xref: /openbmc/qemu/hw/intc/aspeed_vic.c (revision ba632924)
1 /*
2  * ASPEED Interrupt Controller (New)
3  *
4  * Andrew Jeffery <andrew@aj.id.au>
5  *
6  * Copyright 2015, 2016 IBM Corp.
7  *
8  * This code is licensed under the GPL version 2 or later.  See
9  * the COPYING file in the top-level directory.
10  */
11 
12 /* The hardware exposes two register sets, a legacy set and a 'new' set. The
13  * model implements the 'new' register set, and logs warnings on accesses to
14  * the legacy IO space.
15  *
16  * The hardware uses 32bit registers to manage 51 IRQs, with low and high
17  * registers for each conceptual register. The device model's implementation
18  * uses 64bit data types to store both low and high register values (in the one
19  * member), but must cope with access offset values in multiples of 4 passed to
20  * the callbacks. As such the read() and write() implementations process the
21  * provided offset to understand whether the access is requesting the lower or
22  * upper 32 bits of the 64bit member.
23  *
24  * Additionally, the "Interrupt Enable", "Edge Status" and "Software Interrupt"
25  * fields have separate "enable"/"status" and "clear" registers, where set bits
26  * are written to one or the other to change state (avoiding a
27  * read-modify-write sequence).
28  */
29 
30 #include "qemu/osdep.h"
31 #include "hw/intc/aspeed_vic.h"
32 #include "qemu/bitops.h"
33 #include "qemu/log.h"
34 #include "trace.h"
35 
36 #define AVIC_NEW_BASE_OFFSET 0x80
37 
38 #define AVIC_L_MASK 0xFFFFFFFFU
39 #define AVIC_H_MASK 0x0007FFFFU
40 #define AVIC_EVENT_W_MASK (0x78000ULL << 32)
41 
42 static void aspeed_vic_update(AspeedVICState *s)
43 {
44     uint64_t new = (s->raw & s->enable);
45     uint64_t flags;
46 
47     flags = new & s->select;
48     trace_aspeed_vic_update_fiq(!!flags);
49     qemu_set_irq(s->fiq, !!flags);
50 
51     flags = new & ~s->select;
52     trace_aspeed_vic_update_irq(!!flags);
53     qemu_set_irq(s->irq, !!flags);
54 }
55 
56 static void aspeed_vic_set_irq(void *opaque, int irq, int level)
57 {
58     uint64_t irq_mask;
59     bool raise;
60     AspeedVICState *s = (AspeedVICState *)opaque;
61 
62     if (irq > ASPEED_VIC_NR_IRQS) {
63         qemu_log_mask(LOG_GUEST_ERROR, "%s: Invalid interrupt number: %d\n",
64                       __func__, irq);
65         return;
66     }
67 
68     trace_aspeed_vic_set_irq(irq, level);
69 
70     irq_mask = BIT(irq);
71     if (s->sense & irq_mask) {
72         /* level-triggered */
73         if (s->event & irq_mask) {
74             /* high-sensitive */
75             raise = level;
76         } else {
77             /* low-sensitive */
78             raise = !level;
79         }
80         s->raw = deposit64(s->raw, irq, 1, raise);
81     } else {
82         uint64_t old_level = s->level & irq_mask;
83 
84         /* edge-triggered */
85         if (s->dual_edge & irq_mask) {
86             raise = (!!old_level) != (!!level);
87         } else {
88             if (s->event & irq_mask) {
89                 /* rising-sensitive */
90                 raise = !old_level && level;
91             } else {
92                 /* falling-sensitive */
93                 raise = old_level && !level;
94             }
95         }
96         if (raise) {
97             s->raw = deposit64(s->raw, irq, 1, raise);
98         }
99     }
100     s->level = deposit64(s->level, irq, 1, level);
101     aspeed_vic_update(s);
102 }
103 
104 static uint64_t aspeed_vic_read(void *opaque, hwaddr offset, unsigned size)
105 {
106     uint64_t val;
107     const bool high = !!(offset & 0x4);
108     hwaddr n_offset = (offset & ~0x4);
109     AspeedVICState *s = (AspeedVICState *)opaque;
110 
111     if (offset < AVIC_NEW_BASE_OFFSET) {
112         qemu_log_mask(LOG_UNIMP, "%s: Ignoring read from legacy registers "
113                       "at 0x%" HWADDR_PRIx "[%u]\n", __func__, offset, size);
114         return 0;
115     }
