xref: /openbmc/qemu/hw/intc/imx_avic.c (revision 8f1e884b)
1 /*
2  * i.MX31 Vectored Interrupt Controller
3  *
4  * Note this is NOT the PL192 provided by ARM, but
5  * a custom implementation by Freescale.
6  *
7  * Copyright (c) 2008 OKL
8  * Copyright (c) 2011 NICTA Pty Ltd
9  * Originally written by Hans Jiang
10  *
11  * This code is licensed under the GPL version 2 or later.  See
12  * the COPYING file in the top-level directory.
13  *
14  * TODO: implement vectors.
15  */
16 
17 #include "hw/hw.h"
18 #include "hw/sysbus.h"
19 #include "qemu/host-utils.h"
20 
21 #define DEBUG_INT 1
22 #undef DEBUG_INT /* comment out for debugging */
23 
24 #ifdef DEBUG_INT
25 #define DPRINTF(fmt, args...) \
26 do { printf("imx_avic: " fmt , ##args); } while (0)
27 #else
28 #define DPRINTF(fmt, args...) do {} while (0)
29 #endif
30 
31 /*
32  * Define to 1 for messages about attempts to
33  * access unimplemented registers or similar.
34  */
35 #define DEBUG_IMPLEMENTATION 1
36 #if DEBUG_IMPLEMENTATION
37 #  define IPRINTF(fmt, args...) \
38     do  { fprintf(stderr, "imx_avic: " fmt, ##args); } while (0)
39 #else
40 #  define IPRINTF(fmt, args...) do {} while (0)
41 #endif
42 
43 #define IMX_AVIC_NUM_IRQS 64
44 
45 /* Interrupt Control Bits */
46 #define ABFLAG (1<<25)
47 #define ABFEN (1<<24)
48 #define NIDIS (1<<22) /* Normal Interrupt disable */
49 #define FIDIS (1<<21) /* Fast interrupt disable */
50 #define NIAD  (1<<20) /* Normal Interrupt Arbiter Rise ARM level */
51 #define FIAD  (1<<19) /* Fast Interrupt Arbiter Rise ARM level */
52 #define NM    (1<<18) /* Normal interrupt mode */
53 
54 
55 #define PRIO_PER_WORD (sizeof(uint32_t) * 8 / 4)
56 #define PRIO_WORDS (IMX_AVIC_NUM_IRQS/PRIO_PER_WORD)
57 
58 #define TYPE_IMX_AVIC "imx_avic"
59 #define IMX_AVIC(obj) \
60     OBJECT_CHECK(IMXAVICState, (obj), TYPE_IMX_AVIC)
61 
62 typedef struct IMXAVICState {
63     SysBusDevice parent_obj;
64 
65     MemoryRegion iomem;
66     uint64_t pending;
67     uint64_t enabled;
68     uint64_t is_fiq;
69     uint32_t intcntl;
70     uint32_t intmask;
71     qemu_irq irq;
72     qemu_irq fiq;
73     uint32_t prio[PRIO_WORDS]; /* Priorities are 4-bits each */
74 } IMXAVICState;
75 
76 static const VMStateDescription vmstate_imx_avic = {
77     .name = "imx-avic",
78     .version_id = 1,
79     .minimum_version_id = 1,
80     .fields = (VMStateField[]) {
81         VMSTATE_UINT64(pending, IMXAVICState),
82         VMSTATE_UINT64(enabled, IMXAVICState),
83         VMSTATE_UINT64(is_fiq, IMXAVICState),
84         VMSTATE_UINT32(intcntl, IMXAVICState),
85         VMSTATE_UINT32(intmask, IMXAVICState),
86         VMSTATE_UINT32_ARRAY(prio, IMXAVICState, PRIO_WORDS),
87         VMSTATE_END_OF_LIST()
88     },
89 };
90 
91 
92 
93 static inline int imx_avic_prio(IMXAVICState *s, int irq)
94 {
95     uint32_t word = irq / PRIO_PER_WORD;
96     uint32_t part = 4 * (irq % PRIO_PER_WORD);
97     return 0xf & (s->prio[word] >> part);
98 }
99 
100 static inline void imx_avic_set_prio(IMXAVICState *s, int irq, int prio)
101 {
102     uint32_t word = irq / PRIO_PER_WORD;
103     uint32_t part = 4 * (irq % PRIO_PER_WORD);
104     uint32_t mask = ~(0xf << part);
105     s->prio[word] &= mask;
