reset: Make optional functions really optional.

The optional functions weren't really optional so this patch makes them really optional.

Signed-off-by Ramiro Oliveira <[email protected]>

---
 drivers/reset/core.c  | 35 +++++++++++++++++++++++++++++------
 include/linux/reset.h | 45 ++++++++++++++++++++++++++-------------------
 2 files changed, 55 insertions(+), 25 deletions(-)

drivers/reset/core.c +24 -2

index 70023997d031..f933e9dfebc5 100644
@@ -135,9 +135,15 @@ EXPORT_SYMBOL_GPL(devm_reset_controller_register);
  * @rstc: reset controller
  *
  * Calling this on a shared reset controller is an error.
+ *
+ * If rstc is NULL it is an optional reset and the function will just
+ * return 0.
  */
 int reset_control_reset(struct reset_control *rstc)
 {
+	if (!rstc)
+		return 0;
+
 	if (WARN_ON(rstc->shared))
 		return -EINVAL;
 

@@ -158,9 +164,15 @@ EXPORT_SYMBOL_GPL(reset_control_reset);
  *
  * For shared reset controls a driver cannot expect the hw's registers and
  * internal state to be reset, but must be prepared for this to happen.
+ *
+ * If rstc is NULL it is an optional reset and the function will just
+ * return 0.
  */
 int reset_control_assert(struct reset_control *rstc)
 {
+	if (!rstc)
+		return 0;
+
 	if (!rstc->rcdev->ops->assert)
 		return -ENOTSUPP;
 

@@ -181,9 +193,15 @@ EXPORT_SYMBOL_GPL(reset_control_assert);
  * @rstc: reset controller
  *
  * After calling this function, the reset is guaranteed to be deasserted.
+ *
+ * If rstc is NULL it is an optional reset and the function will just
+ * return 0.
  */
 int reset_control_deassert(struct reset_control *rstc)
 {
+	if (!rstc)
+		return 0;
+
 	if (!rstc->rcdev->ops->deassert)
 		return -ENOTSUPP;
 

@@ -199,11 +217,14 @@ EXPORT_SYMBOL_GPL(reset_control_deassert);
 /**
  * reset_control_status - returns a negative errno if not supported, a
  * positive value if the reset line is asserted, or zero if the reset
- * line is not asserted.
+ * line is not asserted or if the desc is NULL (optional reset).
  * @rstc: reset controller
  */
 int reset_control_status(struct reset_control *rstc)
 {
+	if (!rstc)
+		return 0;
+
 	if (rstc->rcdev->ops->status)
 		return rstc->rcdev->ops->status(rstc->rcdev, rstc->id);
 

@@ -258,7 +279,8 @@ static void __reset_control_put(struct reset_control *rstc)
 }
 
 struct reset_control *__of_reset_control_get(struct device_node *node,
-				     const char *id, int index, bool shared)
+				     const char *id, int index, bool shared,
+				     bool optional)
 {
 	struct reset_control *rstc;
 	struct reset_controller_dev *r, *rcdev;

drivers/reset/core.c +3 -2

 	mutex_lock(&reset_list_mutex);
 	rcdev = NULL;

@@ -338,7 +360,8 @@ static void devm_reset_control_release(struct device *dev, void *res)
 }
 
 struct reset_control *__devm_reset_control_get(struct device *dev,
-				     const char *id, int index, bool shared)
+				     const char *id, int index, bool shared,
+				     bool optional)
 {
 	struct reset_control **ptr, *rstc;
 

@@ -348,7 +371,7 @@ struct reset_control *__devm_reset_control_get(struct device *dev,
 		return ERR_PTR(-ENOMEM);
 
 	rstc = __of_reset_control_get(dev ? dev->of_node : NULL,
-				      id, index, shared);
+				      id, index, shared, optional);
 	if (!IS_ERR(rstc)) {
 		*ptr = rstc;
 		devres_add(dev, ptr);

include/linux/reset.h +25 -18

index ec1d1fd28f5f..e4cc7146b5ed 100644
@@ -13,10 +13,12 @@ int reset_control_deassert(struct reset_control *rstc);
 int reset_control_status(struct reset_control *rstc);
 
 struct reset_control *__of_reset_control_get(struct device_node *node,
-				     const char *id, int index, bool shared);
+				     const char *id, int index, bool shared,
+				     bool optional);
 void reset_control_put(struct reset_control *rstc);
 struct reset_control *__devm_reset_control_get(struct device *dev,
-				     const char *id, int index, bool shared);
+				     const char *id, int index, bool shared,
+				     bool optional);
 
 int __must_check device_reset(struct device *dev);
 

