xref: /openbmc/qemu/hw/timer/exynos4210_mct.c (revision 37677d7d)
1 /*
2  * Samsung exynos4210 Multi Core timer
3  *
4  * Copyright (c) 2000 - 2011 Samsung Electronics Co., Ltd.
5  * All rights reserved.
6  *
7  * Evgeny Voevodin <e.voevodin@samsung.com>
8  *
9  * This program is free software; you can redistribute it and/or modify it
10  * under the terms of the GNU General Public License as published by the
11  * Free Software Foundation; either version 2 of the License, or (at your
12  * option) any later version.
13  *
14  * This program is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
17  * See the GNU General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License along
20  * with this program; if not, see <http://www.gnu.org/licenses/>.
21  */
22 
23 /*
24  * Global Timer:
25  *
26  * Consists of two timers. First represents Free Running Counter and second
27  * is used to measure interval from FRC to nearest comparator.
28  *
29  *        0                                                           UINT64_MAX
30  *        |                              timer0                             |
31  *        | <-------------------------------------------------------------- |
32  *        | --------------------------------------------frc---------------> |
33  *        |______________________________________________|__________________|
34  *                CMP0          CMP1             CMP2    |           CMP3
35  *                                                     __|            |_
36  *                                                     |     timer1     |
37  *                                                     | -------------> |
38  *                                                    frc              CMPx
39  *
40  * Problem: when implementing global timer as is, overflow arises.
41  * next_time = cur_time + period * count;
42  * period and count are 64 bits width.
43  * Lets arm timer for MCT_GT_COUNTER_STEP count and update internal G_CNT
44  * register during each event.
45  *
46  * Problem: both timers need to be implemented using MCT_XT_COUNTER_STEP because
47  * local timer contains two counters: TCNT and ICNT. TCNT == 0 -> ICNT--.
48  * IRQ is generated when ICNT riches zero. Implementation where TCNT == 0
49  * generates IRQs suffers from too frequently events. Better to have one
50  * uint64_t counter equal to TCNT*ICNT and arm ptimer.c for a minimum(TCNT*ICNT,
51  * MCT_GT_COUNTER_STEP); (yes, if target tunes ICNT * TCNT to be too low values,
52  * there is no way to avoid frequently events).
53  */
54 
55 #include "qemu/osdep.h"
56 #include "qemu/log.h"
57 #include "hw/sysbus.h"
58 #include "qemu/timer.h"
59 #include "qemu/main-loop.h"
60 #include "qemu/module.h"
61 #include "hw/ptimer.h"
62 
63 #include "hw/arm/exynos4210.h"
64 
65 //#define DEBUG_MCT
66 
67 #ifdef DEBUG_MCT
68 #define DPRINTF(fmt, ...) \
69         do { fprintf(stdout, "MCT: [%24s:%5d] " fmt, __func__, __LINE__, \
70                      ## __VA_ARGS__); } while (0)
71 #else
72 #define DPRINTF(fmt, ...) do {} while (0)
73 #endif
74 
75 #define    MCT_CFG          0x000
76 #define    G_CNT_L          0x100
77 #define    G_CNT_U          0x104
78 #define    G_CNT_WSTAT      0x110
79 #define    G_COMP0_L        0x200
80 #define    G_COMP0_U        0x204
81 #define    G_COMP0_ADD_INCR 0x208
82 #define    G_COMP1_L        0x210
83 #define    G_COMP1_U        0x214
84 #define    G_COMP1_ADD_INCR 0x218
85 #define    G_COMP2_L        0x220
86 #define    G_COMP2_U        0x224
87 #define    G_COMP2_ADD_INCR 0x228
88 #define    G_COMP3_L        0x230
89 #define    G_COMP3_U        0x234
90 #define    G_COMP3_ADD_INCR 0x238
91 #define    G_TCON           0x240
92 #define    G_INT_CSTAT      0x244
93 #define    G_INT_ENB        0x248
94 #define    G_WSTAT          0x24C
95 #define    L0_TCNTB         0x300
96 #define    L0_TCNTO         0x304
97 #define    L0_ICNTB         0x308
98 #define    L0_ICNTO         0x30C
99 #define    L0_FRCNTB        0x310
100 #define    L0_FRCNTO        0x314
101 #define    L0_TCON          0x320
102 #define    L0_INT_CSTAT     0x330
103 #define    L0_INT_ENB       0x334
104 #define    L0_WSTAT         0x340
105 #define    L1_TCNTB         0x400
106 #define    L1_TCNTO         0x404
107 #define    L1_ICNTB         0x408
108 #define    L1_ICNTO         0x40C
109 #define    L1_FRCNTB        0x410
110 #define    L1_FRCNTO        0x414
111 #define    L1_TCON          0x420
112 #define    L1_INT_CSTAT     0x430
113 #define    L1_INT_ENB       0x434
114 #define    L1_WSTAT         0x440
115 
116 #define MCT_CFG_GET_PRESCALER(x)    ((x) & 0xFF)
117 #define MCT_CFG_GET_DIVIDER(x)      (1 << ((x) >> 8 & 7))
118 
119 #define GET_G_COMP_IDX(offset)          (((offset) - G_COMP0_L) / 0x10)
120 #define GET_G_COMP_ADD_INCR_IDX(offset) (((offset) - G_COMP0_ADD_INCR) / 0x10)
121 
122 #define G_COMP_L(x) (G_COMP0_L + (x) * 0x10)
123 #define G_COMP_U(x) (G_COMP0_U + (x) * 0x10)
124 
125 #define G_COMP_ADD_INCR(x)  (G_COMP0_ADD_INCR + (x) * 0x10)
126 
127 /* MCT bits */
128 #define G_TCON_COMP_ENABLE(x)   (1 << 2 * (x))
129 #define G_TCON_AUTO_ICREMENT(x) (1 << (2 * (x) + 1))
130 #define G_TCON_TIMER_ENABLE     (1 << 8)
131 
132 #define G_INT_ENABLE(x)         (1 << (x))
133 #define G_INT_CSTAT_COMP(x)     (1 << (x))
134 
135 #define G_CNT_WSTAT_L           1
136 #define G_CNT_WSTAT_U           2
137 
138 #define G_WSTAT_COMP_L(x)       (1 << 4 * (x))
139 #define G_WSTAT_COMP_U(x)       (1 << ((4 * (x)) + 1))
140 #define G_WSTAT_COMP_ADDINCR(x) (1 << ((4 * (x)) + 2))
141 #define G_WSTAT_TCON_WRITE      (1 << 16)
142 
143 #define GET_L_TIMER_IDX(offset) ((((offset) & 0xF00) - L0_TCNTB) / 0x100)
144 #define GET_L_TIMER_CNT_REG_IDX(offset, lt_i) \
145         (((offset) - (L0_TCNTB + 0x100 * (lt_i))) >> 2)
146 
147 #define L_ICNTB_MANUAL_UPDATE   (1 << 31)
148 
149 #define L_TCON_TICK_START       (1)
150 #define L_TCON_INT_START        (1 << 1)
151 #define L_TCON_INTERVAL_MODE    (1 << 2)
152 #define L_TCON_FRC_START        (1 << 3)
153 
154 #define L_INT_CSTAT_INTCNT      (1 << 0)
155 #define L_INT_CSTAT_FRCCNT      (1 << 1)
156 
157 #define L_INT_INTENB_ICNTEIE    (1 << 0)
158 #define L_INT_INTENB_FRCEIE     (1 << 1)
159 
160 #define L_WSTAT_TCNTB_WRITE     (1 << 0)
161 #define L_WSTAT_ICNTB_WRITE     (1 << 1)
162 #define L_WSTAT_FRCCNTB_WRITE   (1 << 2)
163 #define L_WSTAT_TCON_WRITE      (1 << 3)
164 
165 enum LocalTimerRegCntIndexes {
166     L_REG_CNT_TCNTB,
167     L_REG_CNT_TCNTO,
168     L_REG_CNT_ICNTB,
169     L_REG_CNT_ICNTO,
170     L_REG_CNT_FRCCNTB,
171     L_REG_CNT_FRCCNTO,
172 
173     L_REG_CNT_AMOUNT
174 };
175 
