V4L/DVB (10643): v4l2-device: allow a NULL parent device when registering. (3a63e449) · Commits · e / devices / android_kernel_xiaomi_markw

Documentation/video4linux/v4l2-framework.txt

+6 −4

Original line number	Original line	Diff line number	Diff line
	@@ -84,12 +84,14 @@ You must register the device instance:
	v4l2_device_register(struct device dev, struct v4l2_device v4l2_dev);		v4l2_device_register(struct device dev, struct v4l2_device v4l2_dev);

	Registration will initialize the v4l2_device struct and link dev->driver_data		Registration will initialize the v4l2_device struct and link dev->driver_data
	to v4l2_dev. Registration will also set v4l2_dev->name to a value derived from		to v4l2_dev. If v4l2_dev->name is empty then it will be set to a value derived
	dev (driver name followed by the bus_id, to be precise). You may change the		from dev (driver name followed by the bus_id, to be precise). If you set it
	name after registration if you want.		up before calling v4l2_device_register then it will be untouched. If dev is
			NULL, then you must setup v4l2_dev->name before calling v4l2_device_register.

	The first 'dev' argument is normally the struct device pointer of a pci_dev,		The first 'dev' argument is normally the struct device pointer of a pci_dev,
	usb_device or platform_device.		usb_device or platform_device. It is rare for dev to be NULL, but it happens
			with ISA devices, for example.

	You unregister with:		You unregister with:

drivers/media/video/v4l2-device.c

+24 −13

Original line number	Original line	Diff line number	Diff line
	@@ -26,15 +26,24 @@

	int v4l2_device_register(struct device dev, struct v4l2_device v4l2_dev)		int v4l2_device_register(struct device dev, struct v4l2_device v4l2_dev)
	{		{
	if (dev == NULL \|\| v4l2_dev == NULL)		if (v4l2_dev == NULL)
	return -EINVAL;		return -EINVAL;
	/* Warn if we apparently re-register a device */
	WARN_ON(dev_get_drvdata(dev) != NULL);
	INIT_LIST_HEAD(&v4l2_dev->subdevs);		INIT_LIST_HEAD(&v4l2_dev->subdevs);
	spin_lock_init(&v4l2_dev->lock);		spin_lock_init(&v4l2_dev->lock);
	v4l2_dev->dev = dev;		v4l2_dev->dev = dev;
			if (dev == NULL) {
			/* If dev == NULL, then name must be filled in by the caller */
			WARN_ON(!v4l2_dev->name[0]);
			return 0;
			}

			/* Set name to driver name + device name if it is empty. */
			if (!v4l2_dev->name[0])
	snprintf(v4l2_dev->name, sizeof(v4l2_dev->name), "%s %s",		snprintf(v4l2_dev->name, sizeof(v4l2_dev->name), "%s %s",
	dev->driver->name, dev_name(dev));		dev->driver->name, dev_name(dev));
			if (dev_get_drvdata(dev))
			v4l2_warn(v4l2_dev, "Non-NULL drvdata on register\n");
	dev_set_drvdata(dev, v4l2_dev);		dev_set_drvdata(dev, v4l2_dev);
	return 0;		return 0;
	}		}
	@@ -44,10 +53,11 @@ void v4l2_device_unregister(struct v4l2_device *v4l2_dev)
	{		{
	struct v4l2_subdev sd, next;		struct v4l2_subdev sd, next;

	if (v4l2_dev == NULL \|\| v4l2_dev->dev == NULL)		if (v4l2_dev == NULL)
	return;		return;
			if (v4l2_dev->dev)
	dev_set_drvdata(v4l2_dev->dev, NULL);		dev_set_drvdata(v4l2_dev->dev, NULL);
	/* unregister subdevs */		/* Unregister subdevs */
	list_for_each_entry_safe(sd, next, &v4l2_dev->subdevs, list)		list_for_each_entry_safe(sd, next, &v4l2_dev->subdevs, list)
	v4l2_device_unregister_subdev(sd);		v4l2_device_unregister_subdev(sd);

