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Diffstat (limited to 'include/media/v4l2-async.h')
| -rw-r--r-- | include/media/v4l2-async.h | 226 |
1 files changed, 226 insertions, 0 deletions
diff --git a/include/media/v4l2-async.h b/include/media/v4l2-async.h new file mode 100644 index 000000000..1592d323c --- /dev/null +++ b/include/media/v4l2-async.h @@ -0,0 +1,226 @@ +/* + * V4L2 asynchronous subdevice registration API + * + * Copyright (C) 2012-2013, Guennadi Liakhovetski <g.liakhovetski@gmx.de> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#ifndef V4L2_ASYNC_H +#define V4L2_ASYNC_H + +#include <linux/list.h> +#include <linux/mutex.h> + +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 + +/** + * enum v4l2_async_match_type - type of asynchronous subdevice logic to be used + * in order to identify a match + * + * @V4L2_ASYNC_MATCH_CUSTOM: Match will use the logic provided by &struct + * v4l2_async_subdev.match ops + * @V4L2_ASYNC_MATCH_DEVNAME: Match will use the device name + * @V4L2_ASYNC_MATCH_I2C: Match will check for I2C adapter ID and address + * @V4L2_ASYNC_MATCH_FWNODE: Match will use firmware node + * + * This enum is used by the asyncrhronous sub-device logic to define the + * algorithm that will be used to match an asynchronous device. + */ +enum v4l2_async_match_type { + V4L2_ASYNC_MATCH_CUSTOM, + V4L2_ASYNC_MATCH_DEVNAME, + V4L2_ASYNC_MATCH_I2C, + V4L2_ASYNC_MATCH_FWNODE, +}; + +/** + * struct v4l2_async_subdev - sub-device descriptor, as known to a bridge + * + * @match_type: type of match that will be used + * @match: union of per-bus type matching data sets + * @match.fwnode: + * pointer to &struct fwnode_handle to be matched. + * Used if @match_type is %V4L2_ASYNC_MATCH_FWNODE. + * @match.device_name: + * string containing the device name to be matched. + * Used if @match_type is %V4L2_ASYNC_MATCH_DEVNAME. + * @match.i2c: embedded struct with I2C parameters to be matched. + * Both @match.i2c.adapter_id and @match.i2c.address + * should be matched. + * Used if @match_type is %V4L2_ASYNC_MATCH_I2C. + * @match.i2c.adapter_id: + * I2C adapter ID to be matched. + * Used if @match_type is %V4L2_ASYNC_MATCH_I2C. + * @match.i2c.address: + * I2C address to be matched. + * Used if @match_type is %V4L2_ASYNC_MATCH_I2C. + * @match.custom: + * Driver-specific match criteria. + * Used if @match_type is %V4L2_ASYNC_MATCH_CUSTOM. + * @match.custom.match: + * Driver-specific match function to be used if + * %V4L2_ASYNC_MATCH_CUSTOM. + * @match.custom.priv: + * Driver-specific private struct with match parameters + * to be used if %V4L2_ASYNC_MATCH_CUSTOM. + * @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. + */ +struct v4l2_async_subdev { + enum v4l2_async_match_type match_type; + union { + struct fwnode_handle *fwnode; + const char *device_name; + struct { + int adapter_id; + unsigned short address; + } i2c; + struct { + bool (*match)(struct device *, + struct v4l2_async_subdev *); + void *priv; + } custom; + } match; + + /* v4l2-async core private: not to be used by drivers */ + struct list_head list; +}; + +/** + * struct v4l2_async_notifier_operations - Asynchronous V4L2 notifier operations + * @bound: a subdevice driver has successfully probed one of the subdevices + * @complete: All subdevices have been probed successfully. The complete + * callback is only executed for the root notifier. + * @unbind: a subdevice is leaving + */ +struct v4l2_async_notifier_operations { + int (*bound)(struct v4l2_async_notifier *notifier, + struct v4l2_subdev *subdev, + struct v4l2_async_subdev *asd); + int (*complete)(struct v4l2_async_notifier *notifier); + void (*unbind)(struct v4l2_async_notifier *notifier, + struct v4l2_subdev *subdev, + struct v4l2_async_subdev *asd); +}; + +/** + * struct v4l2_async_notifier - v4l2_device notifier data + * + * @ops: notifier operations + * @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: v4l2_device of the root notifier, NULL otherwise + * @sd: sub-device that registered the notifier, NULL otherwise + * @parent: parent notifier + * @waiting: list of struct v4l2_async_subdev, waiting for their drivers + * @done: list of struct v4l2_subdev, already probed + * @list: member in a global list of notifiers + */ +struct v4l2_async_notifier { + const struct v4l2_async_notifier_operations *ops; + unsigned int num_subdevs; + unsigned int max_subdevs; + struct v4l2_async_subdev **subdevs; + struct v4l2_device *v4l2_dev; + struct v4l2_subdev *sd; + struct v4l2_async_notifier *parent; + struct list_head waiting; + struct list_head done; + struct list_head list; +}; + +/** + * v4l2_async_notifier_register - registers a subdevice asynchronous notifier + * + * @v4l2_dev: pointer to &struct v4l2_device + * @notifier: pointer to &struct v4l2_async_notifier + */ +int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev, + struct v4l2_async_notifier *notifier); + +/** + * v4l2_async_subdev_notifier_register - registers a subdevice asynchronous + * notifier for a sub-device + * + * @sd: pointer to &struct v4l2_subdev + * @notifier: pointer to &struct v4l2_async_notifier + */ +int v4l2_async_subdev_notifier_register(struct v4l2_subdev *sd, + struct v4l2_async_notifier *notifier); + +/** + * v4l2_async_notifier_unregister - unregisters a subdevice asynchronous notifier + * + * @notifier: pointer to &struct v4l2_async_notifier + */ +void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier); + +/** + * v4l2_async_notifier_cleanup - clean up notifier resources + * @notifier: the notifier the resources of which are to be cleaned up + * + * Release memory resources related to a notifier, including the async + * sub-devices allocated for the purposes of the notifier but not the notifier + * itself. The user is responsible for calling this function to clean up the + * notifier after calling @v4l2_async_notifier_parse_fwnode_endpoints or + * @v4l2_fwnode_reference_parse_sensor_common. + * + * There is no harm from calling v4l2_async_notifier_cleanup in other + * cases as long as its memory has been zeroed after it has been + * allocated. + */ +void v4l2_async_notifier_cleanup(struct v4l2_async_notifier *notifier); + +/** + * v4l2_async_register_subdev - registers a sub-device to the asynchronous + * subdevice framework + * + * @sd: pointer to &struct v4l2_subdev + */ +int v4l2_async_register_subdev(struct v4l2_subdev *sd); + +/** + * v4l2_async_register_subdev_sensor_common - registers a sensor sub-device to + * the asynchronous sub-device + * framework and parse set up common + * sensor related devices + * + * @sd: pointer to struct &v4l2_subdev + * + * This function is just like v4l2_async_register_subdev() with the exception + * that calling it will also parse firmware interfaces for remote references + * using v4l2_async_notifier_parse_fwnode_sensor_common() and registers the + * async sub-devices. 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 __must_check v4l2_async_register_subdev_sensor_common( + struct v4l2_subdev *sd); + +/** + * v4l2_async_unregister_subdev - unregisters a sub-device to the asynchronous + * subdevice framework + * + * @sd: pointer to &struct v4l2_subdev + */ +void v4l2_async_unregister_subdev(struct v4l2_subdev *sd); +#endif |