diff mbox series

gpio: Fix return value mismatch of function gpiod_get_from_of_node()

Message ID 1560938081892.33415@sensor-technik.de
State New
Headers show
Series gpio: Fix return value mismatch of function gpiod_get_from_of_node() | expand

Commit Message

Waibel Georg June 19, 2019, 9:54 a.m. UTC
In case the requested gpio property is not found in the device tree, some
callers of gpiod_get_from_of_node() expect a return value of NULL, others
expect -ENOENT.
In particular devm_fwnode_get_index_gpiod_from_child() expects -ENOENT.
Currently it gets a NULL, which breaks the loop that tries all
gpio_suffixes. The result is that a gpio property is not found, even
though it is there.

This patch changes gpiod_get_from_of_node() to return -ENOENT instead
of NULL when the requested gpio property is not found in the device
tree. Additionally it modifies all calling functions to properly
evaluate the return value.

Another approach would be to leave the return value of
gpiod_get_from_of_node() as is and fix the bug in
devm_fwnode_get_index_gpiod_from_child(). Other callers would still need
to be reworked. The effort would be the same as with the chosen solution.

Signed-off-by: Georg Waibel <georg.waibel@sensor-technik.de>
---
 drivers/gpio/gpiolib.c                 | 6 +-----
 drivers/regulator/da9211-regulator.c   | 2 ++
 drivers/regulator/s2mps11.c            | 4 +++-
 drivers/regulator/s5m8767.c            | 4 +++-
 drivers/regulator/tps65090-regulator.c | 7 ++++---
 5 files changed, 13 insertions(+), 10 deletions(-)

