[PATCH v2 0/2] USB: serial: use new GPIO line value setter callbacks

[PATCH v2 0/2] USB: serial: use new GPIO line value setter callbacks

[Bartosz Golaszewski]

Commit 98ce1eb1fd87e ("gpiolib: introduce gpio_chip setters that return
values") added new line setter callbacks to struct gpio_chip. They allow
to indicate failures to callers. We're in the process of converting all
GPIO controllers to using them before removing the old ones. This series
converts all GPIO chips implemented under drivers/usb/serial/.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
---
Changes in v2:
- reduce the number of changes in patch 2/2 by simply changing the
  function prototype and returning a value without reshuffling the
  implementation (Johan)
- Link to v1: https://lore.kernel.org/r/20250610-gpiochip-set-rv-usb-serial-v1-0-a9343ca109e8@linaro.org

---
Bartosz Golaszewski (2):
      USB: serial: ftdi_sio: use new GPIO line value setter callbacks
      USB: serial: cp210x: use new GPIO line value setter callbacks

 drivers/usb/serial/cp210x.c   | 10 ++++++----
 drivers/usb/serial/ftdi_sio.c | 18 ++++++++++++------
 2 files changed, 18 insertions(+), 10 deletions(-)
---
base-commit: 19272b37aa4f83ca52bdf9c16d5d81bdd1354494
change-id: 20250523-gpiochip-set-rv-usb-serial-4f4d4cc2d5ef

Best regards,
-- 
Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

[PATCH v2 1/2] USB: serial: ftdi_sio: use new GPIO line value setter callbacks

[Bartosz Golaszewski]

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

struct gpio_chip now has callbacks for setting line values that return
an integer, allowing to indicate failures. Convert the driver to using
them.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
---
 drivers/usb/serial/ftdi_sio.c | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
index 6ac7a0a5cf074e0629dfdd3b2330bfa05ca31663..d0a190c6dff38f64e393c11d1bc7759e52876d4e 100644
--- a/drivers/usb/serial/ftdi_sio.c
+++ b/drivers/usb/serial/ftdi_sio.c
@@ -1857,10 +1857,11 @@ static int ftdi_gpio_get(struct gpio_chip *gc, unsigned int gpio)
 	return !!(result & BIT(gpio));
 }
 
-static void ftdi_gpio_set(struct gpio_chip *gc, unsigned int gpio, int value)
+static int ftdi_gpio_set(struct gpio_chip *gc, unsigned int gpio, int value)
 {
 	struct usb_serial_port *port = gpiochip_get_data(gc);
 	struct ftdi_private *priv = usb_get_serial_port_data(port);
+	int result;
 
 	mutex_lock(&priv->gpio_lock);
 
@@ -1869,9 +1870,11 @@ static void ftdi_gpio_set(struct gpio_chip *gc, unsigned int gpio, int value)
 	else
 		priv->gpio_value &= ~BIT(gpio);
 
-	ftdi_set_cbus_pins(port);
+	result = ftdi_set_cbus_pins(port);
 
 	mutex_unlock(&priv->gpio_lock);
+
+	return result;
 }
 
 static int ftdi_gpio_get_multiple(struct gpio_chip *gc, unsigned long *mask,
@@ -1889,19 +1892,22 @@ static int ftdi_gpio_get_multiple(struct gpio_chip *gc, unsigned long *mask,
 	return 0;
 }
 
-static void ftdi_gpio_set_multiple(struct gpio_chip *gc, unsigned long *mask,
+static int ftdi_gpio_set_multiple(struct gpio_chip *gc, unsigned long *mask,
 					unsigned long *bits)
 {
 	struct usb_serial_port *port = gpiochip_get_data(gc);
 	struct ftdi_private *priv = usb_get_serial_port_data(port);
+	int result;
 
 	mutex_lock(&priv->gpio_lock);
 
 	priv->gpio_value &= ~(*mask);
 	priv->gpio_value |= *bits & *mask;
-	ftdi_set_cbus_pins(port);
+	result = ftdi_set_cbus_pins(port);
 
 	mutex_unlock(&priv->gpio_lock);
+
+	return result;
 }
 
 static int ftdi_gpio_direction_get(struct gpio_chip *gc, unsigned int gpio)
@@ -2142,9 +2148,9 @@ static int ftdi_gpio_init(struct usb_serial_port *port)
 	priv->gc.direction_output = ftdi_gpio_direction_output;
 	priv->gc.init_valid_mask = ftdi_gpio_init_valid_mask;
 	priv->gc.get = ftdi_gpio_get;
-	priv->gc.set = ftdi_gpio_set;
+	priv->gc.set_rv = ftdi_gpio_set;
 	priv->gc.get_multiple = ftdi_gpio_get_multiple;
-	priv->gc.set_multiple = ftdi_gpio_set_multiple;
+	priv->gc.set_multiple_rv = ftdi_gpio_set_multiple;
 	priv->gc.owner = THIS_MODULE;
 	priv->gc.parent = &serial->interface->dev;
 	priv->gc.base = -1;

