v4l2_fwnode_reference_parse_int_prop() will find an fwnode such that under
the device's own fwnode, it will follow child fwnodes with the given
property -- value pair and return the resulting fwnode.
Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
---
drivers/media/v4l2-core/v4l2-fwnode.c | 145 ++++++++++++++++++++++++++++++++++
1 file changed, 145 insertions(+)
diff --git a/drivers/media/v4l2-core/v4l2-fwnode.c b/drivers/media/v4l2-core/v4l2-fwnode.c
index a32473f95be1..a07599a8f647 100644
--- a/drivers/media/v4l2-core/v4l2-fwnode.c
+++ b/drivers/media/v4l2-core/v4l2-fwnode.c
@@ -567,6 +567,151 @@ static int v4l2_fwnode_reference_parse(
return ret;
}
+/*
+ * v4l2_fwnode_reference_get_int_prop - parse a reference with integer
+ * arguments
+ * @dev: struct device pointer
+ * @notifier: notifier for @dev
+ * @prop: the name of the property
+ * @props: the array of integer property names
+ * @nprops: the number of integer properties
+ *
+ * Find fwnodes referred to by a property @prop, then under that iteratively
+ * follow each child node which has a property the value matches the integer
+ * argument at an index.
+ *
+ * Return: 0 on success
+ * -ENOENT if no entries (or the property itself) were found
+ * -EINVAL if property parsing otherwisefailed
+ * -ENOMEM if memory allocation failed
+ */
+static struct fwnode_handle *v4l2_fwnode_reference_get_int_prop(
+ struct fwnode_handle *fwnode, const char *prop, unsigned int index,
+ const char **props, unsigned int nprops)
+{
+ struct fwnode_reference_args fwnode_args;
+ unsigned int *args = fwnode_args.args;
+ struct fwnode_handle *child;
+ int ret;
+
+ /*
+ * Obtain remote fwnode as well as the integer arguments.
+ *
+ * To-do: handle -ENODATA when "device property: Align return
+ * codes of acpi_fwnode_get_reference_with_args" is merged.
+ */
+ ret = fwnode_property_get_reference_args(fwnode, prop, NULL, nprops,
+ index, &fwnode_args);
+ if (ret)
+ return ERR_PTR(ret == -ENODATA ? -ENOENT : ret);
+
+ /*
+ * Find a node in the tree under the referred fwnode corresponding the
+ * integer arguments.
+ */
+ fwnode = fwnode_args.fwnode;
+ while (nprops) {
+ u32 val;
+
+ /* Loop over all child nodes under fwnode. */
+ fwnode_for_each_child_node(fwnode, child) {
+ if (fwnode_property_read_u32(child, *props, &val))
+ continue;
+
+ /* Found property, see if its value matches. */
+ if (val == *args)
+ break;
+ }
+
+ fwnode_handle_put(fwnode);
+
+ /* No property found; return an error here. */
+ if (!child) {
+ fwnode = ERR_PTR(-ENOENT);
+ break;
+ }
+
+ props++;
+ args++;
+ fwnode = child;
+ nprops--;
+ }
+
+ return fwnode;
+}
+
+/*
+ * v4l2_fwnode_reference_parse_int_props - parse references for async sub-devices
+ * @dev: struct device pointer
+ * @notifier: notifier for @dev
+ * @prop: the name of the property
+ * @props: the array of integer property names
+ * @nprops: the number of integer properties
+ *
+ * Use v4l2_fwnode_reference_get_int_prop to find fwnodes through reference in
+ * property @prop with integer arguments with child nodes matching in properties
+ * @props. Then, set up V4L2 async sub-devices for those fwnodes in the notifier
+ * accordingly.
+ *
+ * While it is technically possible to use this function on DT, it is only
+ * meaningful on ACPI. On Device tree you can refer to any node in the tree but
+ * on ACPI the references are limited to devices.
+ *
+ * Return: 0 on success
+ * -ENOENT if no entries (or the property itself) were found
+ * -EINVAL if property parsing otherwisefailed
+ * -ENOMEM if memory allocation failed
+ */
+static int v4l2_fwnode_reference_parse_int_props(
+ struct device *dev, struct v4l2_async_notifier *notifier,
+ const char *prop, const char **props, unsigned int nprops)
+{
+ struct fwnode_handle *fwnode;
+ unsigned int index;
+ int ret;
+
+ for (index = 0; !IS_ERR((fwnode = v4l2_fwnode_reference_get_int_prop(
+ dev_fwnode(dev), prop, index, props,
+ nprops))); index++)
+ fwnode_handle_put(fwnode);
+
+ if (PTR_ERR(fwnode) != -ENOENT)
+ return PTR_ERR(fwnode);
+
+ ret = v4l2_async_notifier_realloc(notifier,
+ notifier->num_subdevs + index);
+ if (ret)
+ return -ENOMEM;
+
+ for (index = 0; !IS_ERR((fwnode = v4l2_fwnode_reference_get_int_prop(
+ dev_fwnode(dev), prop, index, props,
+ nprops))); index++) {
+ struct v4l2_async_subdev *asd;
+
+ if (WARN_ON(notifier->num_subdevs >= notifier->max_subdevs)) {
+ ret = -EINVAL;
+ goto error;
+ }
+
+ asd = kzalloc(sizeof(struct v4l2_async_subdev), GFP_KERNEL);
+ if (!asd) {
+ ret = -ENOMEM;
+ goto error;
+ }
+
+ notifier->subdevs[notifier->num_subdevs] = asd;
+ asd->match.fwnode.fwnode = fwnode;
+ asd->match_type = V4L2_ASYNC_MATCH_FWNODE;
+ notifier->num_subdevs++;
+ }
+
+ return PTR_ERR(fwnode) == -ENOENT ? 0 : PTR_ERR(fwnode);
+
+error:
+ fwnode_handle_put(fwnode);
+ return ret;
+}
+
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>");
MODULE_AUTHOR("Sylwester Nawrocki <s.nawrocki@xxxxxxxxxxx>");
--
2.11.0
--
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