Hi Sakari,
Thank you for the patch.
On Friday, 15 September 2017 17:17:04 EEST Sakari Ailus wrote:
> Add two functions for parsing devices graph endpoints:
> v4l2_async_notifier_parse_fwnode_endpoints and
> v4l2_async_notifier_parse_fwnode_endpoints_by_port. The former iterates
> over all endpoints whereas the latter only iterates over the endpoints in
> a given port.
>
> The former is mostly useful for existing drivers that currently implement
> the iteration over all the endpoints themselves whereas the latter is
> especially intended for devices with both sinks and sources: async
> sub-devices for external devices connected to the device's sources will
> have already been set up, or they are part of the master device.
Did you mean s/or they/as they/ ?
> Signed-off-by: Sakari Ailus <sakari.ai...@linux.intel.com>
> ---
> drivers/media/v4l2-core/v4l2-async.c | 30 ++++++
> drivers/media/v4l2-core/v4l2-fwnode.c | 185 +++++++++++++++++++++++++++++++
> include/media/v4l2-async.h | 24 ++++-
> include/media/v4l2-fwnode.h | 117 +++++++++++++++++++++
> 4 files changed, 354 insertions(+), 2 deletions(-)
[snip]
> diff --git a/drivers/media/v4l2-core/v4l2-fwnode.c
> b/drivers/media/v4l2-core/v4l2-fwnode.c index 706f9e7b90f1..44ee35f6aad5
> 100644
> --- a/drivers/media/v4l2-core/v4l2-fwnode.c
> +++ b/drivers/media/v4l2-core/v4l2-fwnode.c
[snip]
> +static int v4l2_async_notifier_fwnode_parse_endpoint(
> + struct device *dev, struct v4l2_async_notifier *notifier,
> + struct fwnode_handle *endpoint, unsigned int asd_struct_size,
> + int (*parse_endpoint)(struct device *dev,
> + struct v4l2_fwnode_endpoint *vep,
> + struct v4l2_async_subdev *asd))
> +{
> + struct v4l2_async_subdev *asd;
> + struct v4l2_fwnode_endpoint *vep;
> + int ret = 0;
> +
> + asd = kzalloc(asd_struct_size, GFP_KERNEL);
> + if (!asd)
> + return -ENOMEM;
> +
> + asd->match.fwnode.fwnode =
> + fwnode_graph_get_remote_port_parent(endpoint);
> + if (!asd->match.fwnode.fwnode) {
> + dev_warn(dev, "bad remote port parent\n");
> + ret = -EINVAL;
> + goto out_err;
> + }
> +
> + /* Ignore endpoints the parsing of which failed. */
I think this comment is outdated.
> + vep = v4l2_fwnode_endpoint_alloc_parse(endpoint);
> + if (IS_ERR(vep)) {
> + ret = PTR_ERR(vep);
> + dev_warn(dev, "unable to parse V4L2 fwnode endpoint (%d)\n",
> + ret);
> + goto out_err;
> + }
> +
> + ret = parse_endpoint ? parse_endpoint(dev, vep, asd) : 0;
> + if (ret == -ENOTCONN)
> + dev_dbg(dev, "ignoring endpoint %u,%u\n", vep->base.port,
> + vep->base.id);
How about "ignoring port@%u/endpoint@%u\n" ? It would make the message more
explicit.
> + else if (ret < 0)
> + dev_warn(dev, "driver could not parse endpoint %u,%u (%d)\n",
Same here.
> + vep->base.port, vep->base.id, ret);
> + v4l2_fwnode_endpoint_free(vep);
> + if (ret < 0)
> + goto out_err;
> +
> + asd->match_type = V4L2_ASYNC_MATCH_FWNODE;
I'd move this line right before setting asd->match.fwnode.fwnode.
