/*
      V4L2 controls support header.
  
      Copyright (C) 2010  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_CTRLS_H
  #define _V4L2_CTRLS_H
  
  #include <linux/list.h>
  #include <linux/device.h>

  #include <linux/videodev2.h>

  
  /* forward references */
  struct v4l2_ctrl_handler;

  struct v4l2_ctrl_helper;

  struct v4l2_ctrl;
  struct video_device;
  struct v4l2_subdev;

  struct v4l2_subscribed_event;

  struct v4l2_fh;

  
  /** struct v4l2_ctrl_ops - The control operations that the driver has to provide.
    * @g_volatile_ctrl: Get a new value for this control. Generally only relevant
    *		for volatile (and usually read-only) controls such as a control
    *		that returns the current signal strength which changes
    *		continuously.
    *		If not set, then the currently cached value will be returned.
    * @try_ctrl:	Test whether the control's value is valid. Only relevant when
    *		the usual min/max/step checks are not sufficient.
    * @s_ctrl:	Actually set the new control value. s_ctrl is compulsory. The
    *		ctrl->handler->lock is held when these ops are called, so no
    *		one else can access controls owned by that handler.
    */
  struct v4l2_ctrl_ops {
  	int (*g_volatile_ctrl)(struct v4l2_ctrl *ctrl);
  	int (*try_ctrl)(struct v4l2_ctrl *ctrl);
  	int (*s_ctrl)(struct v4l2_ctrl *ctrl);
  };
  
  /** struct v4l2_ctrl - The control structure.
    * @node:	The list node.

    * @ev_subs:	The list of control event subscriptions.

    * @handler:	The handler that owns the control.
    * @cluster:	Point to start of cluster array.
    * @ncontrols:	Number of controls in cluster array.

    * @done:	Internal flag: set for each processed control.

    * @is_new:	Set when the user specified a new value for this control. It
    *		is also set when called from v4l2_ctrl_handler_setup. Drivers
    *		should never set this flag.

    * @is_private: If set, then this control is private to its handler and it
    *		will not be added to any other handlers. Drivers can set
    *		this flag.

    * @is_auto:   If set, then this control selects whether the other cluster
    *		members are in 'automatic' mode or 'manual' mode. This is
    *		used for autogain/gain type clusters. Drivers should never
    *		set this flag directly.

    * @has_volatiles: If set, then one or more members of the cluster are volatile.
    *		Drivers should never touch this flag.

    * @manual_mode_value: If the is_auto flag is set, then this is the value
    *		of the auto control that determines if that control is in
    *		manual mode. So if the value of the auto control equals this
    *		value, then the whole cluster is in manual mode. Drivers should
    *		never set this flag directly.

    * @ops:	The control ops.
    * @id:	The control ID.
    * @name:	The control name.
    * @type:	The control type.
    * @minimum:	The control's minimum value.
    * @maximum:	The control's maximum value.
    * @default_value: The control's default value.
    * @step:	The control's step value for non-menu controls.
    * @menu_skip_mask: The control's skip mask for menu controls. This makes it
    *		easy to skip menu items that are not valid. If bit X is set,
    *		then menu item X is skipped. Of course, this only works for
    *		menus with <= 32 menu items. There are no menus that come
    *		close to that number, so this is OK. Should we ever need more,
    *		then this will have to be extended to a u64 or a bit array.
    * @qmenu:	A const char * array for all menu items. Array entries that are
    *		empty strings ("") correspond to non-existing menu items (this
    *		is in addition to the menu_skip_mask above). The last entry
    *		must be NULL.
    * @flags:	The control's flags.
    * @cur:	The control's current value.
    * @val:	The control's new s32 value.
    * @val64:	The control's new s64 value.
    * @string:	The control's new string value.
    * @priv:	The control's private pointer. For use by the driver. It is
    *		untouched by the control framework. Note that this pointer is
    *		not freed when the control is deleted. Should this be needed
    *		then a new internal bitfield can be added to tell the framework
    *		to free this pointer.
    */
  struct v4l2_ctrl {
  	/* Administrative fields */
  	struct list_head node;

  	struct list_head ev_subs;

  	struct v4l2_ctrl_handler *handler;
  	struct v4l2_ctrl **cluster;
  	unsigned ncontrols;

  	unsigned int done:1;

