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/param.h>
30 #include <sys/bus.h>
31 #include <sys/conf.h>
32 #include <sys/rman.h>
33 #include <sys/kernel.h>
34 #include <sys/module.h>
35 #include <sys/resource.h>
36 #include <sys/systm.h>
37
38 #include <machine/bus.h>
39 #include <dev/ofw/ofw_bus_subr.h>
40
41 #define AL_NB_ACF_MISC_OFFSET 0xD0
42 #define AL_NB_ACF_MISC_READ_BYPASS (1 << 30)
43
44 static struct resource_spec nb_service_spec[] = {
45 { SYS_RES_MEMORY, 0, RF_ACTIVE },
46 { -1, 0 }
47 };
48
49 struct nb_service_softc {
50 struct resource *res;
51 };
52
53 static int nb_service_probe(device_t dev);
54 static int nb_service_attach(device_t dev);
55 static int nb_service_detach(device_t dev);
56
57 static device_method_t nb_service_methods[] = {
58 DEVMETHOD(device_probe, nb_service_probe),
59 DEVMETHOD(device_attach, nb_service_attach),
60 DEVMETHOD(device_detach, nb_service_detach),
61 { 0, 0 }
62 };
63
64 static driver_t nb_service_driver = {
65 "nb_service",
66 nb_service_methods,
67 sizeof(struct nb_service_softc)
68 };
69
70 EARLY_DRIVER_MODULE(nb_service, simplebus, nb_service_driver, 0, 0,
71 BUS_PASS_CPU + BUS_PASS_ORDER_MIDDLE);
72 EARLY_DRIVER_MODULE(nb_service, ofwbus, nb_service_driver, 0, 0,
73 BUS_PASS_CPU + BUS_PASS_ORDER_MIDDLE);
74
75 static int
nb_service_probe(device_t dev)76 nb_service_probe(device_t dev)
77 {
78
79 if (!ofw_bus_status_okay(dev))
80 return (ENXIO);
81
82 if (!ofw_bus_is_compatible(dev, "annapurna-labs,al-nb-service"))
83 return (ENXIO);
84
85 device_set_desc(dev, "Alpine North Bridge Service");
86
87 return (BUS_PROBE_DEFAULT);
88 }
89
90 static int
nb_service_attach(device_t dev)91 nb_service_attach(device_t dev)
92 {
93 struct nb_service_softc *sc;
94 uint32_t val;
95 int err;
96
97 sc = device_get_softc(dev);
98
99 err = bus_alloc_resources(dev, nb_service_spec, &sc->res);
100 if (err != 0) {
101 device_printf(dev, "could not allocate resources\n");
102 return (err);
103 }
104
105 /* Do not allow reads to bypass writes to different addresses */
106 val = bus_read_4(sc->res, AL_NB_ACF_MISC_OFFSET);
107 val &= ~AL_NB_ACF_MISC_READ_BYPASS;
108 bus_write_4(sc->res, AL_NB_ACF_MISC_OFFSET, val);
109
110 return (0);
111 }
112
113 static int
nb_service_detach(device_t dev)114 nb_service_detach(device_t dev)
115 {
116 struct nb_service_softc *sc;
117
118 sc = device_get_softc(dev);
119
120 bus_release_resources(dev, nb_service_spec, &sc->res);
121
122 return (0);
123 }
124