nvmem: add a notifier chain

Add a blocking notifier chain with four events (add and remove for
both devices and cells) so that users can get notified about the
addition of nvmem resources they're waiting for.

We'll use this instead of the at24 setup callback in the mityomapl138
board file.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Bartosz Golaszewski 2018-09-21 06:40:19 -07:00 committed by Greg Kroah-Hartman
parent 4903d19c20
commit bee1138bea
2 changed files with 57 additions and 0 deletions

View file

@ -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)