The subject still has the 'interger' typo.
On 09/12/2017 03:41 PM, Sakari Ailus wrote:
> 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.
As suggested before: 'property-value' is easier to read than ' -- '.
>
> 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
@index is not documented.
> + * @props: the array of integer property names
> + * @nprops: the number of integer properties
properties -> property names in @props
> + *
> + * 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
"the value" -> "whose value" or "with a value that"
At least, I think that's what you mean here.
How is @props/@nprops used?
> + * argument at an index.
I assume this should be "the @index"?
> + *
> + * Return: 0 on success
> + * -ENOENT if no entries (or the property itself) were found
> + * -EINVAL if property parsing otherwisefailed
Missing space before "failed"
> + * -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
the -> to the
> + * integer arguments.
> + */
> + fwnode = fwnode_args.fwnode;
> + while (nprops) {
This can be '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;
> +}
You really need to add an ACPI example as comment for this source code.
I still don't understand the code. I know you pointed me to an example,
but I can't remember/find what it was. Either copy the example here or
point to the file containing the example (copying is best IMHO).
Regards,
Hans
> +
> +/*
> + * 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>");
>
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