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Diffstat (limited to 'include/media/v4l2-device.h')
| -rw-r--r-- | include/media/v4l2-device.h | 563 |
1 files changed, 463 insertions, 100 deletions
diff --git a/include/media/v4l2-device.h b/include/media/v4l2-device.h index c9b1593923f6..25f69b1b8db0 100644 --- a/include/media/v4l2-device.h +++ b/include/media/v4l2-device.h @@ -1,21 +1,9 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ /* V4L2 device support header. - Copyright (C) 2008 Hans Verkuil <hverkuil@xs4all.nl> + Copyright (C) 2008 Hans Verkuil <hverkuil@kernel.org> - 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_DEVICE_H @@ -25,115 +13,308 @@ #include <media/v4l2-subdev.h> #include <media/v4l2-dev.h> -/* Each instance of a V4L2 device should create the v4l2_device struct, - either stand-alone or embedded in a larger struct. - - It allows easy access to sub-devices (see v4l2-subdev.h) and provides - basic V4L2 device-level support. - */ - -#define V4L2_DEVICE_NAME_SIZE (20 + 16) - struct v4l2_ctrl_handler; +/** + * struct v4l2_device - main struct to for V4L2 device drivers + * + * @dev: pointer to struct device. + * @mdev: pointer to struct media_device, may be NULL. + * @subdevs: used to keep track of the registered subdevs + * @lock: lock this struct; can be used by the driver as well + * if this struct is embedded into a larger struct. + * @name: unique device name, by default the driver name + bus ID + * @notify: notify operation called by some sub-devices. + * @ctrl_handler: The control handler. May be %NULL. + * @prio: Device's priority state + * @ref: Keep track of the references to this struct. + * @release: Release function that is called when the ref count + * goes to 0. + * + * Each instance of a V4L2 device should create the v4l2_device struct, + * either stand-alone or embedded in a larger struct. + * + * It allows easy access to sub-devices (see v4l2-subdev.h) and provides + * basic V4L2 device-level support. + * + * .. note:: + * + * #) @dev->driver_data points to this struct. + * #) @dev might be %NULL if there is no parent device + */ struct v4l2_device { - /* dev->driver_data points to this struct. - Note: dev might be NULL if there is no parent device - as is the case with e.g. ISA devices. */ struct device *dev; -#if defined(CONFIG_MEDIA_CONTROLLER) struct media_device *mdev; -#endif - /* used to keep track of the registered subdevs */ struct list_head subdevs; - /* lock this struct; can be used by the driver as well if this - struct is embedded into a larger struct. */ spinlock_t lock; - /* unique device name, by default the driver name + bus ID */ - char name[V4L2_DEVICE_NAME_SIZE]; - /* notify callback called by some sub-devices. */ + char name[36]; void (*notify)(struct v4l2_subdev *sd, unsigned int notification, void *arg); - /* The control handler. May be NULL. */ struct v4l2_ctrl_handler *ctrl_handler; - /* Device's priority state */ struct v4l2_prio_state prio; - /* BKL replacement mutex. Temporary solution only. */ - struct mutex ioctl_lock; - /* Keep track of the references to this struct. */ struct kref ref; - /* Release function that is called when the ref count goes to 0. */ void (*release)(struct v4l2_device *v4l2_dev); }; +/** + * v4l2_device_get - gets a V4L2 device reference + * + * @v4l2_dev: pointer to struct &v4l2_device + * + * This is an ancillary routine meant to increment the usage for the + * struct &v4l2_device pointed by @v4l2_dev. + */ static inline void v4l2_device_get(struct v4l2_device *v4l2_dev) { kref_get(&v4l2_dev->ref); } +/** + * v4l2_device_put - puts a V4L2 device reference + * + * @v4l2_dev: pointer to struct &v4l2_device + * + * This is an ancillary routine meant to decrement the usage for the + * struct &v4l2_device pointed by @v4l2_dev. + */ int v4l2_device_put(struct v4l2_device *v4l2_dev); -/* Initialize v4l2_dev and make