116 
117     n_offset -= AVIC_NEW_BASE_OFFSET;
118 
119     switch (n_offset) {
120     case 0x0: /* IRQ Status */
121         val = s->raw & ~s->select & s->enable;
122         break;
123     case 0x08: /* FIQ Status */
124         val = s->raw & s->select & s->enable;
125         break;
126     case 0x10: /* Raw Interrupt Status */
127         val = s->raw;
128         break;
129     case 0x18: /* Interrupt Selection */
130         val = s->select;
131         break;
132     case 0x20: /* Interrupt Enable */
133         val = s->enable;
134         break;
135     case 0x30: /* Software Interrupt */
136         val = s->trigger;
137         break;
138     case 0x40: /* Interrupt Sensitivity */
139         val = s->sense;
140         break;
141     case 0x48: /* Interrupt Both Edge Trigger Control */
142         val = s->dual_edge;
143         break;
144     case 0x50: /* Interrupt Event */
145         val = s->event;
146         break;
147     case 0x60: /* Edge Triggered Interrupt Status */
148         val = s->raw & ~s->sense;
149         break;
150         /* Illegal */
151     case 0x28: /* Interrupt Enable Clear */
152     case 0x38: /* Software Interrupt Clear */
153     case 0x58: /* Edge Triggered Interrupt Clear */
154         qemu_log_mask(LOG_GUEST_ERROR,
155                       "%s: Read of write-only register with offset 0x%"
156                       HWADDR_PRIx "\n", __func__, offset);
157         val = 0;
158         break;
159     default:
160         qemu_log_mask(LOG_GUEST_ERROR,
161                       "%s: Bad register at offset 0x%" HWADDR_PRIx "\n",
162                       __func__, offset);
163         val = 0;
164         break;
165     }
166     if (high) {
167         val = extract64(val, 32, 19);
168     }
169     trace_aspeed_vic_read(offset, size, val);
170     return val;
171 }
172 
173 static void aspeed_vic_write(void *opaque, hwaddr offset, uint64_t data,
174                              unsigned size)
175 {
176     const bool high = !!(offset & 0x4);
177     hwaddr n_offset = (offset & ~0x4);
178     AspeedVICState *s = (AspeedVICState *)opaque;
179 
180     if (offset < AVIC_NEW_BASE_OFFSET) {
181         qemu_log_mask(LOG_UNIMP,
182                       "%s: Ignoring write to legacy registers at 0x%"
183                       HWADDR_PRIx "[%u] <- 0x%" PRIx64 "\n", __func__, offset,
184                       size, data);
185         return;
186     }
187 
188     n_offset -= AVIC_NEW_BASE_OFFSET;
189     trace_aspeed_vic_write(offset, size, data);
190 
191     /* Given we have members using separate enable/clear registers, deposit64()
192      * isn't quite the tool for the job. Instead, relocate the incoming bits to
193      * the required bit offset based on the provided access address
194      */
195     if (high) {
196         data &= AVIC_H_MASK;
197         data <<= 32;
198     } else {
199         data &= AVIC_L_MASK;
200     }
201 
202     switch (n_offset) {
203     case 0x18: /* Interrupt Selection */
204         /* Register has deposit64() semantics - overwrite requested 32 bits */
205         if (high) {
206             s->select &= AVIC_L_MASK;
207         } else {
208             s->select &= ((uint64_t) AVIC_H_MASK) << 32;
209         }
210         s->select |= data;
211         break;
212     case 0x20: /* Interrupt Enable */
213         s->enable |= data;
214         break;
215     case 0x28: /* Interrupt Enable Clear */
216         s->enable &= ~data;
217         break;
218     case 0x30: /* Software Interrupt */
219         qemu_log_mask(LOG_UNIMP, "%s: Software interrupts unavailable. "
220                       "IRQs requested: 0x%016" PRIx64 "\n", __func__, data);
221         break;
222     case 0x38: /* Software Interrupt Clear */
223         qemu_log_mask(LOG_UNIMP, "%s: Software interrupts unavailable. "
224                       "IRQs to be cleared: 0x%016" PRIx64 "\n", __func__, data);
225         break;
