xref: /openbmc/qemu/hw/intc/imx_avic.c (revision b45c03f5)
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  * Updated by Jean-Christophe Dubois <jcd@tribudubois.net>
11  *
12  * This code is licensed under the GPL version 2 or later.  See
13  * the COPYING file in the top-level directory.
14  *
15  * TODO: implement vectors.
16  */
17 
18 #include "hw/intc/imx_avic.h"
19 
20 #define DEBUG_INT 1
21 #undef DEBUG_INT /* comment out for debugging */
22 
23 #ifdef DEBUG_INT
24 #define DPRINTF(fmt, args...) \
25 do { printf("%s: " fmt , TYPE_IMX_AVIC, ##args); } while (0)
26 #else
27 #define DPRINTF(fmt, args...) do {} while (0)
28 #endif
29 
30 /*
31  * Define to 1 for messages about attempts to
32  * access unimplemented registers or similar.
33  */
34 #define DEBUG_IMPLEMENTATION 1
35 #if DEBUG_IMPLEMENTATION
36 #  define IPRINTF(fmt, args...) \
37     do  { fprintf(stderr, "%s: " fmt, TYPE_IMX_AVIC, ##args); } while (0)
38 #else
39 #  define IPRINTF(fmt, args...) do {} while (0)
40 #endif
41 
42 static const VMStateDescription vmstate_imx_avic = {
43     .name = TYPE_IMX_AVIC,
44     .version_id = 1,
45     .minimum_version_id = 1,
46     .fields = (VMStateField[]) {
47         VMSTATE_UINT64(pending, IMXAVICState),
48         VMSTATE_UINT64(enabled, IMXAVICState),
49         VMSTATE_UINT64(is_fiq, IMXAVICState),
50         VMSTATE_UINT32(intcntl, IMXAVICState),
51         VMSTATE_UINT32(intmask, IMXAVICState),
52         VMSTATE_UINT32_ARRAY(prio, IMXAVICState, PRIO_WORDS),
53         VMSTATE_END_OF_LIST()
54     },
55 };
56 
57 static inline int imx_avic_prio(IMXAVICState *s, int irq)
58 {
59     uint32_t word = irq / PRIO_PER_WORD;
60     uint32_t part = 4 * (irq % PRIO_PER_WORD);
61     return 0xf & (s->prio[word] >> part);
62 }
63 
64 /* Update interrupts.  */
65 static void imx_avic_update(IMXAVICState *s)
66 {
67     int i;
68     uint64_t new = s->pending & s->enabled;
69     uint64_t flags;
70 
71     flags = new & s->is_fiq;
72     qemu_set_irq(s->fiq, !!flags);
73 
74     flags = new & ~s->is_fiq;
75     if (!flags || (s->intmask == 0x1f)) {
76         qemu_set_irq(s->irq, !!flags);
77         return;
78     }
79 
80     /*
81      * Take interrupt if there's a pending interrupt with
82      * priority higher than the value of intmask
83      */
84     for (i = 0; i < IMX_AVIC_NUM_IRQS; i++) {
85         if (flags & (1UL << i)) {
86             if (imx_avic_prio(s, i) > s->intmask) {
87                 qemu_set_irq(s->irq, 1);
88                 return;
89             }
90         }
91     }
92     qemu_set_irq(s->irq, 0);
93 }
94 
95 static void imx_avic_set_irq(void *opaque, int irq, int level)
96 {
97     IMXAVICState *s = (IMXAVICState *)opaque;
98 
99     if (level) {
100         DPRINTF("Raising IRQ %d, prio %d\n",
101                 irq, imx_avic_prio(s, irq));
102         s->pending |= (1ULL << irq);
103     } else {
104         DPRINTF("Clearing IRQ %d, prio %d\n",
105                 irq, imx_avic_prio(s, irq));
106         s->pending &= ~(1ULL << irq);
107     }
108 
109     imx_avic_update(s);
110 }
111 
112 
113 static uint64_t imx_avic_read(void *opaque,
114                              hwaddr offset, unsigned size)
115 {
116     IMXAVICState *s = (IMXAVICState *)opaque;
117 
118 
119     DPRINTF("read(offset = 0x%x)\n", offset >> 2);
120     switch (offset >> 2) {
121     case 0: /* INTCNTL */
122         return s->intcntl;
123 
124     case 1: /* Normal Interrupt Mask Register, NIMASK */
125         return s->intmask;
126 
127     case 2: /* Interrupt Enable Number Register, INTENNUM */
128     case 3: /* Interrupt Disable Number Register, INTDISNUM */
129         return 0;
130 
131     case 4: /* Interrupt Enabled Number Register High */
132         return s->enabled >> 32;
133 
134     case 5: /* Interrupt Enabled Number Register Low */
135         return s->enabled & 0xffffffffULL;
136 
137     case 6: /* Interrupt Type Register High */
138         return s->is_fiq >> 32;
139 
140     case 7: /* Interrupt Type Register Low */
141         return s->is_fiq & 0xffffffffULL;
142 
143     case 8: /* Normal Interrupt Priority Register 7 */
144     case 9: /* Normal Interrupt Priority Register 6 */
145     case 10:/* Normal Interrupt Priority Register 5 */
146     case 11:/* Normal Interrupt Priority Register 4 */
147     case 12:/* Normal Interrupt Priority Register 3 */
148     case 13:/* Normal Interrupt Priority Register 2 */
149     case 14:/* Normal Interrupt Priority Register 1 */
150     case 15:/* Normal Interrupt Priority Register 0 */
151         return s->prio[15-(offset>>2)];
152 
153     case 16: /* Normal interrupt vector and status register */
154     {
155         /*
156          * This returns the highest priority
157          * outstanding interrupt.  Where there is more than
158          * one pending IRQ with the same priority,
159          * take the highest numbered one.