dev->driver_data point to v4l2_dev. - dev may be NULL in rare cases (ISA devices). In that case you - must fill in the v4l2_dev->name field before calling this function. */ -int __must_check v4l2_device_register(struct device *dev, struct v4l2_device *v4l2_dev); - -/* Optional function to initialize the name field of struct v4l2_device using - the driver name and a driver-global atomic_t instance. - This function will increment the instance counter and returns the instance - value used in the name. - - Example: - - static atomic_t drv_instance = ATOMIC_INIT(0); - - ... - - instance = v4l2_device_set_name(&v4l2_dev, "foo", &drv_instance); - - The first time this is called the name field will be set to foo0 and - this function returns 0. If the name ends with a digit (e.g. cx18), - then the name will be set to cx18-0 since cx180 looks really odd. */ +/** + * v4l2_device_register - Initialize v4l2_dev and make @dev->driver_data + * point to @v4l2_dev. + * + * @dev: pointer to struct &device + * @v4l2_dev: pointer to struct &v4l2_device + * + * .. note:: + * @dev may be %NULL in rare cases (ISA devices). + * In such case the caller must fill in the @v4l2_dev->name field + * before calling this function. + */ +int __must_check v4l2_device_register(struct device *dev, + struct v4l2_device *v4l2_dev); + +/** + * v4l2_device_set_name - Optional function to initialize the + * name field of struct &v4l2_device + * + * @v4l2_dev: pointer to struct &v4l2_device + * @basename: base name for the device name + * @instance: pointer to a static atomic_t var with the instance usage for + * the device driver. + * + * v4l2_device_set_name() initializes the name field of struct &v4l2_device + * using the driver name and a driver-global atomic_t instance. + * + * This function will increment the instance counter and returns the + * instance value used in the name. + * + * Example: + * + * static atomic_t drv_instance = ATOMIC_INIT(0); + * + * ... + * + * instance = v4l2_device_set_name(&\ v4l2_dev, "foo", &\ drv_instance); + * + * The first time this is called the name field will be set to foo0 and + * this function returns 0. If the name ends with a digit (e.g. cx18), + * then the name will be set to cx18-0 since cx180 would look really odd. + */ int v4l2_device_set_name(struct v4l2_device *v4l2_dev, const char *basename, - atomic_t *instance); - -/* Set v4l2_dev->dev to NULL. Call when the USB parent disconnects. - Since the parent disappears this ensures that v4l2_dev doesn't have an - invalid parent pointer. */ + atomic_t *instance); + +/** + * v4l2_device_disconnect - Change V4L2 device state to disconnected. + * + * @v4l2_dev: pointer to struct v4l2_device + * + * Should be called when the USB parent disconnects. + * Since the parent disappears, this ensures that @v4l2_dev doesn't have + * an invalid parent pointer. + * + * .. note:: This function sets @v4l2_dev->dev to NULL. + */ void v4l2_device_disconnect(struct v4l2_device *v4l2_dev); -/* Unregister all sub-devices and any other resources related to v4l2_dev. */ +/** + * v4l2_device_unregister - Unregister all sub-devices and any other + * resources related to @v4l2_dev. + * + * @v4l2_dev: pointer to struct v4l2_device + */ void v4l2_device_unregister(struct v4l2_device *v4l2_dev); -/* Register a subdev with a v4l2 device. While registered the subdev module - is marked as in-use. An error is returned if the module is no longer - loaded when you attempt to register it. */ -int __must_check v4l2_device_register_subdev(struct v4l2_device *v4l2_dev, - struct v4l2_subdev *sd); -/* Unregister a subdev with a v4l2 device. Can also be called if the subdev - wasn't registered. In that case it will do nothing. */ +/** + * v4l2_device_register_subdev - Registers a subdev with a v4l2 device. + * + * @v4l2_dev: pointer to struct &v4l2_device + * @sd: pointer to &struct v4l2_subdev + * + * While registered, the subdev module is marked as in-use. + * + * An error is returned if the module is no longer loaded on any attempts + * to register it. + */ +#define v4l2_device_register_subdev(v4l2_dev, sd) \ + __v4l2_device_register_subdev(v4l2_dev, sd, THIS_MODULE) +int __must_check __v4l2_device_register_subdev(struct v4l2_device *v4l2_dev, + struct v4l2_subdev *sd, + struct module *module); + +/** + * v4l2_device_unregister_subdev - Unregisters a subdev with a v4l2 device. + * + * @sd: pointer to &struct v4l2_subdev + * + * .. note :: + * + * Can also be called if the subdev wasn't registered. In such + * case, it will do nothing. + */ void v4l2_device_unregister_subdev(struct v4l2_subdev *sd); -/* Register device nodes for all subdev of the v4l2 device that are marked with - * the V4L2_SUBDEV_FL_HAS_DEVNODE flag. +/** + * __v4l2_device_register_subdev_nodes - Registers device nodes for + * all subdevs of the v4l2 device that are marked with the + * %V4L2_SUBDEV_FL_HAS_DEVNODE flag. + * + * @v4l2_dev: pointer to struct v4l2_device + * @read_only: subdevices read-only flag. True to register the subdevices + * device nodes in read-only mode, false to allow full access to the + * subdevice userspace API. */ int __must_check -v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev); +__v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev, + bool read_only); + +/** + * v4l2_device_register_subdev_nodes - Registers subdevices device nodes with + * unrestricted access to the subdevice userspace operations + * + * Internally calls __v4l2_device_register_subdev_nodes(). See its documentation + * for more details. + * + * @v4l2_dev: pointer to struct v4l2_device + */ +static inline int __must_check +v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev) +{ +#if defined(CONFIG_VIDEO_V4L2_SUBDEV_API) + return __v4l2_device_register_subdev_nodes(v4l2_dev, false); +#else + return 0; +#endif +} + +/** + * v4l2_device_register_ro_subdev_nodes - Registers subdevices device nodes + * in read-only mode + * + * Internally calls __v4l2_device_register_subdev_nodes(). See its documentation + * for more details. + * + * @v4l2_dev: pointer to struct v4l2_device + */ +static inline int __must_check +v4l2_device_register_ro_subdev_nodes(struct v4l2_device *v4l2_dev) +{ +#if defined(CONFIG_VIDEO_V4L2_SUBDEV_API) + return __v4l2_device_register_subdev_nodes(v4l2_dev, true); +#else + return 0; +#endif +} + +/** + * v4l2_subdev_notify - Sends a notification to v4l2_device. + * + * @sd: pointer to &struct v4l2_subdev + * @notification: type of notification. Please notice that the notification + * type is driver-specific. + * @arg: arguments for the notification. Those are specific to each + * notification type. + */ +static inline void v4l2_subdev_notify(struct v4l2_subdev *sd, + unsigned int notification, void *arg) +{ + if (sd && sd->v4l2_dev && sd->v4l2_dev->notify) + sd->v4l2_dev->notify(sd, notification, arg); +} + +/** + * v4l2_device_supports_requests - Test if requests are supported. + * + * @v4l2_dev: pointer to struct v4l2_device + */ +static inline bool v4l2_device_supports_requests(struct v4l2_device *v4l2_dev) +{ + return v4l2_dev->mdev && v4l2_dev->mdev->ops && + v4l2_dev->mdev->ops->req_queue; +} -/* Iterate over all subdevs. */ +/* Helper macros to iterate over all subdevs. */ + +/** + * v4l2_device_for_each_subdev - Helper macro that interates over all + * sub-devices of a given &v4l2_device. + * + * @sd: pointer that will be filled by the macro with all + * &struct v4l2_subdev pointer used as an iterator by the loop. + * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over. + * + * This macro iterates over all sub-devices owned by the @v4l2_dev device. + * It acts as a for loop iterator and executes the next statement with + * the @sd variable pointing to each sub-device in turn. + */ #define