[PATCH 11/12] gpio: viperboard: use new GPIO line value setter callbacks

Bartosz Golaszewski brgl at bgdev.pl
Mon Jul 7 00:50:24 PDT 2025


From: Bartosz Golaszewski <bartosz.golaszewski at 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 at linaro.org>
---
 drivers/gpio/gpio-viperboard.c | 116 ++++++++++++++++++++++-------------------
 1 file changed, 63 insertions(+), 53 deletions(-)

diff --git a/drivers/gpio/gpio-viperboard.c b/drivers/gpio/gpio-viperboard.c
index e55d28a8a66f25dd0949133c4a7f3bca9b5711dc..3eba77f981d3a502b67a0a7cdea51c706d4c3376 100644
--- a/drivers/gpio/gpio-viperboard.c
+++ b/drivers/gpio/gpio-viperboard.c
@@ -128,45 +128,50 @@ static int vprbrd_gpioa_get(struct gpio_chip *chip,
 	return answer;
 }
 
-static void vprbrd_gpioa_set(struct gpio_chip *chip,
-		unsigned int offset, int value)
+static int vprbrd_gpioa_set(struct gpio_chip *chip, unsigned int offset,
+			    int value)
 {
-	int ret;
+	int ret = 0;
 	struct vprbrd_gpio *gpio = gpiochip_get_data(chip);
 	struct vprbrd *vb = gpio->vb;
 	struct vprbrd_gpioa_msg *gamsg = (struct vprbrd_gpioa_msg *)vb->buf;
 
-	if (gpio->gpioa_out & (1 << offset)) {
-		if (value)
-			gpio->gpioa_val |= (1 << offset);
-		else
-			gpio->gpioa_val &= ~(1 << offset);
+	if (!(gpio->gpioa_out & (1 << offset)))
+		return 0;
 
-		mutex_lock(&vb->lock);
+	if (value)
+		gpio->gpioa_val |= (1 << offset);
+	else
+		gpio->gpioa_val &= ~(1 << offset);
 
-		gamsg->cmd = VPRBRD_GPIOA_CMD_SETOUT;
-		gamsg->clk = 0x00;
-		gamsg->offset = offset;
-		gamsg->t1 = 0x00;
-		gamsg->t2 = 0x00;
-		gamsg->invert = 0x00;
-		gamsg->pwmlevel = 0x00;
-		gamsg->outval = value;
-		gamsg->risefall = 0x00;
-		gamsg->answer = 0x00;
-		gamsg->__fill = 0x00;
+	mutex_lock(&vb->lock);
 
-		ret = usb_control_msg(vb->usb_dev,
-			usb_sndctrlpipe(vb->usb_dev, 0),
-			VPRBRD_USB_REQUEST_GPIOA, VPRBRD_USB_TYPE_OUT,
-			0x0000,	0x0000, gamsg,
-			sizeof(struct vprbrd_gpioa_msg), VPRBRD_USB_TIMEOUT_MS);
+	gamsg->cmd = VPRBRD_GPIOA_CMD_SETOUT;
+	gamsg->clk = 0x00;
+	gamsg->offset = offset;
+	gamsg->t1 = 0x00;
+	gamsg->t2 = 0x00;
+	gamsg->invert = 0x00;
+	gamsg->pwmlevel = 0x00;
+	gamsg->outval = value;
+	gamsg->risefall = 0x00;
+	gamsg->answer = 0x00;
+	gamsg->__fill = 0x00;
 
-		mutex_unlock(&vb->lock);
+	ret = usb_control_msg(vb->usb_dev, usb_sndctrlpipe(vb->usb_dev, 0),
+			      VPRBRD_USB_REQUEST_GPIOA, VPRBRD_USB_TYPE_OUT,
+			      0x0000, 0x0000, gamsg,
+			      sizeof(struct vprbrd_gpioa_msg),
+			      VPRBRD_USB_TIMEOUT_MS);
 
-		if (ret != sizeof(struct vprbrd_gpioa_msg))
-			dev_err(chip->parent, "usb error setting pin value\n");
+	mutex_unlock(&vb->lock);
+
+	if (ret != sizeof(struct vprbrd_gpioa_msg)) {
+		dev_err(chip->parent, "usb error setting pin value\n");
+		return -EREMOTEIO;
 	}
+
+	return 0;
 }
 
 static int vprbrd_gpioa_direction_input(struct gpio_chip *chip,
@@ -304,37 +309,42 @@ static int vprbrd_gpiob_get(struct gpio_chip *chip,
 	return (gpio->gpiob_val >> offset) & 0x1;
 }
 