160          */
161         uint64_t flags = s->pending & s->enabled & ~s->is_fiq;
162         int i;
163         int prio = -1;
164         int irq = -1;
165         for (i = 63; i >= 0; --i) {
166             if (flags & (1ULL<<i)) {
167                 int irq_prio = imx_avic_prio(s, i);
168                 if (irq_prio > prio) {
169                     irq = i;
170                     prio = irq_prio;
171                 }
172             }
173         }
174         if (irq >= 0) {
175             imx_avic_set_irq(s, irq, 0);
176             return irq << 16 | prio;
177         }
178         return 0xffffffffULL;
179     }
180     case 17:/* Fast Interrupt vector and status register */
181     {
182         uint64_t flags = s->pending & s->enabled & s->is_fiq;
183         int i = ctz64(flags);
184         if (i < 64) {
185             imx_avic_set_irq(opaque, i, 0);
186             return i;
187         }
188         return 0xffffffffULL;
189     }
190     case 18:/* Interrupt source register high */
191         return s->pending >> 32;
192 
193     case 19:/* Interrupt source register low */
194         return s->pending & 0xffffffffULL;
195 
196     case 20:/* Interrupt Force Register high */
197     case 21:/* Interrupt Force Register low */
198         return 0;
199 
200     case 22:/* Normal Interrupt Pending Register High */
201         return (s->pending & s->enabled & ~s->is_fiq) >> 32;
202 
203     case 23:/* Normal Interrupt Pending Register Low */
204         return (s->pending & s->enabled & ~s->is_fiq) & 0xffffffffULL;
205 
206     case 24: /* Fast Interrupt Pending Register High  */
207         return (s->pending & s->enabled & s->is_fiq) >> 32;
208 
209     case 25: /* Fast Interrupt Pending Register Low  */
210         return (s->pending & s->enabled & s->is_fiq) & 0xffffffffULL;
211 
212     case 0x40:            /* AVIC vector 0, use for WFI WAR */
213         return 0x4;
214 
215     default:
216         IPRINTF("%s: Bad offset 0x%x\n", __func__, (int)offset);
217         return 0;
218     }
219 }
220 
221 static void imx_avic_write(void *opaque, hwaddr offset,
222                           uint64_t val, unsigned size)
223 {
224     IMXAVICState *s = (IMXAVICState *)opaque;
225 
226     /* Vector Registers not yet supported */
227     if (offset >= 0x100 && offset <= 0x2fc) {
228         IPRINTF("%s to vector register %d ignored\n", __func__,
229                 (unsigned int)((offset - 0x100) >> 2));
230         return;
231     }
232 
233     DPRINTF("%s(0x%x) = %x\n", __func__,
234             (unsigned int)offset>>2, (unsigned int)val);
235     switch (offset >> 2) {
236     case 0: /* Interrupt Control Register, INTCNTL */
237         s->intcntl = val & (ABFEN | NIDIS | FIDIS | NIAD | FIAD | NM);
238         if (s->intcntl & ABFEN) {
239             s->intcntl &= ~(val & ABFLAG);
240         }
241         break;
242 
243     case 1: /* Normal Interrupt Mask Register, NIMASK */
244         s->intmask = val & 0x1f;
245         break;
246 
247     case 2: /* Interrupt Enable Number Register, INTENNUM */
248         DPRINTF("enable(%d)\n", (int)val);
249         val &= 0x3f;
250         s->enabled |= (1ULL << val);
251         break;
252 
253     case 3: /* Interrupt Disable Number Register, INTDISNUM */
254         DPRINTF("disable(%d)\n", (int)val);
255         val &= 0x3f;
256         s->enabled &= ~(1ULL << val);
257         break;
258 
259     case 4: /* Interrupt Enable Number Register High */
260         s->enabled = (s->enabled & 0xffffffffULL) | (val << 32);
261         break;
262 
263     case 5: /* Interrupt Enable Number Register Low */
