xref: /openbmc/qemu/hw/intc/imx_avic.c (revision 9121d02c)
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 typedef struct {
59     SysBusDevice busdev;
60     MemoryRegion iomem;
61     uint64_t pending;
62     uint64_t enabled;
63     uint64_t is_fiq;
64     uint32_t intcntl;
65     uint32_t intmask;
66     qemu_irq irq;
67     qemu_irq fiq;
68     uint32_t prio[PRIO_WORDS]; /* Priorities are 4-bits each */
69 } IMXAVICState;
70 
71 static const VMStateDescription vmstate_imx_avic = {
72     .name = "imx-avic",
73     .version_id = 1,
74     .minimum_version_id = 1,
75     .minimum_version_id_old = 1,
76     .fields = (VMStateField[]) {
77         VMSTATE_UINT64(pending, IMXAVICState),
78         VMSTATE_UINT64(enabled, IMXAVICState),
79         VMSTATE_UINT64(is_fiq, IMXAVICState),
80         VMSTATE_UINT32(intcntl, IMXAVICState),
81         VMSTATE_UINT32(intmask, IMXAVICState),
82         VMSTATE_UINT32_ARRAY(prio, IMXAVICState, PRIO_WORDS),
83         VMSTATE_END_OF_LIST()
84     },
85 };
86 
87 
88 
89 static inline int imx_avic_prio(IMXAVICState *s, int irq)
90 {
91     uint32_t word = irq / PRIO_PER_WORD;
92     uint32_t part = 4 * (irq % PRIO_PER_WORD);
93     return 0xf & (s->prio[word] >> part);
94 }
95 
96 static inline void imx_avic_set_prio(IMXAVICState *s, int irq, int prio)
97 {
98     uint32_t word = irq / PRIO_PER_WORD;
99     uint32_t part = 4 * (irq % PRIO_PER_WORD);
100     uint32_t mask = ~(0xf << part);
101     s->prio[word] &= mask;
102     s->prio[word] |= prio << part;
103 }
104 
105 /* Update interrupts.  */
106 static void imx_avic_update(IMXAVICState *s)
107 {
108     int i;
109     uint64_t new = s->pending & s->enabled;
110     uint64_t flags;
111 
112     flags = new & s->is_fiq;
113     qemu_set_irq(s->fiq, !!flags);
114 
115     flags = new & ~s->is_fiq;
116     if (!flags || (s->intmask == 0x1f)) {
117         qemu_set_irq(s->irq, !!flags);
118         return;
119     }
120 
121     /*
122      * Take interrupt if there's a pending interrupt with
123      * priority higher than the value of intmask
124      */
125     for (i = 0; i < IMX_AVIC_NUM_IRQS; i++) {
126         if (flags & (1UL << i)) {
127             if (imx_avic_prio(s, i) > s->intmask) {
128                 qemu_set_irq(s->irq, 1);
129                 return;
130             }
131         }
132     }
133     qemu_set_irq(s->irq, 0);
134 }
135 
136 static void imx_avic_set_irq(void *opaque, int irq, int level)
137 {
138     IMXAVICState *s = (IMXAVICState *)opaque;
139 
140     if (level) {
141         DPRINTF("Raising IRQ %d, prio %d\n",
142                 irq, imx_avic_prio(s, irq));
143         s->pending |= (1ULL << irq);
144     } else {
145         DPRINTF("Clearing IRQ %d, prio %d\n",
146                 irq, imx_avic_prio(s, irq));
147         s->pending &= ~(1ULL << irq);
148     }
149 
150     imx_avic_update(s);
151 }
152 
153 
154 static uint64_t imx_avic_read(void *opaque,
155                              hwaddr offset, unsigned size)
156 {
157     IMXAVICState *s = (IMXAVICState *)opaque;
158 
159 
160     DPRINTF("read(offset = 0x%x)\n", offset >> 2);
161     switch (offset >> 2) {
162     case 0: /* INTCNTL */
163         return s->intcntl;
164 
165     case 1: /* Normal Interrupt Mask Register, NIMASK */
166         return s->intmask;
167 
168     case 2: /* Interrupt Enable Number Register, INTENNUM */
169     case 3: /* Interrupt Disable Number Register, INTDISNUM */
170         return 0;
171 
172     case 4: /* Interrupt Enabled Number Register High */
173         return s->enabled >> 32;
174 
175     case 5: /* Interrupt Enabled Number Register Low */
176         return s->enabled & 0xffffffffULL;
177 
178     case 6: /* Interrupt Type Register High */
179         return s->is_fiq >> 32;
180 
181     case 7: /* Interrupt Type Register Low */
182         return s->is_fiq & 0xffffffffULL;
183 
184     case 8: /* Normal Interrupt Priority Register 7 */
185     case 9: /* Normal Interrupt Priority Register 6 */
186     case 10:/* Normal Interrupt Priority Register 5 */
187     case 11:/* Normal Interrupt Priority Register 4 */
188     case 12:/* Normal Interrupt Priority Register 3 */
189     case 13:/* Normal Interrupt Priority Register 2 */
190     case 14:/* Normal Interrupt Priority Register 1 */
191     case 15:/* Normal Interrupt Priority Register 0 */
192         return s->prio[15-(offset>>2)];
193 
194     case 16: /* Normal interrupt vector and status register */
195     {
196         /*
197          * This returns the highest priority
198          * outstanding interrupt.  Where there is more than
199          * one pending IRQ with the same priority,
200          * take the highest numbered one.