176 #define MCT_SFR_SIZE            0x444
177 
178 #define MCT_GT_CMP_NUM          4
179 
180 #define MCT_GT_COUNTER_STEP     0x100000000ULL
181 #define MCT_LT_COUNTER_STEP     0x100000000ULL
182 #define MCT_LT_CNT_LOW_LIMIT    0x100
183 
184 /* global timer */
185 typedef struct {
186     qemu_irq  irq[MCT_GT_CMP_NUM];
187 
188     struct gregs {
189         uint64_t cnt;
190         uint32_t cnt_wstat;
191         uint32_t tcon;
192         uint32_t int_cstat;
193         uint32_t int_enb;
194         uint32_t wstat;
195         uint64_t comp[MCT_GT_CMP_NUM];
196         uint32_t comp_add_incr[MCT_GT_CMP_NUM];
197     } reg;
198 
199     uint64_t count;            /* Value FRC was armed with */
200     int32_t curr_comp;             /* Current comparator FRC is running to */
201 
202     ptimer_state *ptimer_frc;                   /* FRC timer */
203 
204 } Exynos4210MCTGT;
205 
206 /* local timer */
207 typedef struct {
208     int         id;             /* timer id */
209     qemu_irq    irq;            /* local timer irq */
210 
211     struct tick_timer {
212         uint32_t cnt_run;           /* cnt timer is running */
213         uint32_t int_run;           /* int timer is running */
214 
215         uint32_t last_icnto;
216         uint32_t last_tcnto;
217         uint32_t tcntb;             /* initial value for TCNTB */
218         uint32_t icntb;             /* initial value for ICNTB */
219 
220         /* for step mode */
221         uint64_t    distance;       /* distance to count to the next event */
222         uint64_t    progress;       /* progress when counting by steps */
223         uint64_t    count;          /* count to arm timer with */
224 
225         ptimer_state *ptimer_tick;  /* timer for tick counter */
226     } tick_timer;
227 
228     /* use ptimer.c to represent count down timer */
229 
230     ptimer_state *ptimer_frc;   /* timer for free running counter */
231 
232     /* registers */
233     struct lregs {
234         uint32_t    cnt[L_REG_CNT_AMOUNT];
235         uint32_t    tcon;
236         uint32_t    int_cstat;
237         uint32_t    int_enb;
238         uint32_t    wstat;
239     } reg;
240 
241 } Exynos4210MCTLT;
242 
243 #define TYPE_EXYNOS4210_MCT "exynos4210.mct"
244 #define EXYNOS4210_MCT(obj) \
245     OBJECT_CHECK(Exynos4210MCTState, (obj), TYPE_EXYNOS4210_MCT)
246 
247 typedef struct Exynos4210MCTState {
248     SysBusDevice parent_obj;
249 
250     MemoryRegion iomem;
251 
252     /* Registers */
253     uint32_t    reg_mct_cfg;
254 
255     Exynos4210MCTLT l_timer[2];
256     Exynos4210MCTGT g_timer;
257 
258     uint32_t    freq;                   /* all timers tick frequency, TCLK */
259 } Exynos4210MCTState;
260 
261 /*** VMState ***/
262 static const VMStateDescription vmstate_tick_timer = {
263     .name = "exynos4210.mct.tick_timer",
264     .version_id = 1,
265     .minimum_version_id = 1,
266     .fields = (VMStateField[]) {
267         VMSTATE_UINT32(cnt_run, struct tick_timer),
268         VMSTATE_UINT32(int_run, struct tick_timer),
269         VMSTATE_UINT32(last_icnto, struct tick_timer),
270         VMSTATE_UINT32(last_tcnto, struct tick_timer),
271         VMSTATE_UINT32(tcntb, struct tick_timer),
272         VMSTATE_UINT32(icntb, struct tick_timer),
273         VMSTATE_UINT64(distance, struct tick_timer),
274         VMSTATE_UINT64(progress, struct tick_timer),
275         VMSTATE_UINT64(count, struct tick_timer),
276         VMSTATE_PTIMER(ptimer_tick, struct tick_timer),
277         VMSTATE_END_OF_LIST()
278     }
279 };
280 
281 static const VMStateDescription vmstate_lregs = {
282     .name = "exynos4210.mct.lregs",
283     .version_id = 1,
284     .minimum_version_id = 1,
285     .fields = (VMStateField[]) {
286         VMSTATE_UINT32_ARRAY(cnt, struct lregs, L_REG_CNT_AMOUNT),
287         VMSTATE_UINT32(tcon, struct lregs),
288         VMSTATE_UINT32(int_cstat, struct lregs),
289         VMSTATE_UINT32(int_enb, struct lregs),
290         VMSTATE_UINT32(wstat, struct lregs),
291         VMSTATE_END_OF_LIST()
292     }
293 };
294 
295 static const VMStateDescription vmstate_exynos4210_mct_lt = {
296     .name = "exynos4210.mct.lt",
297     .version_id = 1,
298     .minimum_version_id = 1,
299     .fields = (VMStateField[]) {
300         VMSTATE_INT32(id, Exynos4210MCTLT),
301         VMSTATE_STRUCT(tick_timer, Exynos4210MCTLT, 0,
302                 vmstate_tick_timer,
303                 struct tick_timer),
304         VMSTATE_PTIMER(ptimer_frc, Exynos4210MCTLT),
305         VMSTATE_STRUCT(reg, Exynos4210MCTLT, 0,
306                 vmstate_lregs,
307                 struct lregs),
308         VMSTATE_END_OF_LIST()
309     }
310 };
311 
312 static const VMStateDescription vmstate_gregs = {
313     .name = "exynos4210.mct.lregs",
314     .version_id = 1,
315     .minimum_version_id = 1,
316     .fields = (VMStateField[]) {
317         VMSTATE_UINT64(cnt, struct gregs),
318         VMSTATE_UINT32(cnt_wstat, struct gregs),
319         VMSTATE_UINT32(tcon, struct gregs),
320         VMSTATE_UINT32(int_cstat, struct gregs),
321         VMSTATE_UINT32(int_enb, struct gregs),
322         VMSTATE_UINT32(wstat, struct gregs),
323         VMSTATE_UINT64_ARRAY(comp, struct gregs, MCT_GT_CMP_NUM),
324         VMSTATE_UINT32_ARRAY(comp_add_incr, struct gregs,
325                 MCT_GT_CMP_NUM),
326         VMSTATE_END_OF_LIST()
327     }
328 };
329 
330 static const VMStateDescription vmstate_exynos4210_mct_gt = {
331     .name = "exynos4210.mct.lt",
332     .version_id = 1,
333     .minimum_version_id = 1,
334     .fields = (VMStateField[]) {
335         VMSTATE_STRUCT(reg, Exynos4210MCTGT, 0, vmstate_gregs,
336                 struct gregs),
337         VMSTATE_UINT64(count, Exynos4210MCTGT),
338         VMSTATE_INT32(curr_comp, Exynos4210MCTGT),
339         VMSTATE_PTIMER(ptimer_frc, Exynos4210MCTGT),
340         VMSTATE_END_OF_LIST()
341     }
342 };
343 
344 static const VMStateDescription vmstate_exynos4210_mct_state = {
345     .name = "exynos4210.mct",
346     .version_id = 1,
347     .minimum_version_id = 1,
348     .fields = (VMStateField[]) {
349         VMSTATE_UINT32(reg_mct_cfg, Exynos4210MCTState),
350         VMSTATE_STRUCT_ARRAY(l_timer, Exynos4210MCTState, 2, 0,
351             vmstate_exynos4210_mct_lt, Exynos4210MCTLT),
352         VMSTATE_STRUCT(g_timer, Exynos4210MCTState, 0,
353             vmstate_exynos4210_mct_gt, Exynos4210MCTGT),
354         VMSTATE_UINT32(freq, Exynos4210MCTState),
355         VMSTATE_END_OF_LIST()
356     }
357 };
358 
359 static void exynos4210_mct_update_freq(Exynos4210MCTState *s);
360 
361 /*
362  * Set counter of FRC global timer.
