xref: /freebsd/sys/arm/allwinner/aw_reset.c (revision cd0d51baaa4509a1db83251a601d34404d20c990)
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  * $FreeBSD$
26  */
27 
28 /*
29  * Allwinner module software reset registers
30  */
31 
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
34 
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/bus.h>
38 #include <sys/rman.h>
39 #include <sys/kernel.h>
40 #include <sys/lock.h>
41 #include <sys/module.h>
42 #include <sys/mutex.h>
43 #include <machine/bus.h>
44 
45 #include <dev/ofw/ofw_bus.h>
46 #include <dev/ofw/ofw_bus_subr.h>
47 
48 #include <dev/extres/hwreset/hwreset.h>
49 
50 #include "hwreset_if.h"
51 
52 #define	RESET_OFFSET(index)	((index / 32) * 4)
53 #define	RESET_SHIFT(index)	(index % 32)
54 
55 static struct ofw_compat_data compat_data[] = {
56 	{ "allwinner,sun6i-a31-ahb1-reset",	1 },
57 	{ "allwinner,sun6i-a31-clock-reset",	1 },
58 	{ NULL,					0 }
59 };
60 
61 struct aw_reset_softc {
62 	struct resource		*res;
63 	struct mtx		mtx;
64 };
65 
66 static struct resource_spec aw_reset_spec[] = {
67 	{ SYS_RES_MEMORY,	0,	RF_ACTIVE },
68 	{ -1, 0 }
69 };
70 
71 #define	RESET_READ(sc, reg)		bus_read_4((sc)->res, (reg))
72 #define	RESET_WRITE(sc, reg, val)	bus_write_4((sc)->res, (reg), (val))
73 
74 static int
75 aw_reset_assert(device_t dev, intptr_t id, bool reset)
76 {
77 	struct aw_reset_softc *sc;
78 	uint32_t reg_value;
79 
80 	sc = device_get_softc(dev);
81 
82 	mtx_lock(&sc->mtx);
83 	reg_value = RESET_READ(sc, RESET_OFFSET(id));
84 	if (reset)
85 		reg_value &= ~(1 << RESET_SHIFT(id));
86 	else
87 		reg_value |= (1 << RESET_SHIFT(id));
88 	RESET_WRITE(sc, RESET_OFFSET(id), reg_value);
89 	mtx_unlock(&sc->mtx);
90 
91 	return (0);
92 }
93 
94 static int
95 aw_reset_is_asserted(device_t dev, intptr_t id, bool *reset)
96 {
97 	struct aw_reset_softc *sc;
98 	uint32_t reg_value;
99 
100 	sc = device_get_softc(dev);
101 
102 	mtx_lock(&sc->mtx);
103 	reg_value = RESET_READ(sc, RESET_OFFSET(id));
104 	mtx_unlock(&sc->mtx);
105 
106 	*reset = (reg_value & (1 << RESET_SHIFT(id))) != 0 ? false : true;
107 
108 	return (0);
109 }
110 
111 static int
112 aw_reset_probe(device_t dev)
113 {
114 	if (!ofw_bus_status_okay(dev))
115 		return (ENXIO);
116 
117 	if (ofw_bus_search_compatible(dev, compat_data)->ocd_data == 0)
118 		return (ENXIO);
119 
120 	device_set_desc(dev, "Allwinner Module Resets");
121 	return (BUS_PROBE_DEFAULT);
122 }
123 
124 static int
125 aw_reset_attach(device_t dev)
126 {
127 	struct aw_reset_softc *sc;
128 
129 	sc = device_get_softc(dev);
130 
131 	if (bus_alloc_resources(dev, aw_reset_spec, &sc->res) != 0) {
132 		device_printf(dev, "cannot allocate resources for device\n");
133 		return (ENXIO);
134 	}
135 
136 	mtx_init(&sc->mtx, device_get_nameunit(dev), NULL, MTX_DEF);
137 
138 	hwreset_register_ofw_provider(dev);
139 
140 	return (0);
141 }
142 
143 static device_method_t aw_reset_methods[] = {
144 	/* Device interface */
145 	DEVMETHOD(device_probe,		aw_reset_probe),
146 	DEVMETHOD(device_attach,	aw_reset_attach),
147 
148 	/* Reset interface */
149 	DEVMETHOD(hwreset_assert,	aw_reset_assert),
150 	DEVMETHOD(hwreset_is_asserted,	aw_reset_is_asserted),
151 
152 	DEVMETHOD_END
153 };
154 
155 static driver_t aw_reset_driver = {
156 	"aw_reset",
157 	aw_reset_methods,
158 	sizeof(struct aw_reset_softc),
159 };
160 
161 static devclass_t aw_reset_devclass;
162 
163 EARLY_DRIVER_MODULE(aw_reset, simplebus, aw_reset_driver, aw_reset_devclass,
164     0, 0, BUS_PASS_RESOURCE + BUS_PASS_ORDER_MIDDLE);
165 MODULE_VERSION(aw_reset, 1);
166