/*
V4L2 controls support header.
Copyright (C) 2010 Hans Verkuil <hverkuil@xs4all.nl>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifndef _V4L2_CTRLS_H
#define _V4L2_CTRLS_H
#include <linux/list.h>
#include <linux/device.h>
/* forward references */
struct v4l2_ctrl_handler;
struct v4l2_ctrl;
struct video_device;
struct v4l2_subdev;
/** struct v4l2_ctrl_ops - The control operations that the driver has to provide.
* @g_volatile_ctrl: Get a new value for this control. Generally only relevant
* for volatile (and usually read-only) controls such as a control
* that returns the current signal strength which changes
* continuously.
* If not set, then the currently cached value will be returned.
* @try_ctrl: Test whether the control's value is valid. Only relevant when
* the usual min/max/step checks are not sufficient.
* @s_ctrl: Actually set the new control value. s_ctrl is compulsory. The
* ctrl->handler->lock is held when these ops are called, so no
* one else can access controls owned by that handler.
*/
struct v4l2_ctrl_ops {
int (*g_volatile_ctrl)(struct v4l2_ctrl *ctrl);
int (*try_ctrl)(struct v4l2_ctrl *ctrl);
int (*s_ctrl)(struct v4l2_ctrl *ctrl);
};
/** struct v4l2_ctrl - The control structure.
* @node: The list node.
* @handler: The handler that owns the control.
* @cluster: Point to start of cluster array.
* @ncontrols: Number of controls in cluster array.
* @has_new: Internal flag: set when there is a valid new value.
* @done: Internal flag: set for each processed control.
* @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_volatile: If set, then this control is volatile. This means that the
* control's current value cannot be cached and needs to be
* retrieved through the g_volatile_ctrl op. Drivers can set
* this flag.
* @ops: The control ops.
* @id: The control ID.
* @name: The control name.
* @type: The control type.
* @minimum: The control's minimum value.
* @maximum: The control's maximum value.
* @default_value: The control's default value.
* @step: The control's step value for non-menu controls.
* @menu_skip_mask: The control's skip mask for menu controls. This makes it
* easy to skip menu items that are not valid. If bit X is set,
* then menu item X is skipped. Of course, this only works for
* menus with <= 32 menu items. There are no menus that come
* close to that number, so this is OK. Should we ever need more,
* then this will have to be extended to a u64 or a bit array.
* @qmenu: A const char * array for all menu items. Array entries that are
* empty strings ("") correspond to non-existing menu items (this
* is in addition to the menu_skip_mask above). The last entry
* must be NULL.
* @flags: The control's flags.
* @cur: The control's current value.
* @val: The control's new s32 value.
* @val64: The control's new s64 value.
* @string: The control's new string value.
* @priv: The control's private pointer. For use by the driver. It is
* untouched by the control framework. Note that this pointer is
* not freed when the control is deleted. Should this be needed
* then a new internal bitfield can be added to tell the framework
* to free this pointer.
*/
struct v4l2_ctrl {
/* Administrative fields */
struct list_head node;
struct v4l2_ctrl_handler *handler;
struct v4l2_ctrl **cluster;
unsigned ncontrols;
unsigned int has_new:1;
unsigned int done:1;
unsigned int is_private:1;
unsigned int is_volatile:1;
const struct v4l2_ctrl_ops *ops;
u32 id;
const char *name;
enum v4l2_ctrl_type type;
s32 minimum, maximum, default_value;
union {
u32 step;
u32 menu_skip_mask;
};
const char * const *qmenu;
unsigned long flags;
union {
s32 val;
s64 val64;
char *string;
} cur;
union {
s32 val;
s64 val64;
char *string;
};
void *priv;
};
/** struct v4l2_ctrl_ref - The control reference.
* @node: List node for the sorted list.
* @next: Single-link list node for the hash.
* @ctrl: The actual control information.
*
* 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_handler - The control handler keeps track of all the
* controls: both the controls owned by the handler and those inherited
* from other handlers.
