Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1591 insertions, 0 deletions

diff --git a/include/media/v4l2-ctrls.h b/include/media/v4l2-ctrls.h
new file mode 100644
index 0000000000..59679a42b3
--- /dev/null
+++ b/include/media/v4l2-ctrls.h
@@ -0,0 +1,1591 @@
+/* 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_av1_sequence:		Pointer to an AV1 sequence structure.
+ * @p_av1_tile_group_entry:	Pointer to an AV1 tile group entry structure.
+ * @p_av1_frame:		Pointer to an AV1 frame structure.
+ * @p_av1_film_grain:		Pointer to an AV1 film grain structure.
+ * @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;
+	struct v4l2_ctrl_av1_sequence *p_av1_sequence;
+	struct v4l2_ctrl_av1_tile_group_entry *p_av1_tile_group_entry;
+	struct v4l2_ctrl_av1_frame *p_av1_frame;
+	struct v4l2_ctrl_av1_film_grain *p_av1_film_grain;
+	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 all ctrl->elems array elements are equal.
+ * @init: initialize the value for array elements from from_idx to ctrl->elems.
+ * @log: log the value.
+ * @validate: validate the value for ctrl->new_elems array elements.
+ *	Return 0 on success and a negative value otherwise.
+ */
+struct v4l2_ctrl_type_ops {
+	bool (*equal)(const struct v4l2_ctrl *ctrl,
+		      union v4l2_ctrl_ptr ptr1, union v4l2_ctrl_ptr ptr2);
+	void (*init)(const struct v4l2_ctrl *ctrl, u32 from_idx,
+		     union v4l2_ctrl_ptr ptr);
+	void (*log)(const struct v4l2_ctrl *ctrl);
+	int (*validate)(const struct v4l2_ctrl *ctrl, 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_array_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_array:	Pointer to the allocated array. Only valid if @is_array is true.
+ * @p_array_alloc_elems: The number of elements in the allocated
+ *		array for both the cur and new values. So @p_array is actually
+ *		sized for 2 * @p_array_alloc_elems * @elem_size. Only valid if
+ *		@is_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_array;
+	u32 p_array_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_array_enomem: If set, then p_req is invalid since allocating space for
+ *		an array failed. Attempting to read this value shall
+ *		result in ENOMEM. Only valid if ctrl->is_array is true.
+ * @p_req_array_alloc_elems: The number of elements allocated for the
+ *		array. Only valid if @p_req_valid and ctrl->is_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_array_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_array_enomem;
+	u32 p_req_array_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_modify_dimensions() - Unlocked variant of v4l2_ctrl_modify_dimensions()
+ *
+ * @ctrl:	The control to update.
+ * @dims:	The control's new dimensions.
+ *
+ * Update the dimensions of an array control on the fly. The elements of the
+ * array are reset to their default value, even if the dimensions are
+ * unchanged.
+ *
+ * An error is returned if @dims is invalid for this control.
+ *
+ * The caller is responsible for acquiring the control handler mutex on behalf
+ * of __v4l2_ctrl_modify_dimensions().
+ *
+ * Note: calling this function when the same control is used in pending requests
+ * is untested. It should work (a request with the wrong size of the control
+ * will drop that control silently), but it will be very confusing.
+ */
+int __v4l2_ctrl_modify_dimensions(struct v4l2_ctrl *ctrl,
+				  u32 dims[V4L2_CTRL_MAX_DIMS]);
+
+/**
+ * v4l2_ctrl_modify_dimensions() - Update the dimensions of an array control.
+ *
+ * @ctrl:	The control to update.
+ * @dims:	The control's new dimensions.
+ *
+ * Update the dimensions of an array control on the fly. The elements of the
+ * array are reset to their default value, even if the dimensions are
+ * unchanged.
+ *
+ * An error is returned if @dims is invalid for this control type.
+ *
+ * This function assumes that the control handler is not locked and will
+ * take the lock itself.
+ *
+ * Note: calling this function when the same control is used in pending requests
+ * is untested. It should work (a request with the wrong size of the control
+ * will drop that control silently), but it will be very confusing.
+ */
+static inline int v4l2_ctrl_modify_dimensions(struct v4l2_ctrl *ctrl,
+					      u32 dims[V4L2_CTRL_MAX_DIMS])
+{
+	int rval;
+
+	v4l2_ctrl_lock(ctrl);
+	rval = __v4l2_ctrl_modify_dimensions(ctrl, dims);
+	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_hdl_put()
+ * 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);
+
+/**
+ * v4l2_ctrl_type_op_equal - Default v4l2_ctrl_type_ops equal callback.
+ *
+ * @ctrl: The v4l2_ctrl pointer.
+ * @ptr1: A v4l2 control value.
+ * @ptr2: A v4l2 control value.
+ *
+ * Return: true if values are equal, otherwise false.
+ */
+bool v4l2_ctrl_type_op_equal(const struct v4l2_ctrl *ctrl,
+			     union v4l2_ctrl_ptr ptr1, union v4l2_ctrl_ptr ptr2);
+
+/**
+ * v4l2_ctrl_type_op_init - Default v4l2_ctrl_type_ops init callback.
+ *
+ * @ctrl: The v4l2_ctrl pointer.
+ * @from_idx: Starting element index.
+ * @ptr: The v4l2 control value.
+ *
+ * Return: void
+ */
+void v4l2_ctrl_type_op_init(const struct v4l2_ctrl *ctrl, u32 from_idx,
+			    union v4l2_ctrl_ptr ptr);
+
+/**
+ * v4l2_ctrl_type_op_log - Default v4l2_ctrl_type_ops log callback.
+ *
+ * @ctrl: The v4l2_ctrl pointer.
+ *
+ * Return: void
+ */
+void v4l2_ctrl_type_op_log(const struct v4l2_ctrl *ctrl);
+
+/**
+ * v4l2_ctrl_type_op_validate - Default v4l2_ctrl_type_ops validate callback.
+ *
+ * @ctrl: The v4l2_ctrl pointer.
+ * @ptr: The v4l2 control value.
+ *
+ * Return: 0 on success, a negative error code on failure.
+ */
+int v4l2_ctrl_type_op_validate(const struct v4l2_ctrl *ctrl, union v4l2_ctrl_ptr ptr);
+
+#endif