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 /* SPDX-License-Identifier: GPL-2.0-or-later */
 /*
  *  V4L2 controls support header.
  *
  *  Copyright (C) 2010  Hans Verkuil <hverkuil@xs4all.nl>
  */
 
 #ifndef _V4L2_CTRLS_H
 #define _V4L2_CTRLS_H
 
 #include <linux/list.h>
 #include <linux/mutex.h>
 #include <linux/videodev2.h>
 #include <media/media-request.h>
 
 /* forward references */
 struct file;
 struct poll_table_struct;
 struct v4l2_ctrl;
 struct v4l2_ctrl_handler;
 struct v4l2_ctrl_helper;
 struct v4l2_fh;
 struct v4l2_fwnode_device_properties;
 struct v4l2_subdev;
 struct v4l2_subscribed_event;
 struct video_device;
 
 /**
  * union v4l2_ctrl_ptr - A pointer to a control value.
  * @p_s32:          Pointer to a 32-bit signed value.
  * @p_s64:          Pointer to a 64-bit signed value.
  * @p_u8:           Pointer to a 8-bit unsigned value.
  * @p_u16:          Pointer to a 16-bit unsigned value.
  * @p_u32:          Pointer to a 32-bit unsigned value.
  * @p_char:         Pointer to a string.
  * @p_mpeg2_sequence:       Pointer to a MPEG2 sequence structure.
  * @p_mpeg2_picture:        Pointer to a MPEG2 picture structure.
  * @p_mpeg2_quantisation:   Pointer to a MPEG2 quantisation data structure.
  * @p_fwht_params:      Pointer to a FWHT stateless parameters structure.
  * @p_h264_sps:         Pointer to a struct v4l2_ctrl_h264_sps.
  * @p_h264_pps:         Pointer to a struct v4l2_ctrl_h264_pps.
  * @p_h264_scaling_matrix:  Pointer to a struct v4l2_ctrl_h264_scaling_matrix.
  * @p_h264_slice_params:    Pointer to a struct v4l2_ctrl_h264_slice_params.
  * @p_h264_decode_params:   Pointer to a struct v4l2_ctrl_h264_decode_params.
  * @p_h264_pred_weights:    Pointer to a struct v4l2_ctrl_h264_pred_weights.
  * @p_vp8_frame:        Pointer to a VP8 frame params structure.
  * @p_vp9_compressed_hdr_probs: Pointer to a VP9 frame compressed header probs structure.
  * @p_vp9_frame:        Pointer to a VP9 frame params structure.
  * @p_hevc_sps:         Pointer to an HEVC sequence parameter set structure.
  * @p_hevc_pps:         Pointer to an HEVC picture parameter set structure.
  * @p_hevc_slice_params:    Pointer to an HEVC slice parameters structure.
  * @p_hdr10_cll:        Pointer to an HDR10 Content Light Level structure.
  * @p_hdr10_mastering:      Pointer to an HDR10 Mastering Display structure.
  * @p_area:         Pointer to an area.
  * @p:              Pointer to a compound value.
  * @p_const:            Pointer to a constant compound value.
  */
 union v4l2_ctrl_ptr {
     s32 *p_s32;
     s64 *p_s64;
     u8 *p_u8;
     u16 *p_u16;
     u32 *p_u32;
     char *p_char;
     struct v4l2_ctrl_mpeg2_sequence *p_mpeg2_sequence;
     struct v4l2_ctrl_mpeg2_picture *p_mpeg2_picture;
     struct v4l2_ctrl_mpeg2_quantisation *p_mpeg2_quantisation;
     struct v4l2_ctrl_fwht_params *p_fwht_params;
     struct v4l2_ctrl_h264_sps *p_h264_sps;
     struct v4l2_ctrl_h264_pps *p_h264_pps;
     struct v4l2_ctrl_h264_scaling_matrix *p_h264_scaling_matrix;
     struct v4l2_ctrl_h264_slice_params *p_h264_slice_params;
     struct v4l2_ctrl_h264_decode_params *p_h264_decode_params;
     struct v4l2_ctrl_h264_pred_weights *p_h264_pred_weights;
     struct v4l2_ctrl_vp8_frame *p_vp8_frame;
     struct v4l2_ctrl_hevc_sps *p_hevc_sps;
     struct v4l2_ctrl_hevc_pps *p_hevc_pps;
     struct v4l2_ctrl_hevc_slice_params *p_hevc_slice_params;
     struct v4l2_ctrl_vp9_compressed_hdr *p_vp9_compressed_hdr_probs;
     struct v4l2_ctrl_vp9_frame *p_vp9_frame;
     struct v4l2_ctrl_hdr10_cll_info *p_hdr10_cll;
     struct v4l2_ctrl_hdr10_mastering_display *p_hdr10_mastering;
     struct v4l2_area *p_area;
     void *p;
     const void *p_const;
 };
 
