minix/kernel/system/do_devio.c
Jorrit Herder 2a165d972e Moved "Changes" comments from system/do_....c to system.h.
All changes are now in a single header file.
2005-08-10 10:23:55 +00:00

41 lines
1.4 KiB
C

/* The system call implemented in this file:
* m_type: SYS_DEVIO
*
* The parameters for this system call are:
* m2_i3: DIO_REQUEST (request input or output)
* m2_i1: DIO_TYPE (flag indicating byte, word, or long)
* m2_l1: DIO_PORT (port to read/ write)
* m2_l2: DIO_VALUE (value to write/ return value read)
*/
#include "../system.h"
#include <minix/devio.h>
#if USE_DEVIO
/*===========================================================================*
* do_devio *
*===========================================================================*/
PUBLIC int do_devio(m_ptr)
register message *m_ptr; /* pointer to request message */
{
/* Process a single I/O request for byte, word, and long values. */
if (m_ptr->DIO_REQUEST == DIO_INPUT) {
switch (m_ptr->DIO_TYPE) {
case DIO_BYTE: m_ptr->DIO_VALUE = inb(m_ptr->DIO_PORT); break;
case DIO_WORD: m_ptr->DIO_VALUE = inw(m_ptr->DIO_PORT); break;
case DIO_LONG: m_ptr->DIO_VALUE = inl(m_ptr->DIO_PORT); break;
default: return(EINVAL);
}
} else {
switch (m_ptr->DIO_TYPE) {
case DIO_BYTE: outb(m_ptr->DIO_PORT, m_ptr->DIO_VALUE); break;
case DIO_WORD: outw(m_ptr->DIO_PORT, m_ptr->DIO_VALUE); break;
case DIO_LONG: outl(m_ptr->DIO_PORT, m_ptr->DIO_VALUE); break;
default: return(EINVAL);
}
}
return(OK);
}
#endif /* USE_DEVIO */