xref: /openbmc/qemu/hw/intc/heathrow_pic.c (revision 735e354a)
1 /*
2  * Heathrow PIC support (OldWorld PowerMac)
3  *
4  * Copyright (c) 2005-2007 Fabrice Bellard
5  * Copyright (c) 2007 Jocelyn Mayer
6  *
7  * Permission is hereby granted, free of charge, to any person obtaining a copy
8  * of this software and associated documentation files (the "Software"), to deal
9  * in the Software without restriction, including without limitation the rights
10  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11  * copies of the Software, and to permit persons to whom the Software is
12  * furnished to do so, subject to the following conditions:
13  *
14  * The above copyright notice and this permission notice shall be included in
15  * all copies or substantial portions of the Software.
16  *
17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
23  * THE SOFTWARE.
24  */
25 
26 #include "qemu/osdep.h"
27 #include "migration/vmstate.h"
28 #include "qemu/module.h"
29 #include "hw/intc/heathrow_pic.h"
30 #include "hw/irq.h"
31 #include "trace.h"
32 
33 static inline int heathrow_check_irq(HeathrowPICState *pic)
34 {
35     return (pic->events | (pic->levels & pic->level_triggered)) & pic->mask;
36 }
37 
38 /* update the CPU irq state */
39 static void heathrow_update_irq(HeathrowState *s)
40 {
41     if (heathrow_check_irq(&s->pics[0]) ||
42             heathrow_check_irq(&s->pics[1])) {
43         qemu_irq_raise(s->irqs[0]);
44     } else {
45         qemu_irq_lower(s->irqs[0]);
46     }
47 }
48 
49 static void heathrow_write(void *opaque, hwaddr addr,
50                            uint64_t value, unsigned size)
51 {
52     HeathrowState *s = opaque;
53     HeathrowPICState *pic;
54     unsigned int n;
55 
56     n = ((addr & 0xfff) - 0x10) >> 4;
57     trace_heathrow_write(addr, n, value);
58     if (n >= 2)
59         return;
60     pic = &s->pics[n];
61     switch(addr & 0xf) {
62     case 0x04:
63         pic->mask = value;
64         heathrow_update_irq(s);
65         break;
66     case 0x08:
67         /* do not reset level triggered IRQs */
68         value &= ~pic->level_triggered;
69         pic->events &= ~value;
70         heathrow_update_irq(s);
71         break;
72     default:
73         break;
74     }
75 }
76 
77 static uint64_t heathrow_read(void *opaque, hwaddr addr,
78                               unsigned size)
79 {
80     HeathrowState *s = opaque;
81     HeathrowPICState *pic;
82     unsigned int n;
83     uint32_t value;
84 
85     n = ((addr & 0xfff) - 0x10) >> 4;
86     if (n >= 2) {
87         value = 0;
88     } else {
89         pic = &s->pics[n];
90         switch(addr & 0xf) {
91         case 0x0:
92             value = pic->events;
93             break;
94         case 0x4:
95             value = pic->mask;
96             break;
97         case 0xc:
98             value = pic->levels;
99             break;
100         default:
101             value = 0;
102             break;
103         }
104     }
105     trace_heathrow_read(addr, n, value);
106     return value;
107 }
108 
109 static const MemoryRegionOps heathrow_ops = {
110     .read = heathrow_read,
111     .write = heathrow_write,
112     .endianness = DEVICE_LITTLE_ENDIAN,
113 };
114 
115 static void heathrow_set_irq(void *opaque, int num, int level)
116 {
117     HeathrowState *s = opaque;
118     HeathrowPICState *pic;
119     unsigned int irq_bit;
120     int last_level;
121 
122     pic = &s->pics[1 - (num >> 5)];
123     irq_bit = 1 << (num & 0x1f);
124     last_level = (pic->levels & irq_bit) ? 1 : 0;
125 
126     if (level) {
127         pic->events |= irq_bit & ~pic->level_triggered;
128         pic->levels |= irq_bit;
129     } else {
130         pic->levels &= ~irq_bit;
131     }
132 
133     if (last_level != level) {
134         trace_heathrow_set_irq(num, level);
135     }
136 
137     heathrow_update_irq(s);
138 }
139 
140 static const VMStateDescription vmstate_heathrow_pic_one = {
141     .name = "heathrow_pic_one",
142     .version_id = 0,
143     .minimum_version_id = 0,
144     .fields = (const VMStateField[]) {
145         VMSTATE_UINT32(events, HeathrowPICState),
146         VMSTATE_UINT32(mask, HeathrowPICState),
147         VMSTATE_UINT32(levels, HeathrowPICState),
148         VMSTATE_UINT32(level_triggered, HeathrowPICState),
149         VMSTATE_END_OF_LIST()
150     }
151 };
152 
153 static const VMStateDescription vmstate_heathrow = {
154     .name = "heathrow_pic",
155     .version_id = 1,
156     .minimum_version_id = 1,
157     .fields = (const VMStateField[]) {
158         VMSTATE_STRUCT_ARRAY(pics, HeathrowState, 2, 1,
159                              vmstate_heathrow_pic_one, HeathrowPICState),
160         VMSTATE_END_OF_LIST()
161     }
162 };
163 
164 static void heathrow_reset(DeviceState *d)
165 {
166     HeathrowState *s = HEATHROW(d);
167 
168     s->pics[0].level_triggered = 0;
169     s->pics[1].level_triggered = 0x1ff00000;
170 }
171 
172 static void heathrow_init(Object *obj)
173 {
174     HeathrowState *s = HEATHROW(obj);
175     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
176 
177     /* only 1 CPU */
178     qdev_init_gpio_out(DEVICE(obj), s->irqs, 1);
179 
180     qdev_init_gpio_in(DEVICE(obj), heathrow_set_irq, HEATHROW_NUM_IRQS);
181 
182     memory_region_init_io(&s->mem, OBJECT(s), &heathrow_ops, s,
183                           "heathrow-pic", 0x1000);
184     sysbus_init_mmio(sbd, &s->mem);
185 }
186 
187 static void heathrow_class_init(ObjectClass *oc, void *data)
188 {
189     DeviceClass *dc = DEVICE_CLASS(oc);
190 
191     dc->reset = heathrow_reset;
192     dc->vmsd = &vmstate_heathrow;
193     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
194 }
195 
196 static const TypeInfo heathrow_type_info = {
197     .name = TYPE_HEATHROW,
198     .parent = TYPE_SYS_BUS_DEVICE,
199     .instance_size = sizeof(HeathrowState),
200     .instance_init = heathrow_init,
201     .class_init = heathrow_class_init,
202 };
203 
204 static void heathrow_register_types(void)
205 {
206     type_register_static(&heathrow_type_info);
207 }
208 
209 type_init(heathrow_register_types)
210