Revert "reset: Add support for shared reset controls"

This reverts commit 0b52297f2288ca239e598afe6c92db83d8d2bfcd.

2 files changed, 26 insertions, 129 deletions

diff --git a/drivers/reset/core.c b/drivers/reset/core.c
index 72b32bd15549..957750600ff3 100644
--- a/drivers/reset/core.c
+++ b/drivers/reset/core.c
@@ -8,7 +8,6 @@
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  */
-#include <linux/atomic.h>
 #include <linux/device.h>
 #include <linux/err.h>
 #include <linux/export.h>
@@ -30,16 +29,12 @@ static LIST_HEAD(reset_controller_list);
  * @id: ID of the reset controller in the reset
  *      controller device
  * @refcnt: Number of gets of this reset_control
- * @shared: Is this a shared (1), or an exclusive (0) reset_control?
- * @deassert_cnt: Number of times this reset line has been deasserted
  */
 struct reset_control {
 	struct reset_controller_dev *rcdev;
 	struct list_head list;
 	unsigned int id;
 	unsigned int refcnt;
-	int shared;
-	atomic_t deassert_count;
 };
 
 /**
@@ -96,14 +91,9 @@ EXPORT_SYMBOL_GPL(reset_controller_unregister);
 /**
  * reset_control_reset - reset the controlled device
  * @rstc: reset controller
- *
- * Calling this on a shared reset controller is an error.
  */
 int reset_control_reset(struct reset_control *rstc)
 {
-	if (WARN_ON(rstc->shared))
-		return -EINVAL;
-
 	if (rstc->rcdev->ops->reset)
 		return rstc->rcdev->ops->reset(rstc->rcdev, rstc->id);
 
@@ -114,48 +104,26 @@ EXPORT_SYMBOL_GPL(reset_control_reset);
 /**
  * reset_control_assert - asserts the reset line
  * @rstc: reset controller
- *
- * Calling this on an exclusive reset controller guarantees that the reset
- * will be asserted. When called on a shared reset controller the line may
- * still be deasserted, as long as other users keep it so.
- *
- * 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.
  */
 int reset_control_assert(struct reset_control *rstc)
 {
-	if (!rstc->rcdev->ops->assert)
-		return -ENOTSUPP;
-
-	if (rstc->shared) {
-		if (WARN_ON(atomic_read(&rstc->deassert_count) == 0))
-			return -EINVAL;
-
-		if (atomic_dec_return(&rstc->deassert_count) != 0)
-			return 0;
-	}
+	if (rstc->rcdev->ops->assert)
+		return rstc->rcdev->ops->assert(rstc->rcdev, rstc->id);
 
-	return rstc->rcdev->ops->assert(rstc->rcdev, rstc->id);
+	return -ENOTSUPP;
 }
 EXPORT_SYMBOL_GPL(reset_control_assert);
 
 /**
  * reset_control_deassert - deasserts the reset line
  * @rstc: reset controller
- *
- * After calling this function, the reset is guaranteed to be deasserted.
  */
 int reset_control_deassert(struct reset_control *rstc)
 {
-	if (!rstc->rcdev->ops->deassert)
-		return -ENOTSUPP;
+	if (rstc->rcdev->ops->deassert)
+		return rstc->rcdev->ops->deassert(rstc->rcdev, rstc->id);
 
-	if (rstc->shared) {
-		if (atomic_inc_return(&rstc->deassert_count) != 1)
-			return 0;
-	}
-
-	return rstc->rcdev->ops->deassert(rstc->rcdev, rstc->id);
+	return -ENOTSUPP;
 }
 EXPORT_SYMBOL_GPL(reset_control_deassert);
 
@@ -176,7 +144,7 @@ EXPORT_SYMBOL_GPL(reset_control_status);
 
 static struct reset_control *__reset_control_get(
 				struct reset_controller_dev *rcdev,
-				unsigned int index, int shared)
+				unsigned int index)
 {
 	struct reset_control *rstc;
 
