nvmem: provide nvmem_dev_name()

Kernel users don't have any means of checking the names of nvmem
devices. Add a routine that returns the name of the nvmem provider.

This will be useful for future nvmem notifier subscribers - otherwise
they can't check what device is being added/removed.
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>

drivers/nvmem/core.c

@@ -1343,6 +1343,19 @@ int nvmem_device_write(struct nvmem_device *nvmem,
 }
 EXPORT_SYMBOL_GPL(nvmem_device_write);
 
+/**
+ * nvmem_dev_name() - Get the name of a given nvmem device.
+ *
+ * @nvmem: nvmem device.
+ *
+ * Return: name of the nvmem device.
+ */
+const char *nvmem_dev_name(struct nvmem_device *nvmem)
+{
+	return dev_name(&nvmem->dev);
+}
+EXPORT_SYMBOL_GPL(nvmem_dev_name);
+
 static int __init nvmem_init(void)
 {
 	return bus_register(&nvmem_bus_type);

include/linux/nvmem-consumer.h

@@ -55,6 +55,8 @@ ssize_t nvmem_device_cell_read(struct nvmem_device *nvmem,
 int nvmem_device_cell_write(struct nvmem_device *nvmem,
 			    struct nvmem_cell_info *info, void *buf);
 
+const char *nvmem_dev_name(struct nvmem_device *nvmem);
+
 #else
 
 static inline struct nvmem_cell *nvmem_cell_get(struct device *dev,
@@ -143,6 +145,12 @@ static inline int nvmem_device_write(struct nvmem_device *nvmem,
 {
 	return -ENOSYS;
 }
+
+static inline const char *nvmem_dev_name(struct nvmem_device *nvmem)
+{
+	return NULL;
+}
+
 #endif /* CONFIG_NVMEM */
 
 #if IS_ENABLED(CONFIG_NVMEM) && IS_ENABLED(CONFIG_OF)