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ast.c revision 1.1 
      1 /*
      2  * Multi-port serial card interrupt demuxing support.
      3  * Roland McGrath 3/20/94
      4  *
      5  *	$Id: ast.c,v 1.1 1994/03/23 01:26:14 cgd Exp $
      6  */
      7 
      8 #include "ast.h"
      9 
     10 #include <sys/types.h>
     11 
     12 #include <machine/pio.h>
     13 #include <i386/isa/isa_device.h>
     14 
     15 int astprobe __P((struct isa_device *));
     16 int astattach __P((struct isa_device *));
     17 
     18 struct	isa_driver astdriver = {
     19 	astprobe, astattach, "ast"
     20 };
     21 
     22 struct astunit			/* XXX ast_softc? */
     23 {
     24 	u_short iobase;
     25 	int alive;		/* Mask of slave units attached. */
     26 	int slaveunits[8];	/* com device unit numbers. XXX - softc ptrs */
     27 } astunits[NAST];
     28 
     29 int
     30 astprobe(struct isa_device *isa_dev)
     31 {
     32 	/*
     33 	 * Do the normal com probe for the first UART and assume
     34 	 * its presence means there is a multiport board there.
     35 	 * XXX needs more robustness.
     36 	 */
     37 	return comprobe1(isa_dev->id_iobase);
     38 }
     39 
     40 int
     41 astattach(struct isa_device *isa_dev)
     42 {
     43 	int unit = isa_dev->id_unit;
     44   	u_short iobase = isa_dev->id_iobase;
     45 	unsigned int x;
     46 
     47 	astunits[unit].iobase = iobase;
     48 
     49 	/*
     50 	 * XXX calculation of master address is a bit hazy --
     51 	 * what if > 4 ports, etc.
     52 	 */
     53 	outb (iobase | 0x1f, 0x80);
     54 	x = inb (iobase | 0x1f);
     55 	/*
     56 	 * My guess is this bitmask tells you how many ports are there.
     57 	 * I only have a 4-port board to try (returns 0xf). --roland
     58 	 */
     59 	printf ("ast%d: 0x%x\n", unit, x);
     60 }
     61 
     62 void
     63 astslave(struct isa_device *slave, int comunit)
     64 {
     65 	struct astunit *a = &astunits[slave->id_parent->id_unit];
     66 
     67 	a->slaveunits[slave->id_physid] = comunit;
     68 	a->alive |= 1 << slave->id_physid;
     69 }
     70 
     71 int
     72 astintr(int unit)
     73 {
     74 	struct astunit *a = &astunits[unit];
     75 	u_short iobase = a->iobase;
     76 	int alive = a->alive;
     77 	int bits;
     78 
     79 	do {
     80 		bits = inb (iobase | 0x1f) & alive;
     81 #define TRY(I)	((bits & (1 << (I))) ? 0 : comintr (a->slaveunits[I]))
     82 		TRY (0), TRY (1), TRY (2), TRY (3);
     83 		/* XXX -- i think the next 4 are bogus, see above -- cgd */
     84 		TRY (4), TRY (5), TRY (6), TRY (7);
     85 #undef TRY
     86  	} while (bits != alive);
     87 
     88 	return 1;
     89 }
     90