sys/arm/annapurna/alpine/alpine_nb_service.c

   1 /*-
   2  * Copyright (c) 2015,2016 Annapurna Labs Ltd. and affiliates
   3  * All rights reserved.
   4  *
   5  * Developed by Semihalf.
   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  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  */
  28
  29 #include <sys/cdefs.h>
  30 __FBSDID("$FreeBSD$");
  31
  32 #include <sys/param.h>
  33 #include <sys/bus.h>
  34 #include <sys/conf.h>
  35 #include <sys/rman.h>
  36 #include <sys/kernel.h>
  37 #include <sys/module.h>
  38 #include <sys/resource.h>
  39 #include <sys/systm.h>
  40
  41 #include <machine/bus.h>
  42 #include <dev/ofw/ofw_bus_subr.h>
  43
  44 #define AL_NB_ACF_MISC_OFFSET                   0xD0
  45 #define AL_NB_ACF_MISC_READ_BYPASS              (1 << 30)
  46
  47 static struct resource_spec nb_service_spec[] = {
  48         { SYS_RES_MEMORY,       0,      RF_ACTIVE },
  49         { -1, 0 }
  50 };
  51
  52 struct nb_service_softc {
  53         struct resource *res;
  54 };
  55
  56 static int nb_service_probe(device_t dev);
  57 static int nb_service_attach(device_t dev);
  58 static int nb_service_detach(device_t dev);
  59
  60 static device_method_t nb_service_methods[] = {
  61         DEVMETHOD(device_probe,         nb_service_probe),
  62         DEVMETHOD(device_attach,        nb_service_attach),
  63         DEVMETHOD(device_detach,        nb_service_detach),
  64
  65         { 0, 0 }
  66 };
  67
  68 static driver_t nb_service_driver = {
  69         "nb_service",
  70         nb_service_methods,
  71         sizeof(struct nb_service_softc)
  72 };
  73
  74 static devclass_t nb_service_devclass;
  75
  76 EARLY_DRIVER_MODULE(nb_service, simplebus, nb_service_driver,
  77     nb_service_devclass, 0, 0, BUS_PASS_CPU + BUS_PASS_ORDER_MIDDLE);
  78 EARLY_DRIVER_MODULE(nb_service, ofwbus, nb_service_driver,
  79     nb_service_devclass, 0, 0, BUS_PASS_CPU + BUS_PASS_ORDER_MIDDLE);
  80
  81 static int
  82 nb_service_probe(device_t dev)
  83 {
  84
  85         if (!ofw_bus_status_okay(dev))
  86                 return (ENXIO);
  87
  88         if (!ofw_bus_is_compatible(dev, "annapurna-labs,al-nb-service"))
  89                 return (ENXIO);
  90
  91         device_set_desc(dev, "Alpine North Bridge Service");
  92
  93         return (BUS_PROBE_DEFAULT);
  94 }
  95
  96 static int
  97 nb_service_attach(device_t dev)
  98 {
  99         struct nb_service_softc *sc;
 100         uint32_t val;
 101         int err;
 102
 103         sc = device_get_softc(dev);
 104
 105         err = bus_alloc_resources(dev, nb_service_spec, &sc->res);
 106         if (err != 0) {
 107                 device_printf(dev, "could not allocate resources\n");
 108                 return (err);
 109         }
 110
 111         /* Do not allow reads to bypass writes to different addresses */
 112         val = bus_read_4(sc->res, AL_NB_ACF_MISC_OFFSET);
 113         val &= ~AL_NB_ACF_MISC_READ_BYPASS;
 114         bus_write_4(sc->res, AL_NB_ACF_MISC_OFFSET, val);
 115
 116         return (0);
 117 }
 118
 119 static int
 120 nb_service_detach(device_t dev)
 121 {
 122         struct nb_service_softc *sc;
 123
 124         sc = device_get_softc(dev);
 125
 126         bus_release_resources(dev, nb_service_spec, &sc->res);
 127
 128         return (0);
 129 }