sys/dev/podulebus/acemidi.c

   1 /* $NetBSD: acemidi.c,v 1.13 2007/10/19 12:01:07 ad 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 1.13 2007/10/19 12:01:07 ad Exp $");
  32
  33 #include <sys/param.h>
  34
  35 #include <sys/device.h>
  36 #include <sys/systm.h>
  37
  38 #include <sys/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
  48 struct com_acemidi_softc {
  49         struct          com_softc sc_com;
  50         struct          evcnt sc_intrcnt;
  51 };
  52
  53 static int acemidi_match(device_t, cfdata_t , void *);
  54 static void acemidi_attach(device_t, device_t, void *);
  55 static int com_acemidi_match(device_t, cfdata_t, void *);
  56 static void com_acemidi_attach(device_t, device_t, void *);
  57
  58 CFATTACH_DECL_NEW(acemidi, 0,
  59     acemidi_match, acemidi_attach, NULL, NULL);
  60
  61 CFATTACH_DECL_NEW(com_acemidi, sizeof(struct com_acemidi_softc),
  62     com_acemidi_match, com_acemidi_attach, NULL, NULL);
  63
  64 static int
  65 acemidi_match(device_t parent, cfdata_t cf, void *aux)
  66 {
  67         struct podulebus_attach_args *pa = aux;
  68
  69         if (pa->pa_product == PODULE_MIDICONNECT)
  70                 return 1;
  71         return 0;
  72 }
  73
  74 static void
  75 acemidi_attach(device_t parent, device_t self, void *aux)
  76 {
  77 /*      struct acemidi_softc *sc = device_private(self); */
  78 /*      struct podulebus_attach_args *pa = aux; */
  79
  80         printf("\n");
  81         config_found_ia(self, "acemidi", aux, NULL);
  82 }
  83
  84 static int
  85 com_acemidi_match(device_t parent, cfdata_t cf, void *aux)
  86 {
  87
  88         return 1;
  89 }
  90
  91 static void
  92 com_acemidi_attach(device_t parent, device_t self, void *aux)
  93 {
  94         struct com_acemidi_softc *sc = device_private(self);
  95         struct com_softc *csc = &sc->sc_com;
  96         struct podulebus_attach_args *pa = aux;
  97         bus_space_handle_t ioh;
  98         bus_space_tag_t iot;
  99         bus_addr_t iobase;
 100
 101         iot = pa->pa_fast_t;
 102         iobase = pa->pa_fast_base + ACEMIDI_16550_BASE;
 103
 104         bus_space_map(iot, iobase, COM_NPORTS, 0, &ioh);
 105         COM_INIT_REGS(csc->sc_regs, iot, ioh, iobase);
 106
 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             device_xname(self), "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  */