drivers/media/dvb-core/dvbdev.c

Source file repositories/reference/linux-study-clean/drivers/media/dvb-core/dvbdev.c

File Facts

System
Linux kernel
Corpus path
drivers/media/dvb-core/dvbdev.c
Extension
.c
Size
26554 bytes
Lines
1138
Domain
Driver Families
Bucket
drivers/media
Inferred role
Driver Families: operation-table or driver-model contract
Status
pattern implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

const struct file_operations *new_fops;

		new_fops = fops_get(dvbdev->fops);
		if (!new_fops)
			goto fail;
		file->private_data = dvb_device_get(dvbdev);
		replace_fops(file, new_fops);
		if (file->f_op->open)
			err = file->f_op->open(inode, file);
		up_read(&minor_rwsem);
		mutex_unlock(&dvbdev_mutex);
		if (err)
			dvb_device_put(dvbdev);
		return err;
	}
fail:
	up_read(&minor_rwsem);
	mutex_unlock(&dvbdev_mutex);
	return -ENODEV;
}

static const struct file_operations dvb_device_fops = {
	.owner =	THIS_MODULE,
	.open =		dvb_device_open,
	.llseek =	noop_llseek,
};

static struct cdev dvb_device_cdev;

int dvb_generic_open(struct inode *inode, struct file *file)
{
	struct dvb_device *dvbdev = file->private_data;

	if (!dvbdev)
		return -ENODEV;

	if (!dvbdev->users)
		return -EBUSY;

	if ((file->f_flags & O_ACCMODE) == O_RDONLY) {
		if (!dvbdev->readers)
			return -EBUSY;
		dvbdev->readers--;
	} else {
		if (!dvbdev->writers)
			return -EBUSY;
		dvbdev->writers--;
	}

	dvbdev->users--;
	return 0;
}
EXPORT_SYMBOL(dvb_generic_open);

int dvb_generic_release(struct inode *inode, struct file *file)
{
	struct dvb_device *dvbdev = file->private_data;

	if (!dvbdev)
		return -ENODEV;

	if ((file->f_flags & O_ACCMODE) == O_RDONLY)
		dvbdev->readers++;
	else
		dvbdev->writers++;

	dvbdev->users++;

	dvb_device_put(dvbdev);

	return 0;
}
EXPORT_SYMBOL(dvb_generic_release);

long dvb_generic_ioctl(struct file *file,
		       unsigned int cmd, unsigned long arg)
{
	struct dvb_device *dvbdev = file->private_data;

	if (!dvbdev)
		return -ENODEV;

	if (!dvbdev->kernel_ioctl)
		return -EINVAL;

	return dvb_usercopy(file, cmd, arg, dvbdev->kernel_ioctl);
}
EXPORT_SYMBOL(dvb_generic_ioctl);

static int dvbdev_get_free_id(struct dvb_adapter *adap, int type)

Annotation

Implementation Notes