xref: /openbmc/qemu/hw/timer/omap_gptimer.c (revision a75b180f)
1 /*
2  * TI OMAP2 general purpose timers emulation.
3  *
4  * Copyright (C) 2007-2008 Nokia Corporation
5  * Written by Andrzej Zaborowski <andrew@openedhand.com>
6  *
7  * This program is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU General Public License as
9  * published by the Free Software Foundation; either version 2 or
10  * (at your option) any later version of the License.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License along
18  * with this program; if not, see <http://www.gnu.org/licenses/>.
19  */
20 
21 #include "qemu/osdep.h"
22 #include "hw/irq.h"
23 #include "qemu/timer.h"
24 #include "hw/arm/omap.h"
25 
26 /* GP timers */
27 struct omap_gp_timer_s {
28     MemoryRegion iomem;
29     qemu_irq irq;
30     qemu_irq wkup;
31     qemu_irq in;
32     qemu_irq out;
33     omap_clk clk;
34     QEMUTimer *timer;
35     QEMUTimer *match;
36     struct omap_target_agent_s *ta;
37 
38     int in_val;
39     int out_val;
40     int64_t time;
41     int64_t rate;
42     int64_t ticks_per_sec;
43 
44     int16_t config;
45     int status;
46     int it_ena;
47     int wu_ena;
48     int enable;
49     int inout;
50     int capt2;
51     int pt;
52     enum {
53         gpt_trigger_none, gpt_trigger_overflow, gpt_trigger_both
54     } trigger;
55     enum {
56         gpt_capture_none, gpt_capture_rising,
57         gpt_capture_falling, gpt_capture_both
58     } capture;
59     int scpwm;
60     int ce;
61     int pre;
62     int ptv;
63     int ar;
64     int st;
65     int posted;
66     uint32_t val;
67     uint32_t load_val;
68     uint32_t capture_val[2];
69     uint32_t match_val;
70     int capt_num;
71 
72     uint16_t writeh;	/* LSB */
73     uint16_t readh;	/* MSB */
74 };
75 
76 #define GPT_TCAR_IT	(1 << 2)
77 #define GPT_OVF_IT	(1 << 1)
78 #define GPT_MAT_IT	(1 << 0)
79 
80 static inline void omap_gp_timer_intr(struct omap_gp_timer_s *timer, int it)
81 {
82     if (timer->it_ena & it) {
83         if (!timer->status)
84             qemu_irq_raise(timer->irq);
85 
86         timer->status |= it;
87         /* Or are the status bits set even when masked?
88          * i.e. is masking applied before or after the status register?  */
89     }
90 
91     if (timer->wu_ena & it)
92         qemu_irq_pulse(timer->wkup);
93 }
94 
95 static inline void omap_gp_timer_out(struct omap_gp_timer_s *timer, int level)
96 {
97     if (!timer->inout && timer->out_val != level) {
98         timer->out_val = level;
99         qemu_set_irq(timer->out, level);
100     }
101 }
102 
103 static inline uint32_t omap_gp_timer_read(struct omap_gp_timer_s *timer)
104 {
105     uint64_t distance;
106 
107     if (timer->st && timer->rate) {
108         distance = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) - timer->time;
109         distance = muldiv64(distance, timer->rate, timer->ticks_per_sec);
110 
111         if (distance >= 0xffffffff - timer->val)
112             return 0xffffffff;
113         else
114             return timer->val + distance;
115     } else
116         return timer->val;
117 }
118 
119 static inline void omap_gp_timer_sync(struct omap_gp_timer_s *timer)
120 {
121     if (timer->st) {
122         timer->val = omap_gp_timer_read(timer);
123         timer->time = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
124     }
125 }
126 
127 static inline void omap_gp_timer_update(struct omap_gp_timer_s *timer)
128 {
129     int64_t expires, matches;
130 
131     if (timer->st && timer->rate) {
132         expires = muldiv64(0x100000000ll - timer->val,
133                         timer->ticks_per_sec, timer->rate);
134         timer_mod(timer->timer, timer->time + expires);
135 
136         if (timer->ce && timer->match_val >= timer->val) {
137             matches = muldiv64(timer->ticks_per_sec,
138                                timer->match_val - timer->val, timer->rate);
139             timer_mod(timer->match, timer->time + matches);
140         } else
141             timer_del(timer->match);
142     } else {
143         timer_del(timer->timer);
144         timer_del(timer->match);
145         omap_gp_timer_out(timer, timer->scpwm);
146     }
147 }
148 
149 static inline void omap_gp_timer_trigger(struct omap_gp_timer_s *timer)
150 {
151     if (timer->pt)
152         /* TODO in overflow-and-match mode if the first event to
153          * occur is the match, don't toggle.  */
154         omap_gp_timer_out(timer, !timer->out_val);
155     else
156         /* TODO inverted pulse on timer->out_val == 1?  */
157         qemu_irq_pulse(timer->out);
158 }
159 
160 static void omap_gp_timer_tick(void *opaque)
161 {
162     struct omap_gp_timer_s *timer = opaque;
163 
164     if (!timer->ar) {
165         timer->st = 0;
166         timer->val = 0;
167     } else {
168         timer->val = timer->load_val;
169         timer->time = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
170     }
171 
172     if (timer->trigger == gpt_trigger_overflow ||