 /**
  * v4l2_ctrl_ptr_create() - Helper function to return a v4l2_ctrl_ptr from a
  * void pointer
  * @ptr:    The void pointer
  */
 static inline union v4l2_ctrl_ptr v4l2_ctrl_ptr_create(void *ptr)
 {
     union v4l2_ctrl_ptr p = { .p = ptr };
 
     return p;
 }
 
 /**
  * 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_type_ops - The control type operations that the driver
  *                 has to provide.
  *
  * @equal: return true if both values are equal.
  * @init: initialize the value.
  * @log: log the value.
  * @validate: validate the value. Return 0 on success and a negative value
  *  otherwise.
  */
 struct v4l2_ctrl_type_ops {
     bool (*equal)(const struct v4l2_ctrl *ctrl, u32 idx,
               union v4l2_ctrl_ptr ptr1,
               union v4l2_ctrl_ptr ptr2);
     void (*init)(const struct v4l2_ctrl *ctrl, u32 idx,
              union v4l2_ctrl_ptr ptr);
     void (*log)(const struct v4l2_ctrl *ctrl);
     int (*validate)(const struct v4l2_ctrl *ctrl, u32 idx,
             union v4l2_ctrl_ptr ptr);
 };
 
 /**
  * typedef v4l2_ctrl_notify_fnc - typedef for a notify argument with a function
  *  that should be called when a control value has changed.
  *
  * @ctrl: pointer to struct &v4l2_ctrl
  * @priv: control private data
  *
  * This typedef definition is used as an argument to v4l2_ctrl_notify()
  * and as an argument at struct &v4l2_ctrl_handler.
  */
 typedef void (*v4l2_ctrl_notify_fnc)(struct v4l2_ctrl *ctrl, void *priv);
 
 /**
  * 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.
  * @has_changed: Set when the current value differs from the new value. Drivers
  *      should never use 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.
  * @is_int:    If set, then this control has a simple integer value (i.e. it
  *      uses ctrl->val).
  * @is_string: If set, then this control has type %V4L2_CTRL_TYPE_STRING.
  * @is_ptr: If set, then this control is an array and/or has type >=
  *      %V4L2_CTRL_COMPOUND_TYPES
  *      and/or has type %V4L2_CTRL_TYPE_STRING. In other words, &struct
  *      v4l2_ext_control uses field p to point to the data.
  * @is_array: If set, then this control contains an N-dimensional array.
  * @is_dyn_array: If set, then this control contains a dynamically sized 1-dimensional array.
  *      If this is set, then @is_array is also set.
  * @has_volatiles: If set, then one or more members of the cluster are volatile.
  *      Drivers should never touch this flag.
  * @call_notify: If set, then call the handler's notify function whenever the
  *      control's value changes.
  * @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.
  * @type_ops:   The control type 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.
  * @elems:  The number of elements in the N-dimensional array.
  * @elem_size:  The size in bytes of the control.
  * @new_elems:  The number of elements in p_new. This is the same as @elems,
  *      except for dynamic arrays. In that case it is in the range of
  *      1 to @p_dyn_alloc_elems.
  * @dims:   The size of each dimension.
  * @nr_of_dims:The number of dimensions in @dims.
  * @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.
  *      Used only if the @type is %V4L2_CTRL_TYPE_MENU.
  * @qmenu_int:  A 64-bit integer array for with integer menu items.
  *      The size of array must be equal to the menu size, e. g.:
  *      :math:`ceil(\frac{maximum - minimum}{step}) + 1`.
  *      Used only if the @type is %V4L2_CTRL_TYPE_INTEGER_MENU.
  * @flags:  The control's flags.
  * @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.
  * @p_dyn:  Pointer to the dynamically allocated array. Only valid if
  *      @is_dyn_array is true.
  * @p_dyn_alloc_elems: The number of elements in the dynamically allocated
  *      array for both the cur and new values. So @p_dyn is actually
  *      sized for 2 * @p_dyn_alloc_elems * @elem_size. Only valid if
  *      @is_dyn_array is true.
  * @cur:    Structure to store the current value.
  * @cur.val:    The control's current value, if the @type is represented via
  *      a u32 integer (see &enum v4l2_ctrl_type).
  * @val:    The control's new s32 value.
  * @p_def:  The control's default value represented via a union which
  *      provides a standard way of accessing control types
  *      through a pointer (for compound controls only).
  * @p_cur:  The control's current value represented via a union which
  *      provides a standard way of accessing control types
  *      through a pointer.
  * @p_new:  The control's new value represented via a union which provides
  *      a standard way of accessing control types
  *      through a 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 int ncontrols;
 
     unsigned int done:1;
 
     unsigned int is_new:1;
     unsigned int has_changed:1;
     unsigned int is_private:1;
     unsigned int is_auto:1;
     unsigned int is_int:1;
     unsigned int is_string:1;
     unsigned int is_ptr:1;
     unsigned int is_array:1;
     unsigned int is_dyn_array:1;
     unsigned int has_volatiles:1;
     unsigned int call_notify:1;
     unsigned int manual_mode_value:8;
 
     const struct v4l2_ctrl_ops *ops;
     const struct v4l2_ctrl_type_ops *type_ops;
     u32 id;
     const char *name;
     enum v4l2_ctrl_type type;
     s64 minimum, maximum, default_value;
     u32 elems;
     u32 elem_size;
     u32 new_elems;
     u32 dims[V4L2_CTRL_MAX_DIMS];
     u32 nr_of_dims;
     union {
         u64 step;
         u64 menu_skip_mask;
     };
     union {
         const char * const *qmenu;
         const s64 *qmenu_int;
     };
     unsigned long flags;
     void *priv;
     void *p_dyn;
     u32 p_dyn_alloc_elems;
     s32 val;
     struct {
         s32 val;
     } cur;
 
     union v4l2_ctrl_ptr p_def;
     union v4l2_ctrl_ptr p_new;
     union v4l2_ctrl_ptr p_cur;
 };
 
