xref: /openbmc/qemu/hw/timer/exynos4210_mct.c (revision 7a1bfee6)
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/hw.h"
58 #include "hw/sysbus.h"
59 #include "migration/vmstate.h"
60 #include "qemu/timer.h"
61 #include "qemu/module.h"
62 #include "hw/ptimer.h"
63 
64 #include "hw/arm/exynos4210.h"
65 #include "hw/hw.h"
66 #include "hw/irq.h"
67 
68 //#define DEBUG_MCT
69 
70 #ifdef DEBUG_MCT
71 #define DPRINTF(fmt, ...) \
72         do { fprintf(stdout, "MCT: [%24s:%5d] " fmt, __func__, __LINE__, \
73                      ## __VA_ARGS__); } while (0)
74 #else
75 #define DPRINTF(fmt, ...) do {} while (0)
76 #endif
77 
78 #define    MCT_CFG          0x000
79 #define    G_CNT_L          0x100
80 #define    G_CNT_U          0x104
81 #define    G_CNT_WSTAT      0x110
82 #define    G_COMP0_L        0x200
83 #define    G_COMP0_U        0x204
84 #define    G_COMP0_ADD_INCR 0x208
85 #define    G_COMP1_L        0x210
86 #define    G_COMP1_U        0x214
87 #define    G_COMP1_ADD_INCR 0x218
88 #define    G_COMP2_L        0x220
89 #define    G_COMP2_U        0x224
90 #define    G_COMP2_ADD_INCR 0x228
91 #define    G_COMP3_L        0x230
92 #define    G_COMP3_U        0x234
93 #define    G_COMP3_ADD_INCR 0x238
94 #define    G_TCON           0x240
95 #define    G_INT_CSTAT      0x244
96 #define    G_INT_ENB        0x248
97 #define    G_WSTAT          0x24C
98 #define    L0_TCNTB         0x300
99 #define    L0_TCNTO         0x304
100 #define    L0_ICNTB         0x308
101 #define    L0_ICNTO         0x30C
102 #define    L0_FRCNTB        0x310
103 #define    L0_FRCNTO        0x314
104 #define    L0_TCON          0x320
105 #define    L0_INT_CSTAT     0x330
106 #define    L0_INT_ENB       0x334
107 #define    L0_WSTAT         0x340
108 #define    L1_TCNTB         0x400
109 #define    L1_TCNTO         0x404
110 #define    L1_ICNTB         0x408
111 #define    L1_ICNTO         0x40C
112 #define    L1_FRCNTB        0x410
113 #define    L1_FRCNTO        0x414
114 #define    L1_TCON          0x420
115 #define    L1_INT_CSTAT     0x430
116 #define    L1_INT_ENB       0x434
117 #define    L1_WSTAT         0x440
118 
119 #define MCT_CFG_GET_PRESCALER(x)    ((x) & 0xFF)
120 #define MCT_CFG_GET_DIVIDER(x)      (1 << ((x) >> 8 & 7))
121 
122 #define GET_G_COMP_IDX(offset)          (((offset) - G_COMP0_L) / 0x10)
123 #define GET_G_COMP_ADD_INCR_IDX(offset) (((offset) - G_COMP0_ADD_INCR) / 0x10)
124 
125 #define G_COMP_L(x) (G_COMP0_L + (x) * 0x10)
126 #define G_COMP_U(x) (G_COMP0_U + (x) * 0x10)
127 
128 #define G_COMP_ADD_INCR(x)  (G_COMP0_ADD_INCR + (x) * 0x10)
129 
130 /* MCT bits */
131 #define G_TCON_COMP_ENABLE(x)   (1 << 2 * (x))
132 #define G_TCON_AUTO_ICREMENT(x) (1 << (2 * (x) + 1))
133 #define G_TCON_TIMER_ENABLE     (1 << 8)
134 
135 #define G_INT_ENABLE(x)         (1 << (x))
136 #define G_INT_CSTAT_COMP(x)     (1 << (x))
137 
138 #define G_CNT_WSTAT_L           1
139 #define G_CNT_WSTAT_U           2
140 
141 #define G_WSTAT_COMP_L(x)       (1 << 4 * (x))
142 #define G_WSTAT_COMP_U(x)       (1 << ((4 * (x)) + 1))
143 #define G_WSTAT_COMP_ADDINCR(x) (1 << ((4 * (x)) + 2))
144 #define G_WSTAT_TCON_WRITE      (1 << 16)
145 
146 #define GET_L_TIMER_IDX(offset) ((((offset) & 0xF00) - L0_TCNTB) / 0x100)
147 #define GET_L_TIMER_CNT_REG_IDX(offset, lt_i) \
148         (((offset) - (L0_TCNTB + 0x100 * (lt_i))) >> 2)
149 
150 #define L_ICNTB_MANUAL_UPDATE   (1 << 31)
151 
152 #define L_TCON_TICK_START       (1)
153 #define L_TCON_INT_START        (1 << 1)
154 #define L_TCON_INTERVAL_MODE    (1 << 2)
155 #define L_TCON_FRC_START        (1 << 3)
156 
157 #define L_INT_CSTAT_INTCNT      (1 << 0)
158 #define L_INT_CSTAT_FRCCNT      (1 << 1)
159 
160 #define L_INT_INTENB_ICNTEIE    (1 << 0)
161 #define L_INT_INTENB_FRCEIE     (1 << 1)
162 
163 #define L_WSTAT_TCNTB_WRITE     (1 << 0)
164 #define L_WSTAT_ICNTB_WRITE     (1 << 1)
165 #define L_WSTAT_FRCCNTB_WRITE   (1 << 2)
166 #define L_WSTAT_TCON_WRITE      (1 << 3)
167 
168 enum LocalTimerRegCntIndexes {
169     L_REG_CNT_TCNTB,
170     L_REG_CNT_TCNTO,
171     L_REG_CNT_ICNTB,
172     L_REG_CNT_ICNTO,
173     L_REG_CNT_FRCCNTB,
174     L_REG_CNT_FRCCNTO,
175 
176     L_REG_CNT_AMOUNT
177 };
178 
179 #define MCT_SFR_SIZE            0x444
180 
181 #define MCT_GT_CMP_NUM          4
182 
183 #define MCT_GT_COUNTER_STEP     0x100000000ULL
184 #define MCT_LT_COUNTER_STEP     0x100000000ULL
185 #define MCT_LT_CNT_LOW_LIMIT    0x100
186 
187 /* global timer */
188 typedef struct {
189     qemu_irq  irq[MCT_GT_CMP_NUM];
190 
191     struct gregs {
192         uint64_t cnt;
193         uint32_t cnt_wstat;
194         uint32_t tcon;
195         uint32_t int_cstat;
196         uint32_t int_enb;
197         uint32_t wstat;
198         uint64_t comp[MCT_GT_CMP_NUM];
199         uint32_t comp_add_incr[MCT_GT_CMP_NUM];
200     } reg;
201 
202     uint64_t count;            /* Value FRC was armed with */
203     int32_t curr_comp;             /* Current comparator FRC is running to */
204 
205     ptimer_state *ptimer_frc;                   /* FRC timer */
206 
207 } Exynos4210MCTGT;
208 
209 /* local timer */
210 typedef struct {
211     int         id;             /* timer id */
212     qemu_irq    irq;            /* local timer irq */
213 
214     struct tick_timer {
215         uint32_t cnt_run;           /* cnt timer is running */
216         uint32_t int_run;           /* int timer is running */
217 
218         uint32_t last_icnto;
219         uint32_t last_tcnto;
220         uint32_t tcntb;             /* initial value for TCNTB */
221         uint32_t icntb;             /* initial value for ICNTB */
222 
223         /* for step mode */
224         uint64_t    distance;       /* distance to count to the next event */
225         uint64_t    progress;       /* progress when counting by steps */
226         uint64_t    count;          /* count to arm timer with */
227 
