/*
      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>

  #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;

  	/* BKL replacement mutex. Temporary solution only. */
  	struct mutex ioctl_lock;

  	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