106     s->prio[word] |= prio << part;
107 }
108 
109 /* Update interrupts.  */
110 static void imx_avic_update(IMXAVICState *s)
111 {
112     int i;
113     uint64_t new = s->pending & s->enabled;
114     uint64_t flags;
115 
116     flags = new & s->is_fiq;
117     qemu_set_irq(s->fiq, !!flags);
118 
119     flags = new & ~s->is_fiq;
120     if (!flags || (s->intmask == 0x1f)) {
121         qemu_set_irq(s->irq, !!flags);
122         return;
123     }
124 
125     /*
126      * Take interrupt if there's a pending interrupt with
127      * priority higher than the value of intmask
128      */
129     for (i = 0; i < IMX_AVIC_NUM_IRQS; i++) {
130         if (flags & (1UL << i)) {
131             if (imx_avic_prio(s, i) > s->intmask) {
132                 qemu_set_irq(s->irq, 1);
133                 return;
134             }
135         }
136     }
137     qemu_set_irq(s->irq, 0);
138 }
139 
140 static void imx_avic_set_irq(void *opaque, int irq, int level)
141 {
142     IMXAVICState *s = (IMXAVICState *)opaque;
143 
144     if (level) {
145         DPRINTF("Raising IRQ %d, prio %d\n",
146                 irq, imx_avic_prio(s, irq));
147         s->pending |= (1ULL << irq);
148     } else {
149         DPRINTF("Clearing IRQ %d, prio %d\n",
150                 irq, imx_avic_prio(s, irq));
151         s->pending &= ~(1ULL << irq);
152     }
153 
154     imx_avic_update(s);
155 }
156 
157 
158 static uint64_t imx_avic_read(void *opaque,
159                              hwaddr offset, unsigned size)
160 {
161     IMXAVICState *s = (IMXAVICState *)opaque;
162 
163 
164     DPRINTF("read(offset = 0x%x)\n", offset >> 2);
165     switch (offset >> 2) {
166     case 0: /* INTCNTL */
167         return s->intcntl;
168 
169     case 1: /* Normal Interrupt Mask Register, NIMASK */
170         return s->intmask;
171 
172     case 2: /* Interrupt Enable Number Register, INTENNUM */
173     case 3: /* Interrupt Disable Number Register, INTDISNUM */
174         return 0;
175 
176     case 4: /* Interrupt Enabled Number Register High */
177         return s->enabled >> 32;
178 
179     case 5: /* Interrupt Enabled Number Register Low */
180         return s->enabled & 0xffffffffULL;
181 
182     case 6: /* Interrupt Type Register High */
183         return s->is_fiq >> 32;
184 
185     case 7: /* Interrupt Type Register Low */
186         return s->is_fiq & 0xffffffffULL;
187 
188     case 8: /* Normal Interrupt Priority Register 7 */
189     case 9: /* Normal Interrupt Priority Register 6 */
190     case 10:/* Normal Interrupt Priority Register 5 */
191     case 11:/* Normal Interrupt Priority Register 4 */
192     case 12:/* Normal Interrupt Priority Register 3 */
193     case 13:/* Normal Interrupt Priority Register 2 */
194     case 14:/* Normal Interrupt Priority Register 1 */
195     case 15:/* Normal Interrupt Priority Register 0 */
196         return s->prio[15-(offset>>2)];
197 
198     case 16: /* Normal interrupt vector and status register */
199     {
200         /*
201          * This returns the highest priority
202          * outstanding interrupt.  Where there is more than
203          * one pending IRQ with the same priority,
204          * take the highest numbered one.