228         ptimer_state *ptimer_tick;  /* timer for tick counter */
229     } tick_timer;
230 
231     /* use ptimer.c to represent count down timer */
232 
233     ptimer_state *ptimer_frc;   /* timer for free running counter */
234 
235     /* registers */
236     struct lregs {
237         uint32_t    cnt[L_REG_CNT_AMOUNT];
238         uint32_t    tcon;
239         uint32_t    int_cstat;
240         uint32_t    int_enb;
241         uint32_t    wstat;
242     } reg;
243 
244 } Exynos4210MCTLT;
245 
246 #define TYPE_EXYNOS4210_MCT "exynos4210.mct"
247 #define EXYNOS4210_MCT(obj) \
248     OBJECT_CHECK(Exynos4210MCTState, (obj), TYPE_EXYNOS4210_MCT)
249 
250 typedef struct Exynos4210MCTState {
251     SysBusDevice parent_obj;
252 
253     MemoryRegion iomem;
254 
255     /* Registers */
256     uint32_t    reg_mct_cfg;
257 
258     Exynos4210MCTLT l_timer[2];
259     Exynos4210MCTGT g_timer;
260 
261     uint32_t    freq;                   /* all timers tick frequency, TCLK */
262 } Exynos4210MCTState;
263 
264 /*** VMState ***/
265 static const VMStateDescription vmstate_tick_timer = {
266     .name = "exynos4210.mct.tick_timer",
267     .version_id = 1,
268     .minimum_version_id = 1,
269     .fields = (VMStateField[]) {
270         VMSTATE_UINT32(cnt_run, struct tick_timer),
271         VMSTATE_UINT32(int_run, struct tick_timer),
272         VMSTATE_UINT32(last_icnto, struct tick_timer),
273         VMSTATE_UINT32(last_tcnto, struct tick_timer),
274         VMSTATE_UINT32(tcntb, struct tick_timer),
275         VMSTATE_UINT32(icntb, struct tick_timer),
276         VMSTATE_UINT64(distance, struct tick_timer),
277         VMSTATE_UINT64(progress, struct tick_timer),
278         VMSTATE_UINT64(count, struct tick_timer),
279         VMSTATE_PTIMER(ptimer_tick, struct tick_timer),
280         VMSTATE_END_OF_LIST()
281     }
282 };
283 
284 static const VMStateDescription vmstate_lregs = {
285     .name = "exynos4210.mct.lregs",
286     .version_id = 1,
287     .minimum_version_id = 1,
288     .fields = (VMStateField[]) {
289         VMSTATE_UINT32_ARRAY(cnt, struct lregs, L_REG_CNT_AMOUNT),
290         VMSTATE_UINT32(tcon, struct lregs),
291         VMSTATE_UINT32(int_cstat, struct lregs),
292         VMSTATE_UINT32(int_enb, struct lregs),
293         VMSTATE_UINT32(wstat, struct lregs),
294         VMSTATE_END_OF_LIST()
295     }
296 };
297 
298 static const VMStateDescription vmstate_exynos4210_mct_lt = {
299     .name = "exynos4210.mct.lt",
300     .version_id = 1,
301     .minimum_version_id = 1,
302     .fields = (VMStateField[]) {
303         VMSTATE_INT32(id, Exynos4210MCTLT),
304         VMSTATE_STRUCT(tick_timer, Exynos4210MCTLT, 0,
305                 vmstate_tick_timer,
306                 struct tick_timer),
307         VMSTATE_PTIMER(ptimer_frc, Exynos4210MCTLT),
308         VMSTATE_STRUCT(reg, Exynos4210MCTLT, 0,
309                 vmstate_lregs,
310                 struct lregs),
311         VMSTATE_END_OF_LIST()
312     }
313 };
314 
315 static const VMStateDescription vmstate_gregs = {
316     .name = "exynos4210.mct.lregs",
317     .version_id = 1,
318     .minimum_version_id = 1,
319     .fields = (VMStateField[]) {
320         VMSTATE_UINT64(cnt, struct gregs),
321         VMSTATE_UINT32(cnt_wstat, struct gregs),
322         VMSTATE_UINT32(tcon, struct gregs),
323         VMSTATE_UINT32(int_cstat, struct gregs),
324         VMSTATE_UINT32(int_enb, struct gregs),
325         VMSTATE_UINT32(wstat, struct gregs),
326         VMSTATE_UINT64_ARRAY(comp, struct gregs, MCT_GT_CMP_NUM),
327         VMSTATE_UINT32_ARRAY(comp_add_incr, struct gregs,
328                 MCT_GT_CMP_NUM),
329         VMSTATE_END_OF_LIST()
330     }
331 };
332 
333 static const VMStateDescription vmstate_exynos4210_mct_gt = {
334     .name = "exynos4210.mct.lt",
335     .version_id = 1,
336     .minimum_version_id = 1,
337     .fields = (VMStateField[]) {
338         VMSTATE_STRUCT(reg, Exynos4210MCTGT, 0, vmstate_gregs,
339                 struct gregs),
340         VMSTATE_UINT64(count, Exynos4210MCTGT),
341         VMSTATE_INT32(curr_comp, Exynos4210MCTGT),
342         VMSTATE_PTIMER(ptimer_frc, Exynos4210MCTGT),
343         VMSTATE_END_OF_LIST()
344     }
345 };
346 
347 static const VMStateDescription vmstate_exynos4210_mct_state = {
348     .name = "exynos4210.mct",
349     .version_id = 1,
350     .minimum_version_id = 1,
351     .fields = (VMStateField[]) {
352         VMSTATE_UINT32(reg_mct_cfg, Exynos4210MCTState),
353         VMSTATE_STRUCT_ARRAY(l_timer, Exynos4210MCTState, 2, 0,
354             vmstate_exynos4210_mct_lt, Exynos4210MCTLT),
355         VMSTATE_STRUCT(g_timer, Exynos4210MCTState, 0,
356             vmstate_exynos4210_mct_gt, Exynos4210MCTGT),
357         VMSTATE_UINT32(freq, Exynos4210MCTState),
358         VMSTATE_END_OF_LIST()
359     }
360 };
361 
362 static void exynos4210_mct_update_freq(Exynos4210MCTState *s);
363 
364 /*
365  * Set counter of FRC global timer.
366  * Must be called within exynos4210_gfrc_tx_begin/commit block.
367  */
368 static void exynos4210_gfrc_set_count(Exynos4210MCTGT *s, uint64_t count)
369 {
370     s->count = count;
371     DPRINTF("global timer frc set count 0x%llx\n", count);
372     ptimer_set_count(s->ptimer_frc, count);
373 }
374 
375 /*
376  * Get counter of FRC global timer.
377  */
378 static uint64_t exynos4210_gfrc_get_count(Exynos4210MCTGT *s)
379 {
380     uint64_t count = 0;
381     count = ptimer_get_count(s->ptimer_frc);
382     count = s->count - count;
383     return s->reg.cnt + count;
384 }
385 
386 /*
387  * Stop global FRC timer
388  * Must be called within exynos4210_gfrc_tx_begin/commit block.
389  */
390 static void exynos4210_gfrc_stop(Exynos4210MCTGT *s)
391 {
392     DPRINTF("global timer frc stop\n");
393 
394     ptimer_stop(s->ptimer_frc);
395 }
396 
397 /*
398  * Start global FRC timer
399  * Must be called within exynos4210_gfrc_tx_begin/commit block.