-- 
2.48.1

[PATCH v2 2/2] USB: serial: cp210x: use new GPIO line value setter callbacks

[Bartosz Golaszewski]

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

struct gpio_chip now has callbacks for setting line values that return
an integer, allowing to indicate failures. Convert the driver to using
them.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
---
 drivers/usb/serial/cp210x.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/serial/cp210x.c b/drivers/usb/serial/cp210x.c
index 9960ac2b10b719192dfbab0a6e81b2cf80f40d36..cfa1d68c7919b998b645143096696bdea9ee4423 100644
--- a/drivers/usb/serial/cp210x.c
+++ b/drivers/usb/serial/cp210x.c
@@ -1504,7 +1504,7 @@ static int cp210x_gpio_get(struct gpio_chip *gc, unsigned int gpio)
 	return !!(mask & BIT(gpio));
 }
 
-static void cp210x_gpio_set(struct gpio_chip *gc, unsigned int gpio, int value)
+static int cp210x_gpio_set(struct gpio_chip *gc, unsigned int gpio, int value)
 {
 	struct usb_serial *serial = gpiochip_get_data(gc);
 	struct cp210x_serial_private *priv = usb_get_serial_data(serial);
@@ -1559,7 +1559,10 @@ static void cp210x_gpio_set(struct gpio_chip *gc, unsigned int gpio, int value)
 	if (result < 0) {
 		dev_err(&serial->interface->dev, "failed to set GPIO value: %d\n",
 				result);
+		return result;
 	}
+
+	return 0;
 }
 
 static int cp210x_gpio_direction_get(struct gpio_chip *gc, unsigned int gpio)
@@ -1599,9 +1602,8 @@ static int cp210x_gpio_direction_output(struct gpio_chip *gc, unsigned int gpio,
 	struct cp210x_serial_private *priv = usb_get_serial_data(serial);
 
 	priv->gpio_input &= ~BIT(gpio);
-	cp210x_gpio_set(gc, gpio, value);
 
-	return 0;
+	return cp210x_gpio_set(gc, gpio, value);
 }
 
 static int cp210x_gpio_set_config(struct gpio_chip *gc, unsigned int gpio,
@@ -1960,7 +1962,7 @@ static int cp210x_gpio_init(struct usb_serial *serial)
 	priv->gc.direction_input = cp210x_gpio_direction_input;
 	priv->gc.direction_output = cp210x_gpio_direction_output;
 	priv->gc.get = cp210x_gpio_get;
-	priv->gc.set = cp210x_gpio_set;
+	priv->gc.set_rv = cp210x_gpio_set;
 	priv->gc.set_config = cp210x_gpio_set_config;
 	priv->gc.init_valid_mask = cp210x_gpio_init_valid_mask;
 	priv->gc.owner = THIS_MODULE;

-- 
2.48.1

Re: [PATCH v2 0/2] USB: serial: use new GPIO line value setter callbacks

[Johan Hovold]

On Thu, Jun 19, 2025 at 11:02:39AM +0200, Bartosz Golaszewski wrote:
> Commit 98ce1eb1fd87e ("gpiolib: introduce gpio_chip setters that return
> values") added new line setter callbacks to struct gpio_chip. They allow
> to indicate failures to callers. We're in the process of converting all
> GPIO controllers to using them before removing the old ones. This series
> converts all GPIO chips implemented under drivers/usb/serial/.
> 
> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
> ---
> Changes in v2:
> - reduce the number of changes in patch 2/2 by simply changing the
>   function prototype and returning a value without reshuffling the
>   implementation (Johan)
> - Link to v1: https://lore.kernel.org/r/20250610-gpiochip-set-rv-usb-serial-v1-0-a9343ca109e8@linaro.org

Thanks for respinning, now applied.

Johan