* @lock: Lock to control access to this handler and its controls.
* @ctrls: The list of controls owned by this handler.
* @ctrl_refs: The list of control references.
* @cached: The last found control reference. It is common that the same
* control is needed multiple times, so this is a simple
* optimization.
* @buckets: Buckets for the hashing. Allows for quick control lookup.
* @nr_of_buckets: Total number of buckets in the array.
* @error: The error code of the first failed control addition.
*/
struct v4l2_ctrl_handler {
struct mutex lock;
struct list_head ctrls;
struct list_head ctrl_refs;
struct v4l2_ctrl_ref *cached;
struct v4l2_ctrl_ref **buckets;
u16 nr_of_buckets;
int error;
};
/** struct v4l2_ctrl_config - Control configuration structure.
* @ops: The control ops.
* @id: The control ID.
* @name: The control name.
* @type: The control type.
* @min: The control's minimum value.
* @max: The control's maximum value.
* @step: The control's step value for non-menu controls.
* @def: The control's default value.
* @flags: The control's flags.
* @menu_skip_mask: The control's skip mask for menu controls. This makes it
* easy to skip menu items that are not valid. If bit X is set,
* then menu item X is skipped. Of course, this only works for
* menus with <= 32 menu items. There are no menus that come
* close to that number, so this is OK. Should we ever need more,
* then this will have to be extended to a u64 or a bit array.
* @qmenu: A const char * array for all menu items. Array entries that are
* empty strings ("") correspond to non-existing menu items (this
* is in addition to the menu_skip_mask above). The last entry
* must be NULL.
* @is_private: If set, then this control is private to its handler and it
* will not be added to any other handlers.
* @is_volatile: If set, then this control is volatile. This means that the
* control's current value cannot be cached and needs to be
* retrieved through the g_volatile_ctrl op.
*/
struct v4l2_ctrl_config {
const struct v4l2_ctrl_ops *ops;
u32 id;
const char *name;
enum v4l2_ctrl_type type;
s32 min;
s32 max;
u32 step;
s32 def;
u32 flags;
u32 menu_skip_mask;
const char * const *qmenu;
unsigned int is_private:1;
unsigned int is_volatile:1;
};
/** v4l2_ctrl_fill() - Fill in the control fields based on the control ID.
*
* This works for all standard V4L2 controls.
* For non-standard controls it will only fill in the given arguments
* and @name will be NULL.
*
* This function will overwrite the contents of @name, @type and @flags.
* The contents of @min, @max, @step and @def may be modified depending on
* the type.
*
* Do not use in drivers! It is used internally for backwards compatibility
* control handling only. Once all drivers are converted to use the new
* control framework this function will no longer be exported.
*/
void v4l2_ctrl_fill(u32 id, const char **name, enum v4l2_ctrl_type *type,
s32 *min, s32 *max, s32 *step, s32 *def, u32 *flags);
/** v4l2_ctrl_handler_init() - Initialize the control handler.
* @hdl: The control handler.
* @nr_of_controls_hint: A hint of how many controls this handler is
* expected to refer to. This is the total number, so including
* any inherited controls. It doesn't have to be precise, but if
* it is way off, then you either waste memory (too many buckets
* are allocated) or the control lookup becomes slower (not enough
* buckets are allocated, so there are more slow list lookups).
* It will always work, though.
*
* Returns an error if the buckets could not be allocated. This error will
* also be stored in @hdl->error.
*/
int v4l2_ctrl_handler_init(struct v4l2_ctrl_handler *hdl,
unsigned nr_of_controls_hint);
/** v4l2_ctrl_handler_free() - Free all controls owned by the handler and free
* the control list.
* @hdl: The control handler.
*
* Does nothing if @hdl == NULL.
*/
void v4l2_ctrl_handler_free(struct v4l2_ctrl_handler *hdl);
/** v4l2_ctrl_handler_setup() - Call the s_ctrl op for all controls belonging
* to the handler to initialize the hardware to the current control values.
* @hdl: The control handler.