400  */
401 static void exynos4210_gfrc_start(Exynos4210MCTGT *s)
402 {
403     DPRINTF("global timer frc start\n");
404 
405     ptimer_run(s->ptimer_frc, 1);
406 }
407 
408 /*
409  * Start ptimer transaction for global FRC timer; this is just for
410  * consistency with the way we wrap operations like stop and run.
411  */
412 static void exynos4210_gfrc_tx_begin(Exynos4210MCTGT *s)
413 {
414     ptimer_transaction_begin(s->ptimer_frc);
415 }
416 
417 /* Commit ptimer transaction for global FRC timer. */
418 static void exynos4210_gfrc_tx_commit(Exynos4210MCTGT *s)
419 {
420     ptimer_transaction_commit(s->ptimer_frc);
421 }
422 
423 /*
424  * Find next nearest Comparator. If current Comparator value equals to other
425  * Comparator value, skip them both
426  */
427 static int32_t exynos4210_gcomp_find(Exynos4210MCTState *s)
428 {
429     int res;
430     int i;
431     int enabled;
432     uint64_t min;
433     int min_comp_i;
434     uint64_t gfrc;
435     uint64_t distance;
436     uint64_t distance_min;
437     int comp_i;
438 
439     /* get gfrc count */
440     gfrc = exynos4210_gfrc_get_count(&s->g_timer);
441 
442     min = UINT64_MAX;
443     distance_min = UINT64_MAX;
444     comp_i = MCT_GT_CMP_NUM;
445     min_comp_i = MCT_GT_CMP_NUM;
446     enabled = 0;
447 
448     /* lookup for nearest comparator */
449     for (i = 0; i < MCT_GT_CMP_NUM; i++) {
450 
451         if (s->g_timer.reg.tcon & G_TCON_COMP_ENABLE(i)) {
452 
453             enabled = 1;
454 
455             if (s->g_timer.reg.comp[i] > gfrc) {
456                 /* Comparator is upper then FRC */
457                 distance = s->g_timer.reg.comp[i] - gfrc;
458 
459                 if (distance <= distance_min) {
460                     distance_min = distance;
461                     comp_i = i;
462                 }
463             } else {
464                 /* Comparator is below FRC, find the smallest */
465 
466                 if (s->g_timer.reg.comp[i] <= min) {
467                     min = s->g_timer.reg.comp[i];
468                     min_comp_i = i;
469                 }
470             }
471         }
472     }
473 
474     if (!enabled) {
475         /* All Comparators disabled */
476         res = -1;
477     } else if (comp_i < MCT_GT_CMP_NUM) {
478         /* Found upper Comparator */
479         res = comp_i;
480     } else {
481         /* All Comparators are below or equal to FRC  */
482         res = min_comp_i;
483     }
484 
485     DPRINTF("found comparator %d: comp 0x%llx distance 0x%llx, gfrc 0x%llx\n",
486             res,
487             s->g_timer.reg.comp[res],
488             distance_min,
489             gfrc);
490 
491     return res;
492 }
493 
494 /*
495  * Get distance to nearest Comparator
496  */
497 static uint64_t exynos4210_gcomp_get_distance(Exynos4210MCTState *s, int32_t id)
498 {
499     if (id == -1) {
500         /* no enabled Comparators, choose max distance */
501         return MCT_GT_COUNTER_STEP;
502     }
503     if (s->g_timer.reg.comp[id] - s->g_timer.reg.cnt < MCT_GT_COUNTER_STEP) {
504         return s->g_timer.reg.comp[id] - s->g_timer.reg.cnt;
505     } else {
506         return MCT_GT_COUNTER_STEP;
507     }
508 }
509 
510 /*
511  * Restart global FRC timer
512  * Must be called within exynos4210_gfrc_tx_begin/commit block.
513  */
514 static void exynos4210_gfrc_restart(Exynos4210MCTState *s)
515 {
516     uint64_t distance;
517 
518     exynos4210_gfrc_stop(&s->g_timer);
519 
520     s->g_timer.curr_comp = exynos4210_gcomp_find(s);
521 
522     distance = exynos4210_gcomp_get_distance(s, s->g_timer.curr_comp);
523 
524     if (distance > MCT_GT_COUNTER_STEP || !distance) {
525         distance = MCT_GT_COUNTER_STEP;
526     }
527 
528     exynos4210_gfrc_set_count(&s->g_timer, distance);
529     exynos4210_gfrc_start(&s->g_timer);
530 }
531 
532 /*
533  * Raise global timer CMP IRQ
534  */
535 static void exynos4210_gcomp_raise_irq(void *opaque, uint32_t id)
536 {
537     Exynos4210MCTGT *s = opaque;
538 
539     /* If CSTAT is pending and IRQ is enabled */
540     if ((s->reg.int_cstat & G_INT_CSTAT_COMP(id)) &&
541             (s->reg.int_enb & G_INT_ENABLE(id))) {
542         DPRINTF("gcmp timer[%d] IRQ\n", id);
543         qemu_irq_raise(s->irq[id]);
544     }
545 }
546 
547 /*
548  * Lower global timer CMP IRQ
549  */
550 static void exynos4210_gcomp_lower_irq(void *opaque, uint32_t id)
551 {
552     Exynos4210MCTGT *s = opaque;
553     qemu_irq_lower(s->irq[id]);
554 }
555 
556 /*
557  * Global timer FRC event handler.
558  * Each event occurs when internal counter reaches counter + MCT_GT_COUNTER_STEP
559  * Every time we arm global FRC timer to count for MCT_GT_COUNTER_STEP value
560  */
561 static void exynos4210_gfrc_event(void *opaque)
562 {
563     Exynos4210MCTState *s = (Exynos4210MCTState *)opaque;
564     int i;
565     uint64_t distance;
566 
567     DPRINTF("\n");
568 
569     s->g_timer.reg.cnt += s->g_timer.count;
570 
571     /* Process all comparators */
572     for (i = 0; i < MCT_GT_CMP_NUM; i++) {
573 
574         if (s->g_timer.reg.cnt == s->g_timer.reg.comp[i]) {
575             /* reached nearest comparator */
576 
577             s->g_timer.reg.int_cstat |= G_INT_CSTAT_COMP(i);
578 
579             /* Auto increment */
580             if (s->g_timer.reg.tcon & G_TCON_AUTO_ICREMENT(i)) {
581                 s->g_timer.reg.comp[i] += s->g_timer.reg.comp_add_incr[i];
582             }
583 
584             /* IRQ */
585             exynos4210_gcomp_raise_irq(&s->g_timer, i);
586         }
587     }
588 
589     /* Reload FRC to reach nearest comparator */
590     s->g_timer.curr_comp = exynos4210_gcomp_find(s);
591     distance = exynos4210_gcomp_get_distance(s, s->g_timer.curr_comp);
592     if (distance > MCT_GT_COUNTER_STEP || !distance) {
593         distance = MCT_GT_COUNTER_STEP;
594     }
595     exynos4210_gfrc_set_count(&s->g_timer, distance);
596 
597     exynos4210_gfrc_start(&s->g_timer);
598 }
599 
600 /*
601  * Get counter of FRC local timer.
602  */
603 static uint64_t exynos4210_lfrc_get_count(Exynos4210MCTLT *s)
604 {
605     return ptimer_get_count(s->ptimer_frc);
606 }
607 
608 /*
609  * Set counter of FRC local timer.
610  * Must be called from within exynos4210_lfrc_tx_begin/commit block.
611  */
612 static void exynos4210_lfrc_update_count(Exynos4210MCTLT *s)
613 {
614     if (!s->reg.cnt[L_REG_CNT_FRCCNTB]) {
615         ptimer_set_count(s->ptimer_frc, MCT_LT_COUNTER_STEP);
616     } else {
617         ptimer_set_count(s->ptimer_frc, s->reg.cnt[L_REG_CNT_FRCCNTB]);
618     }
619 }
620 
621 /*
622  * Start local FRC timer
623  * Must be called from within exynos4210_lfrc_tx_begin/commit block.
