xref: /qemu/hw/m68k/mcf_intc.c (revision a8260d38)
1 /*
2  * ColdFire Interrupt Controller emulation.
3  *
4  * Copyright (c) 2007 CodeSourcery.
5  *
6  * This code is licensed under the GPL
7  */
8 #include "qemu/osdep.h"
9 #include "qemu-common.h"
10 #include "cpu.h"
11 #include "hw/hw.h"
12 #include "hw/sysbus.h"
13 #include "hw/m68k/mcf.h"
14 
15 #define TYPE_MCF_INTC "mcf-intc"
16 #define MCF_INTC(obj) OBJECT_CHECK(mcf_intc_state, (obj), TYPE_MCF_INTC)
17 
18 typedef struct {
19     SysBusDevice parent_obj;
20 
21     MemoryRegion iomem;
22     uint64_t ipr;
23     uint64_t imr;
24     uint64_t ifr;
25     uint64_t enabled;
26     uint8_t icr[64];
27     M68kCPU *cpu;
28     int active_vector;
29 } mcf_intc_state;
30 
31 static void mcf_intc_update(mcf_intc_state *s)
32 {
33     uint64_t active;
34     int i;
35     int best;
36     int best_level;
37 
38     active = (s->ipr | s->ifr) & s->enabled & ~s->imr;
39     best_level = 0;
40     best = 64;
41     if (active) {
42         for (i = 0; i < 64; i++) {
43             if ((active & 1) != 0 && s->icr[i] >= best_level) {
44                 best_level = s->icr[i];
45                 best = i;
46             }
47             active >>= 1;
48         }
49     }
50     s->active_vector = ((best == 64) ? 24 : (best + 64));
51     m68k_set_irq_level(s->cpu, best_level, s->active_vector);
52 }
53 
54 static uint64_t mcf_intc_read(void *opaque, hwaddr addr,
55                               unsigned size)
56 {
57     int offset;
58     mcf_intc_state *s = (mcf_intc_state *)opaque;
59     offset = addr & 0xff;
60     if (offset >= 0x40 && offset < 0x80) {
61         return s->icr[offset - 0x40];
62     }
63     switch (offset) {
64     case 0x00:
65         return (uint32_t)(s->ipr >> 32);
66     case 0x04:
67         return (uint32_t)s->ipr;
68     case 0x08:
69         return (uint32_t)(s->imr >> 32);
70     case 0x0c:
71         return (uint32_t)s->imr;
72     case 0x10:
73         return (uint32_t)(s->ifr >> 32);
74     case 0x14:
75         return (uint32_t)s->ifr;
76     case 0xe0: /* SWIACK.  */
77         return s->active_vector;
78     case 0xe1: case 0xe2: case 0xe3: case 0xe4:
79     case 0xe5: case 0xe6: case 0xe7:
80         /* LnIACK */
81         hw_error("mcf_intc_read: LnIACK not implemented\n");
82     default:
83         return 0;
84     }
85 }
86 
87 static void mcf_intc_write(void *opaque, hwaddr addr,
88                            uint64_t val, unsigned size)
89 {
90     int offset;
91     mcf_intc_state *s = (mcf_intc_state *)opaque;
92     offset = addr & 0xff;
93     if (offset >= 0x40 && offset < 0x80) {
94         int n = offset - 0x40;
95         s->icr[n] = val;
96         if (val == 0)
97             s->enabled &= ~(1ull << n);
98         else
99             s->enabled |= (1ull << n);
100         mcf_intc_update(s);
101         return;
102     }
103     switch (offset) {
104     case 0x00: case 0x04:
105         /* Ignore IPR writes.  */
106         return;
107     case 0x08:
108         s->imr = (s->imr & 0xffffffff) | ((uint64_t)val << 32);
109         break;
110     case 0x0c:
111         s->imr = (s->imr & 0xffffffff00000000ull) | (uint32_t)val;
112         break;
113     case 0x1c:
114         if (val & 0x40) {
115             s->imr = ~0ull;
116         } else {
117             s->imr |= (0x1ull << (val & 0x3f));
118         }
119         break;
120     case 0x1d:
121         if (val & 0x40) {
122             s->imr = 0ull;
123         } else {
124             s->imr &= ~(0x1ull << (val & 0x3f));
125         }
126         break;
127     default:
128         hw_error("mcf_intc_write: Bad write offset %d\n", offset);
129         break;
130     }
131     mcf_intc_update(s);
132 }
133 
134 static void mcf_intc_set_irq(void *opaque, int irq, int level)
135 {
136     mcf_intc_state *s = (mcf_intc_state *)opaque;
137     if (irq >= 64)
138         return;
139     if (level)
140         s->ipr |= 1ull << irq;
141     else
142         s->ipr &= ~(1ull << irq);
143     mcf_intc_update(s);
144 }
145 
146 static void mcf_intc_reset(DeviceState *dev)
147 {
148     mcf_intc_state *s = MCF_INTC(dev);
149 
150     s->imr = ~0ull;
151     s->ipr = 0;
152     s->ifr = 0;
153     s->enabled = 0;
154     memset(s->icr, 0, 64);
155     s->active_vector = 24;
156 }
157 
158 static const MemoryRegionOps mcf_intc_ops = {
159     .read = mcf_intc_read,
160     .write = mcf_intc_write,
161     .endianness = DEVICE_NATIVE_ENDIAN,
162 };
163 
164 static void mcf_intc_instance_init(Object *obj)
165 {
166     mcf_intc_state *s = MCF_INTC(obj);
167 
168     memory_region_init_io(&s->iomem, obj, &mcf_intc_ops, s, "mcf", 0x100);
169 }
170 
171 static void mcf_intc_class_init(ObjectClass *oc, void *data)
172 {
173     DeviceClass *dc = DEVICE_CLASS(oc);
174 
175     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
176     dc->reset = mcf_intc_reset;
177 }
178 
179 static const TypeInfo mcf_intc_gate_info = {
180     .name          = TYPE_MCF_INTC,
181     .parent        = TYPE_SYS_BUS_DEVICE,
182     .instance_size = sizeof(mcf_intc_state),
183     .instance_init = mcf_intc_instance_init,
184     .class_init    = mcf_intc_class_init,
185 };
186 
187 static void mcf_intc_register_types(void)
188 {
189     type_register_static(&mcf_intc_gate_info);
190 }
191 
192 type_init(mcf_intc_register_types)
193 
194 qemu_irq *mcf_intc_init(MemoryRegion *sysmem,
195                         hwaddr base,
196                         M68kCPU *cpu)
197 {
198     DeviceState  *dev;
199     mcf_intc_state *s;
200 
201     dev = qdev_create(NULL, TYPE_MCF_INTC);
202     qdev_init_nofail(dev);
203 
204     s = MCF_INTC(dev);
205     s->cpu = cpu;
206 
207     memory_region_add_subregion(sysmem, base, &s->iomem);
208 
209     return qemu_allocate_irqs(mcf_intc_set_irq, s, 64);
210 }
211