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-rw-r--r--drivers/reset/core.c96
-rw-r--r--include/linux/reset-controller.h30
2 files changed, 125 insertions, 1 deletions
diff --git a/drivers/reset/core.c b/drivers/reset/core.c
index da4292e9de97..6488292e129c 100644
--- a/drivers/reset/core.c
+++ b/drivers/reset/core.c
@@ -23,6 +23,9 @@
static DEFINE_MUTEX(reset_list_mutex);
static LIST_HEAD(reset_controller_list);
+static DEFINE_MUTEX(reset_lookup_mutex);
+static LIST_HEAD(reset_lookup_list);
+
/**
* struct reset_control - a reset control
* @rcdev: a pointer to the reset controller device
@@ -148,6 +151,33 @@ int devm_reset_controller_register(struct device *dev,
}
EXPORT_SYMBOL_GPL(devm_reset_controller_register);
+/**
+ * reset_controller_add_lookup - register a set of lookup entries
+ * @lookup: array of reset lookup entries
+ * @num_entries: number of entries in the lookup array
+ */
+void reset_controller_add_lookup(struct reset_control_lookup *lookup,
+ unsigned int num_entries)
+{
+ struct reset_control_lookup *entry;
+ unsigned int i;
+
+ mutex_lock(&reset_lookup_mutex);
+ for (i = 0; i < num_entries; i++) {
+ entry = &lookup[i];
+
+ if (!entry->dev_id || !entry->provider) {
+ pr_warn("%s(): reset lookup entry badly specified, skipping\n",
+ __func__);
+ continue;
+ }
+
+ list_add_tail(&entry->list, &reset_lookup_list);
+ }
+ mutex_unlock(&reset_lookup_mutex);
+}
+EXPORT_SYMBOL_GPL(reset_controller_add_lookup);
+
static inline struct reset_control_array *
rstc_to_array(struct reset_control *rstc) {
return container_of(rstc, struct reset_control_array, base);
@@ -493,6 +523,70 @@ struct reset_control *__of_reset_control_get(struct device_node *node,
}
EXPORT_SYMBOL_GPL(__of_reset_control_get);
+static struct reset_controller_dev *
+__reset_controller_by_name(const char *name)
+{
+ struct reset_controller_dev *rcdev;
+
+ lockdep_assert_held(&reset_list_mutex);
+
+ list_for_each_entry(rcdev, &reset_controller_list, list) {
+ if (!rcdev->dev)
+ continue;
+
+ if (!strcmp(name, dev_name(rcdev->dev)))
+ return rcdev;
+ }
+
+ return NULL;
+}
+
+static struct reset_control *
+__reset_control_get_from_lookup(struct device *dev, const char *con_id,
+ bool shared, bool optional)
+{
+ const struct reset_control_lookup *lookup;
+ struct reset_controller_dev *rcdev;
+ const char *dev_id = dev_name(dev);
+ struct reset_control *rstc = NULL;
+
+ if (!dev)
+ return ERR_PTR(-EINVAL);
+
+ mutex_lock(&reset_lookup_mutex);
+
+ list_for_each_entry(lookup, &reset_lookup_list, list) {
+ if (strcmp(lookup->dev_id, dev_id))
+ continue;
+
+ if ((!con_id && !lookup->con_id) ||
+ ((con_id && lookup->con_id) &&
+ !strcmp(con_id, lookup->con_id))) {
+ mutex_lock(&reset_list_mutex);
+ rcdev = __reset_controller_by_name(lookup->provider);
+ if (!rcdev) {
+ mutex_unlock(&reset_list_mutex);
+ mutex_unlock(&reset_lookup_mutex);
+ /* Reset provider may not be ready yet. */
+ return ERR_PTR(-EPROBE_DEFER);
+ }
+
+ rstc = __reset_control_get_internal(rcdev,
+ lookup->index,
+ shared);
+ mutex_unlock(&reset_list_mutex);
+ break;
+ }
+ }
+
+ mutex_unlock(&reset_lookup_mutex);
+
+ if (!rstc)
+ return optional ? NULL : ERR_PTR(-ENOENT);
+
+ return rstc;
+}
+
struct reset_control *__reset_control_get(struct device *dev, const char *id,
int index, bool shared, bool optional)
{
@@ -500,7 +594,7 @@ struct reset_control *__reset_control_get(struct device *dev, const char *id,
return __of_reset_control_get(dev->of_node, id, index, shared,
optional);
- return optional ? NULL : ERR_PTR(-EINVAL);
+ return __reset_control_get_from_lookup(dev, id, shared, optional);
}
EXPORT_SYMBOL_GPL(__reset_control_get);
diff --git a/include/linux/reset-controller.h b/include/linux/reset-controller.h
index adb88f8cefbc..9326d671b6e6 100644
--- a/include/linux/reset-controller.h
+++ b/include/linux/reset-controller.h
@@ -27,12 +27,38 @@ struct device_node;
struct of_phandle_args;
/**
+ * struct reset_control_lookup - represents a single lookup entry
+ *
+ * @list: internal list of all reset lookup entries
+ * @provider: name of the reset controller device controlling this reset line
+ * @index: ID of the reset controller in the reset controller device
+ * @dev_id: name of the device associated with this reset line
+ * @con_id name of the reset line (can be NULL)
+ */
+struct reset_control_lookup {
+ struct list_head list;
+ const char *provider;
+ unsigned int index;
+ const char *dev_id;
+ const char *con_id;
+};
+
+#define RESET_LOOKUP(_provider, _index, _dev_id, _con_id) \
+ { \
+ .provider = _provider, \
+ .index = _index, \
+ .dev_id = _dev_id, \
+ .con_id = _con_id, \
+ }
+
+/**
* struct reset_controller_dev - reset controller entity that might
* provide multiple reset controls
* @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
+ * @dev: corresponding driver model device struct
* @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
@@ -44,6 +70,7 @@ struct reset_controller_dev {
struct module *owner;
struct list_head list;
struct list_head reset_control_head;
+ struct device *dev;
struct device_node *of_node;
int of_reset_n_cells;
int (*of_xlate)(struct reset_controller_dev *rcdev,
@@ -58,4 +85,7 @@ struct device;
int devm_reset_controller_register(struct device *dev,
struct reset_controller_dev *rcdev);
+void reset_controller_add_lookup(struct reset_control_lookup *lookup,
+ unsigned int num_entries);
+
#endif