xref: /qemu/hw/m68k/mcf_intc.c (revision db1015e92e04835c9eb50c29625fe566d1202dbd)
1 /*
2  * ColdFire Interrupt Controller emulation.
3  *
4  * Copyright (c) 2007 CodeSourcery.
5  *
6  * This code is licensed under the GPL
7  */
8 
9 #include "qemu/osdep.h"
10 #include "qapi/error.h"
11 #include "qemu/module.h"
12 #include "qemu/log.h"
13 #include "cpu.h"
14 #include "hw/hw.h"
15 #include "hw/irq.h"
16 #include "hw/sysbus.h"
17 #include "hw/m68k/mcf.h"
18 #include "qom/object.h"
19 
20 #define TYPE_MCF_INTC "mcf-intc"
21 typedef struct mcf_intc_state mcf_intc_state;
22 #define MCF_INTC(obj) OBJECT_CHECK(mcf_intc_state, (obj), TYPE_MCF_INTC)
23 
24 struct mcf_intc_state {
25     SysBusDevice parent_obj;
26 
27     MemoryRegion iomem;
28     uint64_t ipr;
29     uint64_t imr;
30     uint64_t ifr;
31     uint64_t enabled;
32     uint8_t icr[64];
33     M68kCPU *cpu;
34     int active_vector;
35 };
36 
37 static void mcf_intc_update(mcf_intc_state *s)
38 {
39     uint64_t active;
40     int i;
41     int best;
42     int best_level;
43 
44     active = (s->ipr | s->ifr) & s->enabled & ~s->imr;
45     best_level = 0;
46     best = 64;
47     if (active) {
48         for (i = 0; i < 64; i++) {
49             if ((active & 1) != 0 && s->icr[i] >= best_level) {
50                 best_level = s->icr[i];
51                 best = i;
52             }
53             active >>= 1;
54         }
55     }
56     s->active_vector = ((best == 64) ? 24 : (best + 64));
57     m68k_set_irq_level(s->cpu, best_level, s->active_vector);
58 }
59 
60 static uint64_t mcf_intc_read(void *opaque, hwaddr addr,
61                               unsigned size)
62 {
63     int offset;
64     mcf_intc_state *s = (mcf_intc_state *)opaque;
65     offset = addr & 0xff;
66     if (offset >= 0x40 && offset < 0x80) {
67         return s->icr[offset - 0x40];
68     }
69     switch (offset) {
70     case 0x00:
71         return (uint32_t)(s->ipr >> 32);
72     case 0x04:
73         return (uint32_t)s->ipr;
74     case 0x08:
75         return (uint32_t)(s->imr >> 32);
76     case 0x0c:
77         return (uint32_t)s->imr;
78     case 0x10:
79         return (uint32_t)(s->ifr >> 32);
80     case 0x14:
81         return (uint32_t)s->ifr;
82     case 0xe0: /* SWIACK.  */
83         return s->active_vector;
84     case 0xe1: case 0xe2: case 0xe3: case 0xe4:
85     case 0xe5: case 0xe6: case 0xe7:
86         /* LnIACK */
87         qemu_log_mask(LOG_UNIMP, "%s: LnIACK not implemented (offset 0x%02x)\n",
88                       __func__, offset);
89         /* fallthru */
90     default:
91         return 0;
92     }
93 }
94 
95 static void mcf_intc_write(void *opaque, hwaddr addr,
96                            uint64_t val, unsigned size)
97 {
98     int offset;
99     mcf_intc_state *s = (mcf_intc_state *)opaque;
100     offset = addr & 0xff;
101     if (offset >= 0x40 && offset < 0x80) {
102         int n = offset - 0x40;
103         s->icr[n] = val;
104         if (val == 0)
105             s->enabled &= ~(1ull << n);
106         else
107             s->enabled |= (1ull << n);
108         mcf_intc_update(s);
109         return;
110     }
111     switch (offset) {
112     case 0x00: case 0x04:
113         /* Ignore IPR writes.  */
114         return;
115     case 0x08:
116         s->imr = (s->imr & 0xffffffff) | ((uint64_t)val << 32);
117         break;
118     case 0x0c:
119         s->imr = (s->imr & 0xffffffff00000000ull) | (uint32_t)val;
120         break;
121     case 0x1c:
122         if (val & 0x40) {
123             s->imr = ~0ull;
124         } else {
125             s->imr |= (0x1ull << (val & 0x3f));
126         }
127         break;
128     case 0x1d:
129         if (val & 0x40) {
130             s->imr = 0ull;
131         } else {
132             s->imr &= ~(0x1ull << (val & 0x3f));
133         }
134         break;
135     default:
136         qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset 0x%02x\n",
137                       __func__, offset);
138         return;
139     }
140     mcf_intc_update(s);
141 }
142 
143 static void mcf_intc_set_irq(void *opaque, int irq, int level)
144 {
145     mcf_intc_state *s = (mcf_intc_state *)opaque;
146     if (irq >= 64)
147         return;
148     if (level)
149         s->ipr |= 1ull << irq;
150     else
151         s->ipr &= ~(1ull << irq);
152     mcf_intc_update(s);
153 }
154 
155 static void mcf_intc_reset(DeviceState *dev)
156 {
157     mcf_intc_state *s = MCF_INTC(dev);
158 
159     s->imr = ~0ull;
160     s->ipr = 0;
161     s->ifr = 0;
162     s->enabled = 0;
163     memset(s->icr, 0, 64);
164     s->active_vector = 24;
165 }
166 
167 static const MemoryRegionOps mcf_intc_ops = {
168     .read = mcf_intc_read,
169     .write = mcf_intc_write,
170     .endianness = DEVICE_NATIVE_ENDIAN,
171 };
172 
173 static void mcf_intc_instance_init(Object *obj)
174 {
175     mcf_intc_state *s = MCF_INTC(obj);
176 
177     memory_region_init_io(&s->iomem, obj, &mcf_intc_ops, s, "mcf", 0x100);
178 }
179 
180 static void mcf_intc_class_init(ObjectClass *oc, void *data)
181 {
182     DeviceClass *dc = DEVICE_CLASS(oc);
183 
184     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
185     dc->reset = mcf_intc_reset;
186 }
187 
188 static const TypeInfo mcf_intc_gate_info = {
189     .name          = TYPE_MCF_INTC,
190     .parent        = TYPE_SYS_BUS_DEVICE,
191     .instance_size = sizeof(mcf_intc_state),
192     .instance_init = mcf_intc_instance_init,
193     .class_init    = mcf_intc_class_init,
194 };
195 
196 static void mcf_intc_register_types(void)
197 {
198     type_register_static(&mcf_intc_gate_info);
199 }
200 
201 type_init(mcf_intc_register_types)
202 
203 qemu_irq *mcf_intc_init(MemoryRegion *sysmem,
204                         hwaddr base,
205                         M68kCPU *cpu)
206 {
207     DeviceState  *dev;
208     mcf_intc_state *s;
209 
210     dev = qdev_new(TYPE_MCF_INTC);
211     sysbus_realize_and_unref(SYS_BUS_DEVICE(dev), &error_fatal);
212 
213     s = MCF_INTC(dev);
214     s->cpu = cpu;
215 
216     memory_region_add_subregion(sysmem, base, &s->iomem);
217 
218     return qemu_allocate_irqs(mcf_intc_set_irq, s, 64);
219 }
220