@@ -69,14 +71,15 @@ static inline int device_reset_optional(struct device *dev)
 
 static inline struct reset_control *__of_reset_control_get(
 					struct device_node *node,
-					const char *id, int index, bool shared)
+					const char *id, int index, bool shared,
+					bool optional)
 {
 	return ERR_PTR(-ENOTSUPP);
 }
 
 static inline struct reset_control *__devm_reset_control_get(
-					struct device *dev,
-					const char *id, int index, bool shared)
+					struct device *dev, const char *id,
+					int index, bool shared, bool optional)
 {
 	return ERR_PTR(-ENOTSUPP);
 }

@@ -104,7 +107,8 @@ __must_check reset_control_get_exclusive(struct device *dev, const char *id)
 #ifndef CONFIG_RESET_CONTROLLER
 	WARN_ON(1);
 #endif
-	return __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, 0);
+	return __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, false,
+									false);
 }
 
 /**

@@ -132,19 +136,22 @@ __must_check reset_control_get_exclusive(struct device *dev, const char *id)
 static inline struct reset_control *reset_control_get_shared(
 					struct device *dev, const char *id)
 {
-	return __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, true);
+	return __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, true,
+									false);
 }
 
 static inline struct reset_control *reset_control_get_optional_exclusive(
 					struct device *dev, const char *id)
 {
-	return __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, false);
+	return __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, false,
+									true);
 }
 
 static inline struct reset_control *reset_control_get_optional_shared(
 					struct device *dev, const char *id)
 {
-	return __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, true);
+	return __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, true,
+									true);
 }
 
 /**

@@ -160,7 +167,7 @@ static inline struct reset_control *reset_control_get_optional_shared(
 static inline struct reset_control *of_reset_control_get_exclusive(
 				struct device_node *node, const char *id)
 {
-	return __of_reset_control_get(node, id, 0, 0);
+	return __of_reset_control_get(node, id, 0, false, false);
 }
 
 /**

@@ -185,7 +192,7 @@ static inline struct reset_control *of_reset_control_get_exclusive(
 static inline struct reset_control *of_reset_control_get_shared(
 				struct device_node *node, const char *id)
 {
-	return __of_reset_control_get(node, id, 0, true);
+	return __of_reset_control_get(node, id, 0, true, false);
 }
 
 /**

@@ -202,7 +209,7 @@ static inline struct reset_control *of_reset_control_get_shared(
 static inline struct reset_control *of_reset_control_get_exclusive_by_index(
 					struct device_node *node, int index)
 {
-	return __of_reset_control_get(node, NULL, index, false);
+	return __of_reset_control_get(node, NULL, index, false, false);
 }
 
 /**

@@ -230,7 +237,7 @@ static inline struct reset_control *of_reset_control_get_exclusive_by_index(
 static inline struct reset_control *of_reset_control_get_shared_by_index(
 					struct device_node *node, int index)
 {
-	return __of_reset_control_get(node, NULL, index, true);
+	return __of_reset_control_get(node, NULL, index, true, false);
 }
 
 /**

@@ -252,7 +259,7 @@ __must_check devm_reset_control_get_exclusive(struct device *dev,
 #ifndef CONFIG_RESET_CONTROLLER
 	WARN_ON(1);
 #endif
-	return __devm_reset_control_get(dev, id, 0, false);
+	return __devm_reset_control_get(dev, id, 0, false, false);
 }
 
 /**

@@ -267,19 +274,19 @@ __must_check devm_reset_control_get_exclusive(struct device *dev,
 static inline struct reset_control *devm_reset_control_get_shared(
 					struct device *dev, const char *id)
 {
-	return __devm_reset_control_get(dev, id, 0, true);
+	return __devm_reset_control_get(dev, id, 0, true, false);
 }
 
 static inline struct reset_control *devm_reset_control_get_optional_exclusive(
 					struct device *dev, const char *id)
 {
-	return __devm_reset_control_get(dev, id, 0, false);
+	return __devm_reset_control_get(dev, id, 0, false, true);
 }
 
 static inline struct reset_control *devm_reset_control_get_optional_shared(
 					struct device *dev, const char *id)
 {
-	return __devm_reset_control_get(dev, id, 0, true);
+	return __devm_reset_control_get(dev, id, 0, true, true);
 }
 
 /**

@@ -297,7 +304,7 @@ static inline struct reset_control *devm_reset_control_get_optional_shared(
 static inline struct reset_control *
 devm_reset_control_get_exclusive_by_index(struct device *dev, int index)
 {
-	return __devm_reset_control_get(dev, NULL, index, false);
+	return __devm_reset_control_get(dev, NULL, index, false, false);
 }
 
 /**

Hi Ramiro,

Am Dienstag, den 27.12.2016, 12:37 +0000 schrieb Ramiro Oliveira:

Quoted 2 lines

The optional functions weren't really optional so this patch makes them really optional.

