1 /* $NetBSD: fdt_powerdomain.c,v 1.1 2022/03/04 08:19:06 skrll Exp $ */
2
3 /*-
4 * Copyright (c) 2022 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Nick Hudson
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 #include <sys/cdefs.h>
33 __KERNEL_RCSID(0, "$NetBSD: fdt_powerdomain.c,v 1.1 2022/03/04 08:19:06 skrll Exp $");
34
35 #include <sys/param.h>
36
37 #include <sys/bus.h>
38 #include <sys/kmem.h>
39 #include <sys/queue.h>
40
41 #include <libfdt.h>
42 #include <dev/fdt/fdtvar.h>
43
44
45 struct fdtbus_powerdomain_controller {
46 device_t pdc_dev;
47 int pdc_phandle;
48
49 void *pdc_cookie;
50
51 int pdc_cells;
52
53 const struct fdtbus_powerdomain_controller_func *pdc_funcs;
54
55 LIST_ENTRY(fdtbus_powerdomain_controller) pdc_next;
56 };
57
58 static LIST_HEAD(, fdtbus_powerdomain_controller) fdtbus_powerdomain_controllers =
59 LIST_HEAD_INITIALIZER(fdtbus_powerdomain_controllers);
60
61 int
fdtbus_register_powerdomain_controller(device_t dev,int phandle,const struct fdtbus_powerdomain_controller_func * funcs)62 fdtbus_register_powerdomain_controller(device_t dev, int phandle,
63 const struct fdtbus_powerdomain_controller_func *funcs)
64 {
65 struct fdtbus_powerdomain_controller *pdc;
66
67 uint32_t cells;
68 if (of_getprop_uint32(phandle, "#power-domain-cells", &cells) != 0) {
69 aprint_debug_dev(dev, "missing #power-domain-cells");
70 return EINVAL;
71 }
72
73 pdc = kmem_alloc(sizeof(*pdc), KM_SLEEP);
74 pdc->pdc_dev = dev;
75 pdc->pdc_phandle = phandle;
76 pdc->pdc_funcs = funcs;
77 pdc->pdc_cells = cells;
78
79 LIST_INSERT_HEAD(&fdtbus_powerdomain_controllers, pdc, pdc_next);
80
81 return 0;
82 }
83
84 static struct fdtbus_powerdomain_controller *
fdtbus_powerdomain_lookup(int phandle)85 fdtbus_powerdomain_lookup(int phandle)
86 {
87 struct fdtbus_powerdomain_controller *pdc;
88
89 LIST_FOREACH(pdc, &fdtbus_powerdomain_controllers, pdc_next) {
90 if (pdc->pdc_phandle == phandle)
91 return pdc;
92 }
93
94 return NULL;
95 }
96
97 static int
fdtbus_powerdomain_enable_internal(int phandle,int index,bool enable)98 fdtbus_powerdomain_enable_internal(int phandle, int index, bool enable)
99 {
100 int len;
101 const uint32_t *pds = fdtbus_get_prop(phandle, "power-domains", &len);
102
103 if (pds == NULL)
104 return EINVAL;
105
106 for (const uint32_t *pd = pds; pd < pds + len; index--) {
107 uint32_t pd_node =
108 fdtbus_get_phandle_from_native(be32toh(pd[0]));
109 struct fdtbus_powerdomain_controller *pdc =
110 fdtbus_powerdomain_lookup(pd_node);
111
112 if (pdc == NULL)
113 return ENXIO;
114
115 if (index < 0 || index == 0)
116 pdc->pdc_funcs->pdc_enable(pdc->pdc_dev, pd, enable);
117 if (index == 0)
118 break;
119
120 pd += pdc->pdc_cells + 1;
121 }
122
123 return 0;
124 }
125
126 int
fdtbus_powerdomain_enable_index(int phandle,int index)127 fdtbus_powerdomain_enable_index(int phandle, int index)
128 {
129 return fdtbus_powerdomain_enable_internal(phandle, index, true);
130 }
131
132 int
fdtbus_powerdomain_disable_index(int phandle,int index)133 fdtbus_powerdomain_disable_index(int phandle, int index)
134 {
135 return fdtbus_powerdomain_enable_internal(phandle, index, false);
136 }
137
138 int
fdtbus_powerdomain_enable(int node)139 fdtbus_powerdomain_enable(int node)
140 {
141 return fdtbus_powerdomain_enable_index(node, -1);
142 }
143
144 int
fdtbus_powerdomain_disable(int node)145 fdtbus_powerdomain_disable(int node)
146 {
147 return fdtbus_powerdomain_disable_index(node, -1);
148 }
149