201          */
202         uint64_t flags = s->pending & s->enabled & ~s->is_fiq;
203         int i;
204         int prio = -1;
205         int irq = -1;
206         for (i = 63; i >= 0; --i) {
207             if (flags & (1ULL<<i)) {
208                 int irq_prio = imx_avic_prio(s, i);
209                 if (irq_prio > prio) {
210                     irq = i;
211                     prio = irq_prio;
212                 }
213             }
214         }
215         if (irq >= 0) {
216             imx_avic_set_irq(s, irq, 0);
217             return irq << 16 | prio;
218         }
219         return 0xffffffffULL;
220     }
221     case 17:/* Fast Interrupt vector and status register */
222     {
223         uint64_t flags = s->pending & s->enabled & s->is_fiq;
224         int i = ctz64(flags);
225         if (i < 64) {
226             imx_avic_set_irq(opaque, i, 0);
227             return i;
228         }
229         return 0xffffffffULL;
230     }
231     case 18:/* Interrupt source register high */
232         return s->pending >> 32;
233 
234     case 19:/* Interrupt source register low */
235         return s->pending & 0xffffffffULL;
236 
237     case 20:/* Interrupt Force Register high */
238     case 21:/* Interrupt Force Register low */
239         return 0;
240 
241     case 22:/* Normal Interrupt Pending Register High */
242         return (s->pending & s->enabled & ~s->is_fiq) >> 32;
243 
244     case 23:/* Normal Interrupt Pending Register Low */
245         return (s->pending & s->enabled & ~s->is_fiq) & 0xffffffffULL;
246 
247     case 24: /* Fast Interrupt Pending Register High  */
248         return (s->pending & s->enabled & s->is_fiq) >> 32;
249 
250     case 25: /* Fast Interrupt Pending Register Low  */
251         return (s->pending & s->enabled & s->is_fiq) & 0xffffffffULL;
252 
253     case 0x40:            /* AVIC vector 0, use for WFI WAR */
254         return 0x4;
255 
256     default:
257         IPRINTF("imx_avic_read: Bad offset 0x%x\n", (int)offset);
258         return 0;
259     }
260 }
261 
262 static void imx_avic_write(void *opaque, hwaddr offset,
263                           uint64_t val, unsigned size)
264 {
265     IMXAVICState *s = (IMXAVICState *)opaque;
266 
267     /* Vector Registers not yet supported */
268     if (offset >= 0x100 && offset <= 0x2fc) {
269         IPRINTF("imx_avic_write to vector register %d ignored\n",
270                 (unsigned int)((offset - 0x100) >> 2));
271         return;
272     }
273 
274     DPRINTF("imx_avic_write(0x%x) = %x\n",
275             (unsigned int)offset>>2, (unsigned int)val);
276     switch (offset >> 2) {
277     case 0: /* Interrupt Control Register, INTCNTL */
278         s->intcntl = val & (ABFEN | NIDIS | FIDIS | NIAD | FIAD | NM);
279         if (s->intcntl & ABFEN) {
280             s->intcntl &= ~(val & ABFLAG);
281         }
282         break;
283 
284     case 1: /* Normal Interrupt Mask Register, NIMASK */
285         s->intmask = val & 0x1f;
286         break;
287 
288     case 2: /* Interrupt Enable Number Register, INTENNUM */
289         DPRINTF("enable(%d)\n", (int)val);
290         val &= 0x3f;
291         s->enabled |= (1ULL << val);
292         break;
293 
294     case 3: /* Interrupt Disable Number Register, INTDISNUM */
295         DPRINTF("disable(%d)\n", (int)val);
296         val &= 0x3f;
297         s->enabled &= ~(1ULL << val);
298         break;
299 
300     case 4: /* Interrupt Enable Number Register High */
301         s->enabled = (s->enabled & 0xffffffffULL) | (val << 32);
302         break;
303 
304     case 5: /* Interrupt Enable Number Register Low */
