Hi Steve, On Mon, Jul 09, 2018 at 03:39:06PM -0700, Steve Longerbeam wrote: > Adds v4l2_async_register_fwnode_subdev(), which is a convenience function > for parsing a sub-device's fwnode port endpoints for connected remote > sub-devices, registering a sub-device notifier, and then registering > the sub-device itself. > > Signed-off-by: Steve Longerbeam > --- > Changes since v5: > - add call to v4l2_async_notifier_init(). > Changes since v4: > - none > Changes since v3: > - remove support for port sub-devices, such sub-devices will have to > role their own. > Changes since v2: > - fix error-out path in v4l2_async_register_fwnode_subdev() that forgot > to put device. > Changes since v1: > - add #include to v4l2-fwnode.h for > 'struct v4l2_subdev' declaration. > --- > drivers/media/v4l2-core/v4l2-fwnode.c | 64 +++++++++++++++++++++++++++++++++++ > include/media/v4l2-fwnode.h | 38 +++++++++++++++++++++ > 2 files changed, 102 insertions(+) > > diff --git a/drivers/media/v4l2-core/v4l2-fwnode.c b/drivers/media/v4l2-core/v4l2-fwnode.c > index 67ad333..94d867a 100644 > --- a/drivers/media/v4l2-core/v4l2-fwnode.c > +++ b/drivers/media/v4l2-core/v4l2-fwnode.c > @@ -872,6 +872,70 @@ int v4l2_async_register_subdev_sensor_common(struct v4l2_subdev *sd) > } > EXPORT_SYMBOL_GPL(v4l2_async_register_subdev_sensor_common); > > +int v4l2_async_register_fwnode_subdev( The meat of this function is to register a subdev with a notifier, so I would make it clear in the function name which is otherwise misleading > + struct v4l2_subdev *sd, size_t asd_struct_size, > + unsigned int *ports, unsigned int num_ports, > + int (*parse_endpoint)(struct device *dev, > + struct v4l2_fwnode_endpoint *vep, > + struct v4l2_async_subdev *asd)) > +{ > + struct v4l2_async_notifier *notifier; > + struct device *dev = sd->dev; > + struct fwnode_handle *fwnode; > + int ret; > + > + if (WARN_ON(!dev)) > + return -ENODEV; > + > + fwnode = dev_fwnode(dev); > + if (!fwnode_device_is_available(fwnode)) > + return -ENODEV; > + > + notifier = kzalloc(sizeof(*notifier), GFP_KERNEL); > + if (!notifier) > + return -ENOMEM; > + > + v4l2_async_notifier_init(notifier); > + > + if (!ports) { > + ret = v4l2_async_notifier_parse_fwnode_endpoints( > + dev, notifier, asd_struct_size, parse_endpoint); > + if (ret < 0) > + goto out_cleanup; > + } else { > + unsigned int i; > + > + for (i = 0; i < num_ports; i++) { It's not particularly exciting to iterate on pointers received from callers without checking for num_ports first. Also the caller has to allocate an array of "ports" and keep track of it just to pass it to this function and I don't see a way to set the notifier's ops before the notifier gets registered here below. > + ret = v4l2_async_notifier_parse_fwnode_endpoints_by_port( > + dev, notifier, asd_struct_size, > + ports[i], parse_endpoint); > + if (ret < 0) > + goto out_cleanup; > + } > + } > + > + ret = v4l2_async_subdev_notifier_register(sd, notifier); > + if (ret < 0) > + goto out_cleanup; > + > + ret = v4l2_async_register_subdev(sd); > + if (ret < 0) > + goto out_unregister; > + > + sd->subdev_notifier = notifier; This is set already by v4l2_async_subdev_notifier_register() In general, I have doubts this function is really needed. It requires the caller to reserve memory just to pass down a list of intergers, and there is no way to set subdev ops. Could you have a look at how drivers/media/platform/rcar-vin/rcar-csi2.c registers a subdevice and an associated notifier and see if in your opinion it can be implemented in the same way in your imx csi/csi2 driver, or you still like this one most? Thanks j > + > + return 0; > + > +out_unregister: > + v4l2_async_notifier_unregister(notifier); > +out_cleanup: > + v4l2_async_notifier_cleanup(notifier); > + kfree(notifier); > + > + return ret; > +} > +EXPORT_SYMBOL_GPL(v4l2_async_register_fwnode_subdev); > + > MODULE_LICENSE("GPL"); > MODULE_AUTHOR("Sakari Ailus "); > MODULE_AUTHOR("Sylwester Nawrocki "); > diff --git a/include/media/v4l2-fwnode.h b/include/media/v4l2-fwnode.h > index ea7a8b2..031ebb0 100644 > --- a/include/media/v4l2-fwnode.h > +++ b/include/media/v4l2-fwnode.h > @@ -23,6 +23,7 @@ > #include > > #include > +#include > > struct fwnode_handle; > struct v4l2_async_notifier; > @@ -360,4 +361,41 @@ int v4l2_async_notifier_parse_fwnode_endpoints_by_port( > int v4l2_async_notifier_parse_fwnode_sensor_common( > struct device *dev, struct v4l2_async_notifier *notifier); > > +/** > + * v4l2_async_register_fwnode_subdev - registers a sub-device to the > + * asynchronous sub-device framework > + * and parses fwnode endpoints > + * > + * @sd: pointer to struct &v4l2_subdev > + * @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. > + * @ports: array of port id's to parse for fwnode endpoints. If NULL, will > + * parse all ports owned by the sub-device. > + * @num_ports: number of ports in @ports array. Ignored if @ports is NULL. > + * @parse_endpoint: Driver's callback function called on each V4L2 fwnode > + * endpoint. Optional. > + * > + * This function is just like v4l2_async_register_subdev() with the > + * exception that calling it will also allocate a notifier for the > + * sub-device, parse the sub-device's firmware node endpoints using > + * v4l2_async_notifier_parse_fwnode_endpoints() or > + * v4l2_async_notifier_parse_fwnode_endpoints_by_port(), and > + * registers the sub-device notifier. The sub-device is similarly > + * unregistered by calling v4l2_async_unregister_subdev(). > + * > + * While registered, the subdev module is marked as in-use. > + * > + * An error is returned if the module is no longer loaded on any attempts > + * to register it. > + */ > +int v4l2_async_register_fwnode_subdev( > + struct v4l2_subdev *sd, size_t asd_struct_size, > + unsigned int *ports, unsigned int num_ports, > + int (*parse_endpoint)(struct device *dev, > + struct v4l2_fwnode_endpoint *vep, > + struct v4l2_async_subdev *asd)); > + > #endif /* _V4L2_FWNODE_H */ > -- > 2.7.4 >