@@ -184,9 +152,6 @@ static struct reset_control *__reset_control_get(
 
 	list_for_each_entry(rstc, &rcdev->reset_control_head, list) {
 		if (rstc->id == index) {
-			if (WARN_ON(!rstc->shared || !shared))
-				return ERR_PTR(-EBUSY);
-
 			rstc->refcnt++;
 			return rstc;
 		}
@@ -202,7 +167,6 @@ static struct reset_control *__reset_control_get(
 	list_add(&rstc->list, &rcdev->reset_control_head);
 	rstc->id = index;
 	rstc->refcnt = 1;
-	rstc->shared = shared;
 
 	return rstc;
 }
@@ -221,7 +185,7 @@ 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, int shared)
+					     const char *id, int index)
 {
 	struct reset_control *rstc;
 	struct reset_controller_dev *r, *rcdev;
@@ -271,7 +235,7 @@ struct reset_control *__of_reset_control_get(struct device_node *node,
 	}
 
 	/* reset_list_mutex also protects the rcdev's reset_control list */
-	rstc = __reset_control_get(rcdev, rstc_id, shared);
+	rstc = __reset_control_get(rcdev, rstc_id);
 
 	mutex_unlock(&reset_list_mutex);
 
@@ -301,7 +265,7 @@ 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, int shared)
+					       const char *id, int index)
 {
 	struct reset_control **ptr, *rstc;
 
@@ -310,8 +274,7 @@ struct reset_control *__devm_reset_control_get(struct device *dev,
 	if (!ptr)
 		return ERR_PTR(-ENOMEM);
 
-	rstc = __of_reset_control_get(dev ? dev->of_node : NULL,
-				      id, index, shared);
+	rstc = __of_reset_control_get(dev ? dev->of_node : NULL, id, index);
 	if (!IS_ERR(rstc)) {
 		*ptr = rstc;
 		devres_add(dev, ptr);
diff --git a/include/linux/reset.h b/include/linux/reset.h
index ec0306ce7b92..dacc0559051f 100644
--- a/include/linux/reset.h
+++ b/include/linux/reset.h
@@ -13,10 +13,10 @@ 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, int shared);
+					     const char *id, int index);
 void reset_control_put(struct reset_control *rstc);
 struct reset_control *__devm_reset_control_get(struct device *dev,
-				     const char *id, int index, int shared);
+					       const char *id, int index);
 
 int __must_check device_reset(struct device *dev);
 
@@ -69,14 +69,14 @@ 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, int shared)
+					const char *id, int index)
 {
 	return ERR_PTR(-EINVAL);
 }
 
 static inline struct reset_control *__devm_reset_control_get(
 					struct device *dev,
-					const char *id, int index, int shared)
+					const char *id, int index)
 {
 	return ERR_PTR(-EINVAL);
 }
@@ -84,17 +84,11 @@ static inline struct reset_control *__devm_reset_control_get(
 #endif /* CONFIG_RESET_CONTROLLER */
 
 /**
- * reset_control_get - Lookup and obtain an exclusive reference to a
- *                     reset controller.
+ * reset_control_get - Lookup and obtain a reference to a reset controller.
  * @dev: device to be reset by the controller
  * @id: reset line name
  *
  * Returns a struct reset_control or IS_ERR() condition containing errno.
- * If this function is called more then once for the same reset_control it will
- * return -EBUSY.
- *
- * See reset_control_get_shared for details on shared references to
- * reset-controls.
  *
  * Use of id names is optional.
  */
@@ -104,46 +98,17 @@ static inline struct reset_control *__must_check reset_control_get(
 #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);
 }
 
 static inline struct reset_control *reset_control_get_optional(
 					struct device *dev, const char *id)
 {
-	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);
 }
 