624  */
625 static void exynos4210_lfrc_start(Exynos4210MCTLT *s)
626 {
627     ptimer_run(s->ptimer_frc, 1);
628 }
629 
630 /*
631  * Stop local FRC timer
632  * Must be called from within exynos4210_lfrc_tx_begin/commit block.
633  */
634 static void exynos4210_lfrc_stop(Exynos4210MCTLT *s)
635 {
636     ptimer_stop(s->ptimer_frc);
637 }
638 
639 /* Start ptimer transaction for local FRC timer */
640 static void exynos4210_lfrc_tx_begin(Exynos4210MCTLT *s)
641 {
642     ptimer_transaction_begin(s->ptimer_frc);
643 }
644 
645 /* Commit ptimer transaction for local FRC timer */
646 static void exynos4210_lfrc_tx_commit(Exynos4210MCTLT *s)
647 {
648     ptimer_transaction_commit(s->ptimer_frc);
649 }
650 
651 /*
652  * Local timer free running counter tick handler
653  */
654 static void exynos4210_lfrc_event(void *opaque)
655 {
656     Exynos4210MCTLT * s = (Exynos4210MCTLT *)opaque;
657 
658     /* local frc expired */
659 
660     DPRINTF("\n");
661 
662     s->reg.int_cstat |= L_INT_CSTAT_FRCCNT;
663 
664     /* update frc counter */
665     exynos4210_lfrc_update_count(s);
666 
667     /* raise irq */
668     if (s->reg.int_enb & L_INT_INTENB_FRCEIE) {
669         qemu_irq_raise(s->irq);
670     }
671 
672     /*  we reached here, this means that timer is enabled */
673     exynos4210_lfrc_start(s);
674 }
675 
676 static uint32_t exynos4210_ltick_int_get_cnto(struct tick_timer *s);
677 static uint32_t exynos4210_ltick_cnt_get_cnto(struct tick_timer *s);
678 static void exynos4210_ltick_recalc_count(struct tick_timer *s);
679 
680 /*
681  * Action on enabling local tick int timer
682  */
683 static void exynos4210_ltick_int_start(struct tick_timer *s)
684 {
685     if (!s->int_run) {
686         s->int_run = 1;
687     }
688 }
689 
690 /*
691  * Action on disabling local tick int timer
692  */
693 static void exynos4210_ltick_int_stop(struct tick_timer *s)
694 {
695     if (s->int_run) {
696         s->last_icnto = exynos4210_ltick_int_get_cnto(s);
697         s->int_run = 0;
698     }
699 }
700 
701 /*
702  * Get count for INT timer
703  */
704 static uint32_t exynos4210_ltick_int_get_cnto(struct tick_timer *s)
705 {
706     uint32_t icnto;
707     uint64_t remain;
708     uint64_t count;
709     uint64_t counted;
710     uint64_t cur_progress;
711 
712     count = ptimer_get_count(s->ptimer_tick);
713     if (count) {
714         /* timer is still counting, called not from event */
715         counted = s->count - ptimer_get_count(s->ptimer_tick);
716         cur_progress = s->progress + counted;
717     } else {
718         /* timer expired earlier */
719         cur_progress = s->progress;
720     }
721 
722     remain = s->distance - cur_progress;
723 
724     if (!s->int_run) {
725         /* INT is stopped. */
726         icnto = s->last_icnto;
727     } else {
728         /* Both are counting */
729         icnto = remain / s->tcntb;
730     }
731 
732     return icnto;
733 }
734 
735 /*
736  * Start local tick cnt timer.
737  * Must be called within exynos4210_ltick_tx_begin/commit block.
738  */
739 static void exynos4210_ltick_cnt_start(struct tick_timer *s)
740 {
741     if (!s->cnt_run) {
742 
743         exynos4210_ltick_recalc_count(s);
744         ptimer_set_count(s->ptimer_tick, s->count);
745         ptimer_run(s->ptimer_tick, 1);
746 
747         s->cnt_run = 1;
748     }
749 }
750 
751 /*
752  * Stop local tick cnt timer.
753  * Must be called within exynos4210_ltick_tx_begin/commit block.
754  */
755 static void exynos4210_ltick_cnt_stop(struct tick_timer *s)
756 {
757     if (s->cnt_run) {
758 
759         s->last_tcnto = exynos4210_ltick_cnt_get_cnto(s);
760 
761         if (s->int_run) {
762             exynos4210_ltick_int_stop(s);
763         }
764 
765         ptimer_stop(s->ptimer_tick);
766 
767         s->cnt_run = 0;
768     }
769 }
770 
771 /* Start ptimer transaction for local tick timer */
772 static void exynos4210_ltick_tx_begin(struct tick_timer *s)
773 {
774     ptimer_transaction_begin(s->ptimer_tick);
775 }
776 
777 /* Commit ptimer transaction for local tick timer */
778 static void exynos4210_ltick_tx_commit(struct tick_timer *s)
779 {
780     ptimer_transaction_commit(s->ptimer_tick);
781 }
782 
783 /*
784  * Get counter for CNT timer
785  */
786 static uint32_t exynos4210_ltick_cnt_get_cnto(struct tick_timer *s)
787 {
788     uint32_t tcnto;
789     uint32_t icnto;
790     uint64_t remain;
791     uint64_t counted;
792     uint64_t count;
793     uint64_t cur_progress;
794 
795     count = ptimer_get_count(s->ptimer_tick);
796     if (count) {
797         /* timer is still counting, called not from event */
798         counted = s->count - ptimer_get_count(s->ptimer_tick);
799         cur_progress = s->progress + counted;
800     } else {
801         /* timer expired earlier */
802         cur_progress = s->progress;
803     }
804 
805     remain = s->distance - cur_progress;
806 
807     if (!s->cnt_run) {
808         /* Both are stopped. */
809         tcnto = s->last_tcnto;
810     } else if (!s->int_run) {
811         /* INT counter is stopped, progress is by CNT timer */
812         tcnto = remain % s->tcntb;
813     } else {
814         /* Both are counting */
815         icnto = remain / s->tcntb;
816         if (icnto) {
817             tcnto = remain % (icnto * s->tcntb);
818         } else {
819             tcnto = remain % s->tcntb;
820         }
821     }
822 
823     return tcnto;
824 }
825 
826 /*
827  * Set new values of counters for CNT and INT timers
828  * Must be called within exynos4210_ltick_tx_begin/commit block.
