/*
      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