264         s->enabled = (s->enabled & 0xffffffff00000000ULL) | val;
265         break;
266 
267     case 6: /* Interrupt Type Register High */
268         s->is_fiq = (s->is_fiq & 0xffffffffULL) | (val << 32);
269         break;
270 
271     case 7: /* Interrupt Type Register Low */
272         s->is_fiq = (s->is_fiq & 0xffffffff00000000ULL) | val;
273         break;
274 
275     case 8: /* Normal Interrupt Priority Register 7 */
276     case 9: /* Normal Interrupt Priority Register 6 */
277     case 10:/* Normal Interrupt Priority Register 5 */
278     case 11:/* Normal Interrupt Priority Register 4 */
279     case 12:/* Normal Interrupt Priority Register 3 */
280     case 13:/* Normal Interrupt Priority Register 2 */
281     case 14:/* Normal Interrupt Priority Register 1 */
282     case 15:/* Normal Interrupt Priority Register 0 */
283         s->prio[15-(offset>>2)] = val;
284         break;
285 
286         /* Read-only registers, writes ignored */
287     case 16:/* Normal Interrupt Vector and Status register */
288     case 17:/* Fast Interrupt vector and status register */
289     case 18:/* Interrupt source register high */
290     case 19:/* Interrupt source register low */
291         return;
292 
293     case 20:/* Interrupt Force Register high */
294         s->pending = (s->pending & 0xffffffffULL) | (val << 32);
295         break;
296 
297     case 21:/* Interrupt Force Register low */
298         s->pending = (s->pending & 0xffffffff00000000ULL) | val;
299         break;
300 
301     case 22:/* Normal Interrupt Pending Register High */
302     case 23:/* Normal Interrupt Pending Register Low */
303     case 24: /* Fast Interrupt Pending Register High  */
304     case 25: /* Fast Interrupt Pending Register Low  */
305         return;
306 
307     default:
308         IPRINTF("%s: Bad offset %x\n", __func__, (int)offset);
309     }
310     imx_avic_update(s);
311 }
312 
313 static const MemoryRegionOps imx_avic_ops = {
314     .read = imx_avic_read,
315     .write = imx_avic_write,
316     .endianness = DEVICE_NATIVE_ENDIAN,
317 };
318 
319 static void imx_avic_reset(DeviceState *dev)
320 {
321     IMXAVICState *s = IMX_AVIC(dev);
322 
323     s->pending = 0;
324     s->enabled = 0;
325     s->is_fiq = 0;
326     s->intmask = 0x1f;
327     s->intcntl = 0;
328     memset(s->prio, 0, sizeof s->prio);
329 }
330 
331 static int imx_avic_init(SysBusDevice *sbd)
332 {
333     DeviceState *dev = DEVICE(sbd);
334     IMXAVICState *s = IMX_AVIC(dev);
335 
336     memory_region_init_io(&s->iomem, OBJECT(s), &imx_avic_ops, s,
337                           TYPE_IMX_AVIC, 0x1000);
338     sysbus_init_mmio(sbd, &s->iomem);
339 
340     qdev_init_gpio_in(dev, imx_avic_set_irq, IMX_AVIC_NUM_IRQS);
341     sysbus_init_irq(sbd, &s->irq);
342     sysbus_init_irq(sbd, &s->fiq);
343 
344     return 0;
345 }
346 
347 
348 static void imx_avic_class_init(ObjectClass *klass, void *data)
349 {
350     DeviceClass *dc = DEVICE_CLASS(klass);
351     SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
352     k->init = imx_avic_init;
353     dc->vmsd = &vmstate_imx_avic;
354     dc->reset = imx_avic_reset;
355     dc->desc = "i.MX Advanced Vector Interrupt Controller";
356 }
357 
358 static const TypeInfo imx_avic_info = {
359     .name = TYPE_IMX_AVIC,
360     .parent = TYPE_SYS_BUS_DEVICE,
361     .instance_size = sizeof(IMXAVICState),
362     .class_init = imx_avic_class_init,
363 };
364 
365 static void imx_avic_register_types(void)
366 {
367     type_register_static(&imx_avic_info);
368 }
369 
370 type_init(imx_avic_register_types)
371