Attach / detach Syscall API

Collaboration diagram for Attach / detach Syscall API:

Functions
int	a4l_sys_attach (int fd, a4l_lnkdesc_t *arg)
	Attach an Analogy device to a driver. More...
int	a4l_sys_detach (int fd)
	Detach an Analogy device from a driver. More...
int	a4l_sys_bufcfg (int fd, unsigned int idx_subd, unsigned long size)
	Configure the buffer size. More...

Detailed Description

Function Documentation

a4l_sys_attach()

int a4l_sys_attach	(	int	fd,
		a4l_lnkdesc_t *	arg
	)

Attach an Analogy device to a driver.

Parameters

[in]	fd	File descriptor as returned by a4l_sys_open()
[in]	arg	Link descriptor argument

Returns

0 on success. Otherwise:

• -ENOMEM is returned if the system is out of memory
• -EINVAL is returned if some argument is missing or wrong (Please, type "dmesg" for more info)
• -EFAULT is returned if a user <-> kernel transfer went wrong
• -ENODEV is returned in case of internal error (Please, type "dmesg" for more info)
• -ENXIO is returned in case of internal error (Please, type "dmesg" for more info)

a4l_sys_bufcfg()

int a4l_sys_bufcfg	(	int	fd,
		unsigned int	idx_subd,
		unsigned long	size
	)

Configure the buffer size.

This function can configure the buffer size of the file descriptor currently in use. If the subdevice index is set to A4L_BUF_DEFMAGIC, it can also define the default buffser size at open time.

Parameters

[in]	fd	File descriptor as returned by a4l_sys_open()
[in]	idx_subd	Index of the concerned subdevice
[in]	size	Buffer size to be set

Returns

0 on success. Otherwise:

• -EINVAL is returned if some argument is missing or wrong (Please, type "dmesg" for more info)
• -EPERM is returned if the function is called in an RT context or if the buffer to resize is mapped in user-space (Please, type "dmesg" for more info)
• -EFAULT is returned if a user <-> kernel transfer went wrong
• -EBUSY is returned if the selected subdevice is already processing an asynchronous operation
• -ENOMEM is returned if the system is out of memory

Referenced by a4l_set_bufsize().

a4l_sys_detach()

int a4l_sys_detach

(

int

fd

)

Detach an Analogy device from a driver.

Parameters

[in]

fd

File descriptor as returned by a4l_sys_open()

Returns

0 on success. Otherwise:

• -EINVAL is returned if some argument is missing or wrong (Please, type "dmesg" for more info)
• -EBUSY is returned if the device to be detached is in use
• -EPERM is returned if the devive to be detached still has some buffer mapped in user-space
• -ENODEV is returned in case of internal error (Please, type "dmesg" for more info)
• -ENXIO is returned in case of internal error (Please, type "dmesg" for more info)