xref: /freebsd/sys/arm/allwinner/aw_reset.c (revision e0c4386e7e71d93b0edc0c8fa156263fc4a8b0b6)
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/param.h>
31 #include <sys/systm.h>
32 #include <sys/bus.h>
33 #include <sys/rman.h>
34 #include <sys/kernel.h>
35 #include <sys/lock.h>
36 #include <sys/module.h>
37 #include <sys/mutex.h>
38 #include <machine/bus.h>
39 
40 #include <dev/ofw/ofw_bus.h>
41 #include <dev/ofw/ofw_bus_subr.h>
42 
43 #include <dev/hwreset/hwreset.h>
44 
45 #include "hwreset_if.h"
46 
47 #define	RESET_OFFSET(index)	((index / 32) * 4)
48 #define	RESET_SHIFT(index)	(index % 32)
49 
50 static struct ofw_compat_data compat_data[] = {
51 	{ "allwinner,sun6i-a31-ahb1-reset",	1 },
52 	{ "allwinner,sun6i-a31-clock-reset",	1 },
53 	{ NULL,					0 }
54 };
55 
56 struct aw_reset_softc {
57 	struct resource		*res;
58 	struct mtx		mtx;
59 };
60 
61 static struct resource_spec aw_reset_spec[] = {
62 	{ SYS_RES_MEMORY,	0,	RF_ACTIVE },
63 	{ -1, 0 }
64 };
65 
66 #define	RESET_READ(sc, reg)		bus_read_4((sc)->res, (reg))
67 #define	RESET_WRITE(sc, reg, val)	bus_write_4((sc)->res, (reg), (val))
68 
69 static int
70 aw_reset_assert(device_t dev, intptr_t id, bool reset)
71 {
72 	struct aw_reset_softc *sc;
73 	uint32_t reg_value;
74 
75 	sc = device_get_softc(dev);
76 
77 	mtx_lock(&sc->mtx);
78 	reg_value = RESET_READ(sc, RESET_OFFSET(id));
79 	if (reset)
80 		reg_value &= ~(1 << RESET_SHIFT(id));
81 	else
82 		reg_value |= (1 << RESET_SHIFT(id));
83 	RESET_WRITE(sc, RESET_OFFSET(id), reg_value);
84 	mtx_unlock(&sc->mtx);
85 
86 	return (0);
87 }
88 
89 static int
90 aw_reset_is_asserted(device_t dev, intptr_t id, bool *reset)
91 {
92 	struct aw_reset_softc *sc;
93 	uint32_t reg_value;
94 
95 	sc = device_get_softc(dev);
96 
97 	mtx_lock(&sc->mtx);
98 	reg_value = RESET_READ(sc, RESET_OFFSET(id));
99 	mtx_unlock(&sc->mtx);
100 
101 	*reset = (reg_value & (1 << RESET_SHIFT(id))) != 0 ? false : true;
102 
103 	return (0);
104 }
105 
106 static int
107 aw_reset_probe(device_t dev)
108 {
109 	if (!ofw_bus_status_okay(dev))
110 		return (ENXIO);
111 
112 	if (ofw_bus_search_compatible(dev, compat_data)->ocd_data == 0)
113 		return (ENXIO);
114 
115 	device_set_desc(dev, "Allwinner Module Resets");
116 	return (BUS_PROBE_DEFAULT);
117 }
118 
119 static int
120 aw_reset_attach(device_t dev)
121 {
122 	struct aw_reset_softc *sc;
123 
124 	sc = device_get_softc(dev);
125 
126 	if (bus_alloc_resources(dev, aw_reset_spec, &sc->res) != 0) {
127 		device_printf(dev, "cannot allocate resources for device\n");
128 		return (ENXIO);
129 	}
130 
131 	mtx_init(&sc->mtx, device_get_nameunit(dev), NULL, MTX_DEF);
132 
133 	hwreset_register_ofw_provider(dev);
134 
135 	return (0);
136 }
137 
138 static device_method_t aw_reset_methods[] = {
139 	/* Device interface */
140 	DEVMETHOD(device_probe,		aw_reset_probe),
141 	DEVMETHOD(device_attach,	aw_reset_attach),
142 
143 	/* Reset interface */
144 	DEVMETHOD(hwreset_assert,	aw_reset_assert),
145 	DEVMETHOD(hwreset_is_asserted,	aw_reset_is_asserted),
146 
147 	DEVMETHOD_END
148 };
149 
150 static driver_t aw_reset_driver = {
151 	"aw_reset",
152 	aw_reset_methods,
153 	sizeof(struct aw_reset_softc),
154 };
155 
156 EARLY_DRIVER_MODULE(aw_reset, simplebus, aw_reset_driver, 0, 0,
157     BUS_PASS_RESOURCE + BUS_PASS_ORDER_MIDDLE);
158 MODULE_VERSION(aw_reset, 1);
159