829  */
830 static void exynos4210_ltick_set_cntb(struct tick_timer *s, uint32_t new_cnt,
831         uint32_t new_int)
832 {
833     uint32_t cnt_stopped = 0;
834     uint32_t int_stopped = 0;
835 
836     if (s->cnt_run) {
837         exynos4210_ltick_cnt_stop(s);
838         cnt_stopped = 1;
839     }
840 
841     if (s->int_run) {
842         exynos4210_ltick_int_stop(s);
843         int_stopped = 1;
844     }
845 
846     s->tcntb = new_cnt + 1;
847     s->icntb = new_int + 1;
848 
849     if (cnt_stopped) {
850         exynos4210_ltick_cnt_start(s);
851     }
852     if (int_stopped) {
853         exynos4210_ltick_int_start(s);
854     }
855 
856 }
857 
858 /*
859  * Calculate new counter value for tick timer
860  */
861 static void exynos4210_ltick_recalc_count(struct tick_timer *s)
862 {
863     uint64_t to_count;
864 
865     if ((s->cnt_run && s->last_tcnto) || (s->int_run && s->last_icnto)) {
866         /*
867          * one or both timers run and not counted to the end;
868          * distance is not passed, recalculate with last_tcnto * last_icnto
869          */
870 
871         if (s->last_tcnto) {
872             to_count = (uint64_t)s->last_tcnto * s->last_icnto;
873         } else {
874             to_count = s->last_icnto;
875         }
876     } else {
877         /* distance is passed, recalculate with tcnto * icnto */
878         if (s->icntb) {
879             s->distance = (uint64_t)s->tcntb * s->icntb;
880         } else {
881             s->distance = s->tcntb;
882         }
883 
884         to_count = s->distance;
885         s->progress = 0;
886     }
887 
888     if (to_count > MCT_LT_COUNTER_STEP) {
889         /* count by step */
890         s->count = MCT_LT_COUNTER_STEP;
891     } else {
892         s->count = to_count;
893     }
894 }
895 
896 /*
897  * Initialize tick_timer
898  */
899 static void exynos4210_ltick_timer_init(struct tick_timer *s)
900 {
901     exynos4210_ltick_int_stop(s);
902     exynos4210_ltick_tx_begin(s);
903     exynos4210_ltick_cnt_stop(s);
904     exynos4210_ltick_tx_commit(s);
905 
906     s->count = 0;
907     s->distance = 0;
908     s->progress = 0;
909     s->icntb = 0;
910     s->tcntb = 0;
911 }
912 
913 /*
914  * tick_timer event.
915  * Raises when abstract tick_timer expires.
916  */
917 static void exynos4210_ltick_timer_event(struct tick_timer *s)
918 {
919     s->progress += s->count;
920 }
921 
922 /*
923  * Local timer tick counter handler.
924  * Don't use reloaded timers. If timer counter = zero
925  * then handler called but after handler finished no
926  * timer reload occurs.
927  */
928 static void exynos4210_ltick_event(void *opaque)
929 {
930     Exynos4210MCTLT * s = (Exynos4210MCTLT *)opaque;
931     uint32_t tcnto;
932     uint32_t icnto;
933 #ifdef DEBUG_MCT
934     static uint64_t time1[2] = {0};
935     static uint64_t time2[2] = {0};
936 #endif
937 
938     /* Call tick_timer event handler, it will update its tcntb and icntb. */
939     exynos4210_ltick_timer_event(&s->tick_timer);
940 
941     /* get tick_timer cnt */
942     tcnto = exynos4210_ltick_cnt_get_cnto(&s->tick_timer);
943 
944     /* get tick_timer int */
945     icnto = exynos4210_ltick_int_get_cnto(&s->tick_timer);
946 
947     /* raise IRQ if needed */
948     if (!icnto && s->reg.tcon & L_TCON_INT_START) {
949         /* INT counter enabled and expired */
950 
951         s->reg.int_cstat |= L_INT_CSTAT_INTCNT;
952 
953         /* raise interrupt if enabled */
954         if (s->reg.int_enb & L_INT_INTENB_ICNTEIE) {
955 #ifdef DEBUG_MCT
956             time2[s->id] = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
957             DPRINTF("local timer[%d] IRQ: %llx\n", s->id,
958                     time2[s->id] - time1[s->id]);
959             time1[s->id] = time2[s->id];
960 #endif
961             qemu_irq_raise(s->irq);
962         }
963 
964         /* reload ICNTB */
965         if (s->reg.tcon & L_TCON_INTERVAL_MODE) {
966             exynos4210_ltick_set_cntb(&s->tick_timer,
967                     s->reg.cnt[L_REG_CNT_TCNTB],
968                     s->reg.cnt[L_REG_CNT_ICNTB]);
969         }
970     } else {
971         /* reload TCNTB */
972         if (!tcnto) {
973             exynos4210_ltick_set_cntb(&s->tick_timer,
974                     s->reg.cnt[L_REG_CNT_TCNTB],
975                     icnto);
976         }
977     }
978 
979     /* start tick_timer cnt */
980     exynos4210_ltick_cnt_start(&s->tick_timer);
981 
982     /* start tick_timer int */
983     exynos4210_ltick_int_start(&s->tick_timer);
984 }
985 
986 static void tx_ptimer_set_freq(ptimer_state *s, uint32_t freq)
987 {
988     /*
989      * callers of exynos4210_mct_update_freq() never do anything
990      * else that needs to be in the same ptimer transaction, so
991      * to avoid a lot of repetition we have a convenience function
992      * for begin/set_freq/commit.
993      */
994     ptimer_transaction_begin(s);
995     ptimer_set_freq(s, freq);
996     ptimer_transaction_commit(s);
997 }
998 
999 /* update timer frequency */
1000 static void exynos4210_mct_update_freq(Exynos4210MCTState *s)
1001 {
1002     uint32_t freq = s->freq;
1003     s->freq = 24000000 /
1004             ((MCT_CFG_GET_PRESCALER(s->reg_mct_cfg) + 1) *
1005                     MCT_CFG_GET_DIVIDER(s->reg_mct_cfg));
1006 
1007     if (freq != s->freq) {
1008         DPRINTF("freq=%dHz\n", s->freq);
1009 
1010         /* global timer */
1011         tx_ptimer_set_freq(s->g_timer.ptimer_frc, s->freq);
1012 
1013         /* local timer */
1014         tx_ptimer_set_freq(s->l_timer[0].tick_timer.ptimer_tick, s->freq);
1015         tx_ptimer_set_freq(s->l_timer[0].ptimer_frc, s->freq);
1016         tx_ptimer_set_freq(s->l_timer[1].tick_timer.ptimer_tick, s->freq);
1017         tx_ptimer_set_freq(s->l_timer[1].ptimer_frc, s->freq);
1018     }
1019 }
1020 
1021 /* set defaul_timer values for all fields */
1022 static void exynos4210_mct_reset(DeviceState *d)
1023 {
1024     Exynos4210MCTState *s = EXYNOS4210_MCT(d);
1025     uint32_t i;
1026 
1027     s->reg_mct_cfg = 0;
1028 
1029     /* global timer */
1030     memset(&s->g_timer.reg, 0, sizeof(s->g_timer.reg));
1031     exynos4210_gfrc_tx_begin(&s->g_timer);
1032     exynos4210_gfrc_stop(&s->g_timer);
1033     exynos4210_gfrc_tx_commit(&s->g_timer);
1034 
1035     /* local timer */
1036     memset(s->l_timer[0].reg.cnt, 0, sizeof(s->l_timer[0].reg.cnt));
1037     memset(s->l_timer[1].reg.cnt, 0, sizeof(s->l_timer[1].reg.cnt));
1038     for (i = 0; i < 2; i++) {
1039         s->l_timer[i].reg.int_cstat = 0;
1040         s->l_timer[i].reg.int_enb = 0;
1041         s->l_timer[i].reg.tcon = 0;
1042         s->l_timer[i].reg.wstat = 0;
