linux-kernel - [PATCH v2 03/15] gpiolib: wrap gpio

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Message-Id: <20250220-gpio-set-retval-v2-3-bc4cfd38dae3@linaro.org>
Date: Thu, 20 Feb 2025 10:57:00 +0100
From: Bartosz Golaszewski <brgl@...ev.pl>
To: Linus Walleij <linus.walleij@...aro.org>, 
 Bartosz Golaszewski <brgl@...ev.pl>, Michael Walle <mwalle@...nel.org>, 
 Bamvor Jian Zhang <bamv2005@...il.com>, 
 Geert Uytterhoeven <geert+renesas@...der.be>, Keerthy <j-keerthy@...com>, 
 Uwe Kleine-König <ukleinek@...nel.org>
Cc: linux-gpio@...r.kernel.org, linux-kernel@...r.kernel.org, 
 linux-pwm@...r.kernel.org, 
 Bartosz Golaszewski <bartosz.golaszewski@...aro.org>
Subject: [PATCH v2 03/15] gpiolib: wrap gpio_chip::set()

From: Bartosz Golaszewski <bartosz.golaszewski@...aro.org>

We have three places where we dereference the gpio_chip::set() callback.
In order to make it easier to incorporate the upcoming new variant of
this callback (one returning an integer value), wrap it in a helper so
that the dereferencing only happens once.

Reviewed-by: Linus Walleij <linus.walleij@...aro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@...aro.org>
---
 drivers/gpio/gpiolib.c | 21 ++++++++++++++++-----
 1 file changed, 16 insertions(+), 5 deletions(-)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 0a47fb38dd61..040b4689eb8e 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -2755,6 +2755,17 @@ int gpiod_direction_input_nonotify(struct gpio_desc *desc)
 	return ret;
 }
 
+static int gpiochip_set(struct gpio_chip *gc, unsigned int offset, int value)
+{
+	lockdep_assert_held(&gc->gpiodev->srcu);
+
+	if (WARN_ON(unlikely(!gc->set)))
+		return -EOPNOTSUPP;
+
+	gc->set(gc, offset, value);
+	return 0;
+}
+
 static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value)
 {
 	int val = !!value, ret = 0;
@@ -2797,7 +2808,9 @@ static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value)
 		 * If we can't actively set the direction, we are some
 		 * output-only chip, so just drive the output as desired.
 		 */
-		guard.gc->set(guard.gc, gpio_chip_hwgpio(desc), val);
+		ret = gpiochip_set(guard.gc, gpio_chip_hwgpio(desc), val);
+		if (ret)
+			return ret;
 	}
 
 	if (!ret)
@@ -3465,9 +3478,7 @@ static int gpiod_set_raw_value_commit(struct gpio_desc *desc, bool value)
 		return -ENODEV;
 
 	trace_gpio_value(desc_to_gpio(desc), 0, value);
-	guard.gc->set(guard.gc, gpio_chip_hwgpio(desc), value);
-
-	return 0;
+	return gpiochip_set(guard.gc, gpio_chip_hwgpio(desc), value);
 }
 
 /*
@@ -3492,7 +3503,7 @@ static void gpio_chip_set_multiple(struct gpio_chip *gc,
 
 		/* set outputs if the corresponding mask bit is set */
 		for_each_set_bit(i, mask, gc->ngpio)
-			gc->set(gc, i, test_bit(i, bits));
+			gpiochip_set(gc, i, test_bit(i, bits));
 	}
 }
 

-- 
2.45.2