 /**
  * 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`` function at ``v4l2-ctrl.c``.
  * @from_other_dev: If true, then @ctrl was defined in another
  *      device than the &struct v4l2_ctrl_handler.
  * @req_done:   Internal flag: if the control handler containing this control
  *      reference is bound to a media request, then this is set when
  *      the control has been applied. This prevents applying controls
  *      from a cluster with multiple controls twice (when the first
  *      control of a cluster is applied, they all are).
  * @p_req_valid: If set, then p_req contains the control value for the request.
  * @p_req_dyn_enomem: If set, then p_req is invalid since allocating space for
  *      a dynamic array failed. Attempting to read this value shall
  *      result in ENOMEM. Only valid if ctrl->is_dyn_array is true.
  * @p_req_dyn_alloc_elems: The number of elements allocated for the dynamic
  *      array. Only valid if @p_req_valid and ctrl->is_dyn_array are
  *      true.
  * @p_req_elems: The number of elements in @p_req. This is the same as
  *      ctrl->elems, except for dynamic arrays. In that case it is in
  *      the range of 1 to @p_req_dyn_alloc_elems. Only valid if
  *      @p_req_valid is true.
  * @p_req:  If the control handler containing this control reference
  *      is bound to a media request, then this points to the
  *      value of the control that must be applied when the request
  *      is executed, or to the value of the control at the time
  *      that the request was completed. If @p_req_valid is false,
  *      then this control was never set for this request and the
  *      control will not be updated when this request is applied.
  *
  * 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;
     bool from_other_dev;
     bool req_done;
     bool p_req_valid;
     bool p_req_dyn_enomem;
     u32 p_req_dyn_alloc_elems;
     u32 p_req_elems;
     union v4l2_ctrl_ptr p_req;
 };
 
 /**
  * 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:  Default for "lock".
  * @lock:   Lock to control access to this handler and its controls.
  *      May be replaced by the user right after init.
  * @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.
  * @notify: A notify callback that is called whenever the control changes
  *      value.
  *      Note that the handler's lock is held when the notify function
  *      is called!
  * @notify_priv: Passed as argument to the v4l2_ctrl notify callback.
  * @nr_of_buckets: Total number of buckets in the array.
  * @error:  The error code of the first failed control addition.
  * @request_is_queued: True if the request was queued.
  * @requests:   List to keep track of open control handler request objects.
  *      For the parent control handler (@req_obj.ops == NULL) this
  *      is the list header. When the parent control handler is
  *      removed, it has to unbind and put all these requests since
  *      they refer to the parent.
  * @requests_queued: List of the queued requests. This determines the order
  *      in which these controls are applied. Once the request is
  *      completed it is removed from this list.
  * @req_obj:    The &struct media_request_object, used to link into a
  *      &struct media_request. This request object has a refcount.
  */
 struct v4l2_ctrl_handler {
     struct mutex _lock;
     struct mutex *lock;
     struct list_head ctrls;
     struct list_head ctrl_refs;
     struct v4l2_ctrl_ref *cached;
     struct v4l2_ctrl_ref **buckets;
     v4l2_ctrl_notify_fnc notify;
     void *notify_priv;
     u16 nr_of_buckets;
     int error;
     bool request_is_queued;
     struct list_head requests;
     struct list_head requests_queued;
     struct media_request_object req_obj;
 };
 
 /**
  * struct v4l2_ctrl_config - Control configuration structure.
  *
  * @ops:    The control ops.
  * @type_ops:   The control type ops. Only needed for compound controls.
  * @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.
  * @p_def:  The control's default value for compound controls.
  * @dims:   The size of each dimension.
  * @elem_size:  The size in bytes of the control.
  * @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 <= 64 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 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.
  * @qmenu_int:  A const s64 integer array for all menu items of the type
  *      V4L2_CTRL_TYPE_INTEGER_MENU.
  * @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;
     const struct v4l2_ctrl_type_ops *type_ops;
     u32 id;
     const char *name;
     enum v4l2_ctrl_type type;
     s64 min;
     s64 max;
     u64 step;
     s64 def;
     union v4l2_ctrl_ptr p_def;
     u32 dims[V4L2_CTRL_MAX_DIMS];
     u32 elem_size;
     u32 flags;
     u64 menu_skip_mask;
     const char * const *qmenu;
     const s64 *qmenu_int;
     unsigned int is_private:1;
 };
 
 /**
  * v4l2_ctrl_fill - Fill in the control fields based on the control ID.
  *
  * @id: ID of the control
  * @name: pointer to be filled with a string with the name of the control
  * @type: pointer for storing the type of the control
  * @min: pointer for storing the minimum value for the control
  * @max: pointer for storing the maximum value for the control
  * @step: pointer for storing the control step
  * @def: pointer for storing the default value for the control
  * @flags: pointer for storing the flags to be used on the control
  *
  * This works for all standard V4L2 controls.
  * For non-standard controls it will only fill in the given arguments
  * and @name content will be set to %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.
  *
  * .. note::
  *
  *    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,
             s64 *min, s64 *max, u64 *step, s64 *def, u32 *flags);
 
