[PATCH v9 19/24] v4l: fwnode: Add a helper function for parsing generic references

Sakari Ailus
2017-09-08T13:18:31Z

Add function v4l2_fwnode_reference_count() for counting external
references and v4l2_fwnode_reference_parse() for parsing them as async
sub-devices.

This can be done on e.g. flash or lens async sub-devices that are not part
of but are associated with a sensor.

struct v4l2_async_notifier.max_subdevs field is added to contain the
maximum number of sub-devices in a notifier to reflect the memory
allocated for the subdevs array.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
---
drivers/media/v4l2-core/v4l2-fwnode.c | 47 +++++++++++++++++++++++++++++++++++
1 file changed, 47 insertions(+)

diff --git a/drivers/media/v4l2-core/v4l2-fwnode.c b/drivers/media/v4l2-core/v4l2-fwnode.c
index d978f2d714ca..4821c4989119 100644
--- a/drivers/media/v4l2-core/v4l2-fwnode.c
+++ b/drivers/media/v4l2-core/v4l2-fwnode.c
@@ -449,6 +449,53 @@ int v4l2_async_notifier_parse_fwnode_endpoints(
}
EXPORT_SYMBOL_GPL(v4l2_async_notifier_parse_fwnode_endpoints);

+static int v4l2_fwnode_reference_parse(
+ struct device *dev, struct v4l2_async_notifier *notifier,
+ const char *prop)
+{
+ struct fwnode_reference_args args;
+ unsigned int index = 0;
+ int ret;
+
+ for (; !fwnode_property_get_reference_args(
+ dev_fwnode(dev), prop, NULL, 0, index, &args); index++)
+ fwnode_handle_put(args.fwnode);
+
+ ret = v4l2_async_notifier_realloc(notifier,
+ notifier->num_subdevs + index);
+ if (ret)
+ return -ENOMEM;
+
+ for (ret = -ENOENT, index = 0;
+ !fwnode_property_get_reference_args(
+ dev_fwnode(dev), prop, NULL, 0, index, &args);
+ index++) {
+ struct v4l2_async_subdev *asd;
+
+ if (WARN_ON(notifier->num_subdevs >= notifier->max_subdevs)) {
+ ret = -EINVAL;
+ goto error;
+ }
+
+ asd = kzalloc(sizeof(*asd), GFP_KERNEL);
+ if (!asd) {
+ ret = -ENOMEM;
+ goto error;
+ }
+
+ notifier->subdevs[notifier->num_subdevs] = asd;
+ asd->match.fwnode.fwnode = args.fwnode;
+ asd->match_type = V4L2_ASYNC_MATCH_FWNODE;
+ notifier->num_subdevs++;
+ }
+
+ return 0;
+
+error:
+ fwnode_handle_put(args.fwnode);
+ return ret;
+}
+
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Sakari Ailus <sakari.ailus@linux.intel.com>");
MODULE_AUTHOR("Sylwester Nawrocki <s.nawrocki@samsung.com>");
--
2.11.0