xref: /openbmc/qemu/hw/m68k/mcf_intc.c (revision a9ded601)
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 #include "exec/address-spaces.h"
15 
16 #define TYPE_MCF_INTC "mcf-intc"
17 #define MCF_INTC(obj) OBJECT_CHECK(mcf_intc_state, (obj), TYPE_MCF_INTC)
18 
19 typedef struct {
20     SysBusDevice parent_obj;
21 
22     MemoryRegion iomem;
23     uint64_t ipr;
24     uint64_t imr;
25     uint64_t ifr;
26     uint64_t enabled;
27     uint8_t icr[64];
28     M68kCPU *cpu;
29     int active_vector;
30 } mcf_intc_state;
31 
32 static void mcf_intc_update(mcf_intc_state *s)
33 {
34     uint64_t active;
35     int i;
36     int best;
37     int best_level;
38 
39     active = (s->ipr | s->ifr) & s->enabled & ~s->imr;
40     best_level = 0;
41     best = 64;
42     if (active) {
43         for (i = 0; i < 64; i++) {
44             if ((active & 1) != 0 && s->icr[i] >= best_level) {
45                 best_level = s->icr[i];
46                 best = i;
47             }
48             active >>= 1;
49         }
50     }
51     s->active_vector = ((best == 64) ? 24 : (best + 64));
52     m68k_set_irq_level(s->cpu, best_level, s->active_vector);
53 }
54 
55 static uint64_t mcf_intc_read(void *opaque, hwaddr addr,
56                               unsigned size)
57 {
58     int offset;
59     mcf_intc_state *s = (mcf_intc_state *)opaque;
60     offset = addr & 0xff;
61     if (offset >= 0x40 && offset < 0x80) {
62         return s->icr[offset - 0x40];
63     }
64     switch (offset) {
65     case 0x00:
66         return (uint32_t)(s->ipr >> 32);
67     case 0x04:
68         return (uint32_t)s->ipr;
69     case 0x08:
70         return (uint32_t)(s->imr >> 32);
71     case 0x0c:
72         return (uint32_t)s->imr;
73     case 0x10:
74         return (uint32_t)(s->ifr >> 32);
75     case 0x14:
76         return (uint32_t)s->ifr;
77     case 0xe0: /* SWIACK.  */
78         return s->active_vector;
79     case 0xe1: case 0xe2: case 0xe3: case 0xe4:
80     case 0xe5: case 0xe6: case 0xe7:
81         /* LnIACK */
82         hw_error("mcf_intc_read: LnIACK not implemented\n");
83     default:
84         return 0;
85     }
86 }
87 
88 static void mcf_intc_write(void *opaque, hwaddr addr,
89                            uint64_t val, unsigned size)
90 {
91     int offset;
92     mcf_intc_state *s = (mcf_intc_state *)opaque;
93     offset = addr & 0xff;
94     if (offset >= 0x40 && offset < 0x80) {
95         int n = offset - 0x40;
96         s->icr[n] = val;
97         if (val == 0)
98             s->enabled &= ~(1ull << n);
99         else
100             s->enabled |= (1ull << n);
101         mcf_intc_update(s);
102         return;
103     }
104     switch (offset) {
105     case 0x00: case 0x04:
106         /* Ignore IPR writes.  */
107         return;
108     case 0x08:
109         s->imr = (s->imr & 0xffffffff) | ((uint64_t)val << 32);
110         break;
111     case 0x0c:
112         s->imr = (s->imr & 0xffffffff00000000ull) | (uint32_t)val;
113         break;
114     case 0x1c:
115         if (val & 0x40) {
116             s->imr = ~0ull;
117         } else {
118             s->imr |= (0x1ull << (val & 0x3f));
119         }
120         break;
121     case 0x1d:
122         if (val & 0x40) {
123             s->imr = 0ull;
124         } else {
125             s->imr &= ~(0x1ull << (val & 0x3f));
126         }
127         break;
128     default:
129         hw_error("mcf_intc_write: Bad write offset %d\n", offset);
130         break;
131     }
132     mcf_intc_update(s);
133 }
134 
135 static void mcf_intc_set_irq(void *opaque, int irq, int level)
136 {
137     mcf_intc_state *s = (mcf_intc_state *)opaque;
138     if (irq >= 64)
139         return;
140     if (level)
141         s->ipr |= 1ull << irq;
142     else
143         s->ipr &= ~(1ull << irq);
144     mcf_intc_update(s);
145 }
146 
147 static void mcf_intc_reset(DeviceState *dev)
148 {
149     mcf_intc_state *s = MCF_INTC(dev);
150 
151     s->imr = ~0ull;
152     s->ipr = 0;
153     s->ifr = 0;
154     s->enabled = 0;
155     memset(s->icr, 0, 64);
156     s->active_vector = 24;
157 }
158 
159 static const MemoryRegionOps mcf_intc_ops = {
160     .read = mcf_intc_read,
161     .write = mcf_intc_write,
162     .endianness = DEVICE_NATIVE_ENDIAN,
163 };
164 
165 static void mcf_intc_instance_init(Object *obj)
166 {
167     mcf_intc_state *s = MCF_INTC(obj);
168 
169     memory_region_init_io(&s->iomem, obj, &mcf_intc_ops, s, "mcf", 0x100);
170 }
171 
172 static void mcf_intc_class_init(ObjectClass *oc, void *data)
173 {
174     DeviceClass *dc = DEVICE_CLASS(oc);
175 
176     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
177     dc->reset = mcf_intc_reset;
178 }
179 
180 static const TypeInfo mcf_intc_gate_info = {
181     .name          = TYPE_MCF_INTC,
182     .parent        = TYPE_SYS_BUS_DEVICE,
183     .instance_size = sizeof(mcf_intc_state),
184     .instance_init = mcf_intc_instance_init,
185     .class_init    = mcf_intc_class_init,
186 };
187 
188 static void mcf_intc_register_types(void)
189 {
190     type_register_static(&mcf_intc_gate_info);
191 }
192 
193 type_init(mcf_intc_register_types)
194 
195 qemu_irq *mcf_intc_init(MemoryRegion *sysmem,
196                         hwaddr base,
197                         M68kCPU *cpu)
198 {
199     DeviceState  *dev;
200     mcf_intc_state *s;
201 
202     dev = qdev_create(NULL, TYPE_MCF_INTC);
203     qdev_init_nofail(dev);
204 
205     s = MCF_INTC(dev);
206     s->cpu = cpu;
207 
208     memory_region_add_subregion(sysmem, base, &s->iomem);
209 
210     return qemu_allocate_irqs(mcf_intc_set_irq, s, 64);
211 }
212