[RFC 09/19] v4l2-fwnode: Add conveniences function for parsing generic references

Sakari Ailus
2017-07-18T19:04:07Z

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 | 53 +++++++++++++++++++++++++++++++++++
include/media/v4l2-fwnode.h | 8 ++++++
2 files changed, 61 insertions(+)

diff --git a/drivers/media/v4l2-core/v4l2-fwnode.c b/drivers/media/v4l2-core/v4l2-fwnode.c
index c3ad9e31e4cb..bfc9e38766f3 100644
--- a/drivers/media/v4l2-core/v4l2-fwnode.c
+++ b/drivers/media/v4l2-core/v4l2-fwnode.c
@@ -433,6 +433,59 @@ int v4l2_fwnode_endpoints_parse(
}
EXPORT_SYMBOL_GPL(v4l2_fwnode_endpoints_parse);

+int v4l2_fwnode_reference_parse(
+ struct device *dev, struct v4l2_async_notifier *notifier,
+ const char *prop, const char *nargs_prop, unsigned int nargs,
+ size_t asd_struct_size,
+ int (*parse_single)(struct device *dev,
+ struct fwnode_reference_args *args,
+ struct v4l2_async_subdev *asd))
+{
+ struct fwnode_reference_args args;
+ unsigned int max_subdevs = notifier->max_subdevs;
+ int ret;
+
+ if (asd_struct_size < sizeof(struct v4l2_async_subdev))
+ return -EINVAL;
+
+ while (!fwnode_property_get_reference_args(
+ dev_fwnode(dev), prop, nargs_prop, nargs,
+ max_subdevs - notifier->max_subdevs, NULL))
+ max_subdevs++;
+
+ ret = notifier_realloc(dev, notifier, max_subdevs);
+ if (ret)
+ return ret;
+
+ for (ret = -ENOENT; !fwnode_property_get_reference_args(
+ dev_fwnode(dev), prop, nargs_prop, nargs,
+ notifier->num_subdevs, &args) &&
+ !WARN_ON(notifier->num_subdevs >= notifier->max_subdevs);
+ notifier->num_subdevs++) {
+ struct v4l2_async_subdev *asd;
+
+ asd = devm_kzalloc(dev, asd_struct_size, GFP_KERNEL);
+ if (!asd) {
+ fwnode_handle_put(args.fwnode);
+ ret = -ENOMEM;
+ goto error;
+ }
+
+ ret = parse_single ? parse_single(dev, &args, asd) : 0;
+ fwnode_handle_put(args.fwnode);
+ if (ret)
+ goto error;
+
+ notifier->subdevs[notifier->num_subdevs] = asd;
+ asd->match.fwnode.fwnode = args.fwnode;
+ asd->match_type = V4L2_ASYNC_MATCH_FWNODE;
+ }
+
+error:
+ return ret;
+}
+EXPORT_SYMBOL_GPL(v4l2_fwnode_reference_parse);
+
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Sakari Ailus <sakari.ailus@linux.intel.com>");
MODULE_AUTHOR("Sylwester Nawrocki <s.nawrocki@samsung.com>");
diff --git a/include/media/v4l2-fwnode.h b/include/media/v4l2-fwnode.h
index 6ba1a0bbc328..e27526bd744d 100644
--- a/include/media/v4l2-fwnode.h
+++ b/include/media/v4l2-fwnode.h
@@ -110,4 +110,12 @@ int v4l2_fwnode_endpoints_parse(
struct v4l2_fwnode_endpoint *vep,
struct v4l2_async_subdev *asd));

+int v4l2_fwnode_reference_parse(
+ struct device *dev, struct v4l2_async_notifier *notifier,
+ const char *prop, const char *nargs_prop, unsigned int nargs,
+ size_t asd_struct_size,
+ int (*parse_single)(struct device *dev,
+ struct fwnode_reference_args *args,
+ struct v4l2_async_subdev *asd));
+
#endif /* _V4L2_FWNODE_H */
--
2.11.0