363  */
364 static void exynos4210_gfrc_set_count(Exynos4210MCTGT *s, uint64_t count)
365 {
366     s->count = count;
367     DPRINTF("global timer frc set count 0x%llx\n", count);
368     ptimer_set_count(s->ptimer_frc, count);
369 }
370 
371 /*
372  * Get counter of FRC global timer.
373  */
374 static uint64_t exynos4210_gfrc_get_count(Exynos4210MCTGT *s)
375 {
376     uint64_t count = 0;
377     count = ptimer_get_count(s->ptimer_frc);
378     count = s->count - count;
379     return s->reg.cnt + count;
380 }
381 
382 /*
383  * Stop global FRC timer
384  */
385 static void exynos4210_gfrc_stop(Exynos4210MCTGT *s)
386 {
387     DPRINTF("global timer frc stop\n");
388 
389     ptimer_stop(s->ptimer_frc);
390 }
391 
392 /*
393  * Start global FRC timer
394  */
395 static void exynos4210_gfrc_start(Exynos4210MCTGT *s)
396 {
397     DPRINTF("global timer frc start\n");
398 
399     ptimer_run(s->ptimer_frc, 1);
400 }
401 
402 /*
403  * Find next nearest Comparator. If current Comparator value equals to other
404  * Comparator value, skip them both
405  */
406 static int32_t exynos4210_gcomp_find(Exynos4210MCTState *s)
407 {
408     int res;
409     int i;
410     int enabled;
411     uint64_t min;
412     int min_comp_i;
413     uint64_t gfrc;
414     uint64_t distance;
415     uint64_t distance_min;
416     int comp_i;
417 
418     /* get gfrc count */
419     gfrc = exynos4210_gfrc_get_count(&s->g_timer);
420 
421     min = UINT64_MAX;
422     distance_min = UINT64_MAX;
423     comp_i = MCT_GT_CMP_NUM;
424     min_comp_i = MCT_GT_CMP_NUM;
425     enabled = 0;
426 
427     /* lookup for nearest comparator */
428     for (i = 0; i < MCT_GT_CMP_NUM; i++) {
429 
430         if (s->g_timer.reg.tcon & G_TCON_COMP_ENABLE(i)) {
431 
432             enabled = 1;
433 
434             if (s->g_timer.reg.comp[i] > gfrc) {
435                 /* Comparator is upper then FRC */
436                 distance = s->g_timer.reg.comp[i] - gfrc;
437 
438                 if (distance <= distance_min) {
439                     distance_min = distance;
440                     comp_i = i;
441                 }
442             } else {
443                 /* Comparator is below FRC, find the smallest */
444 
445                 if (s->g_timer.reg.comp[i] <= min) {
446                     min = s->g_timer.reg.comp[i];
447                     min_comp_i = i;
448                 }
449             }
450         }
451     }
452 
453     if (!enabled) {
454         /* All Comparators disabled */
455         res = -1;
456     } else if (comp_i < MCT_GT_CMP_NUM) {
457         /* Found upper Comparator */
458         res = comp_i;
459     } else {
460         /* All Comparators are below or equal to FRC  */
461         res = min_comp_i;
462     }
463 
464     DPRINTF("found comparator %d: comp 0x%llx distance 0x%llx, gfrc 0x%llx\n",
465             res,
466             s->g_timer.reg.comp[res],
467             distance_min,
468             gfrc);
469 
470     return res;
471 }
472 
473 /*
474  * Get distance to nearest Comparator
475  */
476 static uint64_t exynos4210_gcomp_get_distance(Exynos4210MCTState *s, int32_t id)
477 {
478     if (id == -1) {
479         /* no enabled Comparators, choose max distance */
480         return MCT_GT_COUNTER_STEP;
481     }
482     if (s->g_timer.reg.comp[id] - s->g_timer.reg.cnt < MCT_GT_COUNTER_STEP) {
483         return s->g_timer.reg.comp[id] - s->g_timer.reg.cnt;
484     } else {
485         return MCT_GT_COUNTER_STEP;
486     }
487 }
488 
489 /*
490  * Restart global FRC timer
491  */
492 static void exynos4210_gfrc_restart(Exynos4210MCTState *s)
493 {
494     uint64_t distance;
495 
496     exynos4210_gfrc_stop(&s->g_timer);
497 
498     s->g_timer.curr_comp = exynos4210_gcomp_find(s);
499 
500     distance = exynos4210_gcomp_get_distance(s, s->g_timer.curr_comp);
501 
502     if (distance > MCT_GT_COUNTER_STEP || !distance) {
503         distance = MCT_GT_COUNTER_STEP;
504     }
505 
506     exynos4210_gfrc_set_count(&s->g_timer, distance);
507     exynos4210_gfrc_start(&s->g_timer);
508 }
509 
510 /*
511  * Raise global timer CMP IRQ
512  */
513 static void exynos4210_gcomp_raise_irq(void *opaque, uint32_t id)
514 {
515     Exynos4210MCTGT *s = opaque;
516 
517     /* If CSTAT is pending and IRQ is enabled */
518     if ((s->reg.int_cstat & G_INT_CSTAT_COMP(id)) &&
519             (s->reg.int_enb & G_INT_ENABLE(id))) {
520         DPRINTF("gcmp timer[%d] IRQ\n", id);
521         qemu_irq_raise(s->irq[id]);
522     }
523 }
524 
525 /*
526  * Lower global timer CMP IRQ
527  */
528 static void exynos4210_gcomp_lower_irq(void *opaque, uint32_t id)
529 {
530     Exynos4210MCTGT *s = opaque;
531     qemu_irq_lower(s->irq[id]);
532 }
533 
534 /*
535  * Global timer FRC event handler.