Please add a bit of detail to the description. Since this changes the API, you should mention that the reset_control_get_optional variants now return NULL instead of an error if there is no matching reset phandle in the device tree and that the reset_control_* functions accept NULL rstc pointers.

Quoted 77 lines

Signed-off-by Ramiro Oliveira <[email protected]>

---
 drivers/reset/core.c  | 35 +++++++++++++++++++++++++++++------
 include/linux/reset.h | 45 ++++++++++++++++++++++++++-------------------
 2 files changed, 55 insertions(+), 25 deletions(-)

drivers/reset/core.c +22 -1

index 70023997d031..f933e9dfebc5 100644
@@ -135,9 +135,15 @@ EXPORT_SYMBOL_GPL(devm_reset_controller_register);
  * @rstc: reset controller
  *
  * Calling this on a shared reset controller is an error.
+ *
+ * If rstc is NULL it is an optional reset and the function will just
+ * return 0.
  */
 int reset_control_reset(struct reset_control *rstc)
 {
+	if (!rstc)
+		return 0;
+
 	if (WARN_ON(rstc->shared))
 		return -EINVAL;
 

@@ -158,9 +164,15 @@ EXPORT_SYMBOL_GPL(reset_control_reset);
  *
  * For shared reset controls a driver cannot expect the hw's registers and
  * internal state to be reset, but must be prepared for this to happen.
+ *
+ * If rstc is NULL it is an optional reset and the function will just
+ * return 0.
  */
 int reset_control_assert(struct reset_control *rstc)
 {
+	if (!rstc)
+		return 0;
+
 	if (!rstc->rcdev->ops->assert)
 		return -ENOTSUPP;
 

@@ -181,9 +193,15 @@ EXPORT_SYMBOL_GPL(reset_control_assert);
  * @rstc: reset controller
  *
  * After calling this function, the reset is guaranteed to be deasserted.
+ *
+ * If rstc is NULL it is an optional reset and the function will just
+ * return 0.
  */
 int reset_control_deassert(struct reset_control *rstc)
 {
+	if (!rstc)
+		return 0;
+
 	if (!rstc->rcdev->ops->deassert)
 		return -ENOTSUPP;
 

@@ -199,11 +217,14 @@ EXPORT_SYMBOL_GPL(reset_control_deassert);
 /**
  * reset_control_status - returns a negative errno if not supported, a
  * positive value if the reset line is asserted, or zero if the reset
- * line is not asserted.
+ * line is not asserted or if the desc is NULL (optional reset).
  * @rstc: reset controller
  */
 int reset_control_status(struct reset_control *rstc)
 {
+	if (!rstc)
+		return 0;
+
 	if (rstc->rcdev->ops->status)
 		return rstc->rcdev->ops->status(rstc->rcdev, rstc->id);
 

@@ -258,7 +279,8 @@ static void __reset_control_put(struct reset_control *rstc)
 }
 

drivers/reset/core.c struct reset_control *__of_reset_control_get(struct device_node *node, · line 298

Quoted 13 lines

drivers/reset/core.c +3 -2

 struct reset_control *__of_reset_control_get(struct device_node *node,
-				     const char *id, int index, bool shared)
+				     const char *id, int index, bool shared,
+				     bool optional)
 {
 	struct reset_control *rstc;
 	struct reset_controller_dev *r, *rcdev;

@@ -273,13 +295,13 @@ struct reset_control *__of_reset_control_get(struct device_node *node,
 		index = of_property_match_string(node,
 						 "reset-names", id);
 		if (index < 0)
-			return ERR_PTR(-ENOENT);
+			return optional ? NULL : ERR_PTR(-ENOENT);

of_property_match_string can return -EINVAL, -ENODATA, or -EILSEQ. I think -EILSEQ should still be returned.

drivers/reset/core.c struct reset_control *__of_reset_control_get(struct device_node *node, · line 304

Quoted 7 lines

drivers/reset/core.c +1 -1

 	}
 
 	ret = of_parse_phandle_with_args(node, "resets", "#reset-cells",
 					 index, &args);
 	if (ret)
-		return ERR_PTR(ret);
+		return optional ? NULL : ERR_PTR(ret);

of_parse_phandle_with_args can return -ENOENT or -EINVAL. I think -EINVAL should still be returned.