1043         s->l_timer[i].tick_timer.count = 0;
1044         s->l_timer[i].tick_timer.distance = 0;
1045         s->l_timer[i].tick_timer.progress = 0;
1046         exynos4210_lfrc_tx_begin(&s->l_timer[i]);
1047         ptimer_stop(s->l_timer[i].ptimer_frc);
1048         exynos4210_lfrc_tx_commit(&s->l_timer[i]);
1049 
1050         exynos4210_ltick_timer_init(&s->l_timer[i].tick_timer);
1051     }
1052 
1053     exynos4210_mct_update_freq(s);
1054 
1055 }
1056 
1057 /* Multi Core Timer read */
1058 static uint64_t exynos4210_mct_read(void *opaque, hwaddr offset,
1059         unsigned size)
1060 {
1061     Exynos4210MCTState *s = (Exynos4210MCTState *)opaque;
1062     int index;
1063     int shift;
1064     uint64_t count;
1065     uint32_t value;
1066     int lt_i;
1067 
1068     switch (offset) {
1069 
1070     case MCT_CFG:
1071         value = s->reg_mct_cfg;
1072         break;
1073 
1074     case G_CNT_L: case G_CNT_U:
1075         shift = 8 * (offset & 0x4);
1076         count = exynos4210_gfrc_get_count(&s->g_timer);
1077         value = UINT32_MAX & (count >> shift);
1078         DPRINTF("read FRC=0x%llx\n", count);
1079         break;
1080 
1081     case G_CNT_WSTAT:
1082         value = s->g_timer.reg.cnt_wstat;
1083         break;
1084 
1085     case G_COMP_L(0): case G_COMP_L(1): case G_COMP_L(2): case G_COMP_L(3):
1086     case G_COMP_U(0): case G_COMP_U(1): case G_COMP_U(2): case G_COMP_U(3):
1087         index = GET_G_COMP_IDX(offset);
1088         shift = 8 * (offset & 0x4);
1089         value = UINT32_MAX & (s->g_timer.reg.comp[index] >> shift);
1090     break;
1091 
1092     case G_TCON:
1093         value = s->g_timer.reg.tcon;
1094         break;
1095 
1096     case G_INT_CSTAT:
1097         value = s->g_timer.reg.int_cstat;
1098         break;
1099 
1100     case G_INT_ENB:
1101         value = s->g_timer.reg.int_enb;
1102         break;
1103     case G_WSTAT:
1104         value = s->g_timer.reg.wstat;
1105         break;
1106 
1107     case G_COMP0_ADD_INCR: case G_COMP1_ADD_INCR:
1108     case G_COMP2_ADD_INCR: case G_COMP3_ADD_INCR:
1109         value = s->g_timer.reg.comp_add_incr[GET_G_COMP_ADD_INCR_IDX(offset)];
1110         break;
1111 
1112         /* Local timers */
1113     case L0_TCNTB: case L0_ICNTB: case L0_FRCNTB:
1114     case L1_TCNTB: case L1_ICNTB: case L1_FRCNTB:
1115         lt_i = GET_L_TIMER_IDX(offset);
1116         index = GET_L_TIMER_CNT_REG_IDX(offset, lt_i);
1117         value = s->l_timer[lt_i].reg.cnt[index];
1118         break;
1119 
1120     case L0_TCNTO: case L1_TCNTO:
1121         lt_i = GET_L_TIMER_IDX(offset);
1122 
1123         value = exynos4210_ltick_cnt_get_cnto(&s->l_timer[lt_i].tick_timer);
1124         DPRINTF("local timer[%d] read TCNTO %x\n", lt_i, value);
1125         break;
1126 
1127     case L0_ICNTO: case L1_ICNTO:
1128         lt_i = GET_L_TIMER_IDX(offset);
1129 
1130         value = exynos4210_ltick_int_get_cnto(&s->l_timer[lt_i].tick_timer);
1131         DPRINTF("local timer[%d] read ICNTO %x\n", lt_i, value);
1132         break;
1133 
1134     case L0_FRCNTO: case L1_FRCNTO:
1135         lt_i = GET_L_TIMER_IDX(offset);
1136 
1137         value = exynos4210_lfrc_get_count(&s->l_timer[lt_i]);
1138         break;
1139 
1140     case L0_TCON: case L1_TCON:
1141         lt_i = ((offset & 0xF00) - L0_TCNTB) / 0x100;
1142         value = s->l_timer[lt_i].reg.tcon;
1143         break;
1144 
1145     case L0_INT_CSTAT: case L1_INT_CSTAT:
1146         lt_i = ((offset & 0xF00) - L0_TCNTB) / 0x100;
1147         value = s->l_timer[lt_i].reg.int_cstat;
1148         break;
1149 
1150     case L0_INT_ENB: case L1_INT_ENB:
1151         lt_i = ((offset & 0xF00) - L0_TCNTB) / 0x100;
1152         value = s->l_timer[lt_i].reg.int_enb;
1153         break;
1154 
1155     case L0_WSTAT: case L1_WSTAT:
1156         lt_i = ((offset & 0xF00) - L0_TCNTB) / 0x100;
1157         value = s->l_timer[lt_i].reg.wstat;
1158         break;
1159 
1160     default:
1161         hw_error("exynos4210.mct: bad read offset "
1162                 TARGET_FMT_plx "\n", offset);
1163         break;
1164     }
1165     return value;
1166 }
1167 
1168 /* MCT write */
1169 static void exynos4210_mct_write(void *opaque, hwaddr offset,
1170         uint64_t value, unsigned size)
1171 {
1172     Exynos4210MCTState *s = (Exynos4210MCTState *)opaque;
1173     int index;  /* index in buffer which represents register set */
1174     int shift;
1175     int lt_i;
1176     uint64_t new_frc;
1177     uint32_t i;
1178     uint32_t old_val;
1179 #ifdef DEBUG_MCT
1180     static uint32_t icntb_max[2] = {0};
1181     static uint32_t icntb_min[2] = {UINT32_MAX, UINT32_MAX};
1182     static uint32_t tcntb_max[2] = {0};
1183     static uint32_t tcntb_min[2] = {UINT32_MAX, UINT32_MAX};
1184 #endif
1185 
1186     new_frc = s->g_timer.reg.cnt;
1187 
1188     switch (offset) {
1189 
1190     case MCT_CFG:
1191         s->reg_mct_cfg = value;
1192         exynos4210_mct_update_freq(s);
1193         break;
1194 
1195     case G_CNT_L:
1196     case G_CNT_U:
1197         if (offset == G_CNT_L) {
1198 
1199             DPRINTF("global timer write to reg.cntl %llx\n", value);
1200 
1201             new_frc = (s->g_timer.reg.cnt & (uint64_t)UINT32_MAX << 32) + value;
1202             s->g_timer.reg.cnt_wstat |= G_CNT_WSTAT_L;
1203         }
1204         if (offset == G_CNT_U) {
1205 
1206             DPRINTF("global timer write to reg.cntu %llx\n", value);
1207 
1208             new_frc = (s->g_timer.reg.cnt & UINT32_MAX) +
1209                     ((uint64_t)value << 32);
1210             s->g_timer.reg.cnt_wstat |= G_CNT_WSTAT_U;
1211         }
1212 
1213         s->g_timer.reg.cnt = new_frc;
1214         exynos4210_gfrc_tx_begin(&s->g_timer);
1215         exynos4210_gfrc_restart(s);
1216         exynos4210_gfrc_tx_commit(&s->g_timer);
1217         break;
1218 
1219     case G_CNT_WSTAT:
1220         s->g_timer.reg.cnt_wstat &= ~(value);
1221         break;
1222 
1223     case G_COMP_L(0): case G_COMP_L(1): case G_COMP_L(2): case G_COMP_L(3):
1224     case G_COMP_U(0): case G_COMP_U(1): case G_COMP_U(2): case G_COMP_U(3):
1225         index = GET_G_COMP_IDX(offset);
1226         shift = 8 * (offset & 0x4);
1227         s->g_timer.reg.comp[index] =
1228                 (s->g_timer.reg.comp[index] &
1229                 (((uint64_t)UINT32_MAX << 32) >> shift)) +
1230                 (value << shift);
1231 
1232         DPRINTF("comparator %d write 0x%llx val << %d\n", index, value, shift);
1233 
1234         if (offset & 0x4) {
1235             s->g_timer.reg.wstat |= G_WSTAT_COMP_U(index);
1236         } else {
1237             s->g_timer.reg.wstat |= G_WSTAT_COMP_L(index);
1238         }
1239 
