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      1 /* $NetBSD: acemidi.c,v 1.17 2021/08/07 16:19:15 thorpej 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 1.17 2021/08/07 16:19:15 thorpej 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(self, aux, NULL, CFARGS_NONE);
     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  */
    141