * and output value. These values cannot be OR'd.
  */
 enum gpiod_flags {
-	GPIOD_ASIS	= 0,
+	GPIOD_ASIS	= GPIOF_ASIS,
 	GPIOD_IN	= GPIOF_IN,
 	/*
 	 * To change this later to a different logic level (i.e. taking
-- 
2.47.3