 
 /**
  * v4l2_ctrl_handler_init_class() - 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.
  * @key:    Used by the lock validator if CONFIG_LOCKDEP is set.
  * @name:   Used by the lock validator if CONFIG_LOCKDEP is set.
  *
  * .. attention::
  *
  *    Never use this call directly, always use the v4l2_ctrl_handler_init()
  *    macro that hides the @key and @name arguments.
  *
  * Return: returns an error if the buckets could not be allocated. This
  * error will also be stored in @hdl->error.
  */
 int v4l2_ctrl_handler_init_class(struct v4l2_ctrl_handler *hdl,
                  unsigned int nr_of_controls_hint,
                  struct lock_class_key *key, const char *name);
 
 #ifdef CONFIG_LOCKDEP
 
 /**
  * v4l2_ctrl_handler_init - helper function to create a static struct
  *   &lock_class_key and calls v4l2_ctrl_handler_init_class()
  *
  * @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.
  *
  * This helper function creates a static struct &lock_class_key and
  * calls v4l2_ctrl_handler_init_class(), providing a proper name for the lock
  * validador.
  *
  * Use this helper function to initialize a control handler.
  */
 #define v4l2_ctrl_handler_init(hdl, nr_of_controls_hint)        \
 (                                   \
     ({                              \
         static struct lock_class_key _key;          \
         v4l2_ctrl_handler_init_class(hdl, nr_of_controls_hint,  \
                     &_key,              \
                     KBUILD_BASENAME ":"     \
                     __stringify(__LINE__) ":"   \
                     "(" #hdl ")->_lock");       \
     })                              \
 )
 #else
 #define v4l2_ctrl_handler_init(hdl, nr_of_controls_hint)        \
     v4l2_ctrl_handler_init_class(hdl, nr_of_controls_hint, NULL, NULL)
 #endif
 
 /**
  * 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_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_unlock() - 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_handler_setup() - Call the s_ctrl op for all controls belonging
  * to the handler to initialize the hardware to the current control values. The
  * caller is responsible for acquiring the control handler mutex on behalf of
  * __v4l2_ctrl_handler_setup().
  * @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_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, s64 min, s64 max, u64 step,
                     s64 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 <= 64 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 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, u8 max, u64 mask, u8 def);
 
 /**
  * v4l2_ctrl_new_std_menu_items() - Create a new standard V4L2 menu control
  *  with driver specific menu.
  *
  * @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 <= 64 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 bit array.
  * @def:    The control's default value.
  * @qmenu:  The new menu.
  *
  * Same as v4l2_ctrl_new_std_menu(), but @qmenu will be the driver specific
  * menu of this control.
  *
  */
 struct v4l2_ctrl *v4l2_ctrl_new_std_menu_items(struct v4l2_ctrl_handler *hdl,
                            const struct v4l2_ctrl_ops *ops,
                            u32 id, u8 max,
                            u64 mask, u8 def,
                            const char * const *qmenu);
 
 /**
  * v4l2_ctrl_new_std_compound() - Allocate and initialize a new standard V4L2
  *      compound control.
  *
  * @hdl:       The control handler.
  * @ops:       The control ops.
  * @id:        The control ID.
  * @p_def:     The control's default value.
  *
  * Sames as v4l2_ctrl_new_std(), but with support to compound controls, thanks
  * to the @p_def field. Use v4l2_ctrl_ptr_create() to create @p_def from a
  * pointer. Use v4l2_ctrl_ptr_create(NULL) if the default value of the
  * compound control should be all zeroes.
  *
  */
 struct v4l2_ctrl *v4l2_ctrl_new_std_compound(struct v4l2_ctrl_handler *hdl,
                          const struct v4l2_ctrl_ops *ops,
                          u32 id,
                          const union v4l2_ctrl_ptr p_def);
 
 /**
  * v4l2_ctrl_new_int_menu() - Create a new standard V4L2 integer menu control.
  *
  * @hdl:    The control handler.
  * @ops:    The control ops.
  * @id: The control ID.
  * @max:    The control's maximum value.
  * @def:    The control's default value.
  * @qmenu_int:  The control's menu entries.
  *
  * Same as v4l2_ctrl_new_std_menu(), but @mask is set to 0 and it additionally
  * takes as an argument an array of integers determining the menu items.
  *
  * If @id refers to a non-integer-menu control, then this function will
  * return %NULL.
  */
 struct v4l2_ctrl *v4l2_ctrl_new_int_menu(struct v4l2_ctrl_handler *hdl,
                      const struct v4l2_ctrl_ops *ops,
                      u32 id, u8 max, u8 def,
                      const s64 *qmenu_int);
 
 /**
  * typedef v4l2_ctrl_filter - Typedef to define the filter function to be
  *  used when adding a control handler.
  *
  * @ctrl: pointer to struct &v4l2_ctrl.
  */
 
 typedef bool (*v4l2_ctrl_filter)(const 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.
  * @filter: This function will filter which controls should be added.
  * @from_other_dev: If true, then the controls in @add were defined in another
  *      device than @hdl.
  *
  * Does nothing if either of the two handlers is a NULL pointer.
  * If @filter is NULL, then all controls are added. Otherwise only those
  * controls for which @filter returns true will be added.
  * 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_filter filter,
               bool from_other_dev);
 
