1/*-
2 * Copyright (c) 2016 Jared McNeill <jmcneill@invisible.ca>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
19 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
20 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
21 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
22 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * $FreeBSD$
27 */
28
29/*
30 * Allwinner module software reset registers
31 */
32
33#include <sys/cdefs.h>
34__FBSDID("$FreeBSD$");
35
36#include <sys/param.h>
37#include <sys/systm.h>
38#include <sys/bus.h>
39#include <sys/rman.h>
40#include <sys/kernel.h>
41#include <sys/module.h>
42#include <machine/bus.h>
43
44#include <dev/ofw/ofw_bus.h>
45#include <dev/ofw/ofw_bus_subr.h>
46
47#include <dev/extres/hwreset/hwreset.h>
48
49#include "hwreset_if.h"
50
51#define	RESET_OFFSET(index)	((index / 32) * 4)
52#define	RESET_SHIFT(index)	(index % 32)
53
54static struct ofw_compat_data compat_data[] = {
55	{ "allwinner,sun6i-a31-ahb1-reset",	1 },
56	{ "allwinner,sun6i-a31-clock-reset",	1 },
57	{ NULL,					0 }
58};
59
60struct aw_reset_softc {
61	struct resource		*res;
62	struct mtx		mtx;
63};
64
65static struct resource_spec aw_reset_spec[] = {
66	{ SYS_RES_MEMORY,	0,	RF_ACTIVE },
67	{ -1, 0 }
68};
69
70#define	RESET_READ(sc, reg)		bus_read_4((sc)->res, (reg))
71#define	RESET_WRITE(sc, reg, val)	bus_write_4((sc)->res, (reg), (val))
72
73static int
74aw_reset_assert(device_t dev, intptr_t id, bool reset)
75{
76	struct aw_reset_softc *sc;
77	uint32_t reg_value;
78
79	sc = device_get_softc(dev);
80
81	mtx_lock(&sc->mtx);
82	reg_value = RESET_READ(sc, RESET_OFFSET(id));
83	if (reset)
84		reg_value &= ~(1 << RESET_SHIFT(id));
85	else
86		reg_value |= (1 << RESET_SHIFT(id));
87	RESET_WRITE(sc, RESET_OFFSET(id), reg_value);
88	mtx_unlock(&sc->mtx);
89
90	return (0);
91}
92
93static int
94aw_reset_is_asserted(device_t dev, intptr_t id, bool *reset)
95{
96	struct aw_reset_softc *sc;
97	uint32_t reg_value;
98
99	sc = device_get_softc(dev);
100
101	mtx_lock(&sc->mtx);
102	reg_value = RESET_READ(sc, RESET_OFFSET(id));
103	mtx_unlock(&sc->mtx);
104
105	*reset = (reg_value & (1 << RESET_SHIFT(id))) != 0 ? false : true;
106
107	return (0);
108}
109
110static int
111aw_reset_probe(device_t dev)
112{
113	if (!ofw_bus_status_okay(dev))
114		return (ENXIO);
115
116	if (ofw_bus_search_compatible(dev, compat_data)->ocd_data == 0)
117		return (ENXIO);
118
119	device_set_desc(dev, "Allwinner Module Resets");
120	return (BUS_PROBE_DEFAULT);
121}
122
123static int
124aw_reset_attach(device_t dev)
125{
126	struct aw_reset_softc *sc;
127
128	sc = device_get_softc(dev);
129
130	if (bus_alloc_resources(dev, aw_reset_spec, &sc->res) != 0) {
131		device_printf(dev, "cannot allocate resources for device\n");
132		return (ENXIO);
133	}
134
135	mtx_init(&sc->mtx, device_get_nameunit(dev), NULL, MTX_DEF);
136
137	hwreset_register_ofw_provider(dev);
138
139	return (0);
140}
141
142static device_method_t aw_reset_methods[] = {
143	/* Device interface */
144	DEVMETHOD(device_probe,		aw_reset_probe),
145	DEVMETHOD(device_attach,	aw_reset_attach),
146
147	/* Reset interface */
148	DEVMETHOD(hwreset_assert,	aw_reset_assert),
149	DEVMETHOD(hwreset_is_asserted,	aw_reset_is_asserted),
150
151	DEVMETHOD_END
152};
153
154static driver_t aw_reset_driver = {
155	"aw_reset",
156	aw_reset_methods,
157	sizeof(struct aw_reset_softc),
158};
159
160static devclass_t aw_reset_devclass;
161
162EARLY_DRIVER_MODULE(aw_reset, simplebus, aw_reset_driver, aw_reset_devclass,
163    0, 0, BUS_PASS_RESOURCE + BUS_PASS_ORDER_MIDDLE);
164MODULE_VERSION(aw_reset, 1);
165