xref: /freebsd/sys/arm/allwinner/aw_reset.c (revision b3e7694832e81d7a904a10f525f8797b753bf0d3)
1 /*-
2  * Copyright (c) 2016 Jared McNeill <jmcneill@invisible.ca>
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  *
13  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
14  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
15  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
16  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
17  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
18  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
19  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
20  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
21  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23  * SUCH DAMAGE.
24  */
25 
26 /*
27  * Allwinner module software reset registers
28  */
29 
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/bus.h>
36 #include <sys/rman.h>
37 #include <sys/kernel.h>
38 #include <sys/lock.h>
39 #include <sys/module.h>
40 #include <sys/mutex.h>
41 #include <machine/bus.h>
42 
43 #include <dev/ofw/ofw_bus.h>
44 #include <dev/ofw/ofw_bus_subr.h>
45 
46 #include <dev/extres/hwreset/hwreset.h>
47 
48 #include "hwreset_if.h"
49 
50 #define	RESET_OFFSET(index)	((index / 32) * 4)
51 #define	RESET_SHIFT(index)	(index % 32)
52 
53 static struct ofw_compat_data compat_data[] = {
54 	{ "allwinner,sun6i-a31-ahb1-reset",	1 },
55 	{ "allwinner,sun6i-a31-clock-reset",	1 },
56 	{ NULL,					0 }
57 };
58 
59 struct aw_reset_softc {
60 	struct resource		*res;
61 	struct mtx		mtx;
62 };
63 
64 static struct resource_spec aw_reset_spec[] = {
65 	{ SYS_RES_MEMORY,	0,	RF_ACTIVE },
66 	{ -1, 0 }
67 };
68 
69 #define	RESET_READ(sc, reg)		bus_read_4((sc)->res, (reg))
70 #define	RESET_WRITE(sc, reg, val)	bus_write_4((sc)->res, (reg), (val))
71 
72 static int
73 aw_reset_assert(device_t dev, intptr_t id, bool reset)
74 {
75 	struct aw_reset_softc *sc;
76 	uint32_t reg_value;
77 
78 	sc = device_get_softc(dev);
79 
80 	mtx_lock(&sc->mtx);
81 	reg_value = RESET_READ(sc, RESET_OFFSET(id));
82 	if (reset)
83 		reg_value &= ~(1 << RESET_SHIFT(id));
84 	else
85 		reg_value |= (1 << RESET_SHIFT(id));
86 	RESET_WRITE(sc, RESET_OFFSET(id), reg_value);
87 	mtx_unlock(&sc->mtx);
88 
89 	return (0);
90 }
91 
92 static int
93 aw_reset_is_asserted(device_t dev, intptr_t id, bool *reset)
94 {
95 	struct aw_reset_softc *sc;
96 	uint32_t reg_value;
97 
98 	sc = device_get_softc(dev);
99 
100 	mtx_lock(&sc->mtx);
101 	reg_value = RESET_READ(sc, RESET_OFFSET(id));
102 	mtx_unlock(&sc->mtx);
103 
104 	*reset = (reg_value & (1 << RESET_SHIFT(id))) != 0 ? false : true;
105 
106 	return (0);
107 }
108 
109 static int
110 aw_reset_probe(device_t dev)
111 {
112 	if (!ofw_bus_status_okay(dev))
113 		return (ENXIO);
114 
115 	if (ofw_bus_search_compatible(dev, compat_data)->ocd_data == 0)
116 		return (ENXIO);
117 
118 	device_set_desc(dev, "Allwinner Module Resets");
119 	return (BUS_PROBE_DEFAULT);
120 }
121 
122 static int
123 aw_reset_attach(device_t dev)
124 {
125 	struct aw_reset_softc *sc;
126 
127 	sc = device_get_softc(dev);
128 
129 	if (bus_alloc_resources(dev, aw_reset_spec, &sc->res) != 0) {
130 		device_printf(dev, "cannot allocate resources for device\n");
131 		return (ENXIO);
132 	}
133 
134 	mtx_init(&sc->mtx, device_get_nameunit(dev), NULL, MTX_DEF);
135 
136 	hwreset_register_ofw_provider(dev);
137 
138 	return (0);
139 }
140 
141 static device_method_t aw_reset_methods[] = {
142 	/* Device interface */
143 	DEVMETHOD(device_probe,		aw_reset_probe),
144 	DEVMETHOD(device_attach,	aw_reset_attach),
145 
146 	/* Reset interface */
147 	DEVMETHOD(hwreset_assert,	aw_reset_assert),
148 	DEVMETHOD(hwreset_is_asserted,	aw_reset_is_asserted),
149 
150 	DEVMETHOD_END
151 };
152 
153 static driver_t aw_reset_driver = {
154 	"aw_reset",
155 	aw_reset_methods,
156 	sizeof(struct aw_reset_softc),
157 };
158 
159 EARLY_DRIVER_MODULE(aw_reset, simplebus, aw_reset_driver, 0, 0,
160     BUS_PASS_RESOURCE + BUS_PASS_ORDER_MIDDLE);
161 MODULE_VERSION(aw_reset, 1);
162