acemidi.c revision 1.4 
1/* $NetBSD: acemidi.c,v 1.4 2002/05/22 22:43:13 bjh21 Exp $ */
2
3/*-
4 * Copyright (c) 2001 Ben Harris
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. The name of the author may not be used to endorse or promote products
16 *    derived from this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
29
30#include <sys/cdefs.h>
31__KERNEL_RCSID(0, "$NetBSD: acemidi.c,v 1.4 2002/05/22 22:43:13 bjh21 Exp $");
32
33#include <sys/param.h>
34
35#include <sys/device.h>
36#include <sys/systm.h>
37
38#include <machine/bus.h>
39
40#include <dev/podulebus/podulebus.h>
41#include <dev/podulebus/podules.h>
42#include <dev/podulebus/acemidireg.h>
43
44#include <sys/termios.h>
45#include <dev/ic/comvar.h>
46#include <dev/ic/comreg.h>
47
48struct acemidi_softc {
49	struct		device sc_dev;
50};
51
52struct com_acemidi_softc {
53	struct		com_softc sc_com;
54	struct		evcnt sc_intrcnt;
55};
56
57static int acemidi_match(struct device *, struct cfdata *, void *);
58static void acemidi_attach(struct device *, struct device *, void *);
59static int com_acemidi_match(struct device *, struct cfdata *, void *);
60static void com_acemidi_attach(struct device *, struct device *, void *);
61
62struct cfattach acemidi_ca = {
63	sizeof(struct acemidi_softc), acemidi_match, acemidi_attach
64};
65
66struct cfattach com_acemidi_ca = {
67	sizeof(struct com_acemidi_softc), com_acemidi_match, com_acemidi_attach
68};
69
70static int
71acemidi_match(struct device *parent, struct cfdata *cf, void *aux)
72{
73	struct podulebus_attach_args *pa = aux;
74
75	if (pa->pa_product == PODULE_MIDICONNECT)
76		return 1;
77	return 0;
78}
79
80static void
81acemidi_attach(struct device *parent, struct device *self, void *aux)
82{
83/*	struct acemidi_softc *sc = (void *)self; */
84/*	struct podulebus_attach_args *pa = aux; */
85
86	printf("\n");
87	config_found_sm(self, aux, NULL, NULL);
88}
89
90static int
91com_acemidi_match(struct device *parent, struct cfdata *cf, void *aux)
92{
93
94	return 1;
95}
96
97static void
98com_acemidi_attach(struct device *parent, struct device *self, void *aux)
99{
100	struct com_acemidi_softc *sc = (void *)self;
101	struct com_softc *csc = &sc->sc_com;
102	struct podulebus_attach_args *pa = aux;
103
104	csc->sc_iobase = pa->pa_fast_base + ACEMIDI_16550_BASE;
105	csc->sc_iot = pa->pa_fast_t;
106	bus_space_map(csc->sc_iot, csc->sc_iobase, COM_NPORTS, 0,
107	    &csc->sc_ioh);
108	csc->sc_frequency = ACEMIDI_16550_FREQ;
109
110	com_attach_subr(csc);
111
112	evcnt_attach_dynamic(&sc->sc_intrcnt, EVCNT_TYPE_INTR, NULL,
113	    self->dv_xname, "intr");
114	podulebus_irq_establish(pa->pa_ih, IPL_SERIAL, comintr, sc,
115	    &sc->sc_intrcnt);
116}
117
118/*
119 * Stray IRQ bug:
120 *
121 * Occasionally, when receiving, we get a stray IRQ.  Sometimes, the interrupt
122 * bit on the unixbp reads as clear.  In any case, comintr() gets an IIR
123 * of 0xc1 (no interrupts pending).
124 *
125 * The behaviour can be observed with a logic probe:
126 *
127 * Channel 1 to PIRQ* (pin 19 on IC3 on A540 backplane)
128 * Channel 2 to INTR on 16550
129 * trigger on ch1 low, ch2 falling
130 * 2 us/div
131 *
132 * This catches cases where the 16550 de-asserts the interrupt before
133 * irq_handler is entered and disables the interrupt at unixbp (by calling
134 * splhigh()).
135 *
136 * This gets us 5us pulses on INTR and PIRQ*.  Now to work out why.
137 *
138 * Connecting channel 3 to the CS2* pin on the 16550 shows it high throughout,
139 * so the interrupt isn't being cleared by the host.  MR, similarly, is low
140 * throughout, so it's not being cleared by a reset.
141 */
142