Free access to a device's registers
Warning: Use
munmap() instead of
munmap_device_io(). The
munmap_device_io() function
is a wrapper function for
munmap() and is only provided for backwards
compatibility.
Synopsis:
#include <sys/mman.h>
int munmap_device_io( uintptr_t io,
size_t len );
Arguments:
- io
- The address of the area that you want to unmap.
- len
- The number of bytes of device I/O memory that you want to unmap.
Library:
libc
Use the -l c option to
qcc
to link against this library.
This library is usually included automatically.
Description:
The function munmap_device_io() unmaps len bytes of device I/O memory
that's stored at io and was previously mapped with
mmap_device_io().
Note:
On x86, this function does nothing and just returns 0.
It is only meaningful to call this function on ARM.
Returns:
- -1
- ARM only; an error occurred
(errno is set).
- Any other value
- x86 only; 0 is always returned (see the note above).
- ARM only; the unmapping succeeded.
Errors:
On ARM, this function may set any of the errors that
munmap_flags() does.
Classification:
QNX Neutrino
Safety: |
|
Cancellation point |
No |
Interrupt handler |
No |
Signal handler |
Yes |
Thread |
Yes |