xref: /openbmc/qemu/hw/m68k/mcf_intc.c (revision 65a117da)
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 "qemu/module.h"
11 #include "qemu/log.h"
12 #include "cpu.h"
13 #include "hw/hw.h"
14 #include "hw/irq.h"
15 #include "hw/sysbus.h"
16 #include "hw/m68k/mcf.h"
17 
18 #define TYPE_MCF_INTC "mcf-intc"
19 #define MCF_INTC(obj) OBJECT_CHECK(mcf_intc_state, (obj), TYPE_MCF_INTC)
20 
21 typedef struct {
22     SysBusDevice parent_obj;
23 
24     MemoryRegion iomem;
25     uint64_t ipr;
26     uint64_t imr;
27     uint64_t ifr;
28     uint64_t enabled;
29     uint8_t icr[64];
30     M68kCPU *cpu;
31     int active_vector;
32 } mcf_intc_state;
33 
34 static void mcf_intc_update(mcf_intc_state *s)
35 {
36     uint64_t active;
37     int i;
38     int best;
39     int best_level;
40 
41     active = (s->ipr | s->ifr) & s->enabled & ~s->imr;
42     best_level = 0;
43     best = 64;
44     if (active) {
45         for (i = 0; i < 64; i++) {
46             if ((active & 1) != 0 && s->icr[i] >= best_level) {
47                 best_level = s->icr[i];
48                 best = i;
49             }
50             active >>= 1;
51         }
52     }
53     s->active_vector = ((best == 64) ? 24 : (best + 64));
54     m68k_set_irq_level(s->cpu, best_level, s->active_vector);
55 }
56 
57 static uint64_t mcf_intc_read(void *opaque, hwaddr addr,
58                               unsigned size)
59 {
60     int offset;
61     mcf_intc_state *s = (mcf_intc_state *)opaque;
62     offset = addr & 0xff;
63     if (offset >= 0x40 && offset < 0x80) {
64         return s->icr[offset - 0x40];
65     }
66     switch (offset) {
67     case 0x00:
68         return (uint32_t)(s->ipr >> 32);
69     case 0x04:
70         return (uint32_t)s->ipr;
71     case 0x08:
72         return (uint32_t)(s->imr >> 32);
73     case 0x0c:
74         return (uint32_t)s->imr;
75     case 0x10:
76         return (uint32_t)(s->ifr >> 32);
77     case 0x14:
78         return (uint32_t)s->ifr;
79     case 0xe0: /* SWIACK.  */
80         return s->active_vector;
81     case 0xe1: case 0xe2: case 0xe3: case 0xe4:
82     case 0xe5: case 0xe6: case 0xe7:
83         /* LnIACK */
84         qemu_log_mask(LOG_UNIMP, "%s: LnIACK not implemented (offset 0x%02x)\n",
85                       __func__, offset);
86         /* fallthru */
87     default:
88         return 0;
89     }
90 }
91 
92 static void mcf_intc_write(void *opaque, hwaddr addr,
93                            uint64_t val, unsigned size)
94 {
95     int offset;
96     mcf_intc_state *s = (mcf_intc_state *)opaque;
97     offset = addr & 0xff;
98     if (offset >= 0x40 && offset < 0x80) {
99         int n = offset - 0x40;
100         s->icr[n] = val;
101         if (val == 0)
102             s->enabled &= ~(1ull << n);
103         else
104             s->enabled |= (1ull << n);
105         mcf_intc_update(s);
106         return;
107     }
108     switch (offset) {
109     case 0x00: case 0x04:
110         /* Ignore IPR writes.  */
111         return;
112     case 0x08:
113         s->imr = (s->imr & 0xffffffff) | ((uint64_t)val << 32);
114         break;
115     case 0x0c:
116         s->imr = (s->imr & 0xffffffff00000000ull) | (uint32_t)val;
117         break;
118     case 0x1c:
119         if (val & 0x40) {
120             s->imr = ~0ull;
121         } else {
122             s->imr |= (0x1ull << (val & 0x3f));
123         }
124         break;
125     case 0x1d:
126         if (val & 0x40) {
127             s->imr = 0ull;
128         } else {
129             s->imr &= ~(0x1ull << (val & 0x3f));
130         }
131         break;
132     default:
133         qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset 0x%02x\n",
134                       __func__, offset);
135         return;
136     }
137     mcf_intc_update(s);
138 }
139 
140 static void mcf_intc_set_irq(void *opaque, int irq, int level)
141 {
142     mcf_intc_state *s = (mcf_intc_state *)opaque;
143     if (irq >= 64)
144         return;
145     if (level)
146         s->ipr |= 1ull << irq;
147     else
148         s->ipr &= ~(1ull << irq);
149     mcf_intc_update(s);
150 }
151 
152 static void mcf_intc_reset(DeviceState *dev)
153 {
154     mcf_intc_state *s = MCF_INTC(dev);
155 
156     s->imr = ~0ull;
157     s->ipr = 0;
158     s->ifr = 0;
159     s->enabled = 0;
160     memset(s->icr, 0, 64);
161     s->active_vector = 24;
162 }
163 
164 static const MemoryRegionOps mcf_intc_ops = {
165     .read = mcf_intc_read,
166     .write = mcf_intc_write,
167     .endianness = DEVICE_NATIVE_ENDIAN,
168 };
169 
170 static void mcf_intc_instance_init(Object *obj)
171 {
172     mcf_intc_state *s = MCF_INTC(obj);
173 
174     memory_region_init_io(&s->iomem, obj, &mcf_intc_ops, s, "mcf", 0x100);
175 }
176 
177 static void mcf_intc_class_init(ObjectClass *oc, void *data)
178 {
179     DeviceClass *dc = DEVICE_CLASS(oc);
180 
181     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
182     dc->reset = mcf_intc_reset;
183 }
184 
185 static const TypeInfo mcf_intc_gate_info = {
186     .name          = TYPE_MCF_INTC,
187     .parent        = TYPE_SYS_BUS_DEVICE,
188     .instance_size = sizeof(mcf_intc_state),
189     .instance_init = mcf_intc_instance_init,
190     .class_init    = mcf_intc_class_init,
191 };
192 
193 static void mcf_intc_register_types(void)
194 {
195     type_register_static(&mcf_intc_gate_info);
196 }
197 
198 type_init(mcf_intc_register_types)
199 
200 qemu_irq *mcf_intc_init(MemoryRegion *sysmem,
201                         hwaddr base,
202                         M68kCPU *cpu)
203 {
204     DeviceState  *dev;
205     mcf_intc_state *s;
206 
207     dev = qdev_create(NULL, TYPE_MCF_INTC);
208     qdev_init_nofail(dev);
209 
210     s = MCF_INTC(dev);
211     s->cpu = cpu;
212 
213     memory_region_add_subregion(sysmem, base, &s->iomem);
214 
215     return qemu_allocate_irqs(mcf_intc_set_irq, s, 64);
216 }
217