xref: /openbmc/qemu/hw/m68k/mcf_intc.c (revision 7f6c3d1a)
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 OBJECT_DECLARE_SIMPLE_TYPE(mcf_intc_state, MCF_INTC)
22 
23 struct mcf_intc_state {
24     SysBusDevice parent_obj;
25 
26     MemoryRegion iomem;
27     uint64_t ipr;
28     uint64_t imr;
29     uint64_t ifr;
30     uint64_t enabled;
31     uint8_t icr[64];
32     M68kCPU *cpu;
33     int active_vector;
34 };
35 
36 static void mcf_intc_update(mcf_intc_state *s)
37 {
38     uint64_t active;
39     int i;
40     int best;
41     int best_level;
42 
43     active = (s->ipr | s->ifr) & s->enabled & ~s->imr;
44     best_level = 0;
45     best = 64;
46     if (active) {
47         for (i = 0; i < 64; i++) {
48             if ((active & 1) != 0 && s->icr[i] >= best_level) {
49                 best_level = s->icr[i];
50                 best = i;
51             }
52             active >>= 1;
53         }
54     }
55     s->active_vector = ((best == 64) ? 24 : (best + 64));
56     m68k_set_irq_level(s->cpu, best_level, s->active_vector);
57 }
58 
59 static uint64_t mcf_intc_read(void *opaque, hwaddr addr,
60                               unsigned size)
61 {
62     int offset;
63     mcf_intc_state *s = (mcf_intc_state *)opaque;
64     offset = addr & 0xff;
65     if (offset >= 0x40 && offset < 0x80) {
66         return s->icr[offset - 0x40];
67     }
68     switch (offset) {
69     case 0x00:
70         return (uint32_t)(s->ipr >> 32);
71     case 0x04:
72         return (uint32_t)s->ipr;
73     case 0x08:
74         return (uint32_t)(s->imr >> 32);
75     case 0x0c:
76         return (uint32_t)s->imr;
77     case 0x10:
78         return (uint32_t)(s->ifr >> 32);
79     case 0x14:
80         return (uint32_t)s->ifr;
81     case 0xe0: /* SWIACK.  */
82         return s->active_vector;
83     case 0xe1: case 0xe2: case 0xe3: case 0xe4:
84     case 0xe5: case 0xe6: case 0xe7:
85         /* LnIACK */
86         qemu_log_mask(LOG_UNIMP, "%s: LnIACK not implemented (offset 0x%02x)\n",
87                       __func__, offset);
88         /* fallthru */
89     default:
90         return 0;
91     }
92 }
93 
94 static void mcf_intc_write(void *opaque, hwaddr addr,
95                            uint64_t val, unsigned size)
96 {
97     int offset;
98     mcf_intc_state *s = (mcf_intc_state *)opaque;
99     offset = addr & 0xff;
100     if (offset >= 0x40 && offset < 0x80) {
101         int n = offset - 0x40;
102         s->icr[n] = val;
103         if (val == 0)
104             s->enabled &= ~(1ull << n);
105         else
106             s->enabled |= (1ull << n);
107         mcf_intc_update(s);
108         return;
109     }
110     switch (offset) {
111     case 0x00: case 0x04:
112         /* Ignore IPR writes.  */
113         return;
114     case 0x08:
115         s->imr = (s->imr & 0xffffffff) | ((uint64_t)val << 32);
116         break;
117     case 0x0c:
118         s->imr = (s->imr & 0xffffffff00000000ull) | (uint32_t)val;
119         break;
120     case 0x1c:
121         if (val & 0x40) {
122             s->imr = ~0ull;
123         } else {
124             s->imr |= (0x1ull << (val & 0x3f));
125         }
126         break;
127     case 0x1d:
128         if (val & 0x40) {
129             s->imr = 0ull;
130         } else {
131             s->imr &= ~(0x1ull << (val & 0x3f));
132         }
133         break;
134     default:
135         qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset 0x%02x\n",
136                       __func__, offset);
137         return;
138     }
139     mcf_intc_update(s);
140 }
141 
142 static void mcf_intc_set_irq(void *opaque, int irq, int level)
143 {
144     mcf_intc_state *s = (mcf_intc_state *)opaque;
145     if (irq >= 64)
146         return;
147     if (level)
148         s->ipr |= 1ull << irq;
149     else
150         s->ipr &= ~(1ull << irq);
151     mcf_intc_update(s);
152 }
153 
154 static void mcf_intc_reset(DeviceState *dev)
155 {
156     mcf_intc_state *s = MCF_INTC(dev);
157 
158     s->imr = ~0ull;
159     s->ipr = 0;
160     s->ifr = 0;
161     s->enabled = 0;
162     memset(s->icr, 0, 64);
163     s->active_vector = 24;
164 }
165 
166 static const MemoryRegionOps mcf_intc_ops = {
167     .read = mcf_intc_read,
168     .write = mcf_intc_write,
169     .endianness = DEVICE_NATIVE_ENDIAN,
170 };
171 
172 static void mcf_intc_instance_init(Object *obj)
173 {
174     mcf_intc_state *s = MCF_INTC(obj);
175 
176     memory_region_init_io(&s->iomem, obj, &mcf_intc_ops, s, "mcf", 0x100);
177 }
178 
179 static void mcf_intc_class_init(ObjectClass *oc, void *data)
180 {
181     DeviceClass *dc = DEVICE_CLASS(oc);
182 
183     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
184     dc->reset = mcf_intc_reset;
185 }
186 
187 static const TypeInfo mcf_intc_gate_info = {
188     .name          = TYPE_MCF_INTC,
189     .parent        = TYPE_SYS_BUS_DEVICE,
190     .instance_size = sizeof(mcf_intc_state),
191     .instance_init = mcf_intc_instance_init,
192     .class_init    = mcf_intc_class_init,
193 };
194 
195 static void mcf_intc_register_types(void)
196 {
197     type_register_static(&mcf_intc_gate_info);
198 }
199 
200 type_init(mcf_intc_register_types)
201 
202 qemu_irq *mcf_intc_init(MemoryRegion *sysmem,
203                         hwaddr base,
204                         M68kCPU *cpu)
205 {
206     DeviceState  *dev;
207     mcf_intc_state *s;
208 
209     dev = qdev_new(TYPE_MCF_INTC);
210     sysbus_realize_and_unref(SYS_BUS_DEVICE(dev), &error_fatal);
211 
212     s = MCF_INTC(dev);
213     s->cpu = cpu;
214 
215     memory_region_add_subregion(sysmem, base, &s->iomem);
216 
217     return qemu_allocate_irqs(mcf_intc_set_irq, s, 64);
218 }
219