diff mbox series

[08/13] nvmem: add a notifier chain

Message ID 20180905095738.26406-9-brgl@bgdev.pl (mailing list archive)
State Superseded, archived
Headers show
Series nvmem: rework of the subsystem for non-DT users | expand

Commit Message

Bartosz Golaszewski Sept. 5, 2018, 9:57 a.m. UTC 
From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

Add a blocking notifier chain with two events (add and remove) so that
users can get notified about the addition of nvmem devices 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>
---
 drivers/nvmem/core.c           | 36 ++++++++++++++++++++++++++++++++++
 include/linux/nvmem-consumer.h | 19 ++++++++++++++++++
 2 files changed, 55 insertions(+)

Comments

kernel test robot Sept. 7, 2018, 5:11 a.m. UTC | #1 
Hi Bartosz,

I love your patch! Yet something to improve:

[auto build test ERROR on linus/master]
[also build test ERROR on v4.19-rc2 next-20180906]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Bartosz-Golaszewski/nvmem-rework-of-the-subsystem-for-non-DT-users/20180907-112400
config: i386-randconfig-s3-09061342 (attached as .config)
compiler: gcc-6 (Debian 6.4.0-9) 6.4.0 20171026
reproduce:
        # save the attached .config to linux build tree
        make ARCH=i386 

All errors (new ones prefixed by >>):

   In file included from drivers//of/of_net.c:10:0:
>> include/linux/nvmem-consumer.h:142:19: error: two or more data types in declaration specifiers
    static inline int int nvmem_unregister_notifier(struct notifier_block *nb)
                      ^~~

vim +142 include/linux/nvmem-consumer.h

   141	
 > 142	static inline int int nvmem_unregister_notifier(struct notifier_block *nb)
   143	{
   144		return -ENOSYS;
   145	}
   146	

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
diff mbox series

Patch

diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
index e456aaa6184a..17307015905a 100644
--- a/drivers/nvmem/core.c
+++ b/drivers/nvmem/core.c
@@ -58,6 +58,8 @@  struct nvmem_cell {
 static DEFINE_MUTEX(nvmem_mutex);
 static DEFINE_IDA(nvmem_ida);
 
+static BLOCKING_NOTIFIER_HEAD(nvmem_notifier);
+
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 static struct lock_class_key eeprom_lock_key;
 #endif
@@ -339,6 +341,32 @@  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);
+
 /**
  * nvmem_register() - Register a nvmem device for given nvmem_config.
  * Also creates an binary entry in /sys/bus/nvmem/devices/dev-name/nvmem
@@ -420,8 +448,15 @@  struct nvmem_device *nvmem_register(const struct nvmem_config *config)
 
 	INIT_LIST_HEAD(&nvmem->cells);
 
+	rval = blocking_notifier_call_chain(&nvmem_notifier, NVMEM_ADD, nvmem);
+	if (rval)
+		goto err_teardown_compat;
+
 	return nvmem;
 
+err_teardown_compat:
+	if (config->compat)
+		device_remove_bin_file(nvmem->base_dev, &nvmem->eeprom);
 err_device_del:
 	device_del(&nvmem->dev);
 err_put_device:
@@ -436,6 +471,7 @@  static void nvmem_device_release(struct kref *kref)
 	struct nvmem_device *nvmem;
 
 	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 1313da6731ff..8a6405febc32 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;
@@ -21,6 +22,11 @@  struct device_node;
 struct nvmem_cell;
 struct nvmem_device;
 
+enum {
+	NVMEM_ADD = 1,
+	NVMEM_REMOVE,
+};
+
 #if IS_ENABLED(CONFIG_NVMEM)
 
 /* Cell based interface */
@@ -45,6 +51,9 @@  int nvmem_device_write(struct nvmem_device *nvmem, unsigned int offset,
 
 const char *nvmem_dev_name(struct nvmem_device *nvmem);
 
+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,
@@ -125,6 +134,16 @@  static inline const char *nvmem_dev_name(struct nvmem_device *nvmem)
 	return NULL;
 }
 
+static inline int nvmem_register_notifier(struct notifier_block *nb)
+{
+	return -ENOSYS;
+}
+
+static inline int int nvmem_unregister_notifier(struct notifier_block *nb)
+{
+	return -ENOSYS;
+}
+
 #endif /* CONFIG_NVMEM */
 
 #if IS_ENABLED(CONFIG_NVMEM) && IS_ENABLED(CONFIG_OF)