1240         exynos4210_gfrc_tx_begin(&s->g_timer);
1241         exynos4210_gfrc_restart(s);
1242         exynos4210_gfrc_tx_commit(&s->g_timer);
1243         break;
1244 
1245     case G_TCON:
1246         old_val = s->g_timer.reg.tcon;
1247         s->g_timer.reg.tcon = value;
1248         s->g_timer.reg.wstat |= G_WSTAT_TCON_WRITE;
1249 
1250         DPRINTF("global timer write to reg.g_tcon %llx\n", value);
1251 
1252         exynos4210_gfrc_tx_begin(&s->g_timer);
1253 
1254         /* Start FRC if transition from disabled to enabled */
1255         if ((value & G_TCON_TIMER_ENABLE) > (old_val &
1256                 G_TCON_TIMER_ENABLE)) {
1257             exynos4210_gfrc_restart(s);
1258         }
1259         if ((value & G_TCON_TIMER_ENABLE) < (old_val &
1260                 G_TCON_TIMER_ENABLE)) {
1261             exynos4210_gfrc_stop(&s->g_timer);
1262         }
1263 
1264         /* Start CMP if transition from disabled to enabled */
1265         for (i = 0; i < MCT_GT_CMP_NUM; i++) {
1266             if ((value & G_TCON_COMP_ENABLE(i)) != (old_val &
1267                     G_TCON_COMP_ENABLE(i))) {
1268                 exynos4210_gfrc_restart(s);
1269             }
1270         }
1271 
1272         exynos4210_gfrc_tx_commit(&s->g_timer);
1273         break;
1274 
1275     case G_INT_CSTAT:
1276         s->g_timer.reg.int_cstat &= ~(value);
1277         for (i = 0; i < MCT_GT_CMP_NUM; i++) {
1278             if (value & G_INT_CSTAT_COMP(i)) {
1279                 exynos4210_gcomp_lower_irq(&s->g_timer, i);
1280             }
1281         }
1282         break;
1283 
1284     case G_INT_ENB:
1285         /* Raise IRQ if transition from disabled to enabled and CSTAT pending */
1286         for (i = 0; i < MCT_GT_CMP_NUM; i++) {
1287             if ((value & G_INT_ENABLE(i)) > (s->g_timer.reg.tcon &
1288                     G_INT_ENABLE(i))) {
1289                 if (s->g_timer.reg.int_cstat & G_INT_CSTAT_COMP(i)) {
1290                     exynos4210_gcomp_raise_irq(&s->g_timer, i);
1291                 }
1292             }
1293 
1294             if ((value & G_INT_ENABLE(i)) < (s->g_timer.reg.tcon &
1295                     G_INT_ENABLE(i))) {
1296                 exynos4210_gcomp_lower_irq(&s->g_timer, i);
1297             }
1298         }
1299 
1300         DPRINTF("global timer INT enable %llx\n", value);
1301         s->g_timer.reg.int_enb = value;
1302         break;
1303 
1304     case G_WSTAT:
1305         s->g_timer.reg.wstat &= ~(value);
1306         break;
1307 
1308     case G_COMP0_ADD_INCR: case G_COMP1_ADD_INCR:
1309     case G_COMP2_ADD_INCR: case G_COMP3_ADD_INCR:
1310         index = GET_G_COMP_ADD_INCR_IDX(offset);
1311         s->g_timer.reg.comp_add_incr[index] = value;
1312         s->g_timer.reg.wstat |= G_WSTAT_COMP_ADDINCR(index);
1313         break;
1314 
1315         /* Local timers */
1316     case L0_TCON: case L1_TCON:
1317         lt_i = GET_L_TIMER_IDX(offset);
1318         old_val = s->l_timer[lt_i].reg.tcon;
1319 
1320         s->l_timer[lt_i].reg.wstat |= L_WSTAT_TCON_WRITE;
1321         s->l_timer[lt_i].reg.tcon = value;
1322 
1323         exynos4210_ltick_tx_begin(&s->l_timer[lt_i].tick_timer);
1324         /* Stop local CNT */
1325         if ((value & L_TCON_TICK_START) <
1326                 (old_val & L_TCON_TICK_START)) {
1327             DPRINTF("local timer[%d] stop cnt\n", lt_i);
1328             exynos4210_ltick_cnt_stop(&s->l_timer[lt_i].tick_timer);
1329         }
1330 
1331         /* Stop local INT */
1332         if ((value & L_TCON_INT_START) <
1333                 (old_val & L_TCON_INT_START)) {
1334             DPRINTF("local timer[%d] stop int\n", lt_i);
1335             exynos4210_ltick_int_stop(&s->l_timer[lt_i].tick_timer);
1336         }
1337 
1338         /* Start local CNT */
1339         if ((value & L_TCON_TICK_START) >
1340         (old_val & L_TCON_TICK_START)) {
1341             DPRINTF("local timer[%d] start cnt\n", lt_i);
1342             exynos4210_ltick_cnt_start(&s->l_timer[lt_i].tick_timer);
1343         }
1344 
1345         /* Start local INT */
1346         if ((value & L_TCON_INT_START) >
1347         (old_val & L_TCON_INT_START)) {
1348             DPRINTF("local timer[%d] start int\n", lt_i);
1349             exynos4210_ltick_int_start(&s->l_timer[lt_i].tick_timer);
1350         }
1351         exynos4210_ltick_tx_commit(&s->l_timer[lt_i].tick_timer);
1352 
1353         /* Start or Stop local FRC if TCON changed */
1354         exynos4210_lfrc_tx_begin(&s->l_timer[lt_i]);
1355         if ((value & L_TCON_FRC_START) >
1356         (s->l_timer[lt_i].reg.tcon & L_TCON_FRC_START)) {
1357             DPRINTF("local timer[%d] start frc\n", lt_i);
1358             exynos4210_lfrc_start(&s->l_timer[lt_i]);
1359         }
1360         if ((value & L_TCON_FRC_START) <
1361                 (s->l_timer[lt_i].reg.tcon & L_TCON_FRC_START)) {
1362             DPRINTF("local timer[%d] stop frc\n", lt_i);
1363             exynos4210_lfrc_stop(&s->l_timer[lt_i]);
1364         }
1365         exynos4210_lfrc_tx_commit(&s->l_timer[lt_i]);
1366         break;
1367 
1368     case L0_TCNTB: case L1_TCNTB:
1369         lt_i = GET_L_TIMER_IDX(offset);
1370 
1371         /*
1372          * TCNTB is updated to internal register only after CNT expired.
1373          * Due to this we should reload timer to nearest moment when CNT is
1374          * expired and then in event handler update tcntb to new TCNTB value.
1375          */
1376         exynos4210_ltick_tx_begin(&s->l_timer[lt_i].tick_timer);
1377         exynos4210_ltick_set_cntb(&s->l_timer[lt_i].tick_timer, value,
1378                 s->l_timer[lt_i].tick_timer.icntb);
1379         exynos4210_ltick_tx_commit(&s->l_timer[lt_i].tick_timer);
1380 
1381         s->l_timer[lt_i].reg.wstat |= L_WSTAT_TCNTB_WRITE;
1382         s->l_timer[lt_i].reg.cnt[L_REG_CNT_TCNTB] = value;
1383 
1384 #ifdef DEBUG_MCT
1385         if (tcntb_min[lt_i] > value) {
1386             tcntb_min[lt_i] = value;
1387         }
1388         if (tcntb_max[lt_i] < value) {
1389             tcntb_max[lt_i] = value;
1390         }
1391         DPRINTF("local timer[%d] TCNTB write %llx; max=%x, min=%x\n",
1392                 lt_i, value, tcntb_max[lt_i], tcntb_min[lt_i]);
1393 #endif
1394         break;
1395 
1396     case L0_ICNTB: case L1_ICNTB:
1397         lt_i = GET_L_TIMER_IDX(offset);
1398 
1399         s->l_timer[lt_i].reg.wstat |= L_WSTAT_ICNTB_WRITE;
1400         s->l_timer[lt_i].reg.cnt[L_REG_CNT_ICNTB] = value &
1401                 ~L_ICNTB_MANUAL_UPDATE;
1402 
1403         /*
1404          * We need to avoid too small values for TCNTB*ICNTB. If not, IRQ event
1405          * could raise too fast disallowing QEMU to execute target code.
