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ast.c revision 1.4 
      1 /*
      2  * Multi-port serial card interrupt demuxing support.
      3  * Roland McGrath 3/20/94
      4  * The author disclaims copyright and places this file in the public domain.
      5  *
      6  * Modified by: Charles Hannum, 3/22/94
      7  *
      8  *	$Id: ast.c,v 1.4 1994/03/23 03:55:24 cgd Exp $
      9  */
     10 
     11 #include "ast.h"
     12 
     13 #include <sys/types.h>
     14 #include <sys/device.h>
     15 
     16 #include <machine/pio.h>
     17 #include <i386/isa/isa_device.h>
     18 
     19 int astprobe __P((struct isa_device *));
     20 int astattach __P((struct isa_device *));
     21 
     22 struct	isa_driver astdriver = {
     23 	astprobe, astattach, "ast"
     24 };
     25 
     26 struct ast_softc {
     27 	struct device sc_dev;
     28 	u_short sc_iobase;
     29 	int sc_alive;		/* Mask of slave units attached. */
     30 	int sc_slaves[8];	/* com device unit numbers. XXX - softc ptrs */
     31 } ast_softc[NAST];
     32 
     33 int
     34 astprobe(dev)
     35 	struct isa_device *dev;
     36 {
     37 
     38 	/*
     39 	 * Do the normal com probe for the first UART and assume
     40 	 * its presence means there is a multiport board there.
     41 	 * XXX needs more robustness.
     42 	 */
     43 	return comprobe1(dev->id_iobase);
     44 }
     45 
     46 int
     47 astattach(dev)
     48 	struct isa_device *dev;
     49 {
     50 	struct ast_softc *sc = &ast_softc[dev->id_unit];
     51   	u_short iobase = dev->id_iobase;
     52 	unsigned int x;
     53 
     54 	/* XXX HACK */
     55 	sprintf(sc->sc_dev.dv_xname, "%s%d", astdriver.name, dev->id_unit);
     56 	sc->sc_dev.dv_unit = dev->id_unit;
     57 
     58 	sc->sc_iobase = iobase;
     59 
     60 	/*
     61 	 * Enable the master interrupt.
     62 	 */
     63 	outb(iobase | 0x1f, 0x80);
     64 	x = inb(iobase | 0x1f);
     65 	/*
     66 	 * My guess is this bitmask tells you how many ports are there.
     67 	 * I only have a 4-port board to try (returns 0xf). --roland
     68 	 *
     69 	 * It's also not clear that it would be correct to rely on this, since
     70 	 * there might be an interrupt pending on one of the ports, and thus
     71 	 * its bit wouldn't be set.  I think the AST protocol simply does not
     72 	 * support more than 4 ports.  - mycroft
     73 	 */
     74 	printf("%s: 0x%x\n", sc->sc_dev.dv_xname, x);
     75 }
     76 
     77 void
     78 astslave(dev)
     79 	struct isa_device *dev;
     80 {
     81 	struct ast_softc *sc = &ast_softc[dev->id_parent->id_unit];
     82 
     83 	sc->sc_slaves[dev->id_physid] = dev->id_unit;
     84 	sc->sc_alive |= 1 << dev->id_physid;
     85 }
     86 
     87 int
     88 astintr(unit)
     89 	int unit;
     90 {
     91 	struct ast_softc *sc = &ast_softc[unit];
     92 	u_short iobase = sc->sc_iobase;
     93 	int alive = sc->sc_alive;
     94 	int bits;
     95 
     96 	bits = inb(iobase | 0x1f) & alive;
     97 	if (bits == alive)
     98 		return 0;
     99 
    100 	do {
    101 #define	TRY(n) \
    102 		if ((bits & (1 << (n))) == 0) \
    103 			comintr(sc->sc_slaves[n]);	/* XXX softc ptr */
    104 		TRY(0);
    105 		TRY(1);
    106 		TRY(2);
    107 		TRY(3);
    108 #ifdef notdef
    109 		TRY(4);
    110 		TRY(5);
    111 		TRY(6);
    112 		TRY(7);
    113 #endif
    114 		bits = inb(iobase | 0x1f) & alive;
    115  	} while (bits != alive);
    116 
    117 	return 1;
    118 }
    119