	@@ -55,19 +65,20 @@ void v4l2_device_unregister(struct v4l2_device *v4l2_dev)
	}		}
	EXPORT_SYMBOL_GPL(v4l2_device_unregister);		EXPORT_SYMBOL_GPL(v4l2_device_unregister);

	int v4l2_device_register_subdev(struct v4l2_device dev, struct v4l2_subdev sd)		int v4l2_device_register_subdev(struct v4l2_device *v4l2_dev,
			struct v4l2_subdev *sd)
	{		{
	/* Check for valid input */		/* Check for valid input */
	if (dev == NULL \|\| sd == NULL \|\| !sd->name[0])		if (v4l2_dev == NULL \|\| sd == NULL \|\| !sd->name[0])
	return -EINVAL;		return -EINVAL;
	/* Warn if we apparently re-register a subdev */		/* Warn if we apparently re-register a subdev */
	WARN_ON(sd->dev != NULL);		WARN_ON(sd->dev != NULL);
	if (!try_module_get(sd->owner))		if (!try_module_get(sd->owner))
	return -ENODEV;		return -ENODEV;
	sd->dev = dev;		sd->dev = v4l2_dev;
	spin_lock(&dev->lock);		spin_lock(&v4l2_dev->lock);
	list_add_tail(&sd->list, &dev->subdevs);		list_add_tail(&sd->list, &v4l2_dev->subdevs);
	spin_unlock(&dev->lock);		spin_unlock(&v4l2_dev->lock);
	return 0;		return 0;
	}		}
	EXPORT_SYMBOL_GPL(v4l2_device_register_subdev);		EXPORT_SYMBOL_GPL(v4l2_device_register_subdev);

include/media/v4l2-device.h

+18 −13

Original line number	Original line	Diff line number	Diff line
	@@ -33,7 +33,9 @@
	#define V4L2_DEVICE_NAME_SIZE (BUS_ID_SIZE + 16)		#define V4L2_DEVICE_NAME_SIZE (BUS_ID_SIZE + 16)

	struct v4l2_device {		struct v4l2_device {
	/* dev->driver_data points to this struct */		/* 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;		struct device *dev;
	/* used to keep track of the registered subdevs */		/* used to keep track of the registered subdevs */
	struct list_head subdevs;		struct list_head subdevs;
	@@ -44,7 +46,9 @@ struct v4l2_device {
	char name[V4L2_DEVICE_NAME_SIZE];		char name[V4L2_DEVICE_NAME_SIZE];
	};		};

	/* Initialize v4l2_dev and make dev->driver_data point to 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);		int __must_check v4l2_device_register(struct device dev, struct v4l2_device v4l2_dev);
	/* Set v4l2_dev->dev->driver_data to NULL and unregister all sub-devices */		/* Set v4l2_dev->dev->driver_data to NULL and unregister all sub-devices */
	void v4l2_device_unregister(struct v4l2_device *v4l2_dev);		void v4l2_device_unregister(struct v4l2_device *v4l2_dev);
	@@ -52,23 +56,24 @@ void v4l2_device_unregister(struct v4l2_device *v4l2_dev);
	/* Register a subdev with a v4l2 device. While registered the subdev module		/* 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		is marked as in-use. An error is returned if the module is no longer
	loaded when you attempt to register it. */		loaded when you attempt to register it. */
	int __must_check v4l2_device_register_subdev(struct v4l2_device dev, struct v4l2_subdev sd);		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		/* Unregister a subdev with a v4l2 device. Can also be called if the subdev
	wasn't registered. In that case it will do nothing. */		wasn't registered. In that case it will do nothing. */
	void v4l2_device_unregister_subdev(struct v4l2_subdev *sd);		void v4l2_device_unregister_subdev(struct v4l2_subdev *sd);

	/* Iterate over all subdevs. */		/* Iterate over all subdevs. */
	#define v4l2_device_for_each_subdev(sd, dev) \		#define v4l2_device_for_each_subdev(sd, v4l2_dev) \
	list_for_each_entry(sd, &(dev)->subdevs, list)		list_for_each_entry(sd, &(v4l2_dev)->subdevs, list)