 /**
  * v4l2_ctrl_radio_filter() - Standard filter for radio controls.
  *
  * @ctrl:   The control that is filtered.
  *
  * This will return true for any controls that are valid for radio device
  * nodes. Those are all of the V4L2_CID_AUDIO_* user controls and all FM
  * transmitter class controls.
  *
  * This function is to be used with v4l2_ctrl_add_handler().
  */
 bool v4l2_ctrl_radio_filter(const struct v4l2_ctrl *ctrl);
 
 /**
  * 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 int 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 int 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() - Unlocked variant of v4l2_ctrl_grab.
  *
  * @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 locked by the caller.
  */
 void __v4l2_ctrl_grab(struct v4l2_ctrl *ctrl, bool grabbed);
 
 /**
  * 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.
  */
 static inline void v4l2_ctrl_grab(struct v4l2_ctrl *ctrl, bool grabbed)
 {
     if (!ctrl)
         return;
 
     v4l2_ctrl_lock(ctrl);
     __v4l2_ctrl_grab(ctrl, grabbed);
     v4l2_ctrl_unlock(ctrl);
 }
 
 /**
  *__v4l2_ctrl_modify_range() - Unlocked variant of v4l2_ctrl_modify_range()
  *
  * @ctrl:   The control to update.
  * @min:    The control's minimum value.
  * @max:    The control's maximum value.
  * @step:   The control's step value
  * @def:    The control's default value.
  *
  * Update the range of a control on the fly. This works for control types
  * INTEGER, BOOLEAN, MENU, INTEGER MENU and BITMASK. For menu controls the
  * @step value is interpreted as a menu_skip_mask.
  *
  * An error is returned if one of the range arguments is invalid for this
  * control type.
  *
  * The caller is responsible for acquiring the control handler mutex on behalf
  * of __v4l2_ctrl_modify_range().
  */
 int __v4l2_ctrl_modify_range(struct v4l2_ctrl *ctrl,
                  s64 min, s64 max, u64 step, s64 def);
 
 /**
  * v4l2_ctrl_modify_range() - Update the range of a control.
  *
  * @ctrl:   The control to update.
  * @min:    The control's minimum value.
  * @max:    The control's maximum value.
  * @step:   The control's step value
  * @def:    The control's default value.
  *
  * Update the range of a control on the fly. This works for control types
  * INTEGER, BOOLEAN, MENU, INTEGER MENU and BITMASK. For menu controls the
  * @step value is interpreted as a menu_skip_mask.
  *
  * An error is returned if one of the range arguments is invalid for this
  * control type.
  *
  * This function assumes that the control handler is not locked and will
  * take the lock itself.
  */
 static inline int v4l2_ctrl_modify_range(struct v4l2_ctrl *ctrl,
                      s64 min, s64 max, u64 step, s64 def)
 {
     int rval;
 
     v4l2_ctrl_lock(ctrl);
     rval = __v4l2_ctrl_modify_range(ctrl, min, max, step, def);
     v4l2_ctrl_unlock(ctrl);
 
     return rval;
 }
 
 /**
  * v4l2_ctrl_notify() - Function to set a notify callback for a control.
  *
  * @ctrl:   The control.
  * @notify: The callback function.
  * @priv:   The callback private handle, passed as argument to the callback.
  *
  * This function sets a callback function for the control. If @ctrl is NULL,
  * then it will do nothing. If @notify is NULL, then the notify callback will
  * be removed.
  *
  * There can be only one notify. If another already exists, then a WARN_ON
  * will be issued and the function will do nothing.
  */
 void v4l2_ctrl_notify(struct v4l2_ctrl *ctrl, v4l2_ctrl_notify_fnc notify,
               void *priv);
 
 /**
  * v4l2_ctrl_get_name() - Get the name of the control
  *
  * @id:     The control ID.
  *
  * This function returns the name of the given control ID or NULL if it isn't
  * a known control.
  */
 const char *v4l2_ctrl_get_name(u32 id);
 
 /**
  * v4l2_ctrl_get_menu() - Get the menu string array of the control
  *
  * @id:     The control ID.
  *
  * This function returns the NULL-terminated menu string array name of the
  * given control ID or NULL if it isn't a known menu control.
  */
 const char * const *v4l2_ctrl_get_menu(u32 id);
 
 /**
  * v4l2_ctrl_get_int_menu() - Get the integer menu array of the control
  *
  * @id:     The control ID.
  * @len:    The size of the integer array.
  *
  * This function returns the integer array of the given control ID or NULL if it
  * if it isn't a known integer menu control.
  */
 const s64 *v4l2_ctrl_get_int_menu(u32 id, u32 *len);
 
 /**
  * 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() - Unlocked variant of v4l2_ctrl_s_ctrl().
  *
  * @ctrl:   The control.
  * @val:    The new value.
  *
  * This sets the control's new value safely by going through the control
  * framework. This function assumes the control's handler is already locked,
  * allowing it to 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);
 
