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Diffstat (limited to 'include/media/v4l2-device.h')
| -rw-r--r-- | include/media/v4l2-device.h | 568 |
1 files changed, 568 insertions, 0 deletions
diff --git a/include/media/v4l2-device.h b/include/media/v4l2-device.h new file mode 100644 index 000000000..8a8977a33 --- /dev/null +++ b/include/media/v4l2-device.h @@ -0,0 +1,568 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + V4L2 device support header. + + Copyright (C) 2008 Hans Verkuil <hverkuil@xs4all.nl> + + */ + +#ifndef _V4L2_DEVICE_H +#define _V4L2_DEVICE_H + +#include <media/media-device.h> +#include <media/v4l2-subdev.h> +#include <media/v4l2-dev.h> + +#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 { + struct device *dev; + struct media_device *mdev; + struct list_head subdevs; + spinlock_t lock; + char name[V4L2_DEVICE_NAME_SIZE]; + 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. + */ +int __must_check v4l2_device_register_subdev(struct v4l2_device *v4l2_dev, + struct v4l2_subdev *sd); + +/** + * 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 |