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Diffstat (limited to 'include/media/v4l2-device.h')
| -rw-r--r-- | include/media/v4l2-device.h | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/include/media/v4l2-device.h b/include/media/v4l2-device.h new file mode 100644 index 00000000000..97b283a0428 --- /dev/null +++ b/include/media/v4l2-device.h @@ -0,0 +1,109 @@ +/* + V4L2 device support header. + + Copyright (C) 2008 Hans Verkuil <hverkuil@xs4all.nl> + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#ifndef _V4L2_DEVICE_H +#define _V4L2_DEVICE_H + +#include <media/v4l2-subdev.h> + +/* Each instance of a V4L2 device should create the v4l2_device struct, + either stand-alone or embedded in a larger struct. + + It allows easy access to sub-devices (see v4l2-subdev.h) and provides + basic V4L2 device-level support. + */ + +#define V4L2_DEVICE_NAME_SIZE (BUS_ID_SIZE + 16) + +struct v4l2_device { + /* dev->driver_data points to this struct */ + struct device *dev; + /* used to keep track of the registered subdevs */ + struct list_head subdevs; + /* lock this struct; can be used by the driver as well if this + struct is embedded into a larger struct. */ + spinlock_t lock; + /* unique device name, by default the driver name + bus ID */ + char name[V4L2_DEVICE_NAME_SIZE]; +}; + +/* Initialize v4l2_dev and make dev->driver_data point to v4l2_dev */ +int __must_check v4l2_device_register(struct device *dev, struct v4l2_device *v4l2_dev); +/* Set v4l2_dev->dev->driver_data to NULL and unregister all sub-devices */ +void v4l2_device_unregister(struct v4l2_device *v4l2_dev); + +/* Register a subdev with a v4l2 device. While registered the subdev module + is marked as in-use. An error is returned if the module is no longer + loaded when you attempt to register it. */ +int __must_check v4l2_device_register_subdev(struct v4l2_device *dev, struct v4l2_subdev *sd); +/* Unregister a subdev with a v4l2 device. Can also be called if the subdev + wasn't registered. In that case it will do nothing. */ +void v4l2_device_unregister_subdev(struct v4l2_subdev *sd); + +/* Iterate over all subdevs. */ +#define v4l2_device_for_each_subdev(sd, dev) \ + list_for_each_entry(sd, &(dev)->subdevs, list) + +/* Call the specified callback for all subdevs matching the condition. + Ignore any errors. Note that you cannot add or delete a subdev + while walking the subdevs list. */ +#define __v4l2_device_call_subdevs(dev, cond, o, f, args...) \ + do { \ + struct v4l2_subdev *sd; \ + \ + list_for_each_entry(sd, &(dev)->subdevs, list) \ + if ((cond) && sd->ops->o && sd->ops->o->f) \ + sd->ops->o->f(sd , ##args); \ + } while (0) + +/* Call the specified callback for all subdevs matching the condition. + If the callback returns an error other than 0 or -ENOIOCTLCMD, then + return with that error code. Note that you cannot add or delete a + subdev while walking the subdevs list. */ +#define __v4l2_device_call_subdevs_until_err(dev, cond, o, f, args...) \ +({ \ + struct v4l2_subdev *sd; \ + int err = 0; \ + \ + list_for_each_entry(sd, &(dev)->subdevs, list) { \ + if ((cond) && sd->ops->o && sd->ops->o->f) \ + err = sd->ops->o->f(sd , ##args); \ + if (err && err != -ENOIOCTLCMD) \ + break; \ + } \ + (err == -ENOIOCTLCMD) ? 0 : err; \ +}) + +/* Call the specified callback for all subdevs matching grp_id (if 0, then + match them all). Ignore any errors. Note that you cannot add or delete + a subdev while walking the subdevs list. */ +#define v4l2_device_call_all(dev, grp_id, o, f, args...) \ + __v4l2_device_call_subdevs(dev, \ + !(grp_id) || sd->grp_id == (grp_id), o, f , ##args) + +/* Call the specified callback for all subdevs matching grp_id (if 0, then + match them all). If the callback returns an error other than 0 or + -ENOIOCTLCMD, then return with that error code. Note that you cannot + add or delete a subdev while walking the subdevs list. */ +#define v4l2_device_call_until_err(dev, grp_id, o, f, args...) \ + __v4l2_device_call_subdevs_until_err(dev, \ + !(grp_id) || sd->grp_id == (grp_id), o, f , ##args) + +#endif |