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
47static struct resource_spec nb_service_spec[] = {
48	{ SYS_RES_MEMORY,	0,	RF_ACTIVE },
49	{ -1, 0 }
50};
51
52struct nb_service_softc {
53	struct resource	*res;
54};
55
56static int nb_service_probe(device_t dev);
57static int nb_service_attach(device_t dev);
58static int nb_service_detach(device_t dev);
59
60static 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	{ 0, 0 }
65};
66
67static driver_t nb_service_driver = {
68	"nb_service",
69	nb_service_methods,
70	sizeof(struct nb_service_softc)
71};
72
73static devclass_t nb_service_devclass;
74
75EARLY_DRIVER_MODULE(nb_service, simplebus, nb_service_driver,
76    nb_service_devclass, 0, 0, BUS_PASS_CPU + BUS_PASS_ORDER_MIDDLE);
77EARLY_DRIVER_MODULE(nb_service, ofwbus, nb_service_driver,
78    nb_service_devclass, 0, 0, BUS_PASS_CPU + BUS_PASS_ORDER_MIDDLE);
79
80static int
81nb_service_probe(device_t dev)
82{
83
84	if (!ofw_bus_status_okay(dev))
85		return (ENXIO);
86
87	if (!ofw_bus_is_compatible(dev, "annapurna-labs,al-nb-service"))
88		return (ENXIO);
89
90	device_set_desc(dev, "Alpine North Bridge Service");
91
92	return (BUS_PROBE_DEFAULT);
93}
94
95static int
96nb_service_attach(device_t dev)
97{
98	struct nb_service_softc *sc;
99	uint32_t val;
100	int err;
101
102	sc = device_get_softc(dev);
103
104	err = bus_alloc_resources(dev, nb_service_spec, &sc->res);
105	if (err != 0) {
106		device_printf(dev, "could not allocate resources\n");
107		return (err);
108	}
109
110	/* Do not allow reads to bypass writes to different addresses */
111	val = bus_read_4(sc->res, AL_NB_ACF_MISC_OFFSET);
112	val &= ~AL_NB_ACF_MISC_READ_BYPASS;
113	bus_write_4(sc->res, AL_NB_ACF_MISC_OFFSET, val);
114
115	return (0);
116}
117
118static int
119nb_service_detach(device_t dev)
120{
121	struct nb_service_softc *sc;
122
123	sc = device_get_softc(dev);
124
125	bus_release_resources(dev, nb_service_spec, &sc->res);
126
127	return (0);
128}
129