xref: /openbmc/qemu/hw/intc/heathrow_pic.c (revision 3aff6c2f)
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 #include "hw/hw.h"
26 #include "hw/ppc/mac.h"
27 
28 /* debug PIC */
29 //#define DEBUG_PIC
30 
31 #ifdef DEBUG_PIC
32 #define PIC_DPRINTF(fmt, ...)                                   \
33     do { printf("PIC: " fmt , ## __VA_ARGS__); } while (0)
34 #else
35 #define PIC_DPRINTF(fmt, ...)
36 #endif
37 
38 typedef struct HeathrowPIC {
39     uint32_t events;
40     uint32_t mask;
41     uint32_t levels;
42     uint32_t level_triggered;
43 } HeathrowPIC;
44 
45 typedef struct HeathrowPICS {
46     MemoryRegion mem;
47     HeathrowPIC pics[2];
48     qemu_irq *irqs;
49 } HeathrowPICS;
50 
51 static inline int check_irq(HeathrowPIC *pic)
52 {
53     return (pic->events | (pic->levels & pic->level_triggered)) & pic->mask;
54 }
55 
56 /* update the CPU irq state */
57 static void heathrow_pic_update(HeathrowPICS *s)
58 {
59     if (check_irq(&s->pics[0]) || check_irq(&s->pics[1])) {
60         qemu_irq_raise(s->irqs[0]);
61     } else {
62         qemu_irq_lower(s->irqs[0]);
63     }
64 }
65 
66 static void pic_write(void *opaque, hwaddr addr,
67                       uint64_t value, unsigned size)
68 {
69     HeathrowPICS *s = opaque;
70     HeathrowPIC *pic;
71     unsigned int n;
72 
73     n = ((addr & 0xfff) - 0x10) >> 4;
74     PIC_DPRINTF("writel: " TARGET_FMT_plx " %u: %08x\n", addr, n, value);
75     if (n >= 2)
76         return;
77     pic = &s->pics[n];
78     switch(addr & 0xf) {
79     case 0x04:
80         pic->mask = value;
81         heathrow_pic_update(s);
82         break;
83     case 0x08:
84         /* do not reset level triggered IRQs */
85         value &= ~pic->level_triggered;
86         pic->events &= ~value;
87         heathrow_pic_update(s);
88         break;
89     default:
90         break;
91     }
92 }
93 
94 static uint64_t pic_read(void *opaque, hwaddr addr,
95                          unsigned size)
96 {
97     HeathrowPICS *s = opaque;
98     HeathrowPIC *pic;
99     unsigned int n;
100     uint32_t value;
101 
102     n = ((addr & 0xfff) - 0x10) >> 4;
103     if (n >= 2) {
104         value = 0;
105     } else {
106         pic = &s->pics[n];
107         switch(addr & 0xf) {
108         case 0x0:
109             value = pic->events;
110             break;
111         case 0x4:
112             value = pic->mask;
113             break;
114         case 0xc:
115             value = pic->levels;
116             break;
117         default:
118             value = 0;
119             break;
120         }
121     }
122     PIC_DPRINTF("readl: " TARGET_FMT_plx " %u: %08x\n", addr, n, value);
123     return value;
124 }
125 
126 static const MemoryRegionOps heathrow_pic_ops = {
127     .read = pic_read,
128     .write = pic_write,
129     .endianness = DEVICE_LITTLE_ENDIAN,
130 };
131 
132 static void heathrow_pic_set_irq(void *opaque, int num, int level)
133 {
134     HeathrowPICS *s = opaque;
135     HeathrowPIC *pic;
136     unsigned int irq_bit;
137 
138 #if defined(DEBUG)
139     {
140         static int last_level[64];
141         if (last_level[num] != level) {
142             PIC_DPRINTF("set_irq: num=0x%02x level=%d\n", num, level);
143             last_level[num] = level;
144         }
145     }
146 #endif
147     pic = &s->pics[1 - (num >> 5)];
148     irq_bit = 1 << (num & 0x1f);
149     if (level) {
150         pic->events |= irq_bit & ~pic->level_triggered;
151         pic->levels |= irq_bit;
152     } else {
153         pic->levels &= ~irq_bit;
154     }
155     heathrow_pic_update(s);
156 }
157 
158 static const VMStateDescription vmstate_heathrow_pic_one = {
159     .name = "heathrow_pic_one",
160     .version_id = 0,
161     .minimum_version_id = 0,
162     .fields = (VMStateField[]) {
163         VMSTATE_UINT32(events, HeathrowPIC),
164         VMSTATE_UINT32(mask, HeathrowPIC),
165         VMSTATE_UINT32(levels, HeathrowPIC),
166         VMSTATE_UINT32(level_triggered, HeathrowPIC),
167         VMSTATE_END_OF_LIST()
168     }
169 };
170 
171 static const VMStateDescription vmstate_heathrow_pic = {
172     .name = "heathrow_pic",
173     .version_id = 1,
174     .minimum_version_id = 1,
175     .fields = (VMStateField[]) {
176         VMSTATE_STRUCT_ARRAY(pics, HeathrowPICS, 2, 1,
177                              vmstate_heathrow_pic_one, HeathrowPIC),
178         VMSTATE_END_OF_LIST()
179     }
180 };
181 
182 static void heathrow_pic_reset_one(HeathrowPIC *s)
183 {
184     memset(s, '\0', sizeof(HeathrowPIC));
185 }
186 
187 static void heathrow_pic_reset(void *opaque)
188 {
189     HeathrowPICS *s = opaque;
190 
191     heathrow_pic_reset_one(&s->pics[0]);
192     heathrow_pic_reset_one(&s->pics[1]);
193 
194     s->pics[0].level_triggered = 0;
195     s->pics[1].level_triggered = 0x1ff00000;
196 }
197 
198 qemu_irq *heathrow_pic_init(MemoryRegion **pmem,
199                             int nb_cpus, qemu_irq **irqs)
200 {
201     HeathrowPICS *s;
202 
203     s = g_malloc0(sizeof(HeathrowPICS));
204     /* only 1 CPU */
205     s->irqs = irqs[0];
206     memory_region_init_io(&s->mem, NULL, &heathrow_pic_ops, s,
207                           "heathrow-pic", 0x1000);
208     *pmem = &s->mem;
209 
210     vmstate_register(NULL, -1, &vmstate_heathrow_pic, s);
211     qemu_register_reset(heathrow_pic_reset, s);
212     return qemu_allocate_irqs(heathrow_pic_set_irq, s, 64);
213 }
214