syscon.c revision 1.4 
1/*	$OpenBSD: syscon.c,v 1.4 2018/03/17 18:04:15 kettenis Exp $	*/
2/*
3 * Copyright (c) 2017 Mark Kettenis
4 *
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 */
17
18#include <sys/param.h>
19#include <sys/systm.h>
20#include <sys/device.h>
21
22#include <machine/bus.h>
23#include <machine/fdt.h>
24
25#include <dev/ofw/openfirm.h>
26#include <dev/ofw/ofw_misc.h>
27#include <dev/ofw/fdt.h>
28
29#ifdef __armv7__
30#include <arm/simplebus/simplebusvar.h>
31#else
32#include <arm64/dev/simplebusvar.h>
33#endif
34
35extern void (*cpuresetfn)(void);
36extern void (*powerdownfn)(void);
37
38struct syscon_softc {
39	struct simplebus_softc	sc_sbus;
40	bus_space_tag_t		sc_iot;
41	bus_space_handle_t	sc_ioh;
42	uint32_t		sc_regmap;
43	bus_size_t		sc_offset;
44	uint32_t		sc_mask;
45};
46
47struct syscon_softc *syscon_reboot_sc;
48struct syscon_softc *syscon_poweroff_sc;
49
50int	syscon_match(struct device *, void *, void *);
51void	syscon_attach(struct device *, struct device *, void *);
52
53struct cfattach syscon_ca = {
54	sizeof(struct syscon_softc), syscon_match, syscon_attach
55};
56
57struct cfdriver syscon_cd = {
58	NULL, "syscon", DV_DULL
59};
60
61void	syscon_reset(void);
62void	syscon_powerdown(void);
63
64int
65syscon_match(struct device *parent, void *match, void *aux)
66{
67	struct fdt_attach_args *faa = aux;
68
69	return OF_is_compatible(faa->fa_node, "syscon") ||
70	    OF_is_compatible(faa->fa_node, "syscon-reboot") ||
71	    OF_is_compatible(faa->fa_node, "syscon-poweroff");
72}
73
74void
75syscon_attach(struct device *parent, struct device *self, void *aux)
76{
77	struct syscon_softc *sc = (struct syscon_softc *)self;
78	struct fdt_attach_args *faa = aux;
79	char name[32];
80
81	OF_getprop(faa->fa_node, "name", name, sizeof(name));
82	name[sizeof(name) - 1] = 0;
83
84	if (OF_is_compatible(faa->fa_node, "syscon")) {
85		if (faa->fa_nreg < 1) {
86			printf(": no registers\n");
87			return;
88		}
89
90		sc->sc_iot = faa->fa_iot;
91
92		if (bus_space_map(sc->sc_iot, faa->fa_reg[0].addr,
93		    faa->fa_reg[0].size, 0, &sc->sc_ioh)) {
94			printf(": can't map registers\n");
95			return;
96		}
97
98		regmap_register(faa->fa_node, sc->sc_iot, sc->sc_ioh,
99		    faa->fa_reg[0].size);
100	}
101
102	if (OF_is_compatible(faa->fa_node, "simple-mfd"))
103		simplebus_attach(parent, &sc->sc_sbus.sc_dev, faa);
104	else
105		printf(": \"%s\"\n", name);
106
107	if (OF_is_compatible(faa->fa_node, "syscon-reboot") ||
108	    OF_is_compatible(faa->fa_node, "syscon-poweroff")) {
109		sc->sc_regmap = OF_getpropint(faa->fa_node, "regmap", 0);
110		if (sc->sc_regmap == 0)
111			return;
112
113		if (OF_getproplen(faa->fa_node, "offset") != sizeof(uint32_t) ||
114		    OF_getproplen(faa->fa_node, "mask") != sizeof(uint32_t))
115			return;
116
117		sc->sc_offset = OF_getpropint(faa->fa_node, "offset", 0);
118		sc->sc_mask = OF_getpropint(faa->fa_node, "mask", 0);
119
120		if (OF_is_compatible(faa->fa_node, "syscon-reboot")) {
121			syscon_reboot_sc = sc;
122			cpuresetfn = syscon_reset;
123		} else if (OF_is_compatible(faa->fa_node, "syscon-poweroff")) {
124			syscon_poweroff_sc = sc;
125			powerdownfn = syscon_powerdown;
126		}
127	}
128}
129
130void
131syscon_reset(void)
132{
133	struct syscon_softc *sc = syscon_reboot_sc;
134	struct regmap *rm;
135
136	rm = regmap_byphandle(sc->sc_regmap);
137	if (rm == NULL)
138		return;
139
140	regmap_write_4(rm, sc->sc_offset, sc->sc_mask);
141	delay(1000000);
142}
143
144void
145syscon_powerdown(void)
146{
147	struct syscon_softc *sc = syscon_poweroff_sc;
148	struct regmap *rm;
149
150	rm = regmap_byphandle(sc->sc_regmap);
151	if (rm == NULL)
152		return;
153
154	regmap_write_4(rm, sc->sc_offset, sc->sc_mask);
155	delay(1000000);
156}
157