xref: /openbmc/qemu/hw/intc/imx_avic.c (revision 56c4bfb3)
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     .minimum_version_id_old = 1,
81     .fields = (VMStateField[]) {
82         VMSTATE_UINT64(pending, IMXAVICState),
83         VMSTATE_UINT64(enabled, IMXAVICState),
84         VMSTATE_UINT64(is_fiq, IMXAVICState),
85         VMSTATE_UINT32(intcntl, IMXAVICState),
86         VMSTATE_UINT32(intmask, IMXAVICState),
87         VMSTATE_UINT32_ARRAY(prio, IMXAVICState, PRIO_WORDS),
88         VMSTATE_END_OF_LIST()
89     },
90 };
91 
92 
93 
94 static inline int imx_avic_prio(IMXAVICState *s, int irq)
95 {
96     uint32_t word = irq / PRIO_PER_WORD;
97     uint32_t part = 4 * (irq % PRIO_PER_WORD);
98     return 0xf & (s->prio[word] >> part);
99 }
100 
101 static inline void imx_avic_set_prio(IMXAVICState *s, int irq, int prio)
102 {
103     uint32_t word = irq / PRIO_PER_WORD;
104     uint32_t part = 4 * (irq % PRIO_PER_WORD);
105     uint32_t mask = ~(0xf << part);
106     s->prio[word] &= mask;
107     s->prio[word] |= prio << part;
108 }
109 
110 /* Update interrupts.  */
111 static void imx_avic_update(IMXAVICState *s)
112 {
113     int i;
114     uint64_t new = s->pending & s->enabled;
115     uint64_t flags;
116 
117     flags = new & s->is_fiq;
118     qemu_set_irq(s->fiq, !!flags);
119 
120     flags = new & ~s->is_fiq;
121     if (!flags || (s->intmask == 0x1f)) {
122         qemu_set_irq(s->irq, !!flags);
123         return;
124     }
125 
126     /*
127      * Take interrupt if there's a pending interrupt with
128      * priority higher than the value of intmask
129      */
130     for (i = 0; i < IMX_AVIC_NUM_IRQS; i++) {
131         if (flags & (1UL << i)) {
132             if (imx_avic_prio(s, i) > s->intmask) {
133                 qemu_set_irq(s->irq, 1);
134                 return;
135             }
136         }
137     }
138     qemu_set_irq(s->irq, 0);
139 }
140 
141 static void imx_avic_set_irq(void *opaque, int irq, int level)
142 {
143     IMXAVICState *s = (IMXAVICState *)opaque;
144 
145     if (level) {
146         DPRINTF("Raising IRQ %d, prio %d\n",
147                 irq, imx_avic_prio(s, irq));
148         s->pending |= (1ULL << irq);
149     } else {
150         DPRINTF("Clearing IRQ %d, prio %d\n",
151                 irq, imx_avic_prio(s, irq));
152         s->pending &= ~(1ULL << irq);
153     }
154 
155     imx_avic_update(s);
156 }
157 
158 
159 static uint64_t imx_avic_read(void *opaque,
160                              hwaddr offset, unsigned size)
161 {
162     IMXAVICState *s = (IMXAVICState *)opaque;
163 
164 
165     DPRINTF("read(offset = 0x%x)\n", offset >> 2);
166     switch (offset >> 2) {
167     case 0: /* INTCNTL */
168         return s->intcntl;
169 
170     case 1: /* Normal Interrupt Mask Register, NIMASK */
171         return s->intmask;
172 
173     case 2: /* Interrupt Enable Number Register, INTENNUM */
174     case 3: /* Interrupt Disable Number Register, INTDISNUM */
175         return 0;
176 
177     case 4: /* Interrupt Enabled Number Register High */
178         return s->enabled >> 32;
179 
180     case 5: /* Interrupt Enabled Number Register Low */
181         return s->enabled & 0xffffffffULL;
182 
183     case 6: /* Interrupt Type Register High */
184         return s->is_fiq >> 32;
185 
186     case 7: /* Interrupt Type Register Low */
187         return s->is_fiq & 0xffffffffULL;
188 
189     case 8: /* Normal Interrupt Priority Register 7 */
190     case 9: /* Normal Interrupt Priority Register 6 */
191     case 10:/* Normal Interrupt Priority Register 5 */
192     case 11:/* Normal Interrupt Priority Register 4 */
193     case 12:/* Normal Interrupt Priority Register 3 */
194     case 13:/* Normal Interrupt Priority Register 2 */
195     case 14:/* Normal Interrupt Priority Register 1 */
196     case 15:/* Normal Interrupt Priority Register 0 */
197         return s->prio[15-(offset>>2)];
198 
199     case 16: /* Normal interrupt vector and status register */
200     {
201         /*
202          * This returns the highest priority
203          * outstanding interrupt.  Where there is more than
204          * one pending IRQ with the same priority,
205          * take the highest numbered one.
