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ast.c revision 1.3 
      1 /*
      2  * Multi-port serial card interrupt demuxing support.
      3  * Roland McGrath 3/20/94
      4  * Charles Hannum 3/22/94
      5  *
      6  *	$Id: ast.c,v 1.3 1994/03/23 03:04:32 mycroft Exp $
      7  */
      8 
      9 #include "ast.h"
     10 
     11 #include <sys/types.h>
     12 #include <sys/device.h>
     13 
     14 #include <machine/pio.h>
     15 #include <i386/isa/isa_device.h>
     16 
     17 int astprobe __P((struct isa_device *));
     18 int astattach __P((struct isa_device *));
     19 
     20 struct	isa_driver astdriver = {
     21 	astprobe, astattach, "ast"
     22 };
     23 
     24 struct ast_softc {
     25 	struct device sc_dev;
     26 	u_short sc_iobase;
     27 	int sc_alive;		/* Mask of slave units attached. */
     28 	int sc_slaves[8];	/* com device unit numbers. XXX - softc ptrs */
     29 } ast_softc[NAST];
     30 
     31 int
     32 astprobe(dev)
     33 	struct isa_device *dev;
     34 {
     35 
     36 	/*
     37 	 * Do the normal com probe for the first UART and assume
     38 	 * its presence means there is a multiport board there.
     39 	 * XXX needs more robustness.
     40 	 */
     41 	return comprobe1(dev->id_iobase);
     42 }
     43 
     44 int
     45 astattach(dev)
     46 	struct isa_device *dev;
     47 {
     48 	struct ast_softc *sc = &ast_softc[dev->id_unit];
     49   	u_short iobase = dev->id_iobase;
     50 	unsigned int x;
     51 
     52 	/* XXX HACK */
     53 	sprintf(sc->sc_dev.dv_xname, "%s%d", astdriver.name, dev->id_unit);
     54 	sc->sc_dev.dv_unit = dev->id_unit;
     55 
     56 	sc->sc_iobase = iobase;
     57 
     58 	/*
     59 	 * Enable the master interrupt.
     60 	 */
     61 	outb(iobase | 0x1f, 0x80);
     62 	x = inb(iobase | 0x1f);
     63 	/*
     64 	 * My guess is this bitmask tells you how many ports are there.
     65 	 * I only have a 4-port board to try (returns 0xf). --roland
     66 	 *
     67 	 * It's also not clear that it would be correct to rely on this, since
     68 	 * there might be an interrupt pending on one of the ports, and thus
     69 	 * its bit wouldn't be set.  I think the AST protocol simply does not
     70 	 * support more than 4 ports.  - mycroft
     71 	 */
     72 	printf("%s: 0x%x\n", sc->sc_dev.dv_xname, x);
     73 }
     74 
     75 void
     76 astslave(dev)
     77 	struct isa_device *dev;
     78 {
     79 	struct ast_softc *sc = &ast_softc[dev->id_parent->id_unit];
     80 
     81 	sc->sc_slaves[dev->id_physid] = dev->id_unit;
     82 	sc->sc_alive |= 1 << dev->id_physid;
     83 }
     84 
     85 int
     86 astintr(unit)
     87 	int unit;
     88 {
     89 	struct ast_softc *sc = &ast_softc[unit];
     90 	u_short iobase = sc->sc_iobase;
     91 	int alive = sc->sc_alive;
     92 	int bits;
     93 
     94 	bits = inb(iobase | 0x1f) & alive;
     95 	if (bits == alive)
     96 		return 0;
     97 
     98 	do {
     99 #define	TRY(n) \
    100 		if ((bits & (1 << (n))) == 0) \
    101 			comintr(sc->sc_slaves[n]);	/* XXX softc ptr */
    102 		TRY(0);
    103 		TRY(1);
    104 		TRY(2);
    105 		TRY(3);
    106 #ifdef notdef
    107 		TRY(4);
    108 		TRY(5);
    109 		TRY(6);
    110 		TRY(7);
    111 #endif
    112 		bits = inb(iobase | 0x1f) & alive;
    113  	} while (bits != alive);
    114 
    115 	return 1;
    116 }
    117