  	unsigned int is_new:1;

  	unsigned int is_private:1;

  	unsigned int is_auto:1;

  	unsigned int has_volatiles:1;

  	unsigned int manual_mode_value:8;

  
  	const struct v4l2_ctrl_ops *ops;
  	u32 id;
  	const char *name;
  	enum v4l2_ctrl_type type;
  	s32 minimum, maximum, default_value;
  	union {
  		u32 step;
  		u32 menu_skip_mask;
  	};

  	const char * const *qmenu;

  	unsigned long flags;
  	union {
  		s32 val;
  		s64 val64;
  		char *string;
  	} cur;
  	union {
  		s32 val;
  		s64 val64;
  		char *string;
  	};
  	void *priv;
  };
  
  /** struct v4l2_ctrl_ref - The control reference.
    * @node:	List node for the sorted list.
    * @next:	Single-link list node for the hash.
    * @ctrl:	The actual control information.

    * @helper:	Pointer to helper struct. Used internally in prepare_ext_ctrls().

    *
    * Each control handler has a list of these refs. The list_head is used to
    * keep a sorted-by-control-ID list of all controls, while the next pointer
    * is used to link the control in the hash's bucket.
    */
  struct v4l2_ctrl_ref {
  	struct list_head node;
  	struct v4l2_ctrl_ref *next;
  	struct v4l2_ctrl *ctrl;

  	struct v4l2_ctrl_helper *helper;

  };
  
  /** struct v4l2_ctrl_handler - The control handler keeps track of all the
    * controls: both the controls owned by the handler and those inherited
    * from other handlers.
    * @lock:	Lock to control access to this handler and its controls.
    * @ctrls:	The list of controls owned by this handler.
    * @ctrl_refs:	The list of control references.
    * @cached:	The last found control reference. It is common that the same
    *		control is needed multiple times, so this is a simple
    *		optimization.
    * @buckets:	Buckets for the hashing. Allows for quick control lookup.
    * @nr_of_buckets: Total number of buckets in the array.
    * @error:	The error code of the first failed control addition.
    */
  struct v4l2_ctrl_handler {
  	struct mutex lock;
  	struct list_head ctrls;
  	struct list_head ctrl_refs;
  	struct v4l2_ctrl_ref *cached;
  	struct v4l2_ctrl_ref **buckets;
  	u16 nr_of_buckets;
  	int error;
  };
  
  /** struct v4l2_ctrl_config - Control configuration structure.
    * @ops:	The control ops.
    * @id:	The control ID.
    * @name:	The control name.
    * @type:	The control type.
    * @min:	The control's minimum value.
    * @max:	The control's maximum value.
    * @step:	The control's step value for non-menu controls.
    * @def: 	The control's default value.
    * @flags:	The control's flags.
    * @menu_skip_mask: The control's skip mask for menu controls. This makes it
    *		easy to skip menu items that are not valid. If bit X is set,
    *		then menu item X is skipped. Of course, this only works for
    *		menus with <= 32 menu items. There are no menus that come
    *		close to that number, so this is OK. Should we ever need more,
    *		then this will have to be extended to a u64 or a bit array.
    * @qmenu:	A const char * array for all menu items. Array entries that are
    *		empty strings ("") correspond to non-existing menu items (this
    *		is in addition to the menu_skip_mask above). The last entry
    *		must be NULL.
    * @is_private: If set, then this control is private to its handler and it
    *		will not be added to any other handlers.

    */
  struct v4l2_ctrl_config {
  	const struct v4l2_ctrl_ops *ops;
  	u32 id;
  	const char *name;
  	enum v4l2_ctrl_type type;
  	s32 min;
  	s32 max;
  	u32 step;
  	s32 def;
  	u32 flags;
  	u32 menu_skip_mask;

  	const char * const *qmenu;

  	unsigned int is_private:1;

  };
  
  /** v4l2_ctrl_fill() - Fill in the control fields based on the control ID.
    *
    * This works for all standard V4L2 controls.
    * For non-standard controls it will only fill in the given arguments
    * and @name will be NULL.
    *
    * This function will overwrite the contents of @name, @type and @flags.
    * The contents of @min, @max, @step and @def may be modified depending on
    * the type.
    *
    * Do not use in drivers! It is used internally for backwards compatibility
    * control handling only. Once all drivers are converted to use the new
    * control framework this function will no longer be exported.
    */
  void v4l2_ctrl_fill(u32 id, const char **name, enum v4l2_ctrl_type *type,
  		    s32 *min, s32 *max, s32 *step, s32 *def, u32 *flags);
  