Quoted 181 lines

drivers/reset/core.c +3 -2

 	mutex_lock(&reset_list_mutex);
 	rcdev = NULL;

@@ -338,7 +360,8 @@ static void devm_reset_control_release(struct device *dev, void *res)
 }
 
 struct reset_control *__devm_reset_control_get(struct device *dev,
-				     const char *id, int index, bool shared)
+				     const char *id, int index, bool shared,
+				     bool optional)
 {
 	struct reset_control **ptr, *rstc;
 

@@ -348,7 +371,7 @@ struct reset_control *__devm_reset_control_get(struct device *dev,
 		return ERR_PTR(-ENOMEM);
 
 	rstc = __of_reset_control_get(dev ? dev->of_node : NULL,
-				      id, index, shared);
+				      id, index, shared, optional);
 	if (!IS_ERR(rstc)) {
 		*ptr = rstc;
 		devres_add(dev, ptr);

include/linux/reset.h +26 -19

index ec1d1fd28f5f..e4cc7146b5ed 100644
@@ -13,10 +13,12 @@ int reset_control_deassert(struct reset_control *rstc);
 int reset_control_status(struct reset_control *rstc);
 
 struct reset_control *__of_reset_control_get(struct device_node *node,
-				     const char *id, int index, bool shared);
+				     const char *id, int index, bool shared,
+				     bool optional);
 void reset_control_put(struct reset_control *rstc);
 struct reset_control *__devm_reset_control_get(struct device *dev,
-				     const char *id, int index, bool shared);
+				     const char *id, int index, bool shared,
+				     bool optional);
 
 int __must_check device_reset(struct device *dev);
 

@@ -69,14 +71,15 @@ static inline int device_reset_optional(struct device *dev)
 
 static inline struct reset_control *__of_reset_control_get(
 					struct device_node *node,
-					const char *id, int index, bool shared)
+					const char *id, int index, bool shared,
+					bool optional)
 {
 	return ERR_PTR(-ENOTSUPP);
 }
 
 static inline struct reset_control *__devm_reset_control_get(
-					struct device *dev,
-					const char *id, int index, bool shared)
+					struct device *dev, const char *id,
+					int index, bool shared, bool optional)
 {
 	return ERR_PTR(-ENOTSUPP);
 }

@@ -104,7 +107,8 @@ __must_check reset_control_get_exclusive(struct device *dev, const char *id)
 #ifndef CONFIG_RESET_CONTROLLER
 	WARN_ON(1);
 #endif
-	return __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, 0);
+	return __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, false,
+									false);
 }
 
 /**

@@ -132,19 +136,22 @@ __must_check reset_control_get_exclusive(struct device *dev, const char *id)
 static inline struct reset_control *reset_control_get_shared(
 					struct device *dev, const char *id)
 {
-	return __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, true);
+	return __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, true,
+									false);
 }
 
 static inline struct reset_control *reset_control_get_optional_exclusive(
 					struct device *dev, const char *id)
 {
-	return __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, false);
+	return __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, false,
+									true);
 }
 
 static inline struct reset_control *reset_control_get_optional_shared(
 					struct device *dev, const char *id)
 {
-	return __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, true);
+	return __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, true,
+									true);
 }
 
 /**

@@ -160,7 +167,7 @@ static inline struct reset_control *reset_control_get_optional_shared(
 static inline struct reset_control *of_reset_control_get_exclusive(
 				struct device_node *node, const char *id)
 {
-	return __of_reset_control_get(node, id, 0, 0);
+	return __of_reset_control_get(node, id, 0, false, false);
 }
 
 /**

@@ -185,7 +192,7 @@ static inline struct reset_control *of_reset_control_get_exclusive(
 static inline struct reset_control *of_reset_control_get_shared(
 				struct device_node *node, const char *id)
 {
-	return __of_reset_control_get(node, id, 0, true);
+	return __of_reset_control_get(node, id, 0, true, false);
 }
 
 /**

@@ -202,7 +209,7 @@ static inline struct reset_control *of_reset_control_get_shared(
 static inline struct reset_control *of_reset_control_get_exclusive_by_index(
 					struct device_node *node, int index)
 {
-	return __of_reset_control_get(node, NULL, index, false);
+	return __of_reset_control_get(node, NULL, index, false, false);
 }
 
