xref: /openbmc/qemu/hw/core/or-irq.c (revision 37677d7d)
1 /*
2  * QEMU IRQ/GPIO common code.
3  *
4  * Copyright (c) 2016 Alistair Francis <alistair@alistair23.me>.
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a copy
7  * of this software and associated documentation files (the "Software"), to deal
8  * in the Software without restriction, including without limitation the rights
9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10  * copies of the Software, and to permit persons to whom the Software is
11  * furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in
14  * all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22  * THE SOFTWARE.
23  */
24 
25 #include "qemu/osdep.h"
26 #include "hw/or-irq.h"
27 #include "qemu/module.h"
28 
29 static void or_irq_handler(void *opaque, int n, int level)
30 {
31     qemu_or_irq *s = OR_IRQ(opaque);
32     int or_level = 0;
33     int i;
34 
35     s->levels[n] = level;
36 
37     for (i = 0; i < s->num_lines; i++) {
38         or_level |= s->levels[i];
39     }
40 
41     qemu_set_irq(s->out_irq, or_level);
42 }
43 
44 static void or_irq_reset(DeviceState *dev)
45 {
46     qemu_or_irq *s = OR_IRQ(dev);
47     int i;
48 
49     for (i = 0; i < MAX_OR_LINES; i++) {
50         s->levels[i] = false;
51     }
52 }
53 
54 static void or_irq_realize(DeviceState *dev, Error **errp)
55 {
56     qemu_or_irq *s = OR_IRQ(dev);
57 
58     assert(s->num_lines < MAX_OR_LINES);
59 
60     qdev_init_gpio_in(dev, or_irq_handler, s->num_lines);
61 }
62 
63 static void or_irq_init(Object *obj)
64 {
65     qemu_or_irq *s = OR_IRQ(obj);
66 
67     qdev_init_gpio_out(DEVICE(obj), &s->out_irq, 1);
68 }
69 
70 /* The original version of this device had a fixed 16 entries in its
71  * VMState array; devices with more inputs than this need to
72  * migrate the extra lines via a subsection.
73  * The subsection migrates as much of the levels[] array as is needed
74  * (including repeating the first 16 elements), to avoid the awkwardness
75  * of splitting it in two to meet the requirements of VMSTATE_VARRAY_UINT16.
76  */
77 #define OLD_MAX_OR_LINES 16
78 #if MAX_OR_LINES < OLD_MAX_OR_LINES
79 #error MAX_OR_LINES must be at least 16 for migration compatibility
80 #endif
81 
82 static bool vmstate_extras_needed(void *opaque)
83 {
84     qemu_or_irq *s = OR_IRQ(opaque);
85 
86     return s->num_lines >= OLD_MAX_OR_LINES;
87 }
88 
89 static const VMStateDescription vmstate_or_irq_extras = {
90     .name = "or-irq-extras",
91     .version_id = 1,
92     .minimum_version_id = 1,
93     .needed = vmstate_extras_needed,
94     .fields = (VMStateField[]) {
95         VMSTATE_VARRAY_UINT16_UNSAFE(levels, qemu_or_irq, num_lines, 0,
96                                      vmstate_info_bool, bool),
97         VMSTATE_END_OF_LIST(),
98     },
99 };
100 
101 static const VMStateDescription vmstate_or_irq = {
102     .name = TYPE_OR_IRQ,
103     .version_id = 1,
104     .minimum_version_id = 1,
105     .fields = (VMStateField[]) {
106         VMSTATE_BOOL_SUB_ARRAY(levels, qemu_or_irq, 0, OLD_MAX_OR_LINES),
107         VMSTATE_END_OF_LIST(),
108     },
109     .subsections = (const VMStateDescription*[]) {
110         &vmstate_or_irq_extras,
111         NULL
112     },
113 };
114 
115 static Property or_irq_properties[] = {
116     DEFINE_PROP_UINT16("num-lines", qemu_or_irq, num_lines, 1),
117     DEFINE_PROP_END_OF_LIST(),
118 };
119 
120 static void or_irq_class_init(ObjectClass *klass, void *data)
121 {
122     DeviceClass *dc = DEVICE_CLASS(klass);
123 
124     dc->reset = or_irq_reset;
125     dc->props = or_irq_properties;
126     dc->realize = or_irq_realize;
127     dc->vmsd = &vmstate_or_irq;
128 
129     /* Reason: Needs to be wired up to work, e.g. see stm32f205_soc.c */
130     dc->user_creatable = false;
131 }
132 
133 static const TypeInfo or_irq_type_info = {
134    .name = TYPE_OR_IRQ,
135    .parent = TYPE_DEVICE,
136    .instance_size = sizeof(qemu_or_irq),
137    .instance_init = or_irq_init,
138    .class_init = or_irq_class_init,
139 };
140 
141 static void or_irq_register_types(void)
142 {
143     type_register_static(&or_irq_type_info);
144 }
145 
146 type_init(or_irq_register_types)
147