xref: /openbmc/qemu/hw/m68k/mcf_intc.c (revision 8fa3b702)
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 DECLARE_INSTANCE_CHECKER(mcf_intc_state, MCF_INTC,
23                          TYPE_MCF_INTC)
24 
25 struct mcf_intc_state {
26     SysBusDevice parent_obj;
27 
28     MemoryRegion iomem;
29     uint64_t ipr;
30     uint64_t imr;
31     uint64_t ifr;
32     uint64_t enabled;
33     uint8_t icr[64];
34     M68kCPU *cpu;
35     int active_vector;
36 };
37 
38 static void mcf_intc_update(mcf_intc_state *s)
39 {
40     uint64_t active;
41     int i;
42     int best;
43     int best_level;
44 
45     active = (s->ipr | s->ifr) & s->enabled & ~s->imr;
46     best_level = 0;
47     best = 64;
48     if (active) {
49         for (i = 0; i < 64; i++) {
50             if ((active & 1) != 0 && s->icr[i] >= best_level) {
51                 best_level = s->icr[i];
52                 best = i;
53             }
54             active >>= 1;
55         }
56     }
57     s->active_vector = ((best == 64) ? 24 : (best + 64));
58     m68k_set_irq_level(s->cpu, best_level, s->active_vector);
59 }
60 
61 static uint64_t mcf_intc_read(void *opaque, hwaddr addr,
62                               unsigned size)
63 {
64     int offset;
65     mcf_intc_state *s = (mcf_intc_state *)opaque;
66     offset = addr & 0xff;
67     if (offset >= 0x40 && offset < 0x80) {
68         return s->icr[offset - 0x40];
69     }
70     switch (offset) {
71     case 0x00:
72         return (uint32_t)(s->ipr >> 32);
73     case 0x04:
74         return (uint32_t)s->ipr;
75     case 0x08:
76         return (uint32_t)(s->imr >> 32);
77     case 0x0c:
78         return (uint32_t)s->imr;
79     case 0x10:
80         return (uint32_t)(s->ifr >> 32);
81     case 0x14:
82         return (uint32_t)s->ifr;
83     case 0xe0: /* SWIACK.  */
84         return s->active_vector;
85     case 0xe1: case 0xe2: case 0xe3: case 0xe4:
86     case 0xe5: case 0xe6: case 0xe7:
87         /* LnIACK */
88         qemu_log_mask(LOG_UNIMP, "%s: LnIACK not implemented (offset 0x%02x)\n",
89                       __func__, offset);
90         /* fallthru */
91     default:
92         return 0;
93     }
94 }
95 
96 static void mcf_intc_write(void *opaque, hwaddr addr,
97                            uint64_t val, unsigned size)
98 {
99     int offset;
100     mcf_intc_state *s = (mcf_intc_state *)opaque;
101     offset = addr & 0xff;
102     if (offset >= 0x40 && offset < 0x80) {
103         int n = offset - 0x40;
104         s->icr[n] = val;
105         if (val == 0)
106             s->enabled &= ~(1ull << n);
107         else
108             s->enabled |= (1ull << n);
109         mcf_intc_update(s);
110         return;
111     }
112     switch (offset) {
113     case 0x00: case 0x04:
114         /* Ignore IPR writes.  */
115         return;
116     case 0x08:
117         s->imr = (s->imr & 0xffffffff) | ((uint64_t)val << 32);
118         break;
119     case 0x0c:
120         s->imr = (s->imr & 0xffffffff00000000ull) | (uint32_t)val;
121         break;
122     case 0x1c:
123         if (val & 0x40) {
124             s->imr = ~0ull;
125         } else {
126             s->imr |= (0x1ull << (val & 0x3f));
127         }
128         break;
129     case 0x1d:
130         if (val & 0x40) {
131             s->imr = 0ull;
132         } else {
133             s->imr &= ~(0x1ull << (val & 0x3f));
134         }
135         break;
136     default:
137         qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset 0x%02x\n",
138                       __func__, offset);
139         return;
140     }
141     mcf_intc_update(s);
142 }
143 
144 static void mcf_intc_set_irq(void *opaque, int irq, int level)
145 {
146     mcf_intc_state *s = (mcf_intc_state *)opaque;
147     if (irq >= 64)
148         return;
149     if (level)
150         s->ipr |= 1ull << irq;
151     else
152         s->ipr &= ~(1ull << irq);
153     mcf_intc_update(s);
154 }
155 
156 static void mcf_intc_reset(DeviceState *dev)
157 {
158     mcf_intc_state *s = MCF_INTC(dev);
159 
160     s->imr = ~0ull;
161     s->ipr = 0;
162     s->ifr = 0;
163     s->enabled = 0;
164     memset(s->icr, 0, 64);
165     s->active_vector = 24;
166 }
167 
168 static const MemoryRegionOps mcf_intc_ops = {
169     .read = mcf_intc_read,
170     .write = mcf_intc_write,
171     .endianness = DEVICE_NATIVE_ENDIAN,
172 };
173 
174 static void mcf_intc_instance_init(Object *obj)
175 {
176     mcf_intc_state *s = MCF_INTC(obj);
177 
178     memory_region_init_io(&s->iomem, obj, &mcf_intc_ops, s, "mcf", 0x100);
179 }
180 
181 static void mcf_intc_class_init(ObjectClass *oc, void *data)
182 {
183     DeviceClass *dc = DEVICE_CLASS(oc);
184 
185     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
186     dc->reset = mcf_intc_reset;
187 }
188 
189 static const TypeInfo mcf_intc_gate_info = {
190     .name          = TYPE_MCF_INTC,
191     .parent        = TYPE_SYS_BUS_DEVICE,
192     .instance_size = sizeof(mcf_intc_state),
193     .instance_init = mcf_intc_instance_init,
194     .class_init    = mcf_intc_class_init,
195 };
196 
197 static void mcf_intc_register_types(void)
198 {
199     type_register_static(&mcf_intc_gate_info);
200 }
201 
202 type_init(mcf_intc_register_types)
203 
204 qemu_irq *mcf_intc_init(MemoryRegion *sysmem,
205                         hwaddr base,
206                         M68kCPU *cpu)
207 {
208     DeviceState  *dev;
209     mcf_intc_state *s;
210 
211     dev = qdev_new(TYPE_MCF_INTC);
212     sysbus_realize_and_unref(SYS_BUS_DEVICE(dev), &error_fatal);
213 
214     s = MCF_INTC(dev);
215     s->cpu = cpu;
216 
217     memory_region_add_subregion(sysmem, base, &s->iomem);
218 
219     return qemu_allocate_irqs(mcf_intc_set_irq, s, 64);
220 }
221