v4l2_device_for_each_subdev(sd, v4l2_dev) \ list_for_each_entry(sd, &(v4l2_dev)->subdevs, list) -/* Call the specified callback for all subdevs matching the condition. - Ignore any errors. Note that you cannot add or delete a subdev - while walking the subdevs list. */ +/** + * __v4l2_device_call_subdevs_p - Calls the specified operation for + * all subdevs matching the condition. + * + * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over. + * @sd: pointer that will be filled by the macro with all + * &struct v4l2_subdev pointer used as an iterator by the loop. + * @cond: condition to be match + * @o: name of the element at &struct v4l2_subdev_ops that contains @f. + * Each element there groups a set of operations functions. + * @f: operation function that will be called if @cond matches. + * The operation functions are defined in groups, according to + * each element at &struct v4l2_subdev_ops. + * @args: arguments for @f. + * + * Ignore any errors. + * + * Note: subdevs cannot be added or deleted while walking + * the subdevs list. + */ #define __v4l2_device_call_subdevs_p(v4l2_dev, sd, cond, o, f, args...) \ - do { \ + do { \ list_for_each_entry((sd), &(v4l2_dev)->subdevs, list) \ if ((cond) && (sd)->ops->o && (sd)->ops->o->f) \ (sd)->ops->o->f((sd) , ##args); \ } while (0) +/** + * __v4l2_device_call_subdevs - Calls the specified operation for + * all subdevs matching the condition. + * + * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over. + * @cond: condition to be match + * @o: name of the element at &struct v4l2_subdev_ops that contains @f. + * Each element there groups a set of operations functions. + * @f: operation function that will be called if @cond matches. + * The operation functions are defined in groups, according to + * each element at &struct v4l2_subdev_ops. + * @args: arguments for @f. + * + * Ignore any errors. + * + * Note: subdevs cannot be added or deleted while walking + * the subdevs list. + */ #define __v4l2_device_call_subdevs(v4l2_dev, cond, o, f, args...) \ do { \ struct v4l2_subdev *__sd; \ @@ -142,23 +323,65 @@ v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev); f , ##args); \ } while (0) -/* Call the specified callback for all subdevs matching the condition. - If the callback returns an error other than 0 or -ENOIOCTLCMD, then - return with that error code. Note that you cannot add or delete a - subdev while walking the subdevs list. */ +/** + * __v4l2_device_call_subdevs_until_err_p - Calls the specified operation for + * all subdevs matching the condition. + * + * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over. + * @sd: pointer that will be filled by the macro with all + * &struct v4l2_subdev sub-devices associated with @v4l2_dev. + * @cond: condition to be match + * @o: name of the element at &struct v4l2_subdev_ops that contains @f. + * Each element there groups a set of operations functions. + * @f: operation function that will be called if @cond matches. + * The operation functions are defined in groups, according to + * each element at &struct v4l2_subdev_ops. + * @args: arguments for @f. + * + * Return: + * + * If the operation returns an error other than 0 or ``-ENOIOCTLCMD`` + * for any subdevice, then abort and return with that error code, zero + * otherwise. + * + * Note: subdevs cannot be added or deleted while walking + * the subdevs list. + */ #define __v4l2_device_call_subdevs_until_err_p(v4l2_dev, sd, cond, o, f, args...) \ -({ \ +({ \ long __err = 0; \ \ list_for_each_entry((sd), &(v4l2_dev)->subdevs, list) { \ if ((cond) && (sd)->ops->o && (sd)->ops->o->f) \ __err = (sd)->ops->o->f((sd) , ##args); \ if (__err && __err != -ENOIOCTLCMD) \ - break; \ - } \ + break; \ + } \ (__err == -ENOIOCTLCMD) ? 