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-rw-r--r--drivers/nvmem/core.c36
-rw-r--r--include/linux/nvmem-consumer.h21
2 files changed, 57 insertions, 0 deletions
diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
index 9cc86d131e1e..da441019b609 100644
--- a/drivers/nvmem/core.c
+++ b/drivers/nvmem/core.c
@@ -65,6 +65,8 @@ static LIST_HEAD(nvmem_cell_tables);
static DEFINE_MUTEX(nvmem_lookup_mutex);
static LIST_HEAD(nvmem_lookup_list);
+static BLOCKING_NOTIFIER_HEAD(nvmem_notifier);
+
#ifdef CONFIG_DEBUG_LOCK_ALLOC
static struct lock_class_key eeprom_lock_key;
#endif
@@ -300,6 +302,7 @@ static struct nvmem_device *nvmem_find(const char *name)
static void nvmem_cell_drop(struct nvmem_cell *cell)
{
+ blocking_notifier_call_chain(&nvmem_notifier, NVMEM_CELL_REMOVE, cell);
mutex_lock(&nvmem_mutex);
list_del(&cell->node);
mutex_unlock(&nvmem_mutex);
@@ -319,6 +322,7 @@ static void nvmem_cell_add(struct nvmem_cell *cell)
mutex_lock(&nvmem_mutex);
list_add_tail(&cell->node, &cell->nvmem->cells);
mutex_unlock(&nvmem_mutex);
+ blocking_notifier_call_chain(&nvmem_notifier, NVMEM_CELL_ADD, cell);
}
static int nvmem_cell_info_to_nvmem_cell(struct nvmem_device *nvmem,
@@ -434,6 +438,32 @@ static int nvmem_setup_compat(struct nvmem_device *nvmem,
return 0;
}
+/**
+ * nvmem_register_notifier() - Register a notifier block for nvmem events.
+ *
+ * @nb: notifier block to be called on nvmem events.
+ *
+ * Return: 0 on success, negative error number on failure.
+ */
+int nvmem_register_notifier(struct notifier_block *nb)
+{
+ return blocking_notifier_chain_register(&nvmem_notifier, nb);
+}
+EXPORT_SYMBOL_GPL(nvmem_register_notifier);
+
+/**
+ * nvmem_unregister_notifier() - Unregister a notifier block for nvmem events.
+ *
+ * @nb: notifier block to be unregistered.
+ *
+ * Return: 0 on success, negative error number on failure.
+ */
+int nvmem_unregister_notifier(struct notifier_block *nb)
+{
+ return blocking_notifier_chain_unregister(&nvmem_notifier, nb);
+}
+EXPORT_SYMBOL_GPL(nvmem_unregister_notifier);
+
static int nvmem_add_cells_from_table(struct nvmem_device *nvmem)
{
const struct nvmem_cell_info *info;
@@ -647,6 +677,10 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
if (rval)
goto err_remove_cells;
+ rval = blocking_notifier_call_chain(&nvmem_notifier, NVMEM_ADD, nvmem);
+ if (rval)
+ goto err_remove_cells;
+
return nvmem;
err_remove_cells:
@@ -669,6 +703,8 @@ static void nvmem_device_release(struct kref *kref)
nvmem = container_of(kref, struct nvmem_device, refcnt);
+ blocking_notifier_call_chain(&nvmem_notifier, NVMEM_REMOVE, nvmem);
+
if (nvmem->flags & FLAG_COMPAT)
device_remove_bin_file(nvmem->base_dev, &nvmem->eeprom);
diff --git a/include/linux/nvmem-consumer.h b/include/linux/nvmem-consumer.h
index 27eee3945405..0326b52e906b 100644
--- a/include/linux/nvmem-consumer.h
+++ b/include/linux/nvmem-consumer.h
@@ -14,6 +14,7 @@
#include <linux/err.h>
#include <linux/errno.h>
+#include <linux/notifier.h>
struct device;
struct device_node;
@@ -47,6 +48,13 @@ struct nvmem_cell_lookup {
struct list_head node;
};
+enum {
+ NVMEM_ADD = 1,
+ NVMEM_REMOVE,
+ NVMEM_CELL_ADD,
+ NVMEM_CELL_REMOVE,
+};
+
#if IS_ENABLED(CONFIG_NVMEM)
/* Cell based interface */
@@ -80,6 +88,9 @@ void nvmem_add_cell_lookups(struct nvmem_cell_lookup *entries,
void nvmem_del_cell_lookups(struct nvmem_cell_lookup *entries,
size_t nentries);
+int nvmem_register_notifier(struct notifier_block *nb);
+int nvmem_unregister_notifier(struct notifier_block *nb);
+
#else
static inline struct nvmem_cell *nvmem_cell_get(struct device *dev,
@@ -179,6 +190,16 @@ nvmem_add_cell_lookups(struct nvmem_cell_lookup *entries, size_t nentries) {}
static inline void
nvmem_del_cell_lookups(struct nvmem_cell_lookup *entries, size_t nentries) {}
+static inline int nvmem_register_notifier(struct notifier_block *nb)
+{
+ return -ENOSYS;
+}
+
+static inline int nvmem_unregister_notifier(struct notifier_block *nb)
+{
+ return -ENOSYS;
+}
+
#endif /* CONFIG_NVMEM */
#if IS_ENABLED(CONFIG_NVMEM) && IS_ENABLED(CONFIG_OF)