305         s->enabled = (s->enabled & 0xffffffff00000000ULL) | val;
306         break;
307 
308     case 6: /* Interrupt Type Register High */
309         s->is_fiq = (s->is_fiq & 0xffffffffULL) | (val << 32);
310         break;
311 
312     case 7: /* Interrupt Type Register Low */
313         s->is_fiq = (s->is_fiq & 0xffffffff00000000ULL) | val;
314         break;
315 
316     case 8: /* Normal Interrupt Priority Register 7 */
317     case 9: /* Normal Interrupt Priority Register 6 */
318     case 10:/* Normal Interrupt Priority Register 5 */
319     case 11:/* Normal Interrupt Priority Register 4 */
320     case 12:/* Normal Interrupt Priority Register 3 */
321     case 13:/* Normal Interrupt Priority Register 2 */
322     case 14:/* Normal Interrupt Priority Register 1 */
323     case 15:/* Normal Interrupt Priority Register 0 */
324         s->prio[15-(offset>>2)] = val;
325         break;
326 
327         /* Read-only registers, writes ignored */
328     case 16:/* Normal Interrupt Vector and Status register */
329     case 17:/* Fast Interrupt vector and status register */
330     case 18:/* Interrupt source register high */
331     case 19:/* Interrupt source register low */
332         return;
333 
334     case 20:/* Interrupt Force Register high */
335         s->pending = (s->pending & 0xffffffffULL) | (val << 32);
336         break;
337 
338     case 21:/* Interrupt Force Register low */
339         s->pending = (s->pending & 0xffffffff00000000ULL) | val;
340         break;
341 
342     case 22:/* Normal Interrupt Pending Register High */
343     case 23:/* Normal Interrupt Pending Register Low */
344     case 24: /* Fast Interrupt Pending Register High  */
345     case 25: /* Fast Interrupt Pending Register Low  */
346         return;
347 
348     default:
349         IPRINTF("imx_avic_write: Bad offset %x\n", (int)offset);
350     }
351     imx_avic_update(s);
352 }
353 
354 static const MemoryRegionOps imx_avic_ops = {
355     .read = imx_avic_read,
356     .write = imx_avic_write,
357     .endianness = DEVICE_NATIVE_ENDIAN,
358 };
359 
360 static void imx_avic_reset(DeviceState *dev)
361 {
362     IMXAVICState *s = container_of(dev, IMXAVICState, busdev.qdev);
363     s->pending = 0;
364     s->enabled = 0;
365     s->is_fiq = 0;
366     s->intmask = 0x1f;
367     s->intcntl = 0;
368     memset(s->prio, 0, sizeof s->prio);
369 }
370 
371 static int imx_avic_init(SysBusDevice *dev)
372 {
373     IMXAVICState *s = FROM_SYSBUS(IMXAVICState, dev);
374 
375     memory_region_init_io(&s->iomem, OBJECT(s), &imx_avic_ops, s,
376                           "imx_avic", 0x1000);
377     sysbus_init_mmio(dev, &s->iomem);
378 
379     qdev_init_gpio_in(&dev->qdev, imx_avic_set_irq, IMX_AVIC_NUM_IRQS);
380     sysbus_init_irq(dev, &s->irq);
381     sysbus_init_irq(dev, &s->fiq);
382 
383     return 0;
384 }
385 
386 
387 static void imx_avic_class_init(ObjectClass *klass, void *data)
388 {
389     DeviceClass *dc = DEVICE_CLASS(klass);
390     SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
391     k->init = imx_avic_init;
392     dc->vmsd = &vmstate_imx_avic;
393     dc->reset = imx_avic_reset;
394     dc->desc = "i.MX Advanced Vector Interrupt Controller";
395 }
396 
397 static const TypeInfo imx_avic_info = {
398     .name = "imx_avic",
399     .parent = TYPE_SYS_BUS_DEVICE,
400     .instance_size = sizeof(IMXAVICState),
401     .class_init = imx_avic_class_init,
402 };
403 
404 static void imx_avic_register_types(void)
405 {
406     type_register_static(&imx_avic_info);
407 }
408 
409 type_init(imx_avic_register_types)
410