  
  /** v4l2_ctrl_handler_init() - Initialize the control handler.
    * @hdl:	The control handler.
    * @nr_of_controls_hint: A hint of how many controls this handler is
    *		expected to refer to. This is the total number, so including
    *		any inherited controls. It doesn't have to be precise, but if
    *		it is way off, then you either waste memory (too many buckets
    *		are allocated) or the control lookup becomes slower (not enough
    *		buckets are allocated, so there are more slow list lookups).
    *		It will always work, though.
    *
    * Returns an error if the buckets could not be allocated. This error will
    * also be stored in @hdl->error.
    */
  int v4l2_ctrl_handler_init(struct v4l2_ctrl_handler *hdl,
  			   unsigned nr_of_controls_hint);
  
  /** v4l2_ctrl_handler_free() - Free all controls owned by the handler and free
    * the control list.
    * @hdl:	The control handler.
    *
    * Does nothing if @hdl == NULL.
    */
  void v4l2_ctrl_handler_free(struct v4l2_ctrl_handler *hdl);
  
  /** v4l2_ctrl_handler_setup() - Call the s_ctrl op for all controls belonging
    * to the handler to initialize the hardware to the current control values.
    * @hdl:	The control handler.
    *
    * Button controls will be skipped, as are read-only controls.
    *
    * If @hdl == NULL, then this just returns 0.
    */
  int v4l2_ctrl_handler_setup(struct v4l2_ctrl_handler *hdl);
  
  /** v4l2_ctrl_handler_log_status() - Log all controls owned by the handler.
    * @hdl:	The control handler.
    * @prefix:	The prefix to use when logging the control values. If the
    *		prefix does not end with a space, then ": " will be added
    *		after the prefix. If @prefix == NULL, then no prefix will be
    *		used.
    *
    * For use with VIDIOC_LOG_STATUS.
    *
    * Does nothing if @hdl == NULL.
    */
  void v4l2_ctrl_handler_log_status(struct v4l2_ctrl_handler *hdl,
  				  const char *prefix);
  
  /** v4l2_ctrl_new_custom() - Allocate and initialize a new custom V4L2
    * control.
    * @hdl:	The control handler.
    * @cfg:	The control's configuration data.
    * @priv:	The control's driver-specific private data.
    *
    * If the &v4l2_ctrl struct could not be allocated then NULL is returned
    * and @hdl->error is set to the error code (if it wasn't set already).
    */
  struct v4l2_ctrl *v4l2_ctrl_new_custom(struct v4l2_ctrl_handler *hdl,
  			const struct v4l2_ctrl_config *cfg, void *priv);
  
  /** v4l2_ctrl_new_std() - Allocate and initialize a new standard V4L2 non-menu control.
    * @hdl:	The control handler.
    * @ops:	The control ops.
    * @id:	The control ID.
    * @min:	The control's minimum value.
    * @max:	The control's maximum value.
    * @step:	The control's step value
    * @def: 	The control's default value.
    *
    * If the &v4l2_ctrl struct could not be allocated, or the control
    * ID is not known, then NULL is returned and @hdl->error is set to the
    * appropriate error code (if it wasn't set already).
    *
    * If @id refers to a menu control, then this function will return NULL.
    *
    * Use v4l2_ctrl_new_std_menu() when adding menu controls.
    */
  struct v4l2_ctrl *v4l2_ctrl_new_std(struct v4l2_ctrl_handler *hdl,
  			const struct v4l2_ctrl_ops *ops,
  			u32 id, s32 min, s32 max, u32 step, s32 def);
  