536  * Each event occurs when internal counter reaches counter + MCT_GT_COUNTER_STEP
537  * Every time we arm global FRC timer to count for MCT_GT_COUNTER_STEP value
538  */
539 static void exynos4210_gfrc_event(void *opaque)
540 {
541     Exynos4210MCTState *s = (Exynos4210MCTState *)opaque;
542     int i;
543     uint64_t distance;
544 
545     DPRINTF("\n");
546 
547     s->g_timer.reg.cnt += s->g_timer.count;
548 
549     /* Process all comparators */
550     for (i = 0; i < MCT_GT_CMP_NUM; i++) {
551 
552         if (s->g_timer.reg.cnt == s->g_timer.reg.comp[i]) {
553             /* reached nearest comparator */
554 
555             s->g_timer.reg.int_cstat |= G_INT_CSTAT_COMP(i);
556 
557             /* Auto increment */
558             if (s->g_timer.reg.tcon & G_TCON_AUTO_ICREMENT(i)) {
559                 s->g_timer.reg.comp[i] += s->g_timer.reg.comp_add_incr[i];
560             }
561 
562             /* IRQ */
563             exynos4210_gcomp_raise_irq(&s->g_timer, i);
564         }
565     }
566 
567     /* Reload FRC to reach nearest comparator */
568     s->g_timer.curr_comp = exynos4210_gcomp_find(s);
569     distance = exynos4210_gcomp_get_distance(s, s->g_timer.curr_comp);
570     if (distance > MCT_GT_COUNTER_STEP || !distance) {
571         distance = MCT_GT_COUNTER_STEP;
572     }
573     exynos4210_gfrc_set_count(&s->g_timer, distance);
574 
575     exynos4210_gfrc_start(&s->g_timer);
576 }
577 
578 /*
579  * Get counter of FRC local timer.
580  */
581 static uint64_t exynos4210_lfrc_get_count(Exynos4210MCTLT *s)
582 {
583     return ptimer_get_count(s->ptimer_frc);
584 }
585 
586 /*
587  * Set counter of FRC local timer.
588  */
589 static void exynos4210_lfrc_update_count(Exynos4210MCTLT *s)
590 {
591     if (!s->reg.cnt[L_REG_CNT_FRCCNTB]) {
592         ptimer_set_count(s->ptimer_frc, MCT_LT_COUNTER_STEP);
593     } else {
594         ptimer_set_count(s->ptimer_frc, s->reg.cnt[L_REG_CNT_FRCCNTB]);
595     }
596 }
597 
598 /*
599  * Start local FRC timer
600  */
601 static void exynos4210_lfrc_start(Exynos4210MCTLT *s)
602 {
603     ptimer_run(s->ptimer_frc, 1);
604 }
605 
606 /*
607  * Stop local FRC timer
608  */
609 static void exynos4210_lfrc_stop(Exynos4210MCTLT *s)
610 {
611     ptimer_stop(s->ptimer_frc);
612 }
613 
614 /*
615  * Local timer free running counter tick handler
616  */
617 static void exynos4210_lfrc_event(void *opaque)
618 {
619     Exynos4210MCTLT * s = (Exynos4210MCTLT *)opaque;
620 
621     /* local frc expired */
622 
623     DPRINTF("\n");
624 
625     s->reg.int_cstat |= L_INT_CSTAT_FRCCNT;
626 
627     /* update frc counter */
628     exynos4210_lfrc_update_count(s);
629 
630     /* raise irq */
631     if (s->reg.int_enb & L_INT_INTENB_FRCEIE) {
632         qemu_irq_raise(s->irq);
633     }
634 
635     /*  we reached here, this means that timer is enabled */
636     exynos4210_lfrc_start(s);
637 }
638 
639 static uint32_t exynos4210_ltick_int_get_cnto(struct tick_timer *s);
640 static uint32_t exynos4210_ltick_cnt_get_cnto(struct tick_timer *s);
641 static void exynos4210_ltick_recalc_count(struct tick_timer *s);
642 
643 /*
644  * Action on enabling local tick int timer
645  */
646 static void exynos4210_ltick_int_start(struct tick_timer *s)
647 {
648     if (!s->int_run) {
649         s->int_run = 1;
650     }
651 }
652 
653 /*
654  * Action on disabling local tick int timer
655  */
656 static void exynos4210_ltick_int_stop(struct tick_timer *s)
657 {
658     if (s->int_run) {
659         s->last_icnto = exynos4210_ltick_int_get_cnto(s);
660         s->int_run = 0;
661     }
662 }
663 
664 /*
665  * Get count for INT timer
666  */
667 static uint32_t exynos4210_ltick_int_get_cnto(struct tick_timer *s)
668 {
669     uint32_t icnto;
670     uint64_t remain;
671     uint64_t count;
672     uint64_t counted;
673     uint64_t cur_progress;
674 
675     count = ptimer_get_count(s->ptimer_tick);
676     if (count) {
677         /* timer is still counting, called not from event */
678         counted = s->count - ptimer_get_count(s->ptimer_tick);
679         cur_progress = s->progress + counted;
680     } else {
681         /* timer expired earlier */
682         cur_progress = s->progress;
683     }
684 
685     remain = s->distance - cur_progress;
686 
687     if (!s->int_run) {
688         /* INT is stopped. */
689         icnto = s->last_icnto;
690     } else {
691         /* Both are counting */
692         icnto = remain / s->tcntb;
693     }
694 
695     return icnto;
696 }
697 
698 /*
699  * Start local tick cnt timer.
700  */
701 static void exynos4210_ltick_cnt_start(struct tick_timer *s)
702 {
703     if (!s->cnt_run) {
704 
705         exynos4210_ltick_recalc_count(s);
706         ptimer_set_count(s->ptimer_tick, s->count);
707         ptimer_run(s->ptimer_tick, 1);
708 
709         s->cnt_run = 1;
710     }
711 }
712 
713 /*
714  * Stop local tick cnt timer.
715  */
716 static void exynos4210_ltick_cnt_stop(struct tick_timer *s)
717 {
718     if (s->cnt_run) {
719 
720         s->last_tcnto = exynos4210_ltick_cnt_get_cnto(s);
721 
722         if (s->int_run) {
723             exynos4210_ltick_int_stop(s);
724         }
725 
726         ptimer_stop(s->ptimer_tick);
727 
728         s->cnt_run = 0;
729     }
730 }
731 
732 /*
733  * Get counter for CNT timer
734  */
735 static uint32_t exynos4210_ltick_cnt_get_cnto(struct tick_timer *s)
736 {
737     uint32_t tcnto;
738     uint32_t icnto;
739     uint64_t remain;
740     uint64_t counted;
741     uint64_t count;
742     uint64_t cur_progress;
743 
744     count = ptimer_get_count(s->ptimer_tick);
745     if (count) {
746         /* timer is still counting, called not from event */
747         counted = s->count - ptimer_get_count(s->ptimer_tick);
748         cur_progress = s->progress + counted;
749     } else {
750         /* timer expired earlier */
751         cur_progress = s->progress;
752     }
753 
754     remain = s->distance - cur_progress;
755 
756     if (!s->cnt_run) {
757         /* Both are stopped. */
758         tcnto = s->last_tcnto;
759     } else if (!s->int_run) {
760         /* INT counter is stopped, progress is by CNT timer */
761         tcnto = remain % s->tcntb;
762     } else {
763         /* Both are counting */
764         icnto = remain / s->tcntb;
765         if (icnto) {
766             tcnto = remain % (icnto * s->tcntb);
767         } else {
768             tcnto = remain % s->tcntb;
769         }
770     }
771 
772     return tcnto;
773 }
774 
775 /*
776  * Set new values of counters for CNT and INT timers
777  */
778 static void exynos4210_ltick_set_cntb(struct tick_timer *s, uint32_t new_cnt,
779         uint32_t new_int)
780 {
781     uint32_t cnt_stopped = 0;
782     uint32_t int_stopped = 0;
783 
784     if (s->cnt_run) {
785         exynos4210_ltick_cnt_stop(s);
786         cnt_stopped = 1;
787     }
788 
789     if (s->int_run) {
790         exynos4210_ltick_int_stop(s);
791         int_stopped = 1;
792     }
793 
794     s->tcntb = new_cnt + 1;
795     s->icntb = new_int + 1;
796 
797     if (cnt_stopped) {
798         exynos4210_ltick_cnt_start(s);
799     }
800     if (int_stopped) {
801         exynos4210_ltick_int_start(s);
802     }
803 
804 }
805 
806 /*
807  * Calculate new counter value for tick timer
808  */
809 static void exynos4210_ltick_recalc_count(struct tick_timer *s)
810 {
811     uint64_t to_count;
812 
813     if ((s->cnt_run && s->last_tcnto) || (s->int_run && s->last_icnto)) {
814         /*
815          * one or both timers run and not counted to the end;
816          * distance is not passed, recalculate with last_tcnto * last_icnto
817          */
818 
819         if (s->last_tcnto) {
820             to_count = (uint64_t)s->last_tcnto * s->last_icnto;
821         } else {
822             to_count = s->last_icnto;
823         }
824     } else {
825         /* distance is passed, recalculate with tcnto * icnto */
826         if (s->icntb) {
827             s->distance = (uint64_t)s->tcntb * s->icntb;
828         } else {
829             s->distance = s->tcntb;
830         }
831 
832         to_count = s->distance;
833         s->progress = 0;
834     }
835 
836     if (to_count > MCT_LT_COUNTER_STEP) {
837         /* count by step */
838         s->count = MCT_LT_COUNTER_STEP;
839     } else {
840         s->count = to_count;
841     }
842 }
843 
844 /*
845  * Initialize tick_timer
846  */
847 static void exynos4210_ltick_timer_init(struct tick_timer *s)
848 {
849     exynos4210_ltick_int_stop(s);
850     exynos4210_ltick_cnt_stop(s);
851 
852     s->count = 0;
853     s->distance = 0;
854     s->progress = 0;
855     s->icntb = 0;
856     s->tcntb = 0;
857 }
858 
859 /*
860  * tick_timer event.