> + notifier->subdevs[notifier->num_subdevs] = asd;
> + notifier->num_subdevs++;
> +
> + return 0;
> +
> +out_err:
> + fwnode_handle_put(asd->match.fwnode.fwnode);
> + kfree(asd);
> +
> + return ret == -ENOTCONN ? 0 : ret;
> +}
> +
> +static int __v4l2_async_notifier_parse_fwnode_endpoints(
> + struct device *dev, struct v4l2_async_notifier *notifier,
> + size_t asd_struct_size, unsigned int port, bool has_port,
> + int (*parse_endpoint)(struct device *dev,
> + struct v4l2_fwnode_endpoint *vep,
> + struct v4l2_async_subdev *asd))
> +{
> + struct fwnode_handle *fwnode = NULL;
> + unsigned int max_subdevs = notifier->max_subdevs;
> + int ret;
> +
> + if (WARN_ON(asd_struct_size < sizeof(struct v4l2_async_subdev)))
> + return -EINVAL;
> +
> + for (fwnode = NULL; (fwnode = fwnode_graph_get_next_endpoint(
> + dev_fwnode(dev), fwnode)); ) {
> + if (!fwnode_device_is_available(
> + fwnode_graph_get_port_parent(fwnode)))
Doesn't fwnode_graph_get_port_parent() increment the refcount on the parent,
which you should then release ?
> + continue;
> +
> + if (has_port) {
> + struct fwnode_endpoint ep;
> +
> + ret = fwnode_graph_parse_endpoint(fwnode, &ep);
> + if (ret) {
> + fwnode_handle_put(fwnode);
> + return ret;
> + }
> +
> + if (ep.port != port)
> + continue;
> + }
> + max_subdevs++;
> + }
> +
> + /* No subdevs to add? Return here. */
> + if (max_subdevs == notifier->max_subdevs)
> + return 0;
> +
> + ret = v4l2_async_notifier_realloc(notifier, max_subdevs);
> + if (ret)
> + return ret;
> +
> + for (fwnode = NULL; (fwnode = fwnode_graph_get_next_endpoint(
> + dev_fwnode(dev), fwnode)); ) {
> + if (!fwnode_device_is_available(
> + fwnode_graph_get_port_parent(fwnode)))
Same here.
> + continue;
> +
> + if (WARN_ON(notifier->num_subdevs >= notifier->max_subdevs)) {
> + ret = -EINVAL;
> + break;
> + }
> +
> + if (has_port) {
> + struct fwnode_endpoint ep;
> +
> + ret = fwnode_graph_parse_endpoint(fwnode, &ep);
> + if (ret)
> + break;
> +
> + if (ep.port != port)
> + continue;
> + }
> +
> + ret = v4l2_async_notifier_fwnode_parse_endpoint(
> + dev, notifier, fwnode, asd_struct_size, parse_endpoint);
> + if (ret < 0)
> + break;
> + }
> +
> + fwnode_handle_put(fwnode);
> +
> + return ret;
> +}
[snip]
> diff --git a/include/media/v4l2-async.h b/include/media/v4l2-async.h
> index c69d8c8a66d0..96fa1afc00dd 100644
> --- a/include/media/v4l2-async.h
> +++ b/include/media/v4l2-async.h
> @@ -18,7 +18,6 @@ struct device;
> struct device_node;
> struct v4l2_device;
> struct v4l2_subdev;
> -struct v4l2_async_notifier;
>
> /* A random max subdevice number, used to allocate an array on stack */
> #define V4L2_MAX_SUBDEVS 128U
> @@ -50,6 +49,10 @@ enum v4l2_async_match_type {
> * @match: union of per-bus type matching data sets
> * @list: used to link struct v4l2_async_subdev objects, waiting to be
> * probed, to a notifier->waiting list
> + *
> + * When this struct is used as a member in a driver specific struct,
> + * the driver specific struct shall contain the @struct
> + * v4l2_async_subdev as its first member.
Unless I'm mistaken @ is used to refer to function arguments (sphinx typesets
it using <strong> in HTML). References to structures can be created with &.
