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diff --git a/include/media/v4l2-device.h b/include/media/v4l2-device.h
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+/* 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_ro_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