861  * Raises when abstract tick_timer expires.
862  */
863 static void exynos4210_ltick_timer_event(struct tick_timer *s)
864 {
865     s->progress += s->count;
866 }
867 
868 /*
869  * Local timer tick counter handler.
870  * Don't use reloaded timers. If timer counter = zero
871  * then handler called but after handler finished no
872  * timer reload occurs.
873  */
874 static void exynos4210_ltick_event(void *opaque)
875 {
876     Exynos4210MCTLT * s = (Exynos4210MCTLT *)opaque;
877     uint32_t tcnto;
878     uint32_t icnto;
879 #ifdef DEBUG_MCT
880     static uint64_t time1[2] = {0};
881     static uint64_t time2[2] = {0};
882 #endif
883 
884     /* Call tick_timer event handler, it will update its tcntb and icntb. */
885     exynos4210_ltick_timer_event(&s->tick_timer);
886 
887     /* get tick_timer cnt */
888     tcnto = exynos4210_ltick_cnt_get_cnto(&s->tick_timer);
889 
890     /* get tick_timer int */
891     icnto = exynos4210_ltick_int_get_cnto(&s->tick_timer);
892 
893     /* raise IRQ if needed */
894     if (!icnto && s->reg.tcon & L_TCON_INT_START) {
895         /* INT counter enabled and expired */
896 
897         s->reg.int_cstat |= L_INT_CSTAT_INTCNT;
898 
899         /* raise interrupt if enabled */
900         if (s->reg.int_enb & L_INT_INTENB_ICNTEIE) {
901 #ifdef DEBUG_MCT
902             time2[s->id] = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
903             DPRINTF("local timer[%d] IRQ: %llx\n", s->id,
904                     time2[s->id] - time1[s->id]);
905             time1[s->id] = time2[s->id];
906 #endif
907             qemu_irq_raise(s->irq);
908         }
909 
910         /* reload ICNTB */
911         if (s->reg.tcon & L_TCON_INTERVAL_MODE) {
912             exynos4210_ltick_set_cntb(&s->tick_timer,
913                     s->reg.cnt[L_REG_CNT_TCNTB],
914                     s->reg.cnt[L_REG_CNT_ICNTB]);
915         }
916     } else {
917         /* reload TCNTB */
918         if (!tcnto) {
919             exynos4210_ltick_set_cntb(&s->tick_timer,
920                     s->reg.cnt[L_REG_CNT_TCNTB],
921                     icnto);
922         }
923     }
924 
925     /* start tick_timer cnt */
926     exynos4210_ltick_cnt_start(&s->tick_timer);
927 
928     /* start tick_timer int */
929     exynos4210_ltick_int_start(&s->tick_timer);
930 }
931 
932 /* update timer frequency */
933 static void exynos4210_mct_update_freq(Exynos4210MCTState *s)
934 {
935     uint32_t freq = s->freq;
936     s->freq = 24000000 /
937             ((MCT_CFG_GET_PRESCALER(s->reg_mct_cfg) + 1) *
938                     MCT_CFG_GET_DIVIDER(s->reg_mct_cfg));
939 
940     if (freq != s->freq) {
941         DPRINTF("freq=%dHz\n", s->freq);
942 
943         /* global timer */
944         ptimer_set_freq(s->g_timer.ptimer_frc, s->freq);
945 
946         /* local timer */
947         ptimer_set_freq(s->l_timer[0].tick_timer.ptimer_tick, s->freq);
948         ptimer_set_freq(s->l_timer[0].ptimer_frc, s->freq);
949         ptimer_set_freq(s->l_timer[1].tick_timer.ptimer_tick, s->freq);
950         ptimer_set_freq(s->l_timer[1].ptimer_frc, s->freq);
951     }
952 }
953 
954 /* set defaul_timer values for all fields */
955 static void exynos4210_mct_reset(DeviceState *d)
956 {
957     Exynos4210MCTState *s = EXYNOS4210_MCT(d);
958     uint32_t i;
959 
960     s->reg_mct_cfg = 0;
961 
962     /* global timer */
963     memset(&s->g_timer.reg, 0, sizeof(s->g_timer.reg));
964     exynos4210_gfrc_stop(&s->g_timer);
965 
966     /* local timer */
967     memset(s->l_timer[0].reg.cnt, 0, sizeof(s->l_timer[0].reg.cnt));
968     memset(s->l_timer[1].reg.cnt, 0, sizeof(s->l_timer[1].reg.cnt));
969     for (i = 0; i < 2; i++) {
970         s->l_timer[i].reg.int_cstat = 0;
971         s->l_timer[i].reg.int_enb = 0;
972         s->l_timer[i].reg.tcon = 0;
973         s->l_timer[i].reg.wstat = 0;
974         s->l_timer[i].tick_timer.count = 0;
975         s->l_timer[i].tick_timer.distance = 0;
976         s->l_timer[i].tick_timer.progress = 0;
977         ptimer_stop(s->l_timer[i].ptimer_frc);
978 
979         exynos4210_ltick_timer_init(&s->l_timer[i].tick_timer);
980     }
981 
982     exynos4210_mct_update_freq(s);
983 
984 }
985 
986 /* Multi Core Timer read */
987 static uint64_t exynos4210_mct_read(void *opaque, hwaddr offset,
988         unsigned size)
989 {
990     Exynos4210MCTState *s = (Exynos4210MCTState *)opaque;
991     int index;
992     int shift;
993     uint64_t count;
994     uint32_t value;
995     int lt_i;
996 
997     switch (offset) {
998 
999     case MCT_CFG:
1000         value = s->reg_mct_cfg;
1001         break;
1002 
1003     case G_CNT_L: case G_CNT_U:
1004         shift = 8 * (offset & 0x4);
1005         count = exynos4210_gfrc_get_count(&s->g_timer);
1006         value = UINT32_MAX & (count >> shift);
1007         DPRINTF("read FRC=0x%llx\n", count);
1008         break;
1009 
1010     case G_CNT_WSTAT:
1011         value = s->g_timer.reg.cnt_wstat;
1012         break;
1013 
1014     case G_COMP_L(0): case G_COMP_L(1): case G_COMP_L(2): case G_COMP_L(3):
1015     case G_COMP_U(0): case G_COMP_U(1): case G_COMP_U(2): case G_COMP_U(3):
1016         index = GET_G_COMP_IDX(offset);
1017         shift = 8 * (offset & 0x4);
1018         value = UINT32_MAX & (s->g_timer.reg.comp[index] >> shift);
1019     break;
1020 
1021     case G_TCON:
1022         value = s->g_timer.reg.tcon;
1023         break;
1024 
1025     case G_INT_CSTAT:
1026         value = s->g_timer.reg.int_cstat;
1027         break;
1028 