Comments

Krzysztof Kozlowski June 19, 2019, 12:45 p.m. UTC | #1
On Wed, 19 Jun 2019 at 11:56, Waibel Georg
<Georg.Waibel@sensor-technik.de> wrote:
>
> In case the requested gpio property is not found in the device tree, some
> callers of gpiod_get_from_of_node() expect a return value of NULL, others
> expect -ENOENT.
> In particular devm_fwnode_get_index_gpiod_from_child() expects -ENOENT.
> Currently it gets a NULL, which breaks the loop that tries all
> gpio_suffixes. The result is that a gpio property is not found, even
> though it is there.
>
> This patch changes gpiod_get_from_of_node() to return -ENOENT instead
> of NULL when the requested gpio property is not found in the device
> tree. Additionally it modifies all calling functions to properly
> evaluate the return value.
>
> Another approach would be to leave the return value of
> gpiod_get_from_of_node() as is and fix the bug in
> devm_fwnode_get_index_gpiod_from_child(). Other callers would still need
> to be reworked. The effort would be the same as with the chosen solution.
>
> Signed-off-by: Georg Waibel <georg.waibel@sensor-technik.de>
> ---
>  drivers/gpio/gpiolib.c                 | 6 +-----
>  drivers/regulator/da9211-regulator.c   | 2 ++
>  drivers/regulator/s2mps11.c            | 4 +++-
>  drivers/regulator/s5m8767.c            | 4 +++-
>  drivers/regulator/tps65090-regulator.c | 7 ++++---
>  5 files changed, 13 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
> index e013d417a936..be1d1d2f8aaa 100644
> --- a/drivers/gpio/gpiolib.c
> +++ b/drivers/gpio/gpiolib.c
> @@ -4244,8 +4244,7 @@ EXPORT_SYMBOL_GPL(gpiod_get_index);
>   *
>   * Returns:
>   * On successful request the GPIO pin is configured in accordance with
> - * provided @dflags. If the node does not have the requested GPIO
> - * property, NULL is returned.
> + * provided @dflags.
>   *
>   * In case of error an ERR_PTR() is returned.
>   */
> @@ -4267,9 +4266,6 @@ struct gpio_desc *gpiod_get_from_of_node(struct device_node *node,
>                                         index, &flags);
>
>         if (!desc || IS_ERR(desc)) {
> -               /* If it is not there, just return NULL */
> -               if (PTR_ERR(desc) == -ENOENT)
> -                       return NULL;
>                 return desc;
>         }
>
> diff --git a/drivers/regulator/da9211-regulator.c b/drivers/regulator/da9211-regulator.c
> index da37b4ccd834..0309823d2c72 100644
> --- a/drivers/regulator/da9211-regulator.c
> +++ b/drivers/regulator/da9211-regulator.c
> @@ -289,6 +289,8 @@ static struct da9211_pdata *da9211_parse_regulators_dt(
>                                   0,
>                                   GPIOD_OUT_HIGH | GPIOD_FLAGS_BIT_NONEXCLUSIVE,
>                                   "da9211-enable");
> +               if (IS_ERR(pdata->gpiod_ren[n]))
> +                       pdata->gpiod_ren[n] = NULL;
>                 n++;
>         }
>
> diff --git a/drivers/regulator/s2mps11.c b/drivers/regulator/s2mps11.c
> index 134c62db36c5..b518a81f75a3 100644
> --- a/drivers/regulator/s2mps11.c
> +++ b/drivers/regulator/s2mps11.c
> @@ -821,7 +821,9 @@ static void s2mps14_pmic_dt_parse_ext_control_gpio(struct platform_device *pdev,
>                                 0,
>                                 GPIOD_OUT_HIGH | GPIOD_FLAGS_BIT_NONEXCLUSIVE,
>                                 "s2mps11-regulator");
> -               if (IS_ERR(gpio[reg])) {
> +               if (PTR_ERR(gpio[reg]) == -ENOENT)
> +                       gpio[reg] = NULL;
> +               else if (IS_ERR(gpio[reg])) {
>                         dev_err(&pdev->dev, "Failed to get control GPIO for %d/%s\n",
>                                 reg, rdata[reg].name);
>                         continue;
> diff --git a/drivers/regulator/s5m8767.c b/drivers/regulator/s5m8767.c
> index bb9d1a083299..6ca27e9d5ef7 100644
> --- a/drivers/regulator/s5m8767.c
> +++ b/drivers/regulator/s5m8767.c
> @@ -574,7 +574,9 @@ static int s5m8767_pmic_dt_parse_pdata(struct platform_device *pdev,
>                         0,
>                         GPIOD_OUT_HIGH | GPIOD_FLAGS_BIT_NONEXCLUSIVE,
>                         "s5m8767");
> -               if (IS_ERR(rdata->ext_control_gpiod))
> +               if (PTR_ERR(rdata->ext_control_gpiod) == -ENOENT)
> +                       rdata->ext_control_gpiod = NULL;
> +               else if (IS_ERR(rdata->ext_control_gpiod))
>                         return PTR_ERR(rdata->ext_control_gpiod);
>

For s2mps11 and s5m8767 bits:
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>

The s2mps11 code brought a bug to my attention so you might rebase on top of it.

Best regards,
Krzysztof
Mark Brown June 21, 2019, 12:06 p.m. UTC | #2
On Wed, Jun 19, 2019 at 09:54:48AM +0000, Waibel Georg wrote:
> In case the requested gpio property is not found in the device tree, some
> callers of gpiod_get_from_of_node() expect a return value of NULL, others
> expect -ENOENT.
> In particular devm_fwnode_get_index_gpiod_from_child() expects -ENOENT.
> Currently it gets a NULL, which breaks the loop that tries all
> gpio_suffixes. The result is that a gpio property is not found, even
> though it is there.