  /** v4l2_ctrl_new_std_menu() - Allocate and initialize a new standard V4L2 menu control.
    * @hdl:	The control handler.
    * @ops:	The control ops.
    * @id:	The control ID.
    * @max:	The control's maximum value.
    * @mask: 	The control's skip mask for menu controls. This makes it
    *		easy to skip menu items that are not valid. If bit X is set,
    *		then menu item X is skipped. Of course, this only works for
    *		menus with <= 32 menu items. There are no menus that come
    *		close to that number, so this is OK. Should we ever need more,
    *		then this will have to be extended to a u64 or a bit array.
    * @def: 	The control's default value.
    *
    * Same as v4l2_ctrl_new_std(), but @min is set to 0 and the @mask value
    * determines which menu items are to be skipped.
    *
    * If @id refers to a non-menu control, then this function will return NULL.
    */
  struct v4l2_ctrl *v4l2_ctrl_new_std_menu(struct v4l2_ctrl_handler *hdl,
  			const struct v4l2_ctrl_ops *ops,
  			u32 id, s32 max, s32 mask, s32 def);
  
  /** v4l2_ctrl_add_ctrl() - Add a control from another handler to this handler.
    * @hdl:	The control handler.
    * @ctrl:	The control to add.
    *
    * It will return NULL if it was unable to add the control reference.
    * If the control already belonged to the handler, then it will do
    * nothing and just return @ctrl.
    */
  struct v4l2_ctrl *v4l2_ctrl_add_ctrl(struct v4l2_ctrl_handler *hdl,
  					  struct v4l2_ctrl *ctrl);
  
  /** v4l2_ctrl_add_handler() - Add all controls from handler @add to
    * handler @hdl.
    * @hdl:	The control handler.
    * @add:	The control handler whose controls you want to add to
    *		the @hdl control handler.
    *
    * Does nothing if either of the two is a NULL pointer.
    * In case of an error @hdl->error will be set to the error code (if it
    * wasn't set already).
    */
  int v4l2_ctrl_add_handler(struct v4l2_ctrl_handler *hdl,
  			  struct v4l2_ctrl_handler *add);
  
  
  /** v4l2_ctrl_cluster() - Mark all controls in the cluster as belonging to that cluster.
    * @ncontrols:	The number of controls in this cluster.
    * @controls: 	The cluster control array of size @ncontrols.
    */
  void v4l2_ctrl_cluster(unsigned ncontrols, struct v4l2_ctrl **controls);

  /** v4l2_ctrl_auto_cluster() - Mark all controls in the cluster as belonging to
    * that cluster and set it up for autofoo/foo-type handling.
    * @ncontrols:	The number of controls in this cluster.
    * @controls:	The cluster control array of size @ncontrols. The first control
    *		must be the 'auto' control (e.g. autogain, autoexposure, etc.)
    * @manual_val: The value for the first control in the cluster that equals the
    *		manual setting.
    * @set_volatile: If true, then all controls except the first auto control will

    *		be volatile.

    *
    * Use for control groups where one control selects some automatic feature and
    * the other controls are only active whenever the automatic feature is turned
    * off (manual mode). Typical examples: autogain vs gain, auto-whitebalance vs
    * red and blue balance, etc.
    *
    * The behavior of such controls is as follows:
    *
    * When the autofoo control is set to automatic, then any manual controls
    * are set to inactive and any reads will call g_volatile_ctrl (if the control
    * was marked volatile).
    *
    * When the autofoo control is set to manual, then any manual controls will
    * be marked active, and any reads will just return the current value without
    * going through g_volatile_ctrl.
    *
    * In addition, this function will set the V4L2_CTRL_FLAG_UPDATE flag
    * on the autofoo control and V4L2_CTRL_FLAG_INACTIVE on the foo control(s)
    * if autofoo is in auto mode.
    */
  void v4l2_ctrl_auto_cluster(unsigned ncontrols, struct v4l2_ctrl **controls,
  			u8 manual_val, bool set_volatile);

  /** v4l2_ctrl_find() - Find a control with the given ID.
    * @hdl:	The control handler.
    * @id:	The control ID to find.
    *
    * If @hdl == NULL this will return NULL as well. Will lock the handler so
    * do not use from inside &v4l2_ctrl_ops.
    */
  struct v4l2_ctrl *v4l2_ctrl_find(struct v4l2_ctrl_handler *hdl, u32 id);
  
  /** v4l2_ctrl_activate() - Make the control active or inactive.
    * @ctrl:	The control to (de)activate.
    * @active:	True if the control should become active.
    *
    * This sets or clears the V4L2_CTRL_FLAG_INACTIVE flag atomically.
    * Does nothing if @ctrl == NULL.
    * This will usually be called from within the s_ctrl op.