205          */
206         uint64_t flags = s->pending & s->enabled & ~s->is_fiq;
207         int i;
208         int prio = -1;
209         int irq = -1;
210         for (i = 63; i >= 0; --i) {
211             if (flags & (1ULL<<i)) {
212                 int irq_prio = imx_avic_prio(s, i);
213                 if (irq_prio > prio) {
214                     irq = i;
215                     prio = irq_prio;
216                 }
217             }
218         }
219         if (irq >= 0) {
220             imx_avic_set_irq(s, irq, 0);
221             return irq << 16 | prio;
222         }
223         return 0xffffffffULL;
224     }
225     case 17:/* Fast Interrupt vector and status register */
226     {
227         uint64_t flags = s->pending & s->enabled & s->is_fiq;
228         int i = ctz64(flags);
229         if (i < 64) {
230             imx_avic_set_irq(opaque, i, 0);
231             return i;
232         }
233         return 0xffffffffULL;
234     }
235     case 18:/* Interrupt source register high */
236         return s->pending >> 32;
237 
238     case 19:/* Interrupt source register low */
239         return s->pending & 0xffffffffULL;
240 
241     case 20:/* Interrupt Force Register high */
242     case 21:/* Interrupt Force Register low */
243         return 0;
244 
245     case 22:/* Normal Interrupt Pending Register High */
246         return (s->pending & s->enabled & ~s->is_fiq) >> 32;
247 
248     case 23:/* Normal Interrupt Pending Register Low */
249         return (s->pending & s->enabled & ~s->is_fiq) & 0xffffffffULL;
250 
251     case 24: /* Fast Interrupt Pending Register High  */
252         return (s->pending & s->enabled & s->is_fiq) >> 32;
253 
254     case 25: /* Fast Interrupt Pending Register Low  */
255         return (s->pending & s->enabled & s->is_fiq) & 0xffffffffULL;
256 
257     case 0x40:            /* AVIC vector 0, use for WFI WAR */
258         return 0x4;
259 
260     default:
261         IPRINTF("imx_avic_read: Bad offset 0x%x\n", (int)offset);
262         return 0;
263     }
264 }
265 
266 static void imx_avic_write(void *opaque, hwaddr offset,
267                           uint64_t val, unsigned size)
268 {
269     IMXAVICState *s = (IMXAVICState *)opaque;
270 
271     /* Vector Registers not yet supported */
272     if (offset >= 0x100 && offset <= 0x2fc) {
273         IPRINTF("imx_avic_write to vector register %d ignored\n",
274                 (unsigned int)((offset - 0x100) >> 2));
275         return;
276     }
277 
278     DPRINTF("imx_avic_write(0x%x) = %x\n",
279             (unsigned int)offset>>2, (unsigned int)val);
280     switch (offset >> 2) {
281     case 0: /* Interrupt Control Register, INTCNTL */
282         s->intcntl = val & (ABFEN | NIDIS | FIDIS | NIAD | FIAD | NM);
283         if (s->intcntl & ABFEN) {
284             s->intcntl &= ~(val & ABFLAG);
285         }
286         break;
287 
288     case 1: /* Normal Interrupt Mask Register, NIMASK */
289         s->intmask = val & 0x1f;
290         break;
291 
292     case 2: /* Interrupt Enable Number Register, INTENNUM */
293         DPRINTF("enable(%d)\n", (int)val);
294         val &= 0x3f;
295         s->enabled |= (1ULL << val);
296         break;
297 
298     case 3: /* Interrupt Disable Number Register, INTDISNUM */
299         DPRINTF("disable(%d)\n", (int)val);
300         val &= 0x3f;
301         s->enabled &= ~(1ULL << val);
302         break;
303 
304     case 4: /* Interrupt Enable Number Register High */
305         s->enabled = (s->enabled & 0xffffffffULL) | (val << 32);
306         break;
307 
308     case 5: /* Interrupt Enable Number Register Low */