Acked-by: Mark Brown <broonie@kernel.org>
diff mbox series

Patch

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index e013d417a936..be1d1d2f8aaa 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -4244,8 +4244,7 @@  EXPORT_SYMBOL_GPL(gpiod_get_index);
  *
  * Returns:
  * On successful request the GPIO pin is configured in accordance with
- * provided @dflags. If the node does not have the requested GPIO
- * property, NULL is returned.
+ * provided @dflags.
  *
  * In case of error an ERR_PTR() is returned.
  */
@@ -4267,9 +4266,6 @@  struct gpio_desc *gpiod_get_from_of_node(struct device_node *node,
 					index, &flags);
 
 	if (!desc || IS_ERR(desc)) {
-		/* If it is not there, just return NULL */
-		if (PTR_ERR(desc) == -ENOENT)
-			return NULL;
 		return desc;
 	}
 
diff --git a/drivers/regulator/da9211-regulator.c b/drivers/regulator/da9211-regulator.c
index da37b4ccd834..0309823d2c72 100644
--- a/drivers/regulator/da9211-regulator.c
+++ b/drivers/regulator/da9211-regulator.c
@@ -289,6 +289,8 @@  static struct da9211_pdata *da9211_parse_regulators_dt(
 				  0,
 				  GPIOD_OUT_HIGH | GPIOD_FLAGS_BIT_NONEXCLUSIVE,
 				  "da9211-enable");
+		if (IS_ERR(pdata->gpiod_ren[n]))
+			pdata->gpiod_ren[n] = NULL;
 		n++;
 	}
 
diff --git a/drivers/regulator/s2mps11.c b/drivers/regulator/s2mps11.c
index 134c62db36c5..b518a81f75a3 100644
--- a/drivers/regulator/s2mps11.c
+++ b/drivers/regulator/s2mps11.c
@@ -821,7 +821,9 @@  static void s2mps14_pmic_dt_parse_ext_control_gpio(struct platform_device *pdev,
 				0,
 				GPIOD_OUT_HIGH | GPIOD_FLAGS_BIT_NONEXCLUSIVE,
 				"s2mps11-regulator");
-		if (IS_ERR(gpio[reg])) {
+		if (PTR_ERR(gpio[reg]) == -ENOENT)
+			gpio[reg] = NULL;
+		else if (IS_ERR(gpio[reg])) {
 			dev_err(&pdev->dev, "Failed to get control GPIO for %d/%s\n",
 				reg, rdata[reg].name);
 			continue;
diff --git a/drivers/regulator/s5m8767.c b/drivers/regulator/s5m8767.c
index bb9d1a083299..6ca27e9d5ef7 100644
--- a/drivers/regulator/s5m8767.c
+++ b/drivers/regulator/s5m8767.c
@@ -574,7 +574,9 @@  static int s5m8767_pmic_dt_parse_pdata(struct platform_device *pdev,
 			0,
 			GPIOD_OUT_HIGH | GPIOD_FLAGS_BIT_NONEXCLUSIVE,
 			"s5m8767");
-		if (IS_ERR(rdata->ext_control_gpiod))
+		if (PTR_ERR(rdata->ext_control_gpiod) == -ENOENT)
+			rdata->ext_control_gpiod = NULL;
+		else if (IS_ERR(rdata->ext_control_gpiod))
 			return PTR_ERR(rdata->ext_control_gpiod);
 
 		rdata->id = i;
diff --git a/drivers/regulator/tps65090-regulator.c b/drivers/regulator/tps65090-regulator.c
index ca39b3d55123..10ea4b5a0f55 100644
--- a/drivers/regulator/tps65090-regulator.c
+++ b/drivers/regulator/tps65090-regulator.c
@@ -371,11 +371,12 @@  static struct tps65090_platform_data *tps65090_parse_dt_reg_data(
 								    "dcdc-ext-control-gpios", 0,
 								    gflags,
 								    "tps65090");
-			if (IS_ERR(rpdata->gpiod))
-				return ERR_CAST(rpdata->gpiod);
-			if (!rpdata->gpiod)
+			if (PTR_ERR(rpdata->gpiod) == -ENOENT) {
 				dev_err(&pdev->dev,
 					"could not find DCDC external control GPIO\n");
+				rpdata->gpiod = NULL;
+			} else if (IS_ERR(rpdata->gpiod))
+				return ERR_CAST(rpdata->gpiod);
 		}
 
 		if (of_property_read_u32(tps65090_matches[idx].of_node,