1 /* $NetBSD: fdt_reset.c,v 1.4 2019/02/27 16:56:00 jakllsch Exp $ */
2
3 /*-
4 * Copyright (c) 2015 Jared D. 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: fdt_reset.c,v 1.4 2019/02/27 16:56:00 jakllsch Exp $");
31
32 #include <sys/param.h>
33 #include <sys/bus.h>
34 #include <sys/kmem.h>
35 #include <sys/queue.h>
36
37 #include <libfdt.h>
38 #include <dev/fdt/fdtvar.h>
39
40 struct fdtbus_reset_controller {
41 device_t rc_dev;
42 int rc_phandle;
43 const struct fdtbus_reset_controller_func *rc_funcs;
44
45 LIST_ENTRY(fdtbus_reset_controller) rc_next;
46 };
47
48 static LIST_HEAD(, fdtbus_reset_controller) fdtbus_reset_controllers =
49 LIST_HEAD_INITIALIZER(fdtbus_reset_controllers);
50
51 int
fdtbus_register_reset_controller(device_t dev,int phandle,const struct fdtbus_reset_controller_func * funcs)52 fdtbus_register_reset_controller(device_t dev, int phandle,
53 const struct fdtbus_reset_controller_func *funcs)
54 {
55 struct fdtbus_reset_controller *rc;
56
57 rc = kmem_alloc(sizeof(*rc), KM_SLEEP);
58 rc->rc_dev = dev;
59 rc->rc_phandle = phandle;
60 rc->rc_funcs = funcs;
61
62 LIST_INSERT_HEAD(&fdtbus_reset_controllers, rc, rc_next);
63
64 return 0;
65 }
66
67 static struct fdtbus_reset_controller *
fdtbus_get_reset_controller(int phandle)68 fdtbus_get_reset_controller(int phandle)
69 {
70 struct fdtbus_reset_controller *rc;
71
72 LIST_FOREACH(rc, &fdtbus_reset_controllers, rc_next) {
73 if (rc->rc_phandle == phandle)
74 return rc;
75 }
76
77 return NULL;
78 }
79
80 struct fdtbus_reset *
fdtbus_reset_get_index(int phandle,u_int index)81 fdtbus_reset_get_index(int phandle, u_int index)
82 {
83 struct fdtbus_reset_controller *rc;
84 struct fdtbus_reset *rst = NULL;
85 void *rst_priv = NULL;
86 uint32_t *resets = NULL;
87 uint32_t *p;
88 u_int n, reset_cells;
89 int len, resid;
90
91 len = OF_getproplen(phandle, "resets");
92 if (len <= 0)
93 return NULL;
94
95 resets = kmem_alloc(len, KM_SLEEP);
96 if (OF_getprop(phandle, "resets", resets, len) != len) {
97 kmem_free(resets, len);
98 return NULL;
99 }
100
101 p = resets;
102 for (n = 0, resid = len; resid > 0; n++) {
103 const int rc_phandle =
104 fdtbus_get_phandle_from_native(be32toh(p[0]));
105 if (of_getprop_uint32(rc_phandle, "#reset-cells", &reset_cells))
106 break;
107 if (n == index) {
108 rc = fdtbus_get_reset_controller(rc_phandle);
109 if (rc == NULL)
110 goto done;
111 rst_priv = rc->rc_funcs->acquire(rc->rc_dev,
112 reset_cells > 0 ? &p[1] : NULL, reset_cells * 4);
113 if (rst_priv) {
114 rst = kmem_alloc(sizeof(*rst), KM_SLEEP);
115 rst->rst_rc = rc;
116 rst->rst_priv = rst_priv;
117 }
118 break;
119 }
120 resid -= (reset_cells + 1) * 4;
121 p += reset_cells + 1;
122 }
123
124 done:
125 if (resets)
126 kmem_free(resets, len);
127
128 return rst;
129 }
130
131 struct fdtbus_reset *
fdtbus_reset_get(int phandle,const char * rstname)132 fdtbus_reset_get(int phandle, const char *rstname)
133 {
134 u_int index;
135 int err;
136
137 err = fdtbus_get_index(phandle, "reset-names", rstname, &index);
138 if (err != 0)
139 return NULL;
140
141 return fdtbus_reset_get_index(phandle, index);
142 }
143
144 void
fdtbus_reset_put(struct fdtbus_reset * rst)145 fdtbus_reset_put(struct fdtbus_reset *rst)
146 {
147 struct fdtbus_reset_controller *rc = rst->rst_rc;
148
149 rc->rc_funcs->release(rc->rc_dev, rst->rst_priv);
150 kmem_free(rst, sizeof(*rst));
151 }
152
153 int
fdtbus_reset_assert(struct fdtbus_reset * rst)154 fdtbus_reset_assert(struct fdtbus_reset *rst)
155 {
156 struct fdtbus_reset_controller *rc = rst->rst_rc;
157
158 return rc->rc_funcs->reset_assert(rc->rc_dev, rst->rst_priv);
159 }
160
161 int
fdtbus_reset_deassert(struct fdtbus_reset * rst)162 fdtbus_reset_deassert(struct fdtbus_reset *rst)
163 {
164 struct fdtbus_reset_controller *rc = rst->rst_rc;
165
166 return rc->rc_funcs->reset_deassert(rc->rc_dev, rst->rst_priv);
167 }
168