	/* Call the specified callback for all subdevs matching the condition.		/* Call the specified callback for all subdevs matching the condition.
	Ignore any errors. Note that you cannot add or delete a subdev		Ignore any errors. Note that you cannot add or delete a subdev
	while walking the subdevs list. */		while walking the subdevs list. */
	#define __v4l2_device_call_subdevs(dev, cond, o, f, args...) \		#define __v4l2_device_call_subdevs(v4l2_dev, cond, o, f, args...) \
	do { \		do { \
	struct v4l2_subdev *sd; \		struct v4l2_subdev *sd; \
	\		\
	list_for_each_entry(sd, &(dev)->subdevs, list) \		list_for_each_entry(sd, &(v4l2_dev)->subdevs, list) \
	if ((cond) && sd->ops->o && sd->ops->o->f) \		if ((cond) && sd->ops->o && sd->ops->o->f) \
	sd->ops->o->f(sd , ##args); \		sd->ops->o->f(sd , ##args); \
	} while (0)		} while (0)
	@@ -77,12 +82,12 @@ void v4l2_device_unregister_subdev(struct v4l2_subdev *sd);
	If the callback returns an error other than 0 or -ENOIOCTLCMD, then		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		return with that error code. Note that you cannot add or delete a
	subdev while walking the subdevs list. */		subdev while walking the subdevs list. */
	#define __v4l2_device_call_subdevs_until_err(dev, cond, o, f, args...) \		#define __v4l2_device_call_subdevs_until_err(v4l2_dev, cond, o, f, args...) \
	({ \		({ \
	struct v4l2_subdev *sd; \		struct v4l2_subdev *sd; \
	long err = 0; \		long err = 0; \
	\		\
	list_for_each_entry(sd, &(dev)->subdevs, list) { \		list_for_each_entry(sd, &(v4l2_dev)->subdevs, list) { \
	if ((cond) && sd->ops->o && sd->ops->o->f) \		if ((cond) && sd->ops->o && sd->ops->o->f) \
	err = sd->ops->o->f(sd , ##args); \		err = sd->ops->o->f(sd , ##args); \
	if (err && err != -ENOIOCTLCMD) \		if (err && err != -ENOIOCTLCMD) \
	@@ -94,16 +99,16 @@ void v4l2_device_unregister_subdev(struct v4l2_subdev *sd);
	/* Call the specified callback for all subdevs matching grp_id (if 0, then		/* 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		match them all). Ignore any errors. Note that you cannot add or delete
	a subdev while walking the subdevs list. */		a subdev while walking the subdevs list. */
	#define v4l2_device_call_all(dev, grpid, o, f, args...) \		#define v4l2_device_call_all(v4l2_dev, grpid, o, f, args...) \
	__v4l2_device_call_subdevs(dev, \		__v4l2_device_call_subdevs(v4l2_dev, \
	!(grpid) \|\| sd->grp_id == (grpid), o, f , ##args)		!(grpid) \|\| sd->grp_id == (grpid), o, f , ##args)

	/* Call the specified callback for all subdevs matching grp_id (if 0, then		/* 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		match them all). If the callback returns an error other than 0 or
	-ENOIOCTLCMD, then return with that error code. Note that you cannot		-ENOIOCTLCMD, then return with that error code. Note that you cannot
	add or delete a subdev while walking the subdevs list. */		add or delete a subdev while walking the subdevs list. */
	#define v4l2_device_call_until_err(dev, grpid, o, f, args...) \		#define v4l2_device_call_until_err(v4l2_dev, grpid, o, f, args...) \
	__v4l2_device_call_subdevs_until_err(dev, \		__v4l2_device_call_subdevs_until_err(v4l2_dev, \
	!(grpid) \|\| sd->grp_id == (grpid), o, f , ##args)		!(grpid) \|\| sd->grp_id == (grpid), o, f , ##args)

	#endif		#endif