Have you compiled the documentation ? :-)
> */
> struct v4l2_async_subdev {
> enum v4l2_async_match_type match_type;
> @@ -78,7 +81,8 @@ struct v4l2_async_subdev {
> /**
> * struct v4l2_async_notifier - v4l2_device notifier data
> *
> - * @num_subdevs: number of subdevices
> + * @num_subdevs: number of subdevices used in the subdevs array
> + * @max_subdevs: number of subdevices allocated in the subdevs array
> * @subdevs: array of pointers to subdevice descriptors
> * @v4l2_dev: pointer to struct v4l2_device
> * @waiting: list of struct v4l2_async_subdev, waiting for their drivers
> @@ -90,6 +94,7 @@ struct v4l2_async_subdev {
> */
> struct v4l2_async_notifier {
> unsigned int num_subdevs;
> + unsigned int max_subdevs;
> struct v4l2_async_subdev **subdevs;
> struct v4l2_device *v4l2_dev;
> struct list_head waiting;
> @@ -121,6 +126,21 @@ int v4l2_async_notifier_register(struct v4l2_device
> *v4l2_dev, void v4l2_async_notifier_unregister(struct v4l2_async_notifier
> *notifier);
>
> /**
> + * v4l2_async_notifier_release - release notifier resources
> + * @notifier: the notifier the resources of which are to be released
> + *
> + * Release memory resources related to a notifier, including the async
> + * sub-devices allocated for the purposes of the notifier. The user is
> + * responsible for releasing the notifier's resources after calling
> + * @v4l2_async_notifier_parse_fwnode_endpoints.
Don't use @. If you want sphinx to generate a link, just append () after the
function name.
> + *
> + * There is no harm from calling v4l2_async_notifier_release in other
Here too.
> + * cases as long as its memory has been zeroed after it has been
> + * allocated.
As the function WARNs for types other than V4L2_ASYNC_MATCH_FWNODE you might
want to mention that in the documentation.
> + */
> +void v4l2_async_notifier_release(struct v4l2_async_notifier *notifier);
> +
> +/**
> * v4l2_async_register_subdev - registers a sub-device to the asynchronous
> * subdevice framework
> *
> diff --git a/include/media/v4l2-fwnode.h b/include/media/v4l2-fwnode.h
> index 68eb22ba571b..83afac48ea6b 100644
> --- a/include/media/v4l2-fwnode.h
> +++ b/include/media/v4l2-fwnode.h
> @@ -25,6 +25,8 @@
> #include <media/v4l2-mediabus.h>
>
> struct fwnode_handle;
> +struct v4l2_async_notifier;
> +struct v4l2_async_subdev;
>
> #define V4L2_FWNODE_CSI2_MAX_DATA_LANES 4
>
> @@ -201,4 +203,119 @@ int v4l2_fwnode_parse_link(struct fwnode_handle
> *fwnode, */
> void v4l2_fwnode_put_link(struct v4l2_fwnode_link *link);
>
> +/**
> + * v4l2_async_notifier_parse_fwnode_endpoints - Parse V4L2 fwnode endpoints
> in a
> + * device node
> + * @dev: the device the endpoints of which are to be parsed
> + * @notifier: notifier for @dev
> + * @asd_struct_size: size of the driver's async sub-device struct,
> including
> + * sizeof(struct v4l2_async_subdev). The &struct
> + * v4l2_async_subdev shall be the first member of
> + * the driver's async sub-device struct, i.e. both
> + * begin at the same memory address.
> + * @parse_endpoint: Driver's callback function called on each V4L2 fwnode
> + * endpoint. Optional.
> + * Return: %0 on success
> + * %-ENOTCONN if the endpoint is to be skipped but this
> + * should not be considered as an error
> + * %-EINVAL if the endpoint configuration is invalid
> + *
> + * Parse the fwnode endpoints of the @dev device and populate the async
> sub-
> + * devices array of the notifier. The @parse_endpoint callback function is
> + * called for each endpoint with the corresponding async sub-device pointer
> to
> + * let the caller initialize the driver-specific part of the async sub-
> device
> + * structure.
> + *
> + * The notifier memory shall be zeroed before this function is called on
> the
> + * notifier.
> + *
> + * This function may not be called on a registered notifier and may be
> called on
> + * a notifier only once.
> + *
> + * Do not change the notifier's subdevs array, take references to the
> subdevs
> + * array itself or change the notifier's num_subdevs field. This is because
> this
> + * function allocates and reallocates the subdevs array based on parsing
> + * endpoints.