    * The V4L2_EVENT_CTRL event will be generated afterwards.

    *

    * This function assumes that the control handler is locked.

    */
  void v4l2_ctrl_activate(struct v4l2_ctrl *ctrl, bool active);
  
  /** v4l2_ctrl_grab() - Mark the control as grabbed or not grabbed.
    * @ctrl:	The control to (de)activate.
    * @grabbed:	True if the control should become grabbed.
    *
    * This sets or clears the V4L2_CTRL_FLAG_GRABBED flag atomically.
    * Does nothing if @ctrl == NULL.

    * The V4L2_EVENT_CTRL event will be generated afterwards.

    * This will usually be called when starting or stopping streaming in the
    * driver.
    *

    * This function assumes that the control handler is not locked and will
    * take the lock itself.

    */
  void v4l2_ctrl_grab(struct v4l2_ctrl *ctrl, bool grabbed);
  
  /** v4l2_ctrl_lock() - Helper function to lock the handler
    * associated with the control.
    * @ctrl:	The control to lock.
    */
  static inline void v4l2_ctrl_lock(struct v4l2_ctrl *ctrl)
  {
  	mutex_lock(&ctrl->handler->lock);
  }
  
  /** v4l2_ctrl_lock() - Helper function to unlock the handler
    * associated with the control.
    * @ctrl:	The control to unlock.
    */
  static inline void v4l2_ctrl_unlock(struct v4l2_ctrl *ctrl)
  {
  	mutex_unlock(&ctrl->handler->lock);
  }
  
  /** v4l2_ctrl_g_ctrl() - Helper function to get the control's value from within a driver.
    * @ctrl:	The control.
    *
    * This returns the control's value safely by going through the control
    * framework. This function will lock the control's handler, so it cannot be
    * used from within the &v4l2_ctrl_ops functions.
    *
    * This function is for integer type controls only.
    */
  s32 v4l2_ctrl_g_ctrl(struct v4l2_ctrl *ctrl);
  
  /** v4l2_ctrl_s_ctrl() - Helper function to set the control's value from within a driver.
    * @ctrl:	The control.
    * @val:	The new value.
    *
    * This set the control's new value safely by going through the control
    * framework. This function will lock the control's handler, so it cannot be
    * used from within the &v4l2_ctrl_ops functions.
    *
    * This function is for integer type controls only.
    */
  int v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val);

  /* Internal helper functions that deal with control events. */

  void v4l2_ctrl_add_event(struct v4l2_ctrl *ctrl,
  		struct v4l2_subscribed_event *sev);
  void v4l2_ctrl_del_event(struct v4l2_ctrl *ctrl,
  		struct v4l2_subscribed_event *sev);

  /* Helpers for ioctl_ops. If hdl == NULL then they will all return -EINVAL. */
  int v4l2_queryctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_queryctrl *qc);
  int v4l2_querymenu(struct v4l2_ctrl_handler *hdl, struct v4l2_querymenu *qm);
  int v4l2_g_ctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_control *ctrl);

  int v4l2_s_ctrl(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl,
  						struct v4l2_control *ctrl);

  int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct v4l2_ext_controls *c);
  int v4l2_try_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct v4l2_ext_controls *c);

  int v4l2_s_ext_ctrls(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl,
  						struct v4l2_ext_controls *c);

  
  /* Helpers for subdevices. If the associated ctrl_handler == NULL then they
     will all return -EINVAL. */
  int v4l2_subdev_queryctrl(struct v4l2_subdev *sd, struct v4l2_queryctrl *qc);
  int v4l2_subdev_querymenu(struct v4l2_subdev *sd, struct v4l2_querymenu *qm);
  int v4l2_subdev_g_ext_ctrls(struct v4l2_subdev *sd, struct v4l2_ext_controls *cs);
  int v4l2_subdev_try_ext_ctrls(struct v4l2_subdev *sd, struct v4l2_ext_controls *cs);
  int v4l2_subdev_s_ext_ctrls(struct v4l2_subdev *sd, struct v4l2_ext_controls *cs);
  int v4l2_subdev_g_ctrl(struct v4l2_subdev *sd, struct v4l2_control *ctrl);
  int v4l2_subdev_s_ctrl(struct v4l2_subdev *sd, struct v4l2_control *ctrl);
  
  #endif