[PATCH v16 23/32] v4l: fwnode: Add a helper function for parsing generic references

Sakari Ailus
2017-10-26T07:54:52Z

Add function 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.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
---
drivers/media/v4l2-core/v4l2-fwnode.c | 69 +++++++++++++++++++++++++++++++++++
1 file changed, 69 insertions(+)

diff --git a/drivers/media/v4l2-core/v4l2-fwnode.c b/drivers/media/v4l2-core/v4l2-fwnode.c
index 65bdcd59744a..edd2e8d983a1 100644
--- a/drivers/media/v4l2-core/v4l2-fwnode.c
+++ b/drivers/media/v4l2-core/v4l2-fwnode.c
@@ -509,6 +509,75 @@ int v4l2_async_notifier_parse_fwnode_endpoints_by_port(
}
EXPORT_SYMBOL_GPL(v4l2_async_notifier_parse_fwnode_endpoints_by_port);

+/*
+ * v4l2_fwnode_reference_parse - parse references for async sub-devices
+ * @dev: the device node the properties of which are parsed for references
+ * @notifier: the async notifier where the async subdevs will be added
+ * @prop: the name of the property
+ *
+ * Return: 0 on success
+ * -ENOENT if no entries were found
+ * -ENOMEM if memory allocation failed
+ * -EINVAL if property parsing failed
+ */
+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;
+ int ret;
+
+ for (index = 0;
+ !(ret = fwnode_property_get_reference_args(
+ dev_fwnode(dev), prop, NULL, 0, index, &args));
+ index++)
+ fwnode_handle_put(args.fwnode);
+
+ if (!index)
+ return -ENOENT;
+
+ /*
+ * Note that right now both -ENODATA and -ENOENT may signal
+ * out-of-bounds access. Return the error in cases other than that.
+ */
+ if (ret != -ENOENT && ret != -ENODATA)
+ return ret;
+
+ ret = v4l2_async_notifier_realloc(notifier,
+ notifier->num_subdevs + index);
+ if (ret)
+ return ret;
+
+ for (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