226     case 0x50: /* Interrupt Event */
227         /* Register has deposit64() semantics - overwrite the top four valid
228          * IRQ bits, as only the top four IRQs (GPIOs) can change their event
229          * type */
230         if (high) {
231             s->event &= ~AVIC_EVENT_W_MASK;
232             s->event |= (data & AVIC_EVENT_W_MASK);
233         } else {
234             qemu_log_mask(LOG_GUEST_ERROR,
235                           "Ignoring invalid write to interrupt event register");
236         }
237         break;
238     case 0x58: /* Edge Triggered Interrupt Clear */
239         s->raw &= ~(data & ~s->sense);
240         break;
241     case 0x00: /* IRQ Status */
242     case 0x08: /* FIQ Status */
243     case 0x10: /* Raw Interrupt Status */
244     case 0x40: /* Interrupt Sensitivity */
245     case 0x48: /* Interrupt Both Edge Trigger Control */
246     case 0x60: /* Edge Triggered Interrupt Status */
247         qemu_log_mask(LOG_GUEST_ERROR,
248                       "%s: Write of read-only register with offset 0x%"
249                       HWADDR_PRIx "\n", __func__, offset);
250         break;
251 
252     default:
253         qemu_log_mask(LOG_GUEST_ERROR,
254                       "%s: Bad register at offset 0x%" HWADDR_PRIx "\n",
255                       __func__, offset);
256         break;
257     }
258     aspeed_vic_update(s);
259 }
260 
261 static const MemoryRegionOps aspeed_vic_ops = {
262     .read = aspeed_vic_read,
263     .write = aspeed_vic_write,
264     .endianness = DEVICE_LITTLE_ENDIAN,
265     .valid.min_access_size = 4,
266     .valid.max_access_size = 4,
267     .valid.unaligned = false,
268 };
269 
270 static void aspeed_vic_reset(DeviceState *dev)
271 {
272     AspeedVICState *s = ASPEED_VIC(dev);
273 
274     s->level = 0;
275     s->raw = 0;
276     s->select = 0;
277     s->enable = 0;
278     s->trigger = 0;
279     s->sense = 0x1F07FFF8FFFFULL;
280     s->dual_edge = 0xF800070000ULL;
281     s->event = 0x5F07FFF8FFFFULL;
282 }
283 
284 #define AVIC_IO_REGION_SIZE 0x20000
285 
286 static void aspeed_vic_realize(DeviceState *dev, Error **errp)
287 {
288     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
289     AspeedVICState *s = ASPEED_VIC(dev);
290 
291     memory_region_init_io(&s->iomem, OBJECT(s), &aspeed_vic_ops, s,
292                           TYPE_ASPEED_VIC, AVIC_IO_REGION_SIZE);
293 
294     sysbus_init_mmio(sbd, &s->iomem);
295 
296     qdev_init_gpio_in(dev, aspeed_vic_set_irq, ASPEED_VIC_NR_IRQS);
297     sysbus_init_irq(sbd, &s->irq);
298     sysbus_init_irq(sbd, &s->fiq);
299 }
300 
301 static const VMStateDescription vmstate_aspeed_vic = {
302     .name = "aspeed.new-vic",
303     .version_id = 1,
304     .minimum_version_id = 1,
305     .fields = (VMStateField[]) {
306         VMSTATE_UINT64(level, AspeedVICState),
307         VMSTATE_UINT64(raw, AspeedVICState),
308         VMSTATE_UINT64(select, AspeedVICState),
309         VMSTATE_UINT64(enable, AspeedVICState),
310         VMSTATE_UINT64(trigger, AspeedVICState),
311         VMSTATE_UINT64(sense, AspeedVICState),
312         VMSTATE_UINT64(dual_edge, AspeedVICState),
313         VMSTATE_UINT64(event, AspeedVICState),
314         VMSTATE_END_OF_LIST()
315     }
316 };
317 
318 static void aspeed_vic_class_init(ObjectClass *klass, void *data)
319 {
320     DeviceClass *dc = DEVICE_CLASS(klass);
321     dc->realize = aspeed_vic_realize;
322     dc->reset = aspeed_vic_reset;
323     dc->desc = "ASPEED Interrupt Controller (New)";
324     dc->vmsd = &vmstate_aspeed_vic;
325 }
326 
327 static const TypeInfo aspeed_vic_info = {
328     .name = TYPE_ASPEED_VIC,
329     .parent = TYPE_SYS_BUS_DEVICE,
330     .instance_size = sizeof(AspeedVICState),
331     .class_init = aspeed_vic_class_init,
332 };
333 
334 static void aspeed_vic_register_types(void)
335 {
336     type_register_static(&aspeed_vic_info);
337 }
338 
339 type_init(aspeed_vic_register_types);
340