1029     case G_INT_ENB:
1030         value = s->g_timer.reg.int_enb;
1031         break;
1032     case G_WSTAT:
1033         value = s->g_timer.reg.wstat;
1034         break;
1035 
1036     case G_COMP0_ADD_INCR: case G_COMP1_ADD_INCR:
1037     case G_COMP2_ADD_INCR: case G_COMP3_ADD_INCR:
1038         value = s->g_timer.reg.comp_add_incr[GET_G_COMP_ADD_INCR_IDX(offset)];
1039         break;
1040 
1041         /* Local timers */
1042     case L0_TCNTB: case L0_ICNTB: case L0_FRCNTB:
1043     case L1_TCNTB: case L1_ICNTB: case L1_FRCNTB:
1044         lt_i = GET_L_TIMER_IDX(offset);
1045         index = GET_L_TIMER_CNT_REG_IDX(offset, lt_i);
1046         value = s->l_timer[lt_i].reg.cnt[index];
1047         break;
1048 
1049     case L0_TCNTO: case L1_TCNTO:
1050         lt_i = GET_L_TIMER_IDX(offset);
1051 
1052         value = exynos4210_ltick_cnt_get_cnto(&s->l_timer[lt_i].tick_timer);
1053         DPRINTF("local timer[%d] read TCNTO %x\n", lt_i, value);
1054         break;
1055 
1056     case L0_ICNTO: case L1_ICNTO:
1057         lt_i = GET_L_TIMER_IDX(offset);
1058 
1059         value = exynos4210_ltick_int_get_cnto(&s->l_timer[lt_i].tick_timer);
1060         DPRINTF("local timer[%d] read ICNTO %x\n", lt_i, value);
1061         break;
1062 
1063     case L0_FRCNTO: case L1_FRCNTO:
1064         lt_i = GET_L_TIMER_IDX(offset);
1065 
1066         value = exynos4210_lfrc_get_count(&s->l_timer[lt_i]);
1067         break;
1068 
1069     case L0_TCON: case L1_TCON:
1070         lt_i = ((offset & 0xF00) - L0_TCNTB) / 0x100;
1071         value = s->l_timer[lt_i].reg.tcon;
1072         break;
1073 
1074     case L0_INT_CSTAT: case L1_INT_CSTAT:
1075         lt_i = ((offset & 0xF00) - L0_TCNTB) / 0x100;
1076         value = s->l_timer[lt_i].reg.int_cstat;
1077         break;
1078 
1079     case L0_INT_ENB: case L1_INT_ENB:
1080         lt_i = ((offset & 0xF00) - L0_TCNTB) / 0x100;
1081         value = s->l_timer[lt_i].reg.int_enb;
1082         break;
1083 
1084     case L0_WSTAT: case L1_WSTAT:
1085         lt_i = ((offset & 0xF00) - L0_TCNTB) / 0x100;
1086         value = s->l_timer[lt_i].reg.wstat;
1087         break;
1088 
1089     default:
1090         hw_error("exynos4210.mct: bad read offset "
1091                 TARGET_FMT_plx "\n", offset);
1092         break;
1093     }
1094     return value;
1095 }
1096 
1097 /* MCT write */
1098 static void exynos4210_mct_write(void *opaque, hwaddr offset,
1099         uint64_t value, unsigned size)
1100 {
1101     Exynos4210MCTState *s = (Exynos4210MCTState *)opaque;
1102     int index;  /* index in buffer which represents register set */
1103     int shift;
1104     int lt_i;
1105     uint64_t new_frc;
1106     uint32_t i;
1107     uint32_t old_val;
1108 #ifdef DEBUG_MCT
1109     static uint32_t icntb_max[2] = {0};
1110     static uint32_t icntb_min[2] = {UINT32_MAX, UINT32_MAX};
1111     static uint32_t tcntb_max[2] = {0};
1112     static uint32_t tcntb_min[2] = {UINT32_MAX, UINT32_MAX};
1113 #endif
1114 
1115     new_frc = s->g_timer.reg.cnt;
1116 
1117     switch (offset) {
1118 
1119     case MCT_CFG:
1120         s->reg_mct_cfg = value;
1121         exynos4210_mct_update_freq(s);
1122         break;
1123 
1124     case G_CNT_L:
1125     case G_CNT_U:
1126         if (offset == G_CNT_L) {
1127 
1128             DPRINTF("global timer write to reg.cntl %llx\n", value);
1129 
1130             new_frc = (s->g_timer.reg.cnt & (uint64_t)UINT32_MAX << 32) + value;
1131             s->g_timer.reg.cnt_wstat |= G_CNT_WSTAT_L;
1132         }
1133         if (offset == G_CNT_U) {
1134 
1135             DPRINTF("global timer write to reg.cntu %llx\n", value);
1136 
1137             new_frc = (s->g_timer.reg.cnt & UINT32_MAX) +
1138                     ((uint64_t)value << 32);
1139             s->g_timer.reg.cnt_wstat |= G_CNT_WSTAT_U;
1140         }
1141 
1142         s->g_timer.reg.cnt = new_frc;
1143         exynos4210_gfrc_restart(s);
1144         break;
1145 
1146     case G_CNT_WSTAT:
1147         s->g_timer.reg.cnt_wstat &= ~(value);
1148         break;
1149 
1150     case G_COMP_L(0): case G_COMP_L(1): case G_COMP_L(2): case G_COMP_L(3):
1151     case G_COMP_U(0): case G_COMP_U(1): case G_COMP_U(2): case G_COMP_U(3):
1152         index = GET_G_COMP_IDX(offset);
1153         shift = 8 * (offset & 0x4);
1154         s->g_timer.reg.comp[index] =
1155                 (s->g_timer.reg.comp[index] &
1156                 (((uint64_t)UINT32_MAX << 32) >> shift)) +
1157                 (value << shift);
1158 
1159         DPRINTF("comparator %d write 0x%llx val << %d\n", index, value, shift);
1160 
1161         if (offset & 0x4) {
1162             s->g_timer.reg.wstat |= G_WSTAT_COMP_U(index);
1163         } else {
1164             s->g_timer.reg.wstat |= G_WSTAT_COMP_L(index);
1165         }
1166 
1167         exynos4210_gfrc_restart(s);
1168         break;
1169 
1170     case G_TCON:
1171         old_val = s->g_timer.reg.tcon;
1172         s->g_timer.reg.tcon = value;
1173         s->g_timer.reg.wstat |= G_WSTAT_TCON_WRITE;
1174 
1175         DPRINTF("global timer write to reg.g_tcon %llx\n", value);
1176 
1177         /* Start FRC if transition from disabled to enabled */
1178         if ((value & G_TCON_TIMER_ENABLE) > (old_val &
1179                 G_TCON_TIMER_ENABLE)) {
1180             exynos4210_gfrc_start(&s->g_timer);
1181         }
1182         if ((value & G_TCON_TIMER_ENABLE) < (old_val &
1183                 G_TCON_TIMER_ENABLE)) {
1184             exynos4210_gfrc_stop(&s->g_timer);
1185         }