> + *
> + * The @struct v4l2_fwnode_endpoint passed to the callback function
> + * @parse_endpoint is released once the function is finished. If there is a
> need
> + * to retain that configuration, the user needs to allocate memory for it.
> + *
> + * Any notifier populated using this function must be released with a call
> to
> + * v4l2_async_notifier_release() after it has been unregistered and the
> async
> + * sub-devices are no longer in use, even if the function returned an
> error.
> + *
> + * Return: %0 on success, including when no async sub-devices are found
> + * %-ENOMEM if memory allocation failed
> + * %-EINVAL if graph or endpoint parsing failed
> + * Other error codes as returned by @parse_endpoint
> + */
> +int v4l2_async_notifier_parse_fwnode_endpoints(
> + struct device *dev, struct v4l2_async_notifier *notifier,
> + size_t asd_struct_size,
> + int (*parse_endpoint)(struct device *dev,
> + struct v4l2_fwnode_endpoint *vep,
> + struct v4l2_async_subdev *asd));
> +
> +/**
> + * v4l2_async_notifier_parse_fwnode_endpoints_by_port - Parse V4L2 fwnode
> + * endpoints of a port in a
> + * device node
This clearly shows that the function name is getting a bit long :-)
> + * @dev: the device the endpoints of which are to be parsed
> + * @notifier: notifier for @dev
> + * @asd_struct_size: size of the driver's async sub-device struct,
> including
> + * sizeof(struct v4l2_async_subdev). The &struct
> + * v4l2_async_subdev shall be the first member of
> + * the driver's async sub-device struct, i.e. both
> + * begin at the same memory address.
> + * @port: port number where endpoints are to be parsed
> + * @parse_endpoint: Driver's callback function called on each V4L2 fwnode
> + * endpoint. Optional.
> + * Return: %0 on success
> + * %-ENOTCONN if the endpoint is to be skipped but this
> + * should not be considered as an error
> + * %-EINVAL if the endpoint configuration is invalid
> + *
> + * This function is just like @v4l2_async_notifier_parse_fwnode_endpoints
> with
> + * the exception that it only parses endpoints in a given port. This is
> useful
> + * on devices that have both sinks and sources: the async sub-devices
> connected
> + * to sources have already been set up by another driver (on capture
> devices).
> + *
> + * Parse the fwnode endpoints of the @dev device on a given @port and
> populate
> + * the async sub-devices array of the notifier. The @parse_endpoint
> callback
> + * function is called for each endpoint with the corresponding async sub-
> device
> + * pointer to let the caller initialize the driver-specific part of the
> async
> + * sub-device structure.
> + *
> + * The notifier memory shall be zeroed before this function is called on
> the
> + * notifier the first time.
> + *
> + * This function may not be called on a registered notifier and may be
> called on
> + * a notifier only once per port.
> + *
> + * Do not change the notifier's subdevs array, take references to the
> subdevs
> + * array itself or change the notifier's num_subdevs field. This is because
> this
> + * function allocates and reallocates the subdevs array based on parsing
> + * endpoints.
> + *
> + * The @struct v4l2_fwnode_endpoint passed to the callback function
> + * @parse_endpoint is released once the function is finished. If there is a
> need
> + * to retain that configuration, the user needs to allocate memory for it.
> + *
> + * Any notifier populated using this function must be released with a call
> to
> + * v4l2_async_notifier_release() after it has been unregistered and the
> async
> + * sub-devices are no longer in use, even if the function returned an
> error.
> + *
> + * Return: %0 on success, including when no async sub-devices are found
> + * %-ENOMEM if memory allocation failed
> + * %-EINVAL if graph or endpoint parsing failed
> + * Other error codes as returned by @parse_endpoint
> + */
> +int v4l2_async_notifier_parse_fwnode_endpoints_by_port(
> + struct device *dev, struct v4l2_async_notifier *notifier,
> + size_t asd_struct_size, unsigned int port,
> + int (*parse_endpoint)(struct device *dev,
> + struct v4l2_fwnode_endpoint *vep,
> + struct v4l2_async_subdev *asd));
> +
> #endif /* _V4L2_FWNODE_H */
--
Regards,
Laurent Pinchart
