/* V4L2 controls support header. Copyright (C) 2010 Hans Verkuil 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 #include /* 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