xref: /openbmc/qemu/hw/core/or-irq.c (revision efb91426)
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/irq.h"
27 #include "hw/or-irq.h"
28 #include "hw/qdev-properties.h"
29 #include "migration/vmstate.h"
30 #include "qemu/module.h"
31 
32 static void or_irq_handler(void *opaque, int n, int level)
33 {
34     OrIRQState *s = OR_IRQ(opaque);
35     int or_level = 0;
36     int i;
37 
38     s->levels[n] = level;
39 
40     for (i = 0; i < s->num_lines; i++) {
41         or_level |= s->levels[i];
42     }
43 
44     qemu_set_irq(s->out_irq, or_level);
45 }
46 
47 static void or_irq_reset(DeviceState *dev)
48 {
49     OrIRQState *s = OR_IRQ(dev);
50     int i;
51 
52     for (i = 0; i < MAX_OR_LINES; i++) {
53         s->levels[i] = false;
54     }
55 }
56 
57 static void or_irq_realize(DeviceState *dev, Error **errp)
58 {
59     OrIRQState *s = OR_IRQ(dev);
60 
61     assert(s->num_lines <= MAX_OR_LINES);
62 
63     qdev_init_gpio_in(dev, or_irq_handler, s->num_lines);
64 }
65 
66 static void or_irq_init(Object *obj)
67 {
68     OrIRQState *s = OR_IRQ(obj);
69 
70     qdev_init_gpio_out(DEVICE(obj), &s->out_irq, 1);
71 }
72 
73 /* The original version of this device had a fixed 16 entries in its
74  * VMState array; devices with more inputs than this need to
75  * migrate the extra lines via a subsection.
76  * The subsection migrates as much of the levels[] array as is needed
77  * (including repeating the first 16 elements), to avoid the awkwardness
78  * of splitting it in two to meet the requirements of VMSTATE_VARRAY_UINT16.
79  */
80 #define OLD_MAX_OR_LINES 16
81 #if MAX_OR_LINES < OLD_MAX_OR_LINES
82 #error MAX_OR_LINES must be at least 16 for migration compatibility
83 #endif
84 
85 static bool vmstate_extras_needed(void *opaque)
86 {
87     OrIRQState *s = OR_IRQ(opaque);
88 
89     return s->num_lines >= OLD_MAX_OR_LINES;
90 }
91 
92 static const VMStateDescription vmstate_or_irq_extras = {
93     .name = "or-irq-extras",
94     .version_id = 1,
95     .minimum_version_id = 1,
96     .needed = vmstate_extras_needed,
97     .fields = (const VMStateField[]) {
98         VMSTATE_VARRAY_UINT16_UNSAFE(levels, OrIRQState, num_lines, 0,
99                                      vmstate_info_bool, bool),
100         VMSTATE_END_OF_LIST(),
101     },
102 };
103 
104 static const VMStateDescription vmstate_or_irq = {
105     .name = TYPE_OR_IRQ,
106     .version_id = 1,
107     .minimum_version_id = 1,
108     .fields = (const VMStateField[]) {
109         VMSTATE_BOOL_SUB_ARRAY(levels, OrIRQState, 0, OLD_MAX_OR_LINES),
110         VMSTATE_END_OF_LIST(),
111     },
112     .subsections = (const VMStateDescription * const []) {
113         &vmstate_or_irq_extras,
114         NULL
115     },
116 };
117 
118 static Property or_irq_properties[] = {
119     DEFINE_PROP_UINT16("num-lines", OrIRQState, num_lines, 1),
120     DEFINE_PROP_END_OF_LIST(),
121 };
122 
123 static void or_irq_class_init(ObjectClass *klass, void *data)
124 {
125     DeviceClass *dc = DEVICE_CLASS(klass);
126 
127     dc->reset = or_irq_reset;
128     device_class_set_props(dc, or_irq_properties);
129     dc->realize = or_irq_realize;
130     dc->vmsd = &vmstate_or_irq;
131 
132     /* Reason: Needs to be wired up to work, e.g. see stm32f205_soc.c */
133     dc->user_creatable = false;
134 }
135 
136 static const TypeInfo or_irq_type_info = {
137    .name = TYPE_OR_IRQ,
138    .parent = TYPE_DEVICE,
139    .instance_size = sizeof(OrIRQState),
140    .instance_init = or_irq_init,
141    .class_init = or_irq_class_init,
142 };
143 
144 static void or_irq_register_types(void)
145 {
146     type_register_static(&or_irq_type_info);
147 }
148 
149 type_init(or_irq_register_types)
150