Edit File: v4l2-device.h
/* 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/media-device.h> #include <media/v4l2-subdev.h> #include <media/v4l2-dev.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 (20 + 16) struct v4l2_ctrl_handler; struct v4l2_device { /* dev->driver_data points to this struct. Note: dev might be NULL if there is no parent device as is the case with e.g. ISA devices. */ struct device *dev; #if defined(CONFIG_MEDIA_CONTROLLER) struct media_device *mdev; #endif /* 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]; /* notify callback called by some sub-devices. */ void (*notify)(struct v4l2_subdev *sd, unsigned int notification, void *arg); /* The control handler. May be NULL. */ struct v4l2_ctrl_handler *ctrl_handler; /* Device's priority state */ struct v4l2_prio_state prio; /* BKL replacement mutex. Temporary solution only. */ struct mutex ioctl_lock; /* Keep track of the references to this struct. */ struct kref ref; /* Release function that is called when the ref count goes to 0. */ void (*release)(struct v4l2_device *v4l2_dev); }; static inline void v4l2_device_get(struct v4l2_device *v4l2_dev) { kref_get(&v4l2_dev->ref); } int v4l2_device_put(struct v4l2_device *v4l2_dev); /* Initialize v4l2_dev and make dev->driver_data point to v4l2_dev. dev may be NULL in rare cases (ISA devices). In that case you must fill in the v4l2_dev->name field before calling this function. */ int __must_check v4l2_device_register(struct device *dev, struct v4l2_device *v4l2_dev); /* Optional function to initialize the name field of struct v4l2_device using the driver name and a driver-global atomic_t instance. This function will increment the instance counter and returns the instance value used in the name. Example: static atomic_t drv_instance = ATOMIC_INIT(0); ... instance = v4l2_device_set_name(&v4l2_dev, "foo", &drv_instance); The first time this is called the name field will be set to foo0 and this function returns 0. If the name ends with a digit (e.g. cx18), then the name will be set to cx18-0 since cx180 looks really odd. */ int v4l2_device_set_name(struct v4l2_device *v4l2_dev, const char *basename, atomic_t *instance); /* Set v4l2_dev->dev to NULL. Call when the USB parent disconnects. Since the parent disappears this ensures that v4l2_dev doesn't have an invalid parent pointer. */ void v4l2_device_disconnect(struct v4l2_device *v4l2_dev); /* Unregister all sub-devices and any other resources related to v4l2_dev. */ 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 *v4l2_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); /* Register device nodes for all subdev of the v4l2 device that are marked with * the V4L2_SUBDEV_FL_HAS_DEVNODE flag. */ int __must_check v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev); /* Iterate over all subdevs. */ #define v4l2_device_for_each_subdev(sd, v4l2_dev) \ list_for_each_entry(sd, &(v4l2_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_p(v4l2_dev, sd, cond, o, f, args...) \ do { \ list_for_each_entry((sd), &(v4l2_dev)->subdevs, list) \ if ((cond) && (sd)->ops->o && (sd)->ops->o->f) \ (sd)->ops->o->f((sd) , ##args); \ } while (0) #define __v4l2_device_call_subdevs(v4l2_dev, cond, o, f, args...) \ do { \ struct v4l2_subdev *__sd; \ \ __v4l2_device_call_subdevs_p(v4l2_dev, __sd, cond, o, \ f , ##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_p(v4l2_dev, sd, cond, o, f, args...) \ ({ \ long __err = 0; \ \ list_for_each_entry((sd), &(v4l2_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; \ }) #define __v4l2_device_call_subdevs_until_err(v4l2_dev, cond, o, f, args...) \ ({ \ struct v4l2_subdev *__sd; \ __v4l2_device_call_subdevs_until_err_p(v4l2_dev, __sd, cond, o, \ f , ##args); \ }) /* 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(v4l2_dev, grpid, o, f, args...) \ do { \ struct v4l2_subdev *__sd; \ \ __v4l2_device_call_subdevs_p(v4l2_dev, __sd, \ !(grpid) || __sd->grp_id == (grpid), o, f , \ ##args); \ } while (0) /* 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(v4l2_dev, grpid, o, f, args...) \ ({ \ struct v4l2_subdev *__sd; \ __v4l2_device_call_subdevs_until_err_p(v4l2_dev, __sd, \ !(grpid) || __sd->grp_id == (grpid), o, f , \ ##args); \ }) #define v4l2_device_has_op(v4l2_dev, o, f) \ ({ \ struct v4l2_subdev *__sd; \ bool __result = false; \ list_for_each_entry(__sd, &(v4l2_dev)->subdevs, list) { \ if (v4l2_subdev_has_op(__sd, o, f)) { \ __result = true; \ break; \ } \ } \ __result; \ }) #endif