*
* Button controls will be skipped, as are read-only controls.
*
* If @hdl == NULL, then this just returns 0.
*/
int v4l2_ctrl_handler_setup(struct v4l2_ctrl_handler *hdl);
/** v4l2_ctrl_handler_log_status() - Log all controls owned by the handler.
* @hdl: The control handler.
* @prefix: The prefix to use when logging the control values. If the
* prefix does not end with a space, then ": " will be added
* after the prefix. If @prefix == NULL, then no prefix will be
* used.
*
* For use with VIDIOC_LOG_STATUS.
*
* Does nothing if @hdl == NULL.
*/
void v4l2_ctrl_handler_log_status(struct v4l2_ctrl_handler *hdl,
const char *prefix);
/** v4l2_ctrl_new_custom() - Allocate and initialize a new custom V4L2
* control.
* @hdl: The control handler.
* @cfg: The control's configuration data.
* @priv: The control's driver-specific private data.
*
* If the &v4l2_ctrl struct could not be allocated then NULL is returned
* and @hdl->error is set to the error code (if it wasn't set already).
*/
struct v4l2_ctrl *v4l2_ctrl_new_custom(struct v4l2_ctrl_handler *hdl,
const struct v4l2_ctrl_config *cfg, void *priv);
/** v4l2_ctrl_new_std() - Allocate and initialize a new standard V4L2 non-menu control.
* @hdl: The control handler.
* @ops: The control ops.
* @id: The control ID.
* @min: The control's minimum value.
* @max: The control's maximum value.
* @step: The control's step value
* @def: The control's default value.
*
* If the &v4l2_ctrl struct could not be allocated, or the control
* ID is not known, then NULL is returned and @hdl->error is set to the
* appropriate error code (if it wasn't set already).
*
* If @id refers to a menu control, then this function will return NULL.
*
* Use v4l2_ctrl_new_std_menu() when adding menu controls.
*/
struct v4l2_ctrl *v4l2_ctrl_new_std(struct v4l2_ctrl_handler *hdl,
const struct v4l2_ctrl_ops *ops,
u32 id, s32 min, s32 max, u32 step, s32 def);
/** v4l2_ctrl_new_std_menu() - Allocate and initialize a new standard V4L2 menu control.
* @hdl: The control handler.
* @ops: The control ops.
* @id: The control ID.
* @max: The control's maximum value.
* @mask: The control's skip mask for menu controls. This makes it
* easy to skip menu items that are not valid. If bit X is set,
* then menu item X is skipped. Of course, this only works for
* menus with <= 32 menu items. There are no menus that come
* close to that number, so this is OK. Should we ever need more,
* then this will have to be extended to a u64 or a bit array.
* @def: The control's default value.
*
* Same as v4l2_ctrl_new_std(), but @min is set to 0 and the @mask value
* determines which menu items are to be skipped.
*
* If @id refers to a non-menu control, then this function will return NULL.
*/
struct v4l2_ctrl *v4l2_ctrl_new_std_menu(struct v4l2_ctrl_handler *hdl,
const struct v4l2_ctrl_ops *ops,
u32 id, s32 max, s32 mask, s32 def);
/** v4l2_ctrl_add_ctrl() - Add a control from another handler to this handler.
* @hdl: The control handler.
* @ctrl: The control to add.
*
* It will return NULL if it was unable to add the control reference.
* If the control already belonged to the handler, then it will do
* nothing and just return @ctrl.
*/
struct v4l2_ctrl *v4l2_ctrl_add_ctrl(struct v4l2_ctrl_handler *hdl,
struct v4l2_ctrl *ctrl);
/** v4l2_ctrl_add_handler() - Add all controls from handler @add to
* handler @hdl.
* @hdl: The control handler.
* @add: The control handler whose controls you want to add to
* the @hdl control handler.
*
* Does nothing if either of the two is a NULL pointer.
* In case of an error @hdl->error will be set to the error code (if it
* wasn't set already).