1406          */
1407         if (s->l_timer[lt_i].reg.cnt[L_REG_CNT_ICNTB] *
1408             s->l_timer[lt_i].reg.cnt[L_REG_CNT_TCNTB] < MCT_LT_CNT_LOW_LIMIT) {
1409             if (!s->l_timer[lt_i].reg.cnt[L_REG_CNT_TCNTB]) {
1410                 s->l_timer[lt_i].reg.cnt[L_REG_CNT_ICNTB] =
1411                         MCT_LT_CNT_LOW_LIMIT;
1412             } else {
1413                 s->l_timer[lt_i].reg.cnt[L_REG_CNT_ICNTB] =
1414                         MCT_LT_CNT_LOW_LIMIT /
1415                         s->l_timer[lt_i].reg.cnt[L_REG_CNT_TCNTB];
1416             }
1417         }
1418 
1419         if (value & L_ICNTB_MANUAL_UPDATE) {
1420             exynos4210_ltick_set_cntb(&s->l_timer[lt_i].tick_timer,
1421                     s->l_timer[lt_i].tick_timer.tcntb,
1422                     s->l_timer[lt_i].reg.cnt[L_REG_CNT_ICNTB]);
1423         }
1424 
1425 #ifdef DEBUG_MCT
1426         if (icntb_min[lt_i] > value) {
1427             icntb_min[lt_i] = value;
1428         }
1429         if (icntb_max[lt_i] < value) {
1430             icntb_max[lt_i] = value;
1431         }
1432         DPRINTF("local timer[%d] ICNTB write %llx; max=%x, min=%x\n\n",
1433                 lt_i, value, icntb_max[lt_i], icntb_min[lt_i]);
1434 #endif
1435         break;
1436 
1437     case L0_FRCNTB: case L1_FRCNTB:
1438         lt_i = GET_L_TIMER_IDX(offset);
1439         DPRINTF("local timer[%d] FRCNTB write %llx\n", lt_i, value);
1440 
1441         s->l_timer[lt_i].reg.wstat |= L_WSTAT_FRCCNTB_WRITE;
1442         s->l_timer[lt_i].reg.cnt[L_REG_CNT_FRCCNTB] = value;
1443 
1444         break;
1445 
1446     case L0_TCNTO: case L1_TCNTO:
1447     case L0_ICNTO: case L1_ICNTO:
1448     case L0_FRCNTO: case L1_FRCNTO:
1449         qemu_log_mask(LOG_GUEST_ERROR,
1450                       "exynos4210.mct: write to RO register " TARGET_FMT_plx,
1451                       offset);
1452         break;
1453 
1454     case L0_INT_CSTAT: case L1_INT_CSTAT:
1455         lt_i = GET_L_TIMER_IDX(offset);
1456 
1457         DPRINTF("local timer[%d] CSTAT write %llx\n", lt_i, value);
1458 
1459         s->l_timer[lt_i].reg.int_cstat &= ~value;
1460         if (!s->l_timer[lt_i].reg.int_cstat) {
1461             qemu_irq_lower(s->l_timer[lt_i].irq);
1462         }
1463         break;
1464 
1465     case L0_INT_ENB: case L1_INT_ENB:
1466         lt_i = GET_L_TIMER_IDX(offset);
1467         old_val = s->l_timer[lt_i].reg.int_enb;
1468 
1469         /* Raise Local timer IRQ if cstat is pending */
1470         if ((value & L_INT_INTENB_ICNTEIE) > (old_val & L_INT_INTENB_ICNTEIE)) {
1471             if (s->l_timer[lt_i].reg.int_cstat & L_INT_CSTAT_INTCNT) {
1472                 qemu_irq_raise(s->l_timer[lt_i].irq);
1473             }
1474         }
1475 
1476         s->l_timer[lt_i].reg.int_enb = value;
1477 
1478         break;
1479 
1480     case L0_WSTAT: case L1_WSTAT:
1481         lt_i = GET_L_TIMER_IDX(offset);
1482 
1483         s->l_timer[lt_i].reg.wstat &= ~value;
1484         break;
1485 
1486     default:
1487         hw_error("exynos4210.mct: bad write offset "
1488                 TARGET_FMT_plx "\n", offset);
1489         break;
1490     }
1491 }
1492 
1493 static const MemoryRegionOps exynos4210_mct_ops = {
1494     .read = exynos4210_mct_read,
1495     .write = exynos4210_mct_write,
1496     .endianness = DEVICE_NATIVE_ENDIAN,
1497 };
1498 
1499 /* MCT init */
1500 static void exynos4210_mct_init(Object *obj)
1501 {
1502     int i;
1503     Exynos4210MCTState *s = EXYNOS4210_MCT(obj);
1504     SysBusDevice *dev = SYS_BUS_DEVICE(obj);
1505 
1506     /* Global timer */
1507     s->g_timer.ptimer_frc = ptimer_init(exynos4210_gfrc_event, s,
1508                                         PTIMER_POLICY_DEFAULT);
1509     memset(&s->g_timer.reg, 0, sizeof(struct gregs));
1510 
1511     /* Local timers */
1512     for (i = 0; i < 2; i++) {
1513         s->l_timer[i].tick_timer.ptimer_tick =
1514             ptimer_init(exynos4210_ltick_event, &s->l_timer[i],
1515                         PTIMER_POLICY_DEFAULT);
1516         s->l_timer[i].ptimer_frc =
1517             ptimer_init(exynos4210_lfrc_event, &s->l_timer[i],
1518                         PTIMER_POLICY_DEFAULT);
1519         s->l_timer[i].id = i;
1520     }
1521 
1522     /* IRQs */
1523     for (i = 0; i < MCT_GT_CMP_NUM; i++) {
1524         sysbus_init_irq(dev, &s->g_timer.irq[i]);
1525     }
1526     for (i = 0; i < 2; i++) {
1527         sysbus_init_irq(dev, &s->l_timer[i].irq);
1528     }
1529 
1530     memory_region_init_io(&s->iomem, obj, &exynos4210_mct_ops, s,
1531                           "exynos4210-mct", MCT_SFR_SIZE);
1532     sysbus_init_mmio(dev, &s->iomem);
1533 }
1534 
1535 static void exynos4210_mct_class_init(ObjectClass *klass, void *data)
1536 {
1537     DeviceClass *dc = DEVICE_CLASS(klass);
1538 
1539     dc->reset = exynos4210_mct_reset;
1540     dc->vmsd = &vmstate_exynos4210_mct_state;
1541 }
1542 
1543 static const TypeInfo exynos4210_mct_info = {
1544     .name          = TYPE_EXYNOS4210_MCT,
1545     .parent        = TYPE_SYS_BUS_DEVICE,
1546     .instance_size = sizeof(Exynos4210MCTState),
1547     .instance_init = exynos4210_mct_init,
1548     .class_init    = exynos4210_mct_class_init,
1549 };
1550 
1551 static void exynos4210_mct_register_types(void)
1552 {
1553     type_register_static(&exynos4210_mct_info);
1554 }
1555 
1556 type_init(exynos4210_mct_register_types)
1557