0 : __err; \ }) +/** + * __v4l2_device_call_subdevs_until_err - Calls the specified operation for + * all subdevs matching the condition. + * + * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over. + * @cond: condition to be match + * @o: name of the element at &struct v4l2_subdev_ops that contains @f. + * Each element there groups a set of operations functions. + * @f: operation function that will be called if @cond matches. + * The operation functions are defined in groups, according to + * each element at &struct v4l2_subdev_ops. + * @args: arguments for @f. + * + * Return: + * + * If the operation returns an error other than 0 or ``-ENOIOCTLCMD`` + * for any subdevice, then abort and return with that error code, + * zero otherwise. + * + * Note: subdevs cannot be added or deleted while walking + * the subdevs list. + */ #define __v4l2_device_call_subdevs_until_err(v4l2_dev, cond, o, f, args...) \ ({ \ struct v4l2_subdev *__sd; \ @@ -166,35 +389,175 @@ v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev); f , ##args); \ }) -/* Call the specified callback for all subdevs matching grp_id (if 0, then - match them all). Ignore any errors. Note that you cannot add or delete - a subdev while walking the subdevs list. */ +/** + * v4l2_device_call_all - Calls the specified operation for + * all subdevs matching the &v4l2_subdev.grp_id, as assigned + * by the bridge driver. + * + * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over. + * @grpid: &struct v4l2_subdev->grp_id group ID to match. + * Use 0 to match them all. + * @o: name of the element at &struct v4l2_subdev_ops that contains @f. + * Each element there groups a set of operations functions. + * @f: operation function that will be called if @cond matches. + * The operation functions are defined in groups, according to + * each element at &struct v4l2_subdev_ops. + * @args: arguments for @f. + * + * Ignore any errors. + * + * Note: subdevs cannot be added or deleted while walking + * the subdevs list. + */ #define v4l2_device_call_all(v4l2_dev, grpid, o, f, args...) \ do { \ struct v4l2_subdev *__sd; \ \ __v4l2_device_call_subdevs_p(v4l2_dev, __sd, \ - !(grpid) || __sd->grp_id == (grpid), o, f , \ + (grpid) == 0 || __sd->grp_id == (grpid), o, f , \ ##args); \ } while (0) -/* Call the specified callback for all subdevs matching grp_id (if 0, then - match them all). If the callback returns an error other than 0 or - -ENOIOCTLCMD, then return with that error code. Note that you cannot - add or delete a subdev while walking the subdevs list. */ -#define v4l2_device_call_until_err(v4l2_dev, grpid, o, f, args...) \ +/** + * v4l2_device_call_until_err - Calls the specified operation for + * all subdevs matching the &v4l2_subdev.grp_id, as assigned + * by the bridge driver, until an error occurs. + * + * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over. + * @grpid: &struct v4l2_subdev->grp_id group ID to match. + * Use 0 to match them all. + * @o: name of the element at &struct v4l2_subdev_ops that contains @f. + * Each element there groups a set of operations functions. + * @f: operation function that will be called if @cond matches. + * The operation functions are defined in groups, according to + * each element at &struct v4l2_subdev_ops. + * @args: arguments for @f. + * + * Return: + * + * If the operation returns an error other than 0 or ``-ENOIOCTLCMD`` + * for any subdevice, then abort and return with that error code, + * zero otherwise. + * + * Note: subdevs cannot be added or deleted while walking + * the subdevs list. + */ +#define v4l2_device_call_until_err(v4l2_dev, grpid, o, f, args...) \ ({ \ struct v4l2_subdev *__sd; \ __v4l2_device_call_subdevs_until_err_p(v4l2_dev, __sd, \ - !