/* SPDX-License-Identifier: GPL-2.0-or-later */ /* V4L2 device support header. Copyright (C) 2008 Hans Verkuil <hverkuil@kernel.org> */ #ifndef _V4L2_DEVICE_H #define _V4L2_DEVICE_H #include <media/media-device.h> #include <media/v4l2-subdev.h> #include <media/v4l2-dev.h> 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 { struct device *dev; struct media_device *mdev; struct list_head subdevs; spinlock_t lock; char name[36]; void (*notify)(struct v4l2_subdev *sd, unsigned int notification, void *arg); struct v4l2_ctrl_handler *ctrl_handler; struct v4l2_prio_state prio; struct kref ref; 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); /** * 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); /** * 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); /** * 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); /** * 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); /** * __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, 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; } /* 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) /** * __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 { \ 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; \ \ __v4l2_device_call_subdevs_p(v4l2_dev, __sd, cond, o, \ f , ##args); \ } while (0) /** * __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; \ } \ (__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; \ __v4l2_device_call_subdevs_until_err_p(v4l2_dev, __sd, cond, o, \ f , ##args); \ }) /** * 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) == 0 || __sd->grp_id == (grpid), o, f , \ ##args); \ } while (0) /** * 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) == 0 || __sd->grp_id == (grpid), o, f , \ ##args); \ }) /** * 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; \ } \ } \ __result; \ }) #endif