 /**

@@ -230,7 +237,7 @@ static inline struct reset_control *of_reset_control_get_exclusive_by_index(
 static inline struct reset_control *of_reset_control_get_shared_by_index(
 					struct device_node *node, int index)
 {
-	return __of_reset_control_get(node, NULL, index, true);
+	return __of_reset_control_get(node, NULL, index, true, false);
 }
 
 /**

@@ -252,7 +259,7 @@ __must_check devm_reset_control_get_exclusive(struct device *dev,
 #ifndef CONFIG_RESET_CONTROLLER
 	WARN_ON(1);
 #endif
-	return __devm_reset_control_get(dev, id, 0, false);
+	return __devm_reset_control_get(dev, id, 0, false, false);
 }
 
 /**

@@ -267,19 +274,19 @@ __must_check devm_reset_control_get_exclusive(struct device *dev,
 static inline struct reset_control *devm_reset_control_get_shared(
 					struct device *dev, const char *id)
 {
-	return __devm_reset_control_get(dev, id, 0, true);
+	return __devm_reset_control_get(dev, id, 0, true, false);
 }
 
 static inline struct reset_control *devm_reset_control_get_optional_exclusive(
 					struct device *dev, const char *id)
 {
-	return __devm_reset_control_get(dev, id, 0, false);
+	return __devm_reset_control_get(dev, id, 0, false, true);
 }
 
 static inline struct reset_control *devm_reset_control_get_optional_shared(
 					struct device *dev, const char *id)
 {
-	return __devm_reset_control_get(dev, id, 0, true);
+	return __devm_reset_control_get(dev, id, 0, true, true);
 }
 
 /**

@@ -297,7 +304,7 @@ static inline struct reset_control *devm_reset_control_get_optional_shared(
 static inline struct reset_control *
 devm_reset_control_get_exclusive_by_index(struct device *dev, int index)
 {
-	return __devm_reset_control_get(dev, NULL, index, false);
+	return __devm_reset_control_get(dev, NULL, index, false, false);
 }
 
 /**

@@ -313,7 +320,7 @@ devm_reset_control_get_exclusive_by_index(struct device *dev, int index)
 static inline struct reset_control *
 devm_reset_control_get_shared_by_index(struct device *dev, int index)
 {
-	return __devm_reset_control_get(dev, NULL, index, true);
+	return __devm_reset_control_get(dev, NULL, index, true, false);
 }
 

include/linux/reset.h devm_reset_control_get_exclusive_by_index(struct device *dev, int index) · line 326

Quoted 1 line

include/linux/reset.h +0 -0

 /*

regards
Philipp

Hi Philipp

Quoted 12 lines · Philipp Zabel

Hi Ramiro,

Am Dienstag, den 27.12.2016, 12:37 +0000 schrieb Ramiro Oliveira:

Quoted 2 lines

The optional functions weren't really optional so this patch makes them really optional.

Please add a bit of detail to the description. Since this changes the API, you should mention that the reset_control_get_optional variants now return NULL instead of an error if there is no matching reset phandle in the device tree and that the reset_control_* functions accept NULL rstc pointers.

Would you be ok with something like this:

"The *_get_optional_* functions weren't really optional so this patch makes them really optional.

These *_get_optional_* functions will now return NULL instead of an error if no matching reset phandle is found in the DT, and all the reset_control_* functions now accept NULL rstc pointers

Quoted 10 lines

drivers/reset/core.c struct reset_control *__of_reset_control_get(struct device_node *node, · line 298

Quoted 6 lines

drivers/reset/core.c +1 -1

@@ -273,13 +295,13 @@ struct reset_control *__of_reset_control_get(struct device_node *node,
 		index = of_property_match_string(node,
 						 "reset-names", id);
 		if (index < 0)
-			return ERR_PTR(-ENOENT);
+			return optional ? NULL : ERR_PTR(-ENOENT);

of_property_match_string can return -EINVAL, -ENODATA, or -EILSEQ. I think -EILSEQ should still be returned.

I'll make the function return NULL, -ENOENT, or -EILSEQ.

Quoted 11 lines

drivers/reset/core.c struct reset_control *__of_reset_control_get(struct device_node *node, · line 304

Quoted 7 lines

drivers/reset/core.c +1 -1

 	}
 
 	ret = of_parse_phandle_with_args(node, "resets", "#reset-cells",
 					 index, &args);
 	if (ret)
-		return ERR_PTR(ret);
+		return optional ? NULL : ERR_PTR(ret);

of_parse_phandle_with_args can return -ENOENT or -EINVAL. I think -EINVAL should still be returned.

Same as above. I'll make the function return NULL, -ENOENT, or -EINVAL.