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Diffstat (limited to 'include/media/v4l2-ctrls.h')
| -rw-r--r-- | include/media/v4l2-ctrls.h | 460 |
1 files changed, 460 insertions, 0 deletions
diff --git a/include/media/v4l2-ctrls.h b/include/media/v4l2-ctrls.h new file mode 100644 index 0000000..9b7bea9 --- /dev/null +++ b/include/media/v4l2-ctrls.h @@ -0,0 +1,460 @@ +/* + 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 **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 **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 |