| /* |
| 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> |
| #include <linux/videodev2.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 |