1 /* $NetBSD: meson_resets.c,v 1.4 2021/01/27 03:10:18 thorpej 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 1.4 2021/01/27 03:10:18 thorpej 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
46 static const struct device_compatible_entry compat_data[] = {
47 { .compat = "amlogic,meson8b-reset" },
48 { .compat = "amlogic,meson-axg-reset" },
49 { .compat = "amlogic,meson-gxbb-reset" },
50 DEVICE_COMPAT_EOL
51 };
52
53 struct meson_resets_softc {
54 device_t sc_dev;
55 bus_space_tag_t sc_bst;
56 bus_space_handle_t sc_bsh;
57 };
58
59 #define RESET_READ(sc, reg) \
60 bus_space_read_4((sc)->sc_bst, (sc)->sc_bsh, (reg))
61 #define RESET_WRITE(sc, reg, val) \
62 bus_space_write_4((sc)->sc_bst, (sc)->sc_bsh, (reg), (val))
63
64 static void *
meson_resets_acquire(device_t dev,const void * data,size_t len)65 meson_resets_acquire(device_t dev, const void *data, size_t len)
66 {
67 if (len != 4)
68 return NULL;
69
70 /* Specifier is an index. Just return it. */
71 return (void *)(uintptr_t)be32dec(data);
72 }
73
74 static void
meson_resets_release(device_t dev,void * priv)75 meson_resets_release(device_t dev, void *priv)
76 {
77 }
78
79 static int
meson_resets_assert(device_t dev,void * priv)80 meson_resets_assert(device_t dev, void *priv)
81 {
82 struct meson_resets_softc * const sc = device_private(dev);
83 const uintptr_t index = (uintptr_t)priv;
84
85 const bus_size_t reset_reg = RESET_REG(index) + LEVEL_OFFSET;
86 const uint32_t reset_mask = RESET_MASK(index);
87
88 const uint32_t val = RESET_READ(sc, reset_reg);
89 RESET_WRITE(sc, reset_reg, val & ~reset_mask);
90
91 return 0;
92 }
93
94 static int
meson_resets_deassert(device_t dev,void * priv)95 meson_resets_deassert(device_t dev, void *priv)
96 {
97 struct meson_resets_softc * const sc = device_private(dev);
98 const uintptr_t index = (uintptr_t)priv;
99
100 const bus_size_t reset_reg = RESET_REG(index) + LEVEL_OFFSET;
101 const uint32_t reset_mask = RESET_MASK(index);
102
103 const uint32_t val = RESET_READ(sc, reset_reg);
104 RESET_WRITE(sc, reset_reg, val | reset_mask);
105
106 return 0;
107 }
108
109 static const struct fdtbus_reset_controller_func meson_fdtreset_funcs = {
110 .acquire = meson_resets_acquire,
111 .release = meson_resets_release,
112 .reset_assert = meson_resets_assert,
113 .reset_deassert = meson_resets_deassert,
114 };
115
116 static int
meson_resets_match(device_t parent,cfdata_t cf,void * aux)117 meson_resets_match(device_t parent, cfdata_t cf, void *aux)
118 {
119 struct fdt_attach_args * const faa = aux;
120
121 return of_compatible_match(faa->faa_phandle, compat_data);
122 }
123
124 static void
meson_resets_attach(device_t parent,device_t self,void * aux)125 meson_resets_attach(device_t parent, device_t self, void *aux)
126 {
127 struct meson_resets_softc * const sc = device_private(self);
128 struct fdt_attach_args * const faa = aux;
129 const int phandle = faa->faa_phandle;
130 bus_addr_t addr;
131 bus_size_t size;
132
133 if (fdtbus_get_reg(phandle, 0, &addr, &size) != 0) {
134 aprint_error(": couldn't get registers\n");
135 return;
136 }
137
138 sc->sc_dev = self;
139 sc->sc_bst = faa->faa_bst;
140 if (bus_space_map(sc->sc_bst, addr, size, 0, &sc->sc_bsh) != 0) {
141 aprint_error(": couldn't map registers\n");
142 return;
143 }
144
145 aprint_naive("\n");
146 aprint_normal("\n");
147
148 fdtbus_register_reset_controller(sc->sc_dev, phandle,
149 &meson_fdtreset_funcs);
150 }
151
152 CFATTACH_DECL_NEW(meson_resets, sizeof(struct meson_resets_softc),
153 meson_resets_match, meson_resets_attach, NULL, NULL);
154