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