 /**
  * v4l2_ctrl_s_ctrl() - Helper function to set the control's value from
  *  within a driver.
  * @ctrl:   The control.
  * @val:    The new value.
  *
  * This sets 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.
  */
 static inline int v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val)
 {
     int rval;
 
     v4l2_ctrl_lock(ctrl);
     rval = __v4l2_ctrl_s_ctrl(ctrl, val);
     v4l2_ctrl_unlock(ctrl);
 
     return rval;
 }
 
 /**
  * v4l2_ctrl_g_ctrl_int64() - Helper function to get a 64-bit 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 64-bit integer type controls only.
  */
 s64 v4l2_ctrl_g_ctrl_int64(struct v4l2_ctrl *ctrl);
 
 /**
  * __v4l2_ctrl_s_ctrl_int64() - Unlocked variant of v4l2_ctrl_s_ctrl_int64().
  *
  * @ctrl:   The control.
  * @val:    The new value.
  *
  * This sets the control's new value safely by going through the control
  * framework. This function assumes the control's handler is already locked,
  * allowing it to be used from within the &v4l2_ctrl_ops functions.
  *
  * This function is for 64-bit integer type controls only.
  */
 int __v4l2_ctrl_s_ctrl_int64(struct v4l2_ctrl *ctrl, s64 val);
 
 /**
  * v4l2_ctrl_s_ctrl_int64() - Helper function to set a 64-bit control's value
  *  from within a driver.
  *
  * @ctrl:   The control.
  * @val:    The new value.
  *
  * This sets 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 64-bit integer type controls only.
  */
 static inline int v4l2_ctrl_s_ctrl_int64(struct v4l2_ctrl *ctrl, s64 val)
 {
     int rval;
 
     v4l2_ctrl_lock(ctrl);
     rval = __v4l2_ctrl_s_ctrl_int64(ctrl, val);
     v4l2_ctrl_unlock(ctrl);
 
     return rval;
 }
 
 /**
  * __v4l2_ctrl_s_ctrl_string() - Unlocked variant of v4l2_ctrl_s_ctrl_string().
  *
  * @ctrl:   The control.
  * @s:      The new string.
  *
  * This sets the control's new string safely by going through the control
  * framework. This function assumes the control's handler is already locked,
  * allowing it to be used from within the &v4l2_ctrl_ops functions.
  *
  * This function is for string type controls only.
  */
 int __v4l2_ctrl_s_ctrl_string(struct v4l2_ctrl *ctrl, const char *s);
 
 /**
  * v4l2_ctrl_s_ctrl_string() - Helper function to set a control's string value
  *   from within a driver.
  *
  * @ctrl:   The control.
  * @s:      The new string.
  *
  * This sets the control's new string 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 string type controls only.
  */
 static inline int v4l2_ctrl_s_ctrl_string(struct v4l2_ctrl *ctrl, const char *s)
 {
     int rval;
 
     v4l2_ctrl_lock(ctrl);
     rval = __v4l2_ctrl_s_ctrl_string(ctrl, s);
     v4l2_ctrl_unlock(ctrl);
 
     return rval;
 }
 
 /**
  * __v4l2_ctrl_s_ctrl_compound() - Unlocked variant to set a compound control
  *
  * @ctrl: The control.
  * @type: The type of the data.
  * @p:    The new compound payload.
  *
  * This sets the control's new compound payload safely by going through the
  * control framework. This function assumes the control's handler is already
  * locked, allowing it to be used from within the &v4l2_ctrl_ops functions.
  *
  * This function is for compound type controls only.
  */
 int __v4l2_ctrl_s_ctrl_compound(struct v4l2_ctrl *ctrl,
                 enum v4l2_ctrl_type type, const void *p);
 
 /**
  * v4l2_ctrl_s_ctrl_compound() - Helper function to set a compound control
  *  from within a driver.
  *
  * @ctrl: The control.
  * @type: The type of the data.
  * @p:    The new compound payload.
  *
  * This sets the control's new compound payload 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 compound type controls only.
  */
 static inline int v4l2_ctrl_s_ctrl_compound(struct v4l2_ctrl *ctrl,
                         enum v4l2_ctrl_type type,
                         const void *p)
 {
     int rval;
 
     v4l2_ctrl_lock(ctrl);
     rval = __v4l2_ctrl_s_ctrl_compound(ctrl, type, p);
     v4l2_ctrl_unlock(ctrl);
 
     return rval;
 }
 
 /* Helper defines for area type controls */
 #define __v4l2_ctrl_s_ctrl_area(ctrl, area) \
     __v4l2_ctrl_s_ctrl_compound((ctrl), V4L2_CTRL_TYPE_AREA, (area))
 #define v4l2_ctrl_s_ctrl_area(ctrl, area) \
     v4l2_ctrl_s_ctrl_compound((ctrl), V4L2_CTRL_TYPE_AREA, (area))
 
 /* Internal helper functions that deal with control events. */
 extern const struct v4l2_subscribed_event_ops v4l2_ctrl_sub_ev_ops;
 
 /**
  * v4l2_ctrl_replace - Function to be used as a callback to
  *  &struct v4l2_subscribed_event_ops replace\(\)
  *
  * @old: pointer to struct &v4l2_event with the reported
  *   event;
  * @new: pointer to struct &v4l2_event with the modified
  *   event;
  */
 void v4l2_ctrl_replace(struct v4l2_event *old, const struct v4l2_event *new);
 
 /**
  * v4l2_ctrl_merge - Function to be used as a callback to
  *  &struct v4l2_subscribed_event_ops merge(\)
  *
  * @old: pointer to struct &v4l2_event with the reported
  *   event;
  * @new: pointer to struct &v4l2_event with the merged
  *   event;
  */
 void v4l2_ctrl_merge(const struct v4l2_event *old, struct v4l2_event *new);
 
