xref: /netbsd-src/sys/arch/i386/isa/isapnp_machdep.c (revision a6ce3504542ed8b086b0b8c7681fff4540e0cdd8)
1 /*	$NetBSD: isapnp_machdep.c,v 1.18 2023/12/20 15:00:07 thorpej Exp $	*/
2 
3 /*-
4  * Copyright (c) 1996, 1997 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
9  * NASA Ames Research Center and by Christos Zoulas.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30  * POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 /*
34  * Machine-dependent portions of ISA PnP bus autoconfiguration.
35  *
36  * N.B. This file exists mostly to get around some lameness surrounding
37  * the PnP spec.  ISA PnP registers live where some `normal' ISA
38  * devices do, but are e.g. write-only registers where the normal
39  * device has a read-only register.  This breaks in the presence of
40  * i/o port accounting.  This file takes care of mapping ISA PnP
41  * registers without actually allocating them in extent maps.
42  *
43  * Since this is a machine-dependent file, we make all sorts of
44  * assumptions about bus.h's guts.  Beware!
45  */
46 
47 #include <sys/cdefs.h>
48 __KERNEL_RCSID(0, "$NetBSD: isapnp_machdep.c,v 1.18 2023/12/20 15:00:07 thorpej Exp $");
49 
50 #include <sys/param.h>
51 #include <sys/systm.h>
52 #include <sys/device.h>
53 
54 #include <sys/bus.h>
55 
56 #include <dev/isa/isavar.h>
57 
58 #include <dev/isapnp/isapnpreg.h>
59 #include <dev/isapnp/isapnpvar.h>
60 
61 /* isapnp_map():
62  *	Map I/O regions used by PnP
63  */
64 int
isapnp_map(struct isapnp_softc * sc)65 isapnp_map(struct isapnp_softc *sc)
66 {
67 
68 #ifdef DIAGNOSTIC
69 	if (!bus_space_is_equal(sc->sc_iot, x86_bus_space_io))
70 		panic("isapnp_map: bogus bus space tag");
71 #endif
72 
73 	sc->sc_addr_ioh = ISAPNP_ADDR;
74 	sc->sc_wrdata_ioh = ISAPNP_WRDATA;
75 	return (0);
76 }
77 
78 /* isapnp_unmap():
79  *	Unmap I/O regions used by PnP
80  */
81 void
isapnp_unmap(struct isapnp_softc * sc)82 isapnp_unmap(struct isapnp_softc *sc)
83 {
84 
85 	/* Do nothing. */
86 }
87 
88 /* isapnp_map_readport():
89  *	Called to map the PnP `read port', which is mapped independently
90  *	of the `write' and `addr' ports.
91  *
92  *	NOTE: assumes the caller has filled in sc->sc_read_port!
93  */
94 int
isapnp_map_readport(struct isapnp_softc * sc)95 isapnp_map_readport(struct isapnp_softc *sc)
96 {
97 #ifdef _KERNEL
98 	int error;
99 #endif
100 
101 #ifdef DIAGNOSTIC
102 	if (!bus_space_is_equal(sc->sc_iot, x86_bus_space_io))
103 		panic("isapnp_map_readport: bogus bus space tag");
104 #endif
105 
106 #ifdef _KERNEL
107 	/* Check if some other device has already claimed this port. */
108 	if ((error = bus_space_map(sc->sc_iot, sc->sc_read_port, 1, 0,
109 	    &sc->sc_read_ioh)) != 0)
110 		return error;
111 
112 	/*
113 	 * XXX: We unmap the port because it can and will be used by other
114 	 *	devices such as a joystick. We need a better port accounting
115 	 *	scheme with read and write ports.
116 	 */
117 	bus_space_unmap(sc->sc_iot, sc->sc_read_ioh, 1);
118 #endif
119 	return 0;
120 }
121 
122 /* isapnp_unmap_readport():
123  *	Pretend to unmap a previously mapped `read port'.
124  */
125 void
isapnp_unmap_readport(struct isapnp_softc * sc)126 isapnp_unmap_readport(struct isapnp_softc *sc)
127 {
128 
129 	/* Do nothing */
130 }
131