[PATCH v16 26/32] v4l: fwnode: Add a convenience function for registering sensors

Sakari Ailus
2017-10-26T07:53:36Z

Add a convenience function for parsing firmware for information on related
devices using v4l2_async_notifier_parse_fwnode_sensor_common() registering
the notifier and finally the async sub-device itself.

This should be useful for sensor drivers that do not have device specific
requirements related to firmware information parsing or the async
framework.

Signed-off-by: Sakari Ailus <sakari.ailus-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
Acked-by: Hans Verkuil <hans.verkuil-FYB4Gu1CFyUAvxtiuMwx3w@public.gmane.org>
---
drivers/media/v4l2-core/v4l2-async.c | 19 ++++++++++++----
drivers/media/v4l2-core/v4l2-fwnode.c | 41 +++++++++++++++++++++++++++++++++++
include/media/v4l2-async.h | 22 +++++++++++++++++++
include/media/v4l2-subdev.h | 3 +++
4 files changed, 81 insertions(+), 4 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
index b4e88eef195f..e81a72b8d46e 100644
--- a/drivers/media/v4l2-core/v4l2-async.c
+++ b/drivers/media/v4l2-core/v4l2-async.c
@@ -474,19 +474,25 @@ int v4l2_async_subdev_notifier_register(struct v4l2_subdev *sd,
}
EXPORT_SYMBOL(v4l2_async_subdev_notifier_register);

-void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier)
+static void __v4l2_async_notifier_unregister(
+ struct v4l2_async_notifier *notifier)
{
- if (!notifier->v4l2_dev && !notifier->sd)
+ if (!notifier || (!notifier->v4l2_dev && !notifier->sd))
return;

- mutex_lock(&list_lock);
-
v4l2_async_notifier_unbind_all_subdevs(notifier);

notifier->sd = NULL;
notifier->v4l2_dev = NULL;

list_del(&notifier->list);
+}
+
+void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier)
+{
+ mutex_lock(&list_lock);
+
+ __v4l2_async_notifier_unregister(notifier);

mutex_unlock(&list_lock);
}
@@ -596,6 +602,11 @@ void v4l2_async_unregister_subdev(struct v4l2_subdev *sd)
{
mutex_lock(&list_lock);

+ __v4l2_async_notifier_unregister(sd->subdev_notifier);
+ v4l2_async_notifier_cleanup(sd->subdev_notifier);
+ kfree(sd->subdev_notifier);
+ sd->subdev_notifier = NULL;
+
if (sd->asd) {
struct v4l2_async_notifier *notifier = sd->notifier;

diff --git a/drivers/media/v4l2-core/v4l2-fwnode.c b/drivers/media/v4l2-core/v4l2-fwnode.c
index 1234bd1a2f49..82af608fd626 100644
--- a/drivers/media/v4l2-core/v4l2-fwnode.c
+++ b/drivers/media/v4l2-core/v4l2-fwnode.c
@@ -29,6 +29,7 @@

#include <media/v4l2-async.h>
#include <media/v4l2-fwnode.h>
+#include <media/v4l2-subdev.h>

enum v4l2_fwnode_bus_type {
V4L2_FWNODE_BUS_TYPE_GUESS = 0,
@@ -900,6 +901,46 @@ int v4l2_async_notifier_parse_fwnode_sensor_common(
}
EXPORT_SYMBOL_GPL(v4l2_async_notifier_parse_fwnode_sensor_common);

+int v4l2_async_register_subdev_sensor_common(struct v4l2_subdev *sd)
+{
+ struct v4l2_async_notifier *notifier;
+ int ret;
+
+ if (WARN_ON(!sd->dev))
+ return -ENODEV;
+
+ notifier = kzalloc(sizeof(*notifier), GFP_KERNEL);
+ if (!notifier)
+ return -ENOMEM;
+
+ ret = v4l2_async_notifier_parse_fwnode_sensor_common(sd->dev,
+ notifier);
+ if (ret < 0)
+ goto out_cleanup;
+
+ ret = v4l2_async_subdev_notifier_register(sd, notifier);
+ if (ret < 0)
+ goto out_cleanup;
+
+ ret = v4l2_async_register_subdev(sd);
+ if (ret < 0)
+ goto out_unregister;
+
+ sd->subdev_notifier = notifier;
+
+ return 0;
+
+out_unregister:
+ v4l2_async_notifier_unregister(notifier);
+
+out_cleanup:
+ v4l2_async_notifier_cleanup(notifier);
+ kfree(notifier);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(v4l2_async_register_subdev_sensor_common);
+
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Sakari Ailus <sakari.ailus-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>");
MODULE_AUTHOR("Sylwester Nawrocki <s.nawrocki-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>");
diff --git a/include/media/v4l2-async.h b/include/media/v4l2-async.h
index 8d8cfc3f3100..6152434cbe82 100644
--- a/include/media/v4l2-async.h
+++ b/include/media/v4l2-async.h
@@ -174,6 +174,28 @@ void v4l2_async_notifier_cleanup(struct v4l2_async_notifier *notifier);
int v4l2_async_register_subdev(struct v4l2_subdev *sd);

/**
+ * v4l2_async_register_subdev_sensor_common - registers a sensor sub-device to
+ * the asynchronous sub-device
+ * framework and parse set up common
+ * sensor related devices
+ *
+ * @sd: pointer to struct &v4l2_subdev
+ *
+ * This function is just like v4l2_async_register_subdev() with the exception
+ * that calling it will also parse firmware interfaces for remote references
+ * using v4l2_async_notifier_parse_fwnode_sensor_common() and registers the
+ * async sub-devices. The sub-device is similarly unregistered by calling
+ * v4l2_async_unregister_subdev().
+ *
+ * While registered, the subdev module is marked as in-use.
+ *
+ * An error is returned if the module is no longer loaded on any attempts
+ * to register it.
+ */
+int __must_check v4l2_async_register_subdev_sensor_common(
+ struct v4l2_subdev *sd);
+
+/**
* v4l2_async_unregister_subdev - unregisters a sub-device to the asynchronous
* subdevice framework
*
diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h
index e83872078376..ec399c770301 100644
--- a/include/media/v4l2-subdev.h
+++ b/include/media/v4l2-subdev.h
@@ -793,6 +793,8 @@ struct v4l2_subdev_platform_data {
* list.
* @asd: Pointer to respective &struct v4l2_async_subdev.
* @notifier: Pointer to the managing notifier.
+ * @subdev_notifier: A sub-device notifier implicitly registered for the sub-
+ * device using v4l2_device_register_sensor_subdev().
* @pdata: common part of subdevice platform data
*
* Each instance of a subdev driver should create this struct, either
@@ -823,6 +825,7 @@ struct v4l2_subdev {
struct list_head async_list;
struct v4l2_async_subdev *asd;
struct v4l2_async_notifier *notifier;
+ struct v4l2_async_notifier *subdev_notifier;
struct v4l2_subdev_platform_data *pdata;
};

--
2.11.0

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