*/
int v4l2_ctrl_add_handler(struct v4l2_ctrl_handler *hdl,
struct v4l2_ctrl_handler *add);
/** v4l2_ctrl_cluster() - Mark all controls in the cluster as belonging to that cluster.
* @ncontrols: The number of controls in this cluster.
* @controls: The cluster control array of size @ncontrols.
*/
void v4l2_ctrl_cluster(unsigned ncontrols, struct v4l2_ctrl **controls);
/** v4l2_ctrl_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.
*
* This function can be called regardless of whether the control handler
* is locked or not.
*/
void v4l2_ctrl_activate(struct v4l2_ctrl *ctrl, bool active);
/** v4l2_ctrl_grab() - Mark the control as grabbed or not grabbed.
* @ctrl: The control to (de)activate.
* @grabbed: True if the control should become grabbed.
*
* This sets or clears the V4L2_CTRL_FLAG_GRABBED flag atomically.
* Does nothing if @ctrl == NULL.
* This will usually be called when starting or stopping streaming in the
* driver.
*
* This function can be called regardless of whether the control handler
* is locked or not.
*/
void v4l2_ctrl_grab(struct v4l2_ctrl *ctrl, bool grabbed);
/** v4l2_ctrl_lock() - Helper function to lock the handler
* associated with the control.
* @ctrl: The control to lock.
*/
static inline void v4l2_ctrl_lock(struct v4l2_ctrl *ctrl)
{
mutex_lock(&ctrl->handler->lock);
}
/** v4l2_ctrl_lock() - Helper function to unlock the handler
* associated with the control.
* @ctrl: The control to unlock.
*/
static inline void v4l2_ctrl_unlock(struct v4l2_ctrl *ctrl)
{
mutex_unlock(&ctrl->handler->lock);
}
/** v4l2_ctrl_g_ctrl() - Helper function to get the control's value from within a driver.
* @ctrl: The control.
*
* This returns the control's value safely by going through the control
* framework. This function will lock the control's handler, so it cannot be
* used from within the &v4l2_ctrl_ops functions.
*
* This function is for integer type controls only.
*/
s32 v4l2_ctrl_g_ctrl(struct v4l2_ctrl *ctrl);
/** v4l2_ctrl_s_ctrl() - Helper function to set the control's value from within a driver.
* @ctrl: The control.
* @val: The new value.
*
* This set the control's new value safely by going through the control
* framework. This function will lock the control's handler, so it cannot be
* used from within the &v4l2_ctrl_ops functions.
*
* This function is for integer type controls only.
*/
int v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val);
/* Helpers for ioctl_ops. If hdl == NULL then they will all return -EINVAL. */
int v4l2_queryctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_queryctrl *qc);
int v4l2_querymenu(struct v4l2_ctrl_handler *hdl, struct v4l2_querymenu *qm);
int v4l2_g_ctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_control *ctrl);
int v4l2_s_ctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_control *ctrl);
int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct v4l2_ext_controls *c);
int v4l2_try_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct v4l2_ext_controls *c);
int v4l2_s_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct v4l2_ext_controls *c);
/* Helpers for subdevices. If the associated ctrl_handler == NULL then they
will all return -EINVAL. */
int v4l2_subdev_queryctrl(struct v4l2_subdev *sd, struct v4l2_queryctrl *qc);
int v4l2_subdev_querymenu(struct v4l2_subdev *sd, struct v4l2_querymenu *qm);
int v4l2_subdev_g_ext_ctrls(struct v4l2_subdev *sd, struct v4l2_ext_controls *cs);
int v4l2_subdev_try_ext_ctrls(struct v4l2_subdev *sd, struct v4l2_ext_controls *cs);
int v4l2_subdev_s_ext_ctrls(struct v4l2_subdev *sd, struct v4l2_ext_controls *cs);
int v4l2_subdev_g_ctrl(struct v4l2_subdev *sd, struct v4l2_control *ctrl);
int v4l2_subdev_s_ctrl(struct v4l2_subdev *sd, struct v4l2_control *ctrl);
#endif
