/* V4L2 device support header. Copyright (C) 2008 Hans Verkuil 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 #include #include #define V4L2_DEVICE_NAME_SIZE (20 + 16) struct v4l2_ctrl_handler; /** * struct v4l2_device - main struct to for V4L2 device drivers * * @dev: pointer to struct device. * @mdev: pointer to struct media_device * @subdevs: used to keep track of the registered subdevs * @lock: lock this struct; can be used by the driver as well * if this struct is embedded into a larger struct. * @name: unique device name, by default the driver name + bus ID * @notify: notify callback called by some sub-devices. * @ctrl_handler: The control handler. May be %NULL. * @prio: Device's priority state * @ref: Keep track of the references to this struct. * @release: Release function that is called when the ref count * goes to 0. * * 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. * * .. note:: * * #) @dev->driver_data points to this struct. * #) @dev might be %NULL if there is no parent device */ struct v4l2_device { struct device *dev; #if defined(CONFIG_MEDIA_CONTROLLER) struct media_device *mdev; #endif struct list_head subdevs; spinlock_t lock; char name[V4L2_DEVICE_NAME_SIZE]; void (*notify)(struct v4l2_subdev *sd, unsigned int notification, void *arg); struct v4l2_ctrl_handler *ctrl_handler; struct v4l2_prio_state prio; struct kref ref; void (*release)(struct v4l2_device *v4l2_dev); }; /** * v4l2_device_get - gets a V4L2 device reference * * @v4l2_dev: pointer to struct &v4l2_device * * This is an ancillary routine meant to increment the usage for the * struct &v4l2_device pointed by @v4l2_dev. */ static inline void v4l2_device_get(struct v4l2_device *v4l2_dev) { kref_get(&v4l2_dev->ref); } /** * v4l2_device_put - putss a V4L2 device reference * * @v4l2_dev: pointer to struct &v4l2_device * * This is an ancillary routine meant to decrement the usage for the * struct &v4l2_device pointed by @v4l2_dev. */ int v4l2_device_put(struct v4l2_device *v4l2_dev); /** * v4l2_device_register - Initialize v4l2_dev and make @dev->driver_data * point to @v4l2_dev. * * @dev: pointer to struct &device * @v4l2_dev: pointer to struct &v4l2_device * * .. note:: * @dev may be %NULL in rare cases (ISA devices). * In such case the caller 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); /** * v4l2_device_set_name - Optional function to initialize the * name field of struct &v4l2_device * * @v4l2_dev: pointer to struct &v4l2_device * @basename: base name for the device name * @instance: pointer to a static atomic_t var with the instance usage for * the device driver. * * v4l2_device_set_name() initializes 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 would look really odd. */ int v4l2_device_set_name(struct v4l2_device *v4l2_dev, const char *basename, atomic_t *instance); /** * v4l2_device_disconnect - Change V4L2 device state to disconnected. * * @v4l2_dev: pointer to struct v4l2_device * * Should be called when the USB parent disconnects. * Since the parent disappears, this ensures that @v4l2_dev doesn't have * an invalid parent pointer. * * .. note:: This function sets @v4l2_dev->dev to NULL. */ void v4l2_device_disconnect(struct v4l2_device *v4l2_dev); /** * v4l2_device_unregister - Unregister all sub-devices and any other * resources related to @v4l2_dev. * * @v4l2_dev: pointer to struct v4l2_device */ void v4l2_device_unregister(struct v4l2_device *v4l2_dev); /** * v4l2_device_register_subdev - Registers a subdev with a v4l2 device. * * @v4l2_dev: pointer to struct &v4l2_device * @sd: pointer to struct &v4l2_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_device_register_subdev(struct v4l2_device *v4l2_dev, struct v4l2_subdev *sd); /** * v4l2_device_unregister_subdev - Unregisters a subdev with a v4l2 device. * * @sd: pointer to struct &v4l2_subdev * * .. note :: * * Can also be called if the subdev wasn't registered. In such * case, it will do nothing. */ void v4l2_device_unregister_subdev(struct v4l2_subdev *sd); /** * v4l2_device_register_subdev_nodes - Registers device nodes for all subdevs * of the v4l2 device that are marked with * the %V4L2_SUBDEV_FL_HAS_DEVNODE flag. * * @v4l2_dev: pointer to struct v4l2_device */ int __must_check v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev); /** * v4l2_subdev_notify - Sends a notification to v4l2_device. * * @sd: pointer to struct &v4l2_subdev * @notification: type of notification. Please notice that the notification * type is driver-specific. * @arg: arguments for the notification. Those are specific to each * notification type. */ static inline void v4l2_subdev_notify(struct v4l2_subdev *sd, unsigned int notification, void *arg) { if (sd && sd->v4l2_dev && sd->v4l2_dev->notify) sd->v4l2_dev->notify(sd, notification, arg); } /* 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); \ }) /* * Call the specified callback for all subdevs where grp_id & grpmsk != 0 * (if grpmsk == `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_mask_call_all(v4l2_dev, grpmsk, o, f, args...) \ do { \ struct v4l2_subdev *__sd; \ \ __v4l2_device_call_subdevs_p(v4l2_dev, __sd, \ !(grpmsk) || (__sd->grp_id & (grpmsk)), o, f , \ ##args); \ } while (0) /* * Call the specified callback for all subdevs where grp_id & grpmsk != 0 * (if grpmsk == 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_mask_call_until_err(v4l2_dev, grpmsk, o, f, args...) \ ({ \ struct v4l2_subdev *__sd; \ __v4l2_device_call_subdevs_until_err_p(v4l2_dev, __sd, \ !(grpmsk) || (__sd->grp_id & (grpmsk)), o, f , \ ##args); \ }) /* * Does any subdev with matching grpid (or all if grpid == 0) has the given * op? */ #define v4l2_device_has_op(v4l2_dev, grpid, o, f) \ ({ \ struct v4l2_subdev *__sd; \ bool __result = false; \ list_for_each_entry(__sd, &(v4l2_dev)->subdevs, list) { \ if ((grpid) && __sd->grp_id != (grpid)) \ continue; \ if (v4l2_subdev_has_op(__sd, o, f)) { \ __result = true; \ break; \ } \ } \ __result; \ }) /* * Does any subdev with matching grpmsk (or all if grpmsk == 0) has the given * op? */ #define v4l2_device_mask_has_op(v4l2_dev, grpmsk, o, f) \ ({ \ struct v4l2_subdev *__sd; \ bool __result = false; \ list_for_each_entry(__sd, &(v4l2_dev)->subdevs, list) { \ if ((grpmsk) && !(__sd->grp_id & (grpmsk))) \ continue; \ if (v4l2_subdev_has_op(__sd, o, f)) { \ __result = true; \ break; \ } \ } \ __result; \ }) #endif