 /**
  * v4l2_ctrl_log_status - helper function to implement %VIDIOC_LOG_STATUS ioctl
  *
  * @file: pointer to struct file
  * @fh: unused. Kept just to be compatible to the arguments expected by
  *  &struct v4l2_ioctl_ops.vidioc_log_status.
  *
  * Can be used as a vidioc_log_status function that just dumps all controls
  * associated with the filehandle.
  */
 int v4l2_ctrl_log_status(struct file *file, void *fh);
 
 /**
  * v4l2_ctrl_subscribe_event - Subscribes to an event
  *
  *
  * @fh: pointer to struct v4l2_fh
  * @sub: pointer to &struct v4l2_event_subscription
  *
  * Can be used as a vidioc_subscribe_event function that just subscribes
  * control events.
  */
 int v4l2_ctrl_subscribe_event(struct v4l2_fh *fh,
                 const struct v4l2_event_subscription *sub);
 
 /**
  * v4l2_ctrl_poll - function to be used as a callback to the poll()
  *  That just polls for control events.
  *
  * @file: pointer to struct file
  * @wait: pointer to struct poll_table_struct
  */
 __poll_t v4l2_ctrl_poll(struct file *file, struct poll_table_struct *wait);
 
 /**
  * v4l2_ctrl_request_setup - helper function to apply control values in a request
  *
  * @req: The request
  * @parent: The parent control handler ('priv' in media_request_object_find())
  *
  * This is a helper function to call the control handler's s_ctrl callback with
  * the control values contained in the request. Do note that this approach of
  * applying control values in a request is only applicable to memory-to-memory
  * devices.
  */
 int v4l2_ctrl_request_setup(struct media_request *req,
                  struct v4l2_ctrl_handler *parent);
 
 /**
  * v4l2_ctrl_request_complete - Complete a control handler request object
  *
  * @req: The request
  * @parent: The parent control handler ('priv' in media_request_object_find())
  *
  * This function is to be called on each control handler that may have had a
  * request object associated with it, i.e. control handlers of a driver that
  * supports requests.
  *
  * The function first obtains the values of any volatile controls in the control
  * handler and attach them to the request. Then, the function completes the
  * request object.
  */
 void v4l2_ctrl_request_complete(struct media_request *req,
                 struct v4l2_ctrl_handler *parent);
 
 /**
  * v4l2_ctrl_request_hdl_find - Find the control handler in the request
  *
  * @req: The request
  * @parent: The parent control handler ('priv' in media_request_object_find())
  *
  * This function finds the control handler in the request. It may return
  * NULL if not found. When done, you must call v4l2_ctrl_request_put_hdl()
  * with the returned handler pointer.
  *
  * If the request is not in state VALIDATING or QUEUED, then this function
  * will always return NULL.
  *
  * Note that in state VALIDATING the req_queue_mutex is held, so
  * no objects can be added or deleted from the request.
  *
  * In state QUEUED it is the driver that will have to ensure this.
  */
 struct v4l2_ctrl_handler *v4l2_ctrl_request_hdl_find(struct media_request *req,
                     struct v4l2_ctrl_handler *parent);
 
 /**
  * v4l2_ctrl_request_hdl_put - Put the control handler
  *
  * @hdl: Put this control handler
  *
  * This function released the control handler previously obtained from'
  * v4l2_ctrl_request_hdl_find().
  */
 static inline void v4l2_ctrl_request_hdl_put(struct v4l2_ctrl_handler *hdl)
 {
     if (hdl)
         media_request_object_put(&hdl->req_obj);
 }
 
 /**
  * v4l2_ctrl_request_hdl_ctrl_find() - Find a control with the given ID.
  *
  * @hdl: The control handler from the request.
  * @id: The ID of the control to find.
  *
  * This function returns a pointer to the control if this control is
  * part of the request or NULL otherwise.
  */
 struct v4l2_ctrl *
 v4l2_ctrl_request_hdl_ctrl_find(struct v4l2_ctrl_handler *hdl, u32 id);
 
 /* Helpers for ioctl_ops */
 
 /**
  * v4l2_queryctrl - Helper function to implement
  *  :ref:`VIDIOC_QUERYCTRL <vidioc_queryctrl>` ioctl
  *
  * @hdl: pointer to &struct v4l2_ctrl_handler
  * @qc: pointer to &struct v4l2_queryctrl
  *
  * If hdl == NULL then they will all return -EINVAL.
  */
 int v4l2_queryctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_queryctrl *qc);
 
 /**
  * v4l2_query_ext_ctrl - Helper function to implement
  *   :ref:`VIDIOC_QUERY_EXT_CTRL <vidioc_queryctrl>` ioctl
  *
  * @hdl: pointer to &struct v4l2_ctrl_handler
  * @qc: pointer to &struct v4l2_query_ext_ctrl
  *
  * If hdl == NULL then they will all return -EINVAL.
  */
 int v4l2_query_ext_ctrl(struct v4l2_ctrl_handler *hdl,
             struct v4l2_query_ext_ctrl *qc);
 