309         s->enabled = (s->enabled & 0xffffffff00000000ULL) | val;
310         break;
311 
312     case 6: /* Interrupt Type Register High */
313         s->is_fiq = (s->is_fiq & 0xffffffffULL) | (val << 32);
314         break;
315 
316     case 7: /* Interrupt Type Register Low */
317         s->is_fiq = (s->is_fiq & 0xffffffff00000000ULL) | val;
318         break;
319 
320     case 8: /* Normal Interrupt Priority Register 7 */
321     case 9: /* Normal Interrupt Priority Register 6 */
322     case 10:/* Normal Interrupt Priority Register 5 */
323     case 11:/* Normal Interrupt Priority Register 4 */
324     case 12:/* Normal Interrupt Priority Register 3 */
325     case 13:/* Normal Interrupt Priority Register 2 */
326     case 14:/* Normal Interrupt Priority Register 1 */
327     case 15:/* Normal Interrupt Priority Register 0 */
328         s->prio[15-(offset>>2)] = val;
329         break;
330 
331         /* Read-only registers, writes ignored */
332     case 16:/* Normal Interrupt Vector and Status register */
333     case 17:/* Fast Interrupt vector and status register */
334     case 18:/* Interrupt source register high */
335     case 19:/* Interrupt source register low */
336         return;
337 
338     case 20:/* Interrupt Force Register high */
339         s->pending = (s->pending & 0xffffffffULL) | (val << 32);
340         break;
341 
342     case 21:/* Interrupt Force Register low */
343         s->pending = (s->pending & 0xffffffff00000000ULL) | val;
344         break;
345 
346     case 22:/* Normal Interrupt Pending Register High */
347     case 23:/* Normal Interrupt Pending Register Low */
348     case 24: /* Fast Interrupt Pending Register High  */
349     case 25: /* Fast Interrupt Pending Register Low  */
350         return;
351 
352     default:
353         IPRINTF("imx_avic_write: Bad offset %x\n", (int)offset);
354     }
355     imx_avic_update(s);
356 }
357 
358 static const MemoryRegionOps imx_avic_ops = {
359     .read = imx_avic_read,
360     .write = imx_avic_write,
361     .endianness = DEVICE_NATIVE_ENDIAN,
362 };
363 
364 static void imx_avic_reset(DeviceState *dev)
365 {
366     IMXAVICState *s = IMX_AVIC(dev);
367 
368     s->pending = 0;
369     s->enabled = 0;
370     s->is_fiq = 0;
371     s->intmask = 0x1f;
372     s->intcntl = 0;
373     memset(s->prio, 0, sizeof s->prio);
374 }
375 
376 static int imx_avic_init(SysBusDevice *sbd)
377 {
378     DeviceState *dev = DEVICE(sbd);
379     IMXAVICState *s = IMX_AVIC(dev);
380 
381     memory_region_init_io(&s->iomem, OBJECT(s), &imx_avic_ops, s,
382                           "imx_avic", 0x1000);
383     sysbus_init_mmio(sbd, &s->iomem);
384 
385     qdev_init_gpio_in(dev, imx_avic_set_irq, IMX_AVIC_NUM_IRQS);
386     sysbus_init_irq(sbd, &s->irq);
387     sysbus_init_irq(sbd, &s->fiq);
388 
389     return 0;
390 }
391 
392 
393 static void imx_avic_class_init(ObjectClass *klass, void *data)
394 {
395     DeviceClass *dc = DEVICE_CLASS(klass);
396     SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
397     k->init = imx_avic_init;
398     dc->vmsd = &vmstate_imx_avic;
399     dc->reset = imx_avic_reset;
400     dc->desc = "i.MX Advanced Vector Interrupt Controller";
401 }
402 
403 static const TypeInfo imx_avic_info = {
404     .name = TYPE_IMX_AVIC,
405     .parent = TYPE_SYS_BUS_DEVICE,
406     .instance_size = sizeof(IMXAVICState),
407     .class_init = imx_avic_class_init,
408 };
409 
410 static void imx_avic_register_types(void)
411 {
412     type_register_static(&imx_avic_info);
413 }
414 
415 type_init(imx_avic_register_types)
416