173                     timer->trigger == gpt_trigger_both)
174         omap_gp_timer_trigger(timer);
175 
176     omap_gp_timer_intr(timer, GPT_OVF_IT);
177     omap_gp_timer_update(timer);
178 }
179 
180 static void omap_gp_timer_match(void *opaque)
181 {
182     struct omap_gp_timer_s *timer = opaque;
183 
184     if (timer->trigger == gpt_trigger_both)
185         omap_gp_timer_trigger(timer);
186 
187     omap_gp_timer_intr(timer, GPT_MAT_IT);
188 }
189 
190 static void omap_gp_timer_input(void *opaque, int line, int on)
191 {
192     struct omap_gp_timer_s *s = opaque;
193     int trigger;
194 
195     switch (s->capture) {
196     default:
197     case gpt_capture_none:
198         trigger = 0;
199         break;
200     case gpt_capture_rising:
201         trigger = !s->in_val && on;
202         break;
203     case gpt_capture_falling:
204         trigger = s->in_val && !on;
205         break;
206     case gpt_capture_both:
207         trigger = (s->in_val == !on);
208         break;
209     }
210     s->in_val = on;
211 
212     if (s->inout && trigger && s->capt_num < 2) {
213         s->capture_val[s->capt_num] = omap_gp_timer_read(s);
214 
215         if (s->capt2 == s->capt_num ++)
216             omap_gp_timer_intr(s, GPT_TCAR_IT);
217     }
218 }
219 
220 static void omap_gp_timer_clk_update(void *opaque, int line, int on)
221 {
222     struct omap_gp_timer_s *timer = opaque;
223 
224     omap_gp_timer_sync(timer);
225     timer->rate = on ? omap_clk_getrate(timer->clk) : 0;
226     omap_gp_timer_update(timer);
227 }
228 
229 static void omap_gp_timer_clk_setup(struct omap_gp_timer_s *timer)
230 {
231     omap_clk_adduser(timer->clk,
232                      qemu_allocate_irq(omap_gp_timer_clk_update, timer, 0));
233     timer->rate = omap_clk_getrate(timer->clk);
234 }
235 
236 void omap_gp_timer_reset(struct omap_gp_timer_s *s)
237 {
238     s->config = 0x000;
239     s->status = 0;
240     s->it_ena = 0;
241     s->wu_ena = 0;
242     s->inout = 0;
243     s->capt2 = 0;
244     s->capt_num = 0;
245     s->pt = 0;
246     s->trigger = gpt_trigger_none;
247     s->capture = gpt_capture_none;
248     s->scpwm = 0;
249     s->ce = 0;
250     s->pre = 0;
251     s->ptv = 0;
252     s->ar = 0;
253     s->st = 0;
254     s->posted = 1;
255     s->val = 0x00000000;
256     s->load_val = 0x00000000;
257     s->capture_val[0] = 0x00000000;
258     s->capture_val[1] = 0x00000000;
259     s->match_val = 0x00000000;
260     omap_gp_timer_update(s);
261 }
262 
263 static uint32_t omap_gp_timer_readw(void *opaque, hwaddr addr)
264 {
265     struct omap_gp_timer_s *s = opaque;
266 
267     switch (addr) {
268     case 0x00:	/* TIDR */
269         return 0x21;
270 
271     case 0x10:	/* TIOCP_CFG */
272         return s->config;
273 
274     case 0x14:	/* TISTAT */
275         /* ??? When's this bit reset? */
276         return 1;						/* RESETDONE */
277 
278     case 0x18:	/* TISR */
279         return s->status;
280 
281     case 0x1c:	/* TIER */
282         return s->it_ena;
283 
284     case 0x20:	/* TWER */
285         return s->wu_ena;
286 
287     case 0x24:	/* TCLR */
288         return (s->inout << 14) |
289                 (s->capt2 << 13) |
290                 (s->pt << 12) |
291                 (s->trigger << 10) |
292                 (s->capture << 8) |
293                 (s->scpwm << 7) |
294                 (s->ce << 6) |
295                 (s->pre << 5) |
296                 (s->ptv << 2) |
297                 (s->ar << 1) |
298                 (s->st << 0);
299 
300     case 0x28:	/* TCRR */
301         return omap_gp_timer_read(s);
302 
303     case 0x2c:	/* TLDR */
304         return s->load_val;
305 
306     case 0x30:	/* TTGR */
307         return 0xffffffff;
308 
309     case 0x34:	/* TWPS */
310         return 0x00000000;	/* No posted writes pending.  */
311 
312     case 0x38:	/* TMAR */
313         return s->match_val;
314 
315     case 0x3c:	/* TCAR1 */
316         return s->capture_val[0];
317 
318     case 0x40:	/* TSICR */
319         return s->posted << 2;
320 
321     case 0x44:	/* TCAR2 */
322         return s->capture_val[1];
323     }
324 
325     OMAP_BAD_REG(addr);
326     return 0;
327 }
328 
329 static uint32_t omap_gp_timer_readh(void *opaque, hwaddr addr)
330 {
331     struct omap_gp_timer_s *s = opaque;
332     uint32_t ret;
333 
334     if (addr & 2)
335         return s->readh;
336     else {
337         ret = omap_gp_timer_readw(opaque, addr);
338         s->readh = ret >> 16;
339         return ret & 0xffff;
340     }
341 }
342 
343 static void omap_gp_timer_write(void *opaque, hwaddr addr, uint32_t value)
344 {
345     struct omap_gp_timer_s *s = opaque;
346 
347     switch (addr) {
348     case 0x00:	/* TIDR */
349     case 0x14:	/* TISTAT */
350     case 0x34:	/* TWPS */
351     case 0x3c:	/* TCAR1 */
352     case 0x44:	/* TCAR2 */
353         OMAP_RO_REG(addr);
354         break;
355 
356     case 0x10:	/* TIOCP_CFG */
357         s->config = value & 0x33d;
358         if (((value >> 3) & 