 /**
  * v4l2_querymenu - Helper function to implement
  *  :ref:`VIDIOC_QUERYMENU <vidioc_queryctrl>` ioctl
  *
  * @hdl: pointer to &struct v4l2_ctrl_handler
  * @qm: pointer to &struct v4l2_querymenu
  *
  * If hdl == NULL then they will all return -EINVAL.
  */
 int v4l2_querymenu(struct v4l2_ctrl_handler *hdl, struct v4l2_querymenu *qm);
 
 /**
  * v4l2_g_ctrl - Helper function to implement
  *  :ref:`VIDIOC_G_CTRL <vidioc_g_ctrl>` ioctl
  *
  * @hdl: pointer to &struct v4l2_ctrl_handler
  * @ctrl: pointer to &struct v4l2_control
  *
  * If hdl == NULL then they will all return -EINVAL.
  */
 int v4l2_g_ctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_control *ctrl);
 
 /**
  * v4l2_s_ctrl - Helper function to implement
  *  :ref:`VIDIOC_S_CTRL <vidioc_g_ctrl>` ioctl
  *
  * @fh: pointer to &struct v4l2_fh
  * @hdl: pointer to &struct v4l2_ctrl_handler
  *
  * @ctrl: pointer to &struct v4l2_control
  *
  * If hdl == NULL then they will all return -EINVAL.
  */
 int v4l2_s_ctrl(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl,
         struct v4l2_control *ctrl);
 
 /**
  * v4l2_g_ext_ctrls - Helper function to implement
  *  :ref:`VIDIOC_G_EXT_CTRLS <vidioc_g_ext_ctrls>` ioctl
  *
  * @hdl: pointer to &struct v4l2_ctrl_handler
  * @vdev: pointer to &struct video_device
  * @mdev: pointer to &struct media_device
  * @c: pointer to &struct v4l2_ext_controls
  *
  * If hdl == NULL then they will all return -EINVAL.
  */
 int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct video_device *vdev,
              struct media_device *mdev, struct v4l2_ext_controls *c);
 
 /**
  * v4l2_try_ext_ctrls - Helper function to implement
  *  :ref:`VIDIOC_TRY_EXT_CTRLS <vidioc_g_ext_ctrls>` ioctl
  *
  * @hdl: pointer to &struct v4l2_ctrl_handler
  * @vdev: pointer to &struct video_device
  * @mdev: pointer to &struct media_device
  * @c: pointer to &struct v4l2_ext_controls
  *
  * If hdl == NULL then they will all return -EINVAL.
  */
 int v4l2_try_ext_ctrls(struct v4l2_ctrl_handler *hdl,
                struct video_device *vdev,
                struct media_device *mdev,
                struct v4l2_ext_controls *c);
 
 /**
  * v4l2_s_ext_ctrls - Helper function to implement
  *  :ref:`VIDIOC_S_EXT_CTRLS <vidioc_g_ext_ctrls>` ioctl
  *
  * @fh: pointer to &struct v4l2_fh
  * @hdl: pointer to &struct v4l2_ctrl_handler
  * @vdev: pointer to &struct video_device
  * @mdev: pointer to &struct media_device
  * @c: pointer to &struct v4l2_ext_controls
  *
  * If hdl == NULL then they will all return -EINVAL.
  */
 int v4l2_s_ext_ctrls(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl,
              struct video_device *vdev,
              struct media_device *mdev,
              struct v4l2_ext_controls *c);
 
 /**
  * v4l2_ctrl_subdev_subscribe_event - Helper function to implement
  *  as a &struct v4l2_subdev_core_ops subscribe_event function
  *  that just subscribes control events.
  *
  * @sd: pointer to &struct v4l2_subdev
  * @fh: pointer to &struct v4l2_fh
  * @sub: pointer to &struct v4l2_event_subscription
  */
 int v4l2_ctrl_subdev_subscribe_event(struct v4l2_subdev *sd, struct v4l2_fh *fh,
                      struct v4l2_event_subscription *sub);
 
 /**
  * v4l2_ctrl_subdev_log_status - Log all controls owned by subdev's control
  *   handler.
  *
  * @sd: pointer to &struct v4l2_subdev
  */
 int v4l2_ctrl_subdev_log_status(struct v4l2_subdev *sd);
 
 /**
  * v4l2_ctrl_new_fwnode_properties() - Register controls for the device
  *                     properties
  *
  * @hdl: pointer to &struct v4l2_ctrl_handler to register controls on
  * @ctrl_ops: pointer to &struct v4l2_ctrl_ops to register controls with
  * @p: pointer to &struct v4l2_fwnode_device_properties
  *
  * This function registers controls associated to device properties, using the
  * property values contained in @p parameter, if the property has been set to
  * a value.
  *
  * Currently the following v4l2 controls are parsed and registered:
  * - V4L2_CID_CAMERA_ORIENTATION
  * - V4L2_CID_CAMERA_SENSOR_ROTATION;
  *
  * Controls already registered by the caller with the @hdl control handler are
  * not overwritten. Callers should register the controls they want to handle
  * themselves before calling this function.
  *
  * Return: 0 on success, a negative error code on failure.
  */
 int v4l2_ctrl_new_fwnode_properties(struct v4l2_ctrl_handler *hdl,
                     const struct v4l2_ctrl_ops *ctrl_ops,
                     const struct v4l2_fwnode_device_properties *p);
 #endif

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