 /**
- * reset_control_get_shared - Lookup and obtain a shared reference to a
- *                            reset controller.
- * @dev: device to be reset by the controller
- * @id: reset line name
- *
- * Returns a struct reset_control or IS_ERR() condition containing errno.
- * This function is intended for use with reset-controls which are shared
- * between hardware-blocks.
- *
- * When a reset-control is shared, the behavior of reset_control_assert /
- * deassert is changed, the reset-core will keep track of a deassert_count
- * and only (re-)assert the reset after reset_control_assert has been called
- * as many times as reset_control_deassert was called. Also see the remark
- * about shared reset-controls in the reset_control_assert docs.
- *
- * Calling reset_control_assert without first calling reset_control_deassert
- * is not allowed on a shared reset control. Calling reset_control_reset is
- * also not allowed on a shared reset control.
- *
- * Use of id names is optional.
- */
-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, 1);
-}
-
-/**
- * of_reset_control_get - Lookup and obtain an exclusive reference to a
- *                        reset controller.
+ * of_reset_control_get - Lookup and obtain a reference to a reset controller.
  * @node: device to be reset by the controller
  * @id: reset line name
  *
@@ -154,12 +119,12 @@ static inline struct reset_control *reset_control_get_shared(
 static inline struct reset_control *of_reset_control_get(
 				struct device_node *node, const char *id)
 {
-	return __of_reset_control_get(node, id, 0, 0);
+	return __of_reset_control_get(node, id, 0);
 }
 
 /**
- * of_reset_control_get_by_index - Lookup and obtain an exclusive reference to
- *                                 a reset controller by index.
+ * of_reset_control_get_by_index - Lookup and obtain a reference to a reset
+ * controller by index.
  * @node: device to be reset by the controller
  * @index: index of the reset controller
  *
@@ -170,7 +135,7 @@ static inline struct reset_control *of_reset_control_get(
 static inline struct reset_control *of_reset_control_get_by_index(
 					struct device_node *node, int index)
 {
-	return __of_reset_control_get(node, NULL, index, 0);
+	return __of_reset_control_get(node, NULL, index);
 }
 
 /**
@@ -188,13 +153,13 @@ static inline struct reset_control *__must_check devm_reset_control_get(
 #ifndef CONFIG_RESET_CONTROLLER
 	WARN_ON(1);
 #endif
-	return __devm_reset_control_get(dev, id, 0, 0);
+	return __devm_reset_control_get(dev, id, 0);
 }
 
 static inline struct reset_control *devm_reset_control_get_optional(
 					struct device *dev, const char *id)
 {
-	return __devm_reset_control_get(dev, id, 0, 0);
+	return __devm_reset_control_get(dev, id, 0);
 }
 
 /**
@@ -209,38 +174,7 @@ static inline struct reset_control *devm_reset_control_get_optional(
 static inline struct reset_control *devm_reset_control_get_by_index(
 					struct device *dev, int index)
 {
-	return __devm_reset_control_get(dev, NULL, index, 0);
-}
-
-/**
- * devm_reset_control_get_shared - resource managed reset_control_get_shared()
- * @dev: device to be reset by the controller
- * @id: reset line name
- *
- * Managed reset_control_get_shared(). For reset controllers returned from
- * this function, reset_control_put() is called automatically on driver detach.
- * See reset_control_get_shared() for more information.
- */
-static inline struct reset_control *devm_reset_control_get_shared(
-					struct device *dev, const char *id)
-{
-	return __devm_reset_control_get(dev, id, 0, 1);
-}
-
-/**
- * devm_reset_control_get_shared_by_index - resource managed
- * reset_control_get_shared
- * @dev: device to be reset by the controller
- * @index: index of the reset controller
- *
- * Managed reset_control_get_shared(). For reset controllers returned from
- * this function, reset_control_put() is called automatically on driver detach.
- * See reset_control_get_shared() for more information.
- */
-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, 1);
+	return __devm_reset_control_get(dev, NULL, index);
 }
 
 #endif