-static void vprbrd_gpiob_set(struct gpio_chip *chip,
-		unsigned int offset, int value)
+static int vprbrd_gpiob_set(struct gpio_chip *chip, unsigned int offset,
+			    int value)
 {
 	int ret;
 	struct vprbrd_gpio *gpio = gpiochip_get_data(chip);
 	struct vprbrd *vb = gpio->vb;
 	struct vprbrd_gpiob_msg *gbmsg = (struct vprbrd_gpiob_msg *)vb->buf;
 
-	if (gpio->gpiob_out & (1 << offset)) {
-		if (value)
-			gpio->gpiob_val |= (1 << offset);
-		else
-			gpio->gpiob_val &= ~(1 << offset);
+	if (!(gpio->gpiob_out & (1 << offset)))
+		return 0;
 
-		mutex_lock(&vb->lock);
+	if (value)
+		gpio->gpiob_val |= (1 << offset);
+	else
+		gpio->gpiob_val &= ~(1 << offset);
 
-		gbmsg->cmd = VPRBRD_GPIOB_CMD_SETVAL;
-		gbmsg->val = cpu_to_be16(value << offset);
-		gbmsg->mask = cpu_to_be16(0x0001 << offset);
+	mutex_lock(&vb->lock);
 
-		ret = usb_control_msg(vb->usb_dev,
-			usb_sndctrlpipe(vb->usb_dev, 0),
-			VPRBRD_USB_REQUEST_GPIOB, VPRBRD_USB_TYPE_OUT,
-			0x0000,	0x0000, gbmsg,
-			sizeof(struct vprbrd_gpiob_msg), VPRBRD_USB_TIMEOUT_MS);
+	gbmsg->cmd = VPRBRD_GPIOB_CMD_SETVAL;
+	gbmsg->val = cpu_to_be16(value << offset);
+	gbmsg->mask = cpu_to_be16(0x0001 << offset);
 
-		mutex_unlock(&vb->lock);
+	ret = usb_control_msg(vb->usb_dev, usb_sndctrlpipe(vb->usb_dev, 0),
+			      VPRBRD_USB_REQUEST_GPIOB, VPRBRD_USB_TYPE_OUT,
+			      0x0000, 0x0000, gbmsg,
+			      sizeof(struct vprbrd_gpiob_msg),
+			      VPRBRD_USB_TIMEOUT_MS);
 
-		if (ret != sizeof(struct vprbrd_gpiob_msg))
-			dev_err(chip->parent, "usb error setting pin value\n");
+	mutex_unlock(&vb->lock);
+
+	if (ret != sizeof(struct vprbrd_gpiob_msg)) {
+		dev_err(chip->parent, "usb error setting pin value\n");
+		return -EREMOTEIO;
 	}
+
+	return 0;
 }
 
 static int vprbrd_gpiob_direction_input(struct gpio_chip *chip,
@@ -370,14 +380,14 @@ static int vprbrd_gpiob_direction_output(struct gpio_chip *chip,
 	mutex_lock(&vb->lock);
 
 	ret = vprbrd_gpiob_setdir(vb, offset, 1);
-	if (ret)
+	if (ret) {
 		dev_err(chip->parent, "usb error setting pin to output\n");
+		return ret;
+	}
 
 	mutex_unlock(&vb->lock);
 
-	vprbrd_gpiob_set(chip, offset, value);
-
-	return ret;
+	return vprbrd_gpiob_set(chip, offset, value);
 }
 
 /* ----- end of gpio b chip ---------------------------------------------- */
@@ -400,7 +410,7 @@ static int vprbrd_gpio_probe(struct platform_device *pdev)
 	vb_gpio->gpioa.base = -1;
 	vb_gpio->gpioa.ngpio = 16;
 	vb_gpio->gpioa.can_sleep = true;
-	vb_gpio->gpioa.set = vprbrd_gpioa_set;
+	vb_gpio->gpioa.set_rv = vprbrd_gpioa_set;
 	vb_gpio->gpioa.get = vprbrd_gpioa_get;
 	vb_gpio->gpioa.direction_input = vprbrd_gpioa_direction_input;
 	vb_gpio->gpioa.direction_output = vprbrd_gpioa_direction_output;
@@ -416,7 +426,7 @@ static int vprbrd_gpio_probe(struct platform_device *pdev)
 	vb_gpio->gpiob.base = -1;
 	vb_gpio->gpiob.ngpio = 16;
 	vb_gpio->gpiob.can_sleep = true;
-	vb_gpio->gpiob.set = vprbrd_gpiob_set;
+	vb_gpio->gpiob.set_rv = vprbrd_gpiob_set;
 	vb_gpio->gpiob.get = vprbrd_gpiob_get;
 	vb_gpio->gpiob.direction_input = vprbrd_gpiob_direction_input;
 	vb_gpio->gpiob.direction_output = vprbrd_gpiob_direction_output;

-- 
2.48.1




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