(grpid) || __sd->grp_id == (grpid), o, f , \ + (grpid) == 0 || __sd->grp_id == (grpid), o, f , \ ##args); \ }) -#define v4l2_device_has_op(v4l2_dev, o, f) \ +/** + * v4l2_device_mask_call_all - Calls the specified operation for + * all subdevices where a group ID matches a specified bitmask. + * + * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over. + * @grpmsk: bitmask to be checked against &struct v4l2_subdev->grp_id + * group ID to be matched. Use 0 to match them all. + * @o: name of the element at &struct v4l2_subdev_ops that contains @f. + * Each element there groups a set of operations functions. + * @f: operation function that will be called if @cond matches. + * The operation functions are defined in groups, according to + * each element at &struct v4l2_subdev_ops. + * @args: arguments for @f. + * + * Ignore any errors. + * + * Note: subdevs cannot be added or deleted while walking + * the subdevs list. + */ +#define v4l2_device_mask_call_all(v4l2_dev, grpmsk, o, f, args...) \ + do { \ + struct v4l2_subdev *__sd; \ + \ + __v4l2_device_call_subdevs_p(v4l2_dev, __sd, \ + (grpmsk) == 0 || (__sd->grp_id & (grpmsk)), o, \ + f , ##args); \ + } while (0) + +/** + * v4l2_device_mask_call_until_err - Calls the specified operation for + * all subdevices where a group ID matches a specified bitmask. + * + * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over. + * @grpmsk: bitmask to be checked against &struct v4l2_subdev->grp_id + * group ID to be matched. Use 0 to match them all. + * @o: name of the element at &struct v4l2_subdev_ops that contains @f. + * Each element there groups a set of operations functions. + * @f: operation function that will be called if @cond matches. + * The operation functions are defined in groups, according to + * each element at &struct v4l2_subdev_ops. + * @args: arguments for @f. + * + * Return: + * + * If the operation returns an error other than 0 or ``-ENOIOCTLCMD`` + * for any subdevice, then abort and return with that error code, + * zero otherwise. + * + * Note: subdevs cannot be added or deleted while walking + * the subdevs list. + */ +#define v4l2_device_mask_call_until_err(v4l2_dev, grpmsk, o, f, args...) \ +({ \ + struct v4l2_subdev *__sd; \ + __v4l2_device_call_subdevs_until_err_p(v4l2_dev, __sd, \ + (grpmsk) == 0 || (__sd->grp_id & (grpmsk)), o, \ + f , ##args); \ +}) + + +/** + * v4l2_device_has_op - checks if any subdev with matching grpid has a + * given ops. + * + * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over. + * @grpid: &struct v4l2_subdev->grp_id group ID to match. + * Use 0 to match them all. + * @o: name of the element at &struct v4l2_subdev_ops that contains @f. + * Each element there groups a set of operations functions. + * @f: operation function that will be called if @cond matches. + * The operation functions are defined in groups, according to + * each element at &struct v4l2_subdev_ops. + */ +#define v4l2_device_has_op(v4l2_dev, grpid, o, f) \ +({ \ + struct v4l2_subdev *__sd; \ + bool __result = false; \ + list_for_each_entry(__sd, &(v4l2_dev)->subdevs, list) { \ + if ((grpid) && __sd->grp_id != (grpid)) \ + continue; \ + if (v4l2_subdev_has_op(__sd, o, f)) { \ + __result = true; \ + break; \ + } \ + } \ + __result; \ +}) + +/** + * v4l2_device_mask_has_op - checks if any subdev with matching group + * mask has a given ops. + * + * @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over. + * @grpmsk: bitmask to be checked against &struct v4l2_subdev->grp_id + * group ID to be matched. Use 0 to match them all. + * @o: name of the element at &struct v4l2_subdev_ops that contains @f. + * Each element there groups a set of operations functions. + * @f: operation function that will be called if @cond matches. + * The operation functions are defined in groups, according to + * each element at &struct v4l2_subdev_ops. + */ +#define v4l2_device_mask_has_op(v4l2_dev, grpmsk, o, f) \ ({ \ struct v4l2_subdev *__sd; \ bool __result = false; \ list_for_each_entry(__sd, &(v4l2_dev)->subdevs, list) { \ + if ((grpmsk) && !(__sd->grp_id & (grpmsk))) \ + continue; \ if (v4l2_subdev_has_op(__sd, o, f)) { \ __result = true; \ break; \ |