Merge tag 'reset-for-4.7' of git://git.pengutronix.de/git/pza/linux into next/drivers

Reset controller changes for v4.7

- add support for shared reset controls
- remove global variables from the lpc18xx driver

* tag 'reset-for-4.7' of git://git.pengutronix.de/git/pza/linux:
  reset: lpc18xx: get rid of global variables for restart notifier
  reset: Add support for shared reset controls
  reset: Share struct reset_control between reset_control_get calls
  reset: Make [of_]reset_control_get[_foo] functions wrappers

Signed-off-by: Olof Johansson <olof@lixom.net>

2 files changed, 156 insertions, 34 deletions

diff --git a/include/linux/reset-controller.h b/include/linux/reset-controller.h
index a3a5bcdb1d02..b91ba932bbd4 100644
--- a/include/linux/reset-controller.h
+++ b/include/linux/reset-controller.h
@@ -31,6 +31,7 @@ struct of_phandle_args;
  * @ops: a pointer to device specific struct reset_control_ops
  * @owner: kernel module of the reset controller driver
  * @list: internal list of reset controller devices
+ * @reset_control_head: head of internal list of requested reset controls
  * @of_node: corresponding device tree node as phandle target
  * @of_reset_n_cells: number of cells in reset line specifiers
  * @of_xlate: translation function to translate from specifier as found in the
@@ -41,6 +42,7 @@ struct reset_controller_dev {
 	const struct reset_control_ops *ops;
 	struct module *owner;
 	struct list_head list;
+	struct list_head reset_control_head;
 	struct device_node *of_node;
 	int of_reset_n_cells;
 	int (*of_xlate)(struct reset_controller_dev *rcdev,
diff --git a/include/linux/reset.h b/include/linux/reset.h
index c4c097de0ba9..a552134a209e 100644
--- a/include/linux/reset.h
+++ b/include/linux/reset.h
@@ -1,8 +1,8 @@
 #ifndef _LINUX_RESET_H_
 #define _LINUX_RESET_H_
 
-struct device;
-struct device_node;
+#include <linux/device.h>
+
 struct reset_control;
 
 #ifdef CONFIG_RESET_CONTROLLER
@@ -12,9 +12,11 @@ int reset_control_assert(struct reset_control *rstc);
 int reset_control_deassert(struct reset_control *rstc);
 int reset_control_status(struct reset_control *rstc);
 
-struct reset_control *reset_control_get(struct device *dev, const char *id);
+struct reset_control *__of_reset_control_get(struct device_node *node,
+				     const char *id, int index, int shared);
 void reset_control_put(struct reset_control *rstc);
-struct reset_control *devm_reset_control_get(struct device *dev, const char *id);
+struct reset_control *__devm_reset_control_get(struct device *dev,
+				     const char *id, int index, int shared);
 
 int __must_check device_reset(struct device *dev);
 
@@ -23,24 +25,6 @@ static inline int device_reset_optional(struct device *dev)
 	return device_reset(dev);
 }
 
-static inline struct reset_control *reset_control_get_optional(
-					struct device *dev, const char *id)
-{
-	return reset_control_get(dev, id);
-}
-
-static inline struct reset_control *devm_reset_control_get_optional(
-					struct device *dev, const char *id)
-{
-	return devm_reset_control_get(dev, id);
-}
-
-struct reset_control *of_reset_control_get(struct device_node *node,
-					   const char *id);
-
-struct reset_control *of_reset_control_get_by_index(
-					struct device_node *node, int index);
-
 #else
 
 static inline int reset_control_reset(struct reset_control *rstc)
@@ -77,44 +61,180 @@ static inline int device_reset_optional(struct device *dev)
 	return -ENOTSUPP;
 }
 
-static inline struct reset_control *__must_check reset_control_get(
-					struct device *dev, const char *id)
+static inline struct reset_control *__of_reset_control_get(
+					struct device_node *node,
+					const char *id, int index, int shared)
 {
-	WARN_ON(1);
 	return ERR_PTR(-EINVAL);
 }
 
-static inline struct reset_control *__must_check devm_reset_control_get(
+static inline struct reset_control *__devm_reset_control_get(
+					struct device *dev,
+					const char *id, int index, int shared)
+{
+	return ERR_PTR(-EINVAL);
+}
+
+#endif /* CONFIG_RESET_CONTROLLER */
+
+/**
+ * reset_control_get - Lookup and obtain an exclusive 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.
+ */
+static inline struct reset_control *__must_check reset_control_get(
 					struct device *dev, const char *id)
 {
+#ifndef CONFIG_RESET_CONTROLLER
 	WARN_ON(1);
-	return ERR_PTR(-EINVAL);
+#endif
+	return __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, 0);
 }
 
 static inline struct reset_control *reset_control_get_optional(
 					struct device *dev, const char *id)
 {
-	return ERR_PTR(-ENOTSUPP);
+	return __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, 0);
 }
 
-static inline struct reset_control *devm_reset_control_get_optional(
+/**
+ * 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 ERR_PTR(-ENOTSUPP);
+	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.
+ * @node: device to be reset by the controller
+ * @id: reset line name
+ *
+ * Returns a struct reset_control or IS_ERR() condition containing errno.
+ *
+ * Use of id names is optional.
+ */
 static inline struct reset_control *of_reset_control_get(
 				struct device_node *node, const char *id)
 {
-	return ERR_PTR(-ENOTSUPP);
+	return __of_reset_control_get(node, id, 0, 0);
 }
 
+/**
+ * of_reset_control_get_by_index - Lookup and obtain an exclusive reference to
+ *                                 a reset controller by index.
+ * @node: device to be reset by the controller
+ * @index: index of the reset controller
+ *
+ * This is to be used to perform a list of resets for a device or power domain
+ * in whatever order. Returns a struct reset_control or IS_ERR() condition
+ * containing errno.
+ */
 static inline struct reset_control *of_reset_control_get_by_index(
-				struct device_node *node, int index)
+					struct device_node *node, int index)
 {
-	return ERR_PTR(-ENOTSUPP);
+	return __of_reset_control_get(node, NULL, index, 0);
 }
 
-#endif /* CONFIG_RESET_CONTROLLER */
+/**
+ * devm_reset_control_get - resource managed reset_control_get()
+ * @dev: device to be reset by the controller
+ * @id: reset line name
+ *
+ * Managed reset_control_get(). For reset controllers returned from this
+ * function, reset_control_put() is called automatically on driver detach.
+ * See reset_control_get() for more information.
+ */
+static inline struct reset_control *__must_check devm_reset_control_get(
+					struct device *dev, const char *id)
+{
+#ifndef CONFIG_RESET_CONTROLLER
+	WARN_ON(1);
+#endif
+	return __devm_reset_control_get(dev, id, 0, 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);
+}
+
+/**
+ * devm_reset_control_get_by_index - resource managed reset_control_get
+ * @dev: device to be reset by the controller
+ * @index: index of the reset controller
+ *
+ * Managed reset_control_get(). For reset controllers returned from this
+ * function, reset_control_put() is called automatically on driver detach.
+ * See reset_control_get() for more information.
+ */
+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);
+}
 
 #endif