Add device managed devm_iio_device_{register,unregister}()
to automatically unregister IIO drivers thus leading to
simplified IIO driver code.
Signed-off-by: Sachin Kamat <sachin.kamat@xxxxxxxxxx>
Cc: Lars-Peter Clausen <lars@xxxxxxxxxx>
---
Changes since v1:
Incorporated review comments from Lars-Peter Clausen
* Renamed variables
* Fixed the broken implementation
* Moved kernel doc from .h to .c file
---
Documentation/driver-model/devres.txt | 2 ++
drivers/iio/industrialio-core.c | 59 +++++++++++++++++++++++++++++++++
include/linux/iio/iio.h | 3 ++
3 files changed, 64 insertions(+)
diff --git a/Documentation/driver-model/devres.txt b/Documentation/driver-model/devres.txt
index fcb34a5..ffeab1d 100644
--- a/Documentation/driver-model/devres.txt
+++ b/Documentation/driver-model/devres.txt
@@ -242,6 +242,8 @@ IIO
devm_iio_device_free()
devm_iio_trigger_alloc()
devm_iio_trigger_free()
+ devm_iio_device_register()
+ devm_iio_device_unregister()
IO region
devm_request_region()
diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
index 24db185..9f2f5fb 100644
--- a/drivers/iio/industrialio-core.c
+++ b/drivers/iio/industrialio-core.c
@@ -1125,6 +1125,65 @@ void iio_device_unregister(struct iio_dev *indio_dev)
device_del(&indio_dev->dev);
}
EXPORT_SYMBOL(iio_device_unregister);
+
+static void devm_iio_device_unreg(struct device *dev, void *res)
+{
+ iio_device_unregister(*(struct iio_dev **)res);
+}
+
+/**
+ * devm_iio_device_register - Resource-managed iio_device_register()
+ * @dev: Device to allocate iio_dev for
+ * @indio_dev: Device structure filled by the device driver
+ *
+ * Managed iio_device_register. The IIO device registered with this
+ * function is automatically unregistered on driver detach. This function
+ * calls iio_device_register() internally. Refer to that function for more
+ * information.
+ *
+ * If an iio_dev registered with this function needs to be unregistered
+ * separately, devm_iio_device_unregister() must be used.
+ *
+ * RETURNS:
+ * 0 on success, negative error number on failure.
+ */
+int devm_iio_device_register(struct device *dev, struct iio_dev *indio_dev)
+{
+ struct iio_dev **ptr;
+ int ret;
+
+ ptr = devres_alloc(devm_iio_device_unreg, sizeof(*ptr), GFP_KERNEL);
+ if (!ptr)
+ return -ENOMEM;
+
+ *ptr = indio_dev;
+ ret = iio_device_register(indio_dev);
+ if (!ret)
+ devres_add(dev, ptr);
+ else
+ devres_free(ptr);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(devm_iio_device_register);
+
+/**
+ * devm_iio_device_unregister - Resource-managed iio_device_unregister()
+ * @dev: Device this iio_dev belongs to
+ * @indio_dev: the iio_dev associated with the device
+ *
+ * Unregister iio_dev registered with devm_iio_device_register().
+ */
+void devm_iio_device_unregister(struct device *dev, struct iio_dev *indio_dev)
+{
+ int rc;
+
+ rc = devres_release(dev, devm_iio_device_unreg,
+ devm_iio_device_match, indio_dev);
+ WARN_ON(rc);
+}
+EXPORT_SYMBOL_GPL(devm_iio_device_unregister);
+
subsys_initcall(iio_init);
module_exit(iio_exit);
diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h
index ac1cb8f..bdda69f 100644
--- a/include/linux/iio/iio.h
+++ b/include/linux/iio/iio.h
@@ -452,6 +452,9 @@ int iio_device_register(struct iio_dev *indio_dev);
**/
void iio_device_unregister(struct iio_dev *indio_dev);
+int devm_iio_device_register(struct device *dev, struct iio_dev *indio_dev);
+void devm_iio_device_unregister(struct device *dev, struct iio_dev *indio_dev);
+
/**
* iio_push_event() - try to add event to the list for userspace reading
* @indio_dev: IIO device structure
--
1.7.9.5
--
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