1186 
1187         /* Start CMP if transition from disabled to enabled */
1188         for (i = 0; i < MCT_GT_CMP_NUM; i++) {
1189             if ((value & G_TCON_COMP_ENABLE(i)) != (old_val &
1190                     G_TCON_COMP_ENABLE(i))) {
1191                 exynos4210_gfrc_restart(s);
1192             }
1193         }
1194         break;
1195 
1196     case G_INT_CSTAT:
1197         s->g_timer.reg.int_cstat &= ~(value);
1198         for (i = 0; i < MCT_GT_CMP_NUM; i++) {
1199             if (value & G_INT_CSTAT_COMP(i)) {
1200                 exynos4210_gcomp_lower_irq(&s->g_timer, i);
1201             }
1202         }
1203         break;
1204 
1205     case G_INT_ENB:
1206         /* Raise IRQ if transition from disabled to enabled and CSTAT pending */
1207         for (i = 0; i < MCT_GT_CMP_NUM; i++) {
1208             if ((value & G_INT_ENABLE(i)) > (s->g_timer.reg.tcon &
1209                     G_INT_ENABLE(i))) {
1210                 if (s->g_timer.reg.int_cstat & G_INT_CSTAT_COMP(i)) {
1211                     exynos4210_gcomp_raise_irq(&s->g_timer, i);
1212                 }
1213             }
1214 
1215             if ((value & G_INT_ENABLE(i)) < (s->g_timer.reg.tcon &
1216                     G_INT_ENABLE(i))) {
1217                 exynos4210_gcomp_lower_irq(&s->g_timer, i);
1218             }
1219         }
1220 
1221         DPRINTF("global timer INT enable %llx\n", value);
1222         s->g_timer.reg.int_enb = value;
1223         break;
1224 
1225     case G_WSTAT:
1226         s->g_timer.reg.wstat &= ~(value);
1227         break;
1228 
1229     case G_COMP0_ADD_INCR: case G_COMP1_ADD_INCR:
1230     case G_COMP2_ADD_INCR: case G_COMP3_ADD_INCR:
1231         index = GET_G_COMP_ADD_INCR_IDX(offset);
1232         s->g_timer.reg.comp_add_incr[index] = value;
1233         s->g_timer.reg.wstat |= G_WSTAT_COMP_ADDINCR(index);
1234         break;
1235 
1236         /* Local timers */
1237     case L0_TCON: case L1_TCON:
1238         lt_i = GET_L_TIMER_IDX(offset);
1239         old_val = s->l_timer[lt_i].reg.tcon;
1240 
1241         s->l_timer[lt_i].reg.wstat |= L_WSTAT_TCON_WRITE;
1242         s->l_timer[lt_i].reg.tcon = value;
1243 
1244         /* Stop local CNT */
1245         if ((value & L_TCON_TICK_START) <
1246                 (old_val & L_TCON_TICK_START)) {
1247             DPRINTF("local timer[%d] stop cnt\n", lt_i);
1248             exynos4210_ltick_cnt_stop(&s->l_timer[lt_i].tick_timer);
1249         }
1250 
1251         /* Stop local INT */
1252         if ((value & L_TCON_INT_START) <
1253                 (old_val & L_TCON_INT_START)) {
1254             DPRINTF("local timer[%d] stop int\n", lt_i);
1255             exynos4210_ltick_int_stop(&s->l_timer[lt_i].tick_timer);
1256         }
1257 
1258         /* Start local CNT */
1259         if ((value & L_TCON_TICK_START) >
1260         (old_val & L_TCON_TICK_START)) {
1261             DPRINTF("local timer[%d] start cnt\n", lt_i);
1262             exynos4210_ltick_cnt_start(&s->l_timer[lt_i].tick_timer);
1263         }
1264 
1265         /* Start local INT */
1266         if ((value & L_TCON_INT_START) >
1267         (old_val & L_TCON_INT_START)) {
1268             DPRINTF("local timer[%d] start int\n", lt_i);
1269             exynos4210_ltick_int_start(&s->l_timer[lt_i].tick_timer);
1270         }
1271 
1272         /* Start or Stop local FRC if TCON changed */
1273         if ((value & L_TCON_FRC_START) >
1274         (s->l_timer[lt_i].reg.tcon & L_TCON_FRC_START)) {
1275             DPRINTF("local timer[%d] start frc\n", lt_i);
1276             exynos4210_lfrc_start(&s->l_timer[lt_i]);
1277         }
1278         if ((value & L_TCON_FRC_START) <
1279                 (s->l_timer[lt_i].reg.tcon & L_TCON_FRC_START)) {
1280             DPRINTF("local timer[%d] stop frc\n", lt_i);
1281             exynos4210_lfrc_stop(&s->l_timer[lt_i]);
1282         }
1283         break;
1284 
1285     case L0_TCNTB: case L1_TCNTB:
1286         lt_i = GET_L_TIMER_IDX(offset);
1287         index = GET_L_TIMER_CNT_REG_IDX(offset, lt_i);
1288 
1289         /*
1290          * TCNTB is updated to internal register only after CNT expired.
1291          * Due to this we should reload timer to nearest moment when CNT is
1292          * expired and then in event handler update tcntb to new TCNTB value.
1293          */
1294         exynos4210_ltick_set_cntb(&s->l_timer[lt_i].tick_timer, value,
1295                 s->l_timer[lt_i].tick_timer.icntb);
1296 
1297         s->l_timer[lt_i].reg.wstat |= L_WSTAT_TCNTB_WRITE;
1298         s->l_timer[lt_i].reg.cnt[L_REG_CNT_TCNTB] = value;
1299 
1300 #ifdef DEBUG_MCT
1301         if (tcntb_min[lt_i] > value) {
1302             tcntb_min[lt_i] = value;
1303         }
1304         if (tcntb_max[lt_i] < value) {
1305             tcntb_max[lt_i] = value;
1306         }
1307         DPRINTF("local timer[%d] TCNTB write %llx; max=%x, min=%x\n",
1308                 lt_i, value, tcntb_max[lt_i], tcntb_min[lt_i]);
1309 #endif
1310         break;
1311 
1312     case L0_ICNTB: case L1_ICNTB:
1313         lt_i = GET_L_TIMER_IDX(offset);
1314         index = GET_L_TIMER_CNT_REG_IDX(offset, lt_i);
1315 
1316         s->l_timer[lt_i].reg.wstat |= L_WSTAT_ICNTB_WRITE;
1317         s->l_timer[lt_i].reg.cnt[L_REG_CNT_ICNTB] = value &
1318                 ~L_ICNTB_MANUAL_UPDATE;
1319 
1320         /*
1321          * We need to avoid too small values for TCNTB*ICNTB. If not, IRQ event
1322          * could raise too fast disallowing QEMU to execute target code.