206          */
207         uint64_t flags = s->pending & s->enabled & ~s->is_fiq;
208         int i;
209         int prio = -1;
210         int irq = -1;
211         for (i = 63; i >= 0; --i) {
212             if (flags & (1ULL<<i)) {
213                 int irq_prio = imx_avic_prio(s, i);
214                 if (irq_prio > prio) {
215                     irq = i;
216                     prio = irq_prio;
217                 }
218             }
219         }
220         if (irq >= 0) {
221             imx_avic_set_irq(s, irq, 0);
222             return irq << 16 | prio;
223         }
224         return 0xffffffffULL;
225     }
226     case 17:/* Fast Interrupt vector and status register */
227     {
228         uint64_t flags = s->pending & s->enabled & s->is_fiq;
229         int i = ctz64(flags);
230         if (i < 64) {
231             imx_avic_set_irq(opaque, i, 0);
232             return i;
233         }
234         return 0xffffffffULL;
235     }
236     case 18:/* Interrupt source register high */
237         return s->pending >> 32;
238 
239     case 19:/* Interrupt source register low */
240         return s->pending & 0xffffffffULL;
241 
242     case 20:/* Interrupt Force Register high */
243     case 21:/* Interrupt Force Register low */
244         return 0;
245 
246     case 22:/* Normal Interrupt Pending Register High */
247         return (s->pending & s->enabled & ~s->is_fiq) >> 32;
248 
249     case 23:/* Normal Interrupt Pending Register Low */
250         return (s->pending & s->enabled & ~s->is_fiq) & 0xffffffffULL;
251 
252     case 24: /* Fast Interrupt Pending Register High  */
253         return (s->pending & s->enabled & s->is_fiq) >> 32;
254 
255     case 25: /* Fast Interrupt Pending Register Low  */
256         return (s->pending & s->enabled & s->is_fiq) & 0xffffffffULL;
257 
258     case 0x40:            /* AVIC vector 0, use for WFI WAR */
259         return 0x4;
260 
261     default:
262         IPRINTF("imx_avic_read: Bad offset 0x%x\n", (int)offset);
263         return 0;
264     }
265 }
266 
267 static void imx_avic_write(void *opaque, hwaddr offset,
268                           uint64_t val, unsigned size)
269 {
270     IMXAVICState *s = (IMXAVICState *)opaque;
271 
272     /* Vector Registers not yet supported */
273     if (offset >= 0x100 && offset <= 0x2fc) {
274         IPRINTF("imx_avic_write to vector register %d ignored\n",
275                 (unsigned int)((offset - 0x100) >> 2));
276         return;
277     }
278 
279     DPRINTF("imx_avic_write(0x%x) = %x\n",
280             (unsigned int)offset>>2, (unsigned int)val);
281     switch (offset >> 2) {
282     case 0: /* Interrupt Control Register, INTCNTL */
283         s->intcntl = val & (ABFEN | NIDIS | FIDIS | NIAD | FIAD | NM);
284         if (s->intcntl & ABFEN) {
285             s->intcntl &= ~(val & ABFLAG);
286         }
287         break;
288 
289     case 1: /* Normal Interrupt Mask Register, NIMASK */
290         s->intmask = val & 0x1f;
291         break;
292 
293     case 2: /* Interrupt Enable Number Register, INTENNUM */
294         DPRINTF("enable(%d)\n", (int)val);
295         val &= 0x3f;
296         s->enabled |= (1ULL << val);
297         break;
298 
299     case 3: /* Interrupt Disable Number Register, INTDISNUM */
300         DPRINTF("disable(%d)\n", (int)val);
301         val &= 0x3f;
302         s->enabled &= ~(1ULL << val);
303         break;
304 
305     case 4: /* Interrupt Enable Number Register High */
306         s->enabled = (s->enabled & 0xffffffffULL) | (val << 32);
307         break;
308 
309     case 5: /* Interrupt Enable Number Register Low */
310         s->enabled = (s->enabled & 0xffffffff00000000ULL) | val;
311         break;
312 
313     case 6: /* Interrupt Type Register High */
314         s->is_fiq = (s->is_fiq & 0xffffffffULL) | (val << 32);
315         break;
316 
317     case 7: /* Interrupt Type Register Low */
318         s->is_fiq = (s->is_fiq & 0xffffffff00000000ULL) | val;
319         break;
320 
321     case 8: /* Normal Interrupt Priority Register 7 */
322     case 9: /* Normal Interrupt Priority Register 6 */
323     case 10:/* Normal Interrupt Priority Register 5 */
324     case 11:/* Normal Interrupt Priority Register 4 */
325     case 12:/* Normal Interrupt Priority Register 3 */
326     case 13:/* Normal Interrupt Priority Register 2 */
327     case 14:/* Normal Interrupt Priority Register 1 */
328     case 15:/* Normal Interrupt Priority Register 0 */
329         s->prio[15-(offset>>2)] = val;
330         break;
331 
332         /* Read-only registers, writes ignored */
333     case 16:/* Normal Interrupt Vector and Status register */
334     case 17:/* Fast Interrupt vector and status register */
335     case 18:/* Interrupt source register high */
336     case 19:/* Interrupt source register low */
337         return;
338 
339     case 20:/* Interrupt Force Register high */
340         s->pending = (s->pending & 0xffffffffULL) | (val << 32);
341         break;
342 
343     case 21:/* Interrupt Force Register low */
344         s->pending = (s->pending & 0xffffffff00000000ULL) | val;
345         break;
346 
347     case 22:/* Normal Interrupt Pending Register High */
348     case 23:/* Normal Interrupt Pending Register Low */
349     case 24: /* Fast Interrupt Pending Register High  */
350     case 25: /* Fast Interrupt Pending Register Low  */
351         return;
352 
353     default:
354         IPRINTF("imx_avic_write: Bad offset %x\n", (int)offset);
355     }
356     imx_avic_update(s);
357 }
358 
359 static const MemoryRegionOps imx_avic_ops = {
360     .read = imx_avic_read,
361     .write = imx_avic_write,
362     .endianness = DEVICE_NATIVE_ENDIAN,
363 };
364 
365 static void imx_avic_reset(DeviceState *dev)
366 {
367     IMXAVICState *s = IMX_AVIC(dev);
368 
369     s->pending = 0;
370     s->enabled = 0;
371     s->is_fiq = 0;
372     s->intmask = 0x1f;
373     s->intcntl = 0;
374     memset(s->prio, 0, sizeof s->prio);
375 }
376 
377 static int imx_avic_init(SysBusDevice *sbd)
378 {
379     DeviceState *dev = DEVICE(sbd);
380     IMXAVICState *s = IMX_AVIC(dev);
381 
382     memory_region_init_io(&s->iomem, OBJECT(s), &imx_avic_ops, s,
383                           "imx_avic", 0x1000);
384     sysbus_init_mmio(sbd, &s->iomem);
385 
386     qdev_init_gpio_in(dev, imx_avic_set_irq, IMX_AVIC_NUM_IRQS);
387     sysbus_init_irq(sbd, &s->irq);
388     sysbus_init_irq(sbd, &s->fiq);
389 
390     return 0;
391 }
392 
393 
394 static void imx_avic_class_init(ObjectClass *klass, void *data)
395 {
396     DeviceClass *dc = DEVICE_CLASS(klass);
397     SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
398     k->init = imx_avic_init;
399     dc->vmsd = &vmstate_imx_avic;
400     dc->reset = imx_avic_reset;
401     dc->desc = "i.MX Advanced Vector Interrupt Controller";
402 }
403 
404 static const TypeInfo imx_avic_info = {
405     .name = TYPE_IMX_AVIC,
406     .parent = TYPE_SYS_BUS_DEVICE,
407     .instance_size = sizeof(IMXAVICState),
408     .class_init = imx_avic_class_init,
409 };
410 
411 static void imx_avic_register_types(void)
412 {
413     type_register_static(&imx_avic_info);
414 }
415 
416 type_init(imx_avic_register_types)
417