[PATCH 1/3] reset: Fix of_reset_control_get() for consistent return values

[PATCH 1/3] reset: Fix of_reset_control_get() for consistent return values

[Ahmad Fatoum]

When of_reset_control_get() is called without connection ID it returns
-ENOENT when the 'resets' property doesn't exists or is an empty entry.
However when a connection ID is given it returns -EINVAL when the 'resets'
property doesn't exists or the requested name can't be found. This is
because the error code returned by of_property_match_string() is just
passed down as an index to of_parse_phandle_with_args(), which then
returns -EINVAL.

To get a consistent return value with both code paths we must return
-ENOENT when of_property_match_string() fails.
Signed-off-by: Alban Bedel <albeu@free.fr>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
[afa: ported from Linux 3d81216fde465e76c5eae98f61d3666163634395]
Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
---
 drivers/reset/core.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/reset/core.c b/drivers/reset/core.c
index 4355c3415eb0..93fbaeccafd2 100644
--- a/drivers/reset/core.c
+++ b/drivers/reset/core.c
@@ -236,8 +236,11 @@ struct reset_control *of_reset_control_get(struct device_node *node,
 {
 	int index = 0;
 
-	if (id)
+	if (id) {
 		index = of_property_match_string(node, "reset-names", id);
+		if (index < 0)
+			return ERR_PTR(-ENOENT);
+	}
 
 	return of_reset_control_get_by_index(node, index);
 }
-- 
2.30.2

[PATCH 2/3] reset: implement reset_control_get_optional()

[Ahmad Fatoum]

Make porting kernel code easier by providing a compatible
reset_control_get_optional() function.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
---
 include/linux/reset.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/include/linux/reset.h b/include/linux/reset.h
index d0677b1d9f63..91e9cdfb3279 100644
--- a/include/linux/reset.h
+++ b/include/linux/reset.h
@@ -73,4 +73,10 @@ static inline int device_reset_all(struct device_d *dev)
 
 #endif /* CONFIG_RESET_CONTROLLER */
 
+static inline struct reset_control *reset_control_get_optional(struct device_d *dev, const char *id)
+{
+	struct reset_control *rstc = reset_control_get(dev, id);
+	return rstc == ERR_PTR(-ENOENT) ? NULL : rstc;
+}
+
 #endif
-- 
2.30.2

[PATCH 3/3] reset: implement reset_control_get_count()

[Ahmad Fatoum]

We have a nearly equivalent of_reset_control_get_count(). Rename it and
adjust the prototype to make kernel code easier to port.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
---
 drivers/reset/core.c  | 10 +++++-----
 include/linux/reset.h |  7 +++++++
 2 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/drivers/reset/core.c b/drivers/reset/core.c
index 93fbaeccafd2..b252f94d6eb9 100644
--- a/drivers/reset/core.c
+++ b/drivers/reset/core.c
@@ -157,14 +157,14 @@ int reset_control_deassert(struct reset_control *rstc)
 EXPORT_SYMBOL_GPL(reset_control_deassert);
 
 /**
- * of_reset_control_count - Count reset lines
- * @node: device node
+ * reset_control_get_count - Count reset lines
+ * @dev: device
  *
  * Returns number of resets, 0 if none specified
  */
-static int of_reset_control_count(struct device_node *node)
+int reset_control_get_count(struct device_d *dev)
 {
-	return of_count_phandle_with_args(node, "resets", "#reset-cells");
+	return of_count_phandle_with_args(dev->device_node, "resets", "#reset-cells");
 }
 
 /**
@@ -357,7 +357,7 @@ int device_reset_all(struct device_d *dev)
 	struct reset_control *rstc;
 	int ret, i;
 
-	for (i = 0; i < of_reset_control_count(dev->device_node); i++) {
+	for (i = 0; i < reset_control_get_count(dev); i++) {
 		int ret;
 
 		rstc = of_reset_control_get_by_index(dev->device_node, i);
diff --git a/include/linux/reset.h b/include/linux/reset.h
index 91e9cdfb3279..c1282a84c72c 100644
--- a/include/linux/reset.h
+++ b/include/linux/reset.h
@@ -24,6 +24,8 @@ int __must_check device_reset_us(struct device_d *dev, int us);
 
 int __must_check device_reset_all(struct device_d *dev);
 
+int reset_control_get_count(struct device_d *dev);
+
 #else
 
 static inline int reset_control_status(struct reset_control *rstc)
@@ -71,6 +73,11 @@ static inline int device_reset_all(struct device_d *dev)
 	return 0;
 }
 
+static inline int reset_control_get_count(struct device_d *dev)
+{
+	return 0;
+}
+
 #endif /* CONFIG_RESET_CONTROLLER */
 
 static inline struct reset_control *reset_control_get_optional(struct device_d *dev, const char *id)
-- 
2.30.2

Re: [PATCH 1/3] reset: Fix of_reset_control_get() for consistent return values

[Sascha Hauer]

On Fri, Aug 05, 2022 at 02:59:29PM +0200, Ahmad Fatoum wrote:
> When of_reset_control_get() is called without connection ID it returns
> -ENOENT when the 'resets' property doesn't exists or is an empty entry.
> However when a connection ID is given it returns -EINVAL when the 'resets'
> property doesn't exists or the requested name can't be found. This is
> because the error code returned by of_property_match_string() is just
> passed down as an index to of_parse_phandle_with_args(), which then
> returns -EINVAL.
> 
> To get a consistent return value with both code paths we must return
> -ENOENT when of_property_match_string() fails.
> Signed-off-by: Alban Bedel <albeu@free.fr>
> Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
> [afa: ported from Linux 3d81216fde465e76c5eae98f61d3666163634395]
> Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
> ---
>  drivers/reset/core.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)

Applied, thanks

Sascha

> 
> diff --git a/drivers/reset/core.c b/drivers/reset/core.c
> index 4355c3415eb0..93fbaeccafd2 100644
> --- a/drivers/reset/core.c
> +++ b/drivers/reset/core.c
> @@ -236,8 +236,11 @@ struct reset_control *of_reset_control_get(struct device_node *node,
>  {
>  	int index = 0;
>  
> -	if (id)
> +	if (id) {
>  		index = of_property_match_string(node, "reset-names", id);
> +		if (index < 0)
> +			return ERR_PTR(-ENOENT);
> +	}
>  
>  	return of_reset_control_get_by_index(node, index);
>  }
> -- 
> 2.30.2
> 
> 
> 

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