1323          */
1324         if (s->l_timer[lt_i].reg.cnt[L_REG_CNT_ICNTB] *
1325             s->l_timer[lt_i].reg.cnt[L_REG_CNT_TCNTB] < MCT_LT_CNT_LOW_LIMIT) {
1326             if (!s->l_timer[lt_i].reg.cnt[L_REG_CNT_TCNTB]) {
1327                 s->l_timer[lt_i].reg.cnt[L_REG_CNT_ICNTB] =
1328                         MCT_LT_CNT_LOW_LIMIT;
1329             } else {
1330                 s->l_timer[lt_i].reg.cnt[L_REG_CNT_ICNTB] =
1331                         MCT_LT_CNT_LOW_LIMIT /
1332                         s->l_timer[lt_i].reg.cnt[L_REG_CNT_TCNTB];
1333             }
1334         }
1335 
1336         if (value & L_ICNTB_MANUAL_UPDATE) {
1337             exynos4210_ltick_set_cntb(&s->l_timer[lt_i].tick_timer,
1338                     s->l_timer[lt_i].tick_timer.tcntb,
1339                     s->l_timer[lt_i].reg.cnt[L_REG_CNT_ICNTB]);
1340         }
1341 
1342 #ifdef DEBUG_MCT
1343         if (icntb_min[lt_i] > value) {
1344             icntb_min[lt_i] = value;
1345         }
1346         if (icntb_max[lt_i] < value) {
1347             icntb_max[lt_i] = value;
1348         }
1349         DPRINTF("local timer[%d] ICNTB write %llx; max=%x, min=%x\n\n",
1350                 lt_i, value, icntb_max[lt_i], icntb_min[lt_i]);
1351 #endif
1352         break;
1353 
1354     case L0_FRCNTB: case L1_FRCNTB:
1355         lt_i = GET_L_TIMER_IDX(offset);
1356         index = GET_L_TIMER_CNT_REG_IDX(offset, lt_i);
1357 
1358         DPRINTF("local timer[%d] FRCNTB write %llx\n", lt_i, value);
1359 
1360         s->l_timer[lt_i].reg.wstat |= L_WSTAT_FRCCNTB_WRITE;
1361         s->l_timer[lt_i].reg.cnt[L_REG_CNT_FRCCNTB] = value;
1362 
1363         break;
1364 
1365     case L0_TCNTO: case L1_TCNTO:
1366     case L0_ICNTO: case L1_ICNTO:
1367     case L0_FRCNTO: case L1_FRCNTO:
1368         qemu_log_mask(LOG_GUEST_ERROR,
1369                       "exynos4210.mct: write to RO register " TARGET_FMT_plx,
1370                       offset);
1371         break;
1372 
1373     case L0_INT_CSTAT: case L1_INT_CSTAT:
1374         lt_i = GET_L_TIMER_IDX(offset);
1375 
1376         DPRINTF("local timer[%d] CSTAT write %llx\n", lt_i, value);
1377 
1378         s->l_timer[lt_i].reg.int_cstat &= ~value;
1379         if (!s->l_timer[lt_i].reg.int_cstat) {
1380             qemu_irq_lower(s->l_timer[lt_i].irq);
1381         }
1382         break;
1383 
1384     case L0_INT_ENB: case L1_INT_ENB:
1385         lt_i = GET_L_TIMER_IDX(offset);
1386         old_val = s->l_timer[lt_i].reg.int_enb;
1387 
1388         /* Raise Local timer IRQ if cstat is pending */
1389         if ((value & L_INT_INTENB_ICNTEIE) > (old_val & L_INT_INTENB_ICNTEIE)) {
1390             if (s->l_timer[lt_i].reg.int_cstat & L_INT_CSTAT_INTCNT) {
1391                 qemu_irq_raise(s->l_timer[lt_i].irq);
1392             }
1393         }
1394 
1395         s->l_timer[lt_i].reg.int_enb = value;
1396 
1397         break;
1398 
1399     case L0_WSTAT: case L1_WSTAT:
1400         lt_i = GET_L_TIMER_IDX(offset);
1401 
1402         s->l_timer[lt_i].reg.wstat &= ~value;
1403         break;
1404 
1405     default:
1406         hw_error("exynos4210.mct: bad write offset "
1407                 TARGET_FMT_plx "\n", offset);
1408         break;
1409     }
1410 }
1411 
1412 static const MemoryRegionOps exynos4210_mct_ops = {
1413     .read = exynos4210_mct_read,
1414     .write = exynos4210_mct_write,
1415     .endianness = DEVICE_NATIVE_ENDIAN,
1416 };
1417 
1418 /* MCT init */
1419 static void exynos4210_mct_init(Object *obj)
1420 {
1421     int i;
1422     Exynos4210MCTState *s = EXYNOS4210_MCT(obj);
1423     SysBusDevice *dev = SYS_BUS_DEVICE(obj);
1424     QEMUBH *bh[2];
1425 
1426     /* Global timer */
1427     bh[0] = qemu_bh_new(exynos4210_gfrc_event, s);
1428     s->g_timer.ptimer_frc = ptimer_init(bh[0], PTIMER_POLICY_DEFAULT);
1429     memset(&s->g_timer.reg, 0, sizeof(struct gregs));
1430 
1431     /* Local timers */
1432     for (i = 0; i < 2; i++) {
1433         bh[0] = qemu_bh_new(exynos4210_ltick_event, &s->l_timer[i]);
1434         bh[1] = qemu_bh_new(exynos4210_lfrc_event, &s->l_timer[i]);
1435         s->l_timer[i].tick_timer.ptimer_tick =
1436                                    ptimer_init(bh[0], PTIMER_POLICY_DEFAULT);
1437         s->l_timer[i].ptimer_frc = ptimer_init(bh[1], PTIMER_POLICY_DEFAULT);
1438         s->l_timer[i].id = i;
1439     }
1440 
1441     /* IRQs */
1442     for (i = 0; i < MCT_GT_CMP_NUM; i++) {
1443         sysbus_init_irq(dev, &s->g_timer.irq[i]);
1444     }
1445     for (i = 0; i < 2; i++) {
1446         sysbus_init_irq(dev, &s->l_timer[i].irq);
1447     }
1448 
1449     memory_region_init_io(&s->iomem, obj, &exynos4210_mct_ops, s,
1450                           "exynos4210-mct", MCT_SFR_SIZE);
1451     sysbus_init_mmio(dev, &s->iomem);
1452 }
1453 
1454 static void exynos4210_mct_class_init(ObjectClass *klass, void *data)
1455 {
1456     DeviceClass *dc = DEVICE_CLASS(klass);
1457 
1458     dc->reset = exynos4210_mct_reset;
1459     dc->vmsd = &vmstate_exynos4210_mct_state;
1460 }
1461 
1462 static const TypeInfo exynos4210_mct_info = {
1463     .name          = TYPE_EXYNOS4210_MCT,
1464     .parent        = TYPE_SYS_BUS_DEVICE,
1465     .instance_size = sizeof(Exynos4210MCTState),
1466     .instance_init = exynos4210_mct_init,
1467     .class_init    = exynos4210_mct_class_init,
1468 };
1469 
1470 static void exynos4210_mct_register_types(void)
1471 {
1472     type_register_static(&exynos4210_mct_info);
1473 }
1474 
1475 type_init(exynos4210_mct_register_types)
1476