acemidi.c revision 1.2 
1/* $NetBSD: acemidi.c,v 1.2 2001/06/12 11:49:18 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/param.h>
31
32__KERNEL_RCSID(0, "$NetBSD: acemidi.c,v 1.2 2001/06/12 11:49:18 bjh21 Exp $");
33
34#include <sys/device.h>
35#include <sys/systm.h>
36
37#include <machine/bus.h>
38
39#include <dev/podulebus/podulebus.h>
40#include <dev/podulebus/podules.h>
41#include <dev/podulebus/acemidireg.h>
42
43#include <sys/termios.h>
44#include <dev/ic/comvar.h>
45#include <dev/ic/comreg.h>
46
47struct acemidi_softc {
48	struct		device sc_dev;
49};
50
51struct com_acemidi_softc {
52	struct		com_softc sc_com;
53	struct		evcnt sc_intrcnt;
54};
55
56static int acemidi_match(struct device *, struct cfdata *, void *);
57static void acemidi_attach(struct device *, struct device *, void *);
58static int com_acemidi_match(struct device *, struct cfdata *, void *);
59static void com_acemidi_attach(struct device *, struct device *, void *);
60
61struct cfattach acemidi_ca = {
62	sizeof(struct acemidi_softc), acemidi_match, acemidi_attach
63};
64
65struct cfattach com_acemidi_ca = {
66	sizeof(struct com_acemidi_softc), com_acemidi_match, com_acemidi_attach
67};
68
69static int
70acemidi_match(struct device *parent, struct cfdata *cf, void *aux)
71{
72	struct podulebus_attach_args *pa = aux;
73
74	if (pa->pa_product == PODULE_MCS_MIDICONNECT)
75		return 1;
76	return 0;
77}
78
79static void
80acemidi_attach(struct device *parent, struct device *self, void *aux)
81{
82/*	struct acemidi_softc *sc = (void *)self; */
83/*	struct podulebus_attach_args *pa = aux; */
84
85	printf("\n");
86	config_found_sm(self, aux, NULL, NULL);
87}
88
89static int
90com_acemidi_match(struct device *parent, struct cfdata *cf, void *aux)
91{
92
93	return 1;
94}
95
96static void
97com_acemidi_attach(struct device *parent, struct device *self, void *aux)
98{
99	struct com_acemidi_softc *sc = (void *)self;
100	struct com_softc *csc = &sc->sc_com;
101	struct podulebus_attach_args *pa = aux;
102
103	csc->sc_iobase = pa->pa_fast_base + ACEMIDI_16550_BASE;
104	csc->sc_iot = pa->pa_fast_t;
105	bus_space_map(csc->sc_iot, csc->sc_iobase, COM_NPORTS, 0,
106	    &csc->sc_ioh);
107	csc->sc_frequency = ACEMIDI_16550_FREQ;
108
109	com_attach_subr(csc);
110
111	evcnt_attach_dynamic(&sc->sc_intrcnt, EVCNT_TYPE_INTR, NULL,
112	    self->dv_xname, "intr");
113	podulebus_irq_establish(pa->pa_ih, IPL_SERIAL, comintr, sc,
114	    &sc->sc_intrcnt);
115}
116
117/*
118 * Stray IRQ bug:
119 *
120 * Occasionally, when receiving, we get a stray IRQ.  Sometimes, the interrupt
121 * bit on the unixbp reads as clear.  In any case, comintr() gets an IIR
122 * of 0xc1 (no interrupts pending).
123 *
124 * The behaviour can be observed with a logic probe:
125 *
126 * Channel 1 to PIRQ* (pin 19 on IC3 on A540 backplane)
127 * Channel 2 to INTR on 16550
128 * trigger on ch1 low, ch2 falling
129 * 2 us/div
130 *
131 * This catches cases where the 16550 de-asserts the interrupt before
132 * irq_handler is entered and disables the interrupt at unixbp (by calling
133 * splhigh()).
134 *
135 * This gets us 5us pulses on INTR and PIRQ*.  Now to work out why.
136 *
137 * Connecting channel 3 to the CS2* pin on the 16550 shows it high throughout,
138 * so the interrupt isn't being cleared by the host.  MR, similarly, is low
139 * throughout, so it's not being cleared by a reset.
140 */
141