meson_resets.c revision 1.1 
1/* $NetBSD: meson_resets.c,v 1.1 2019/01/19 20:56:03 jmcneill Exp $ */
2
3/*-
4 * Copyright (c) 2017-2019 Jared McNeill <jmcneill@invisible.ca>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
22 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29#include <sys/cdefs.h>
30__KERNEL_RCSID(0, "$NetBSD: meson_resets.c,v 1.1 2019/01/19 20:56:03 jmcneill Exp $");
31
32#include <sys/param.h>
33#include <sys/bus.h>
34#include <sys/cpu.h>
35#include <sys/device.h>
36
37#include <dev/fdt/fdtvar.h>
38
39#include <dev/clk/clk_backend.h>
40
41#define	RESET_REG(index)	(((index) / 32) * 4)
42#define	RESET_MASK(index)	__BIT((index) % 32)
43
44#define	LEVEL_OFFSET		0x7c
45
46static const char * compatible[] = {
47	"amlogic,meson8b-reset",
48	NULL
49};
50
51struct meson_resets_softc {
52	device_t		sc_dev;
53	bus_space_tag_t		sc_bst;
54	bus_space_handle_t	sc_bsh;
55};
56
57#define	RESET_READ(sc, reg)		\
58	bus_space_read_4((sc)->sc_bst, (sc)->sc_bsh, (reg))
59#define	RESET_WRITE(sc, reg, val)	\
60	bus_space_write_4((sc)->sc_bst, (sc)->sc_bsh, (reg), (val))
61
62static void *
63meson_resets_acquire(device_t dev, const void *data, size_t len)
64{
65	if (len != 4)
66		return NULL;
67
68	/* Specifier is an index. Just return it. */
69	return (void *)(uintptr_t)be32dec(data);
70}
71
72static void
73meson_resets_release(device_t dev, void *priv)
74{
75}
76
77static int
78meson_resets_assert(device_t dev, void *priv)
79{
80	struct meson_resets_softc * const sc = device_private(dev);
81	const uintptr_t index = (uintptr_t)priv;
82
83	const bus_size_t reset_reg = RESET_REG(index) + LEVEL_OFFSET;
84	const uint32_t reset_mask = RESET_MASK(index);
85
86	const uint32_t val = RESET_READ(sc, reset_reg);
87	RESET_WRITE(sc, reset_reg, val & ~reset_mask);
88
89	return 0;
90}
91
92static int
93meson_resets_deassert(device_t dev, void *priv)
94{
95	struct meson_resets_softc * const sc = device_private(dev);
96	const uintptr_t index = (uintptr_t)priv;
97
98	const bus_size_t reset_reg = RESET_REG(index) + LEVEL_OFFSET;
99	const uint32_t reset_mask = RESET_MASK(index);
100
101	const uint32_t val = RESET_READ(sc, reset_reg);
102	RESET_WRITE(sc, reset_reg, val | reset_mask);
103
104	return 0;
105}
106
107static const struct fdtbus_reset_controller_func meson_fdtreset_funcs = {
108	.acquire = meson_resets_acquire,
109	.release = meson_resets_release,
110	.reset_assert = meson_resets_assert,
111	.reset_deassert = meson_resets_deassert,
112};
113
114static int
115meson_resets_match(device_t parent, cfdata_t cf, void *aux)
116{
117	struct fdt_attach_args * const faa = aux;
118
119	return of_match_compatible(faa->faa_phandle, compatible);
120}
121
122static void
123meson_resets_attach(device_t parent, device_t self, void *aux)
124{
125	struct meson_resets_softc * const sc = device_private(self);
126	struct fdt_attach_args * const faa = aux;
127	const int phandle = faa->faa_phandle;
128	bus_addr_t addr;
129	bus_size_t size;
130
131	if (fdtbus_get_reg(phandle, 0, &addr, &size) != 0) {
132		aprint_error(": couldn't get registers\n");
133		return;
134	}
135
136	sc->sc_dev = self;
137	sc->sc_bst = faa->faa_bst;
138	if (bus_space_map(sc->sc_bst, addr, size, 0, &sc->sc_bsh) != 0) {
139		aprint_error(": couldn't map registers\n");
140		return;
141	}
142
143	aprint_naive("\n");
144	aprint_normal("\n");
145
146	fdtbus_register_reset_controller(sc->sc_dev, phandle,
147	    &meson_fdtreset_funcs);
148}
149
150CFATTACH_DECL_NEW(meson_resets, sizeof(struct meson_resets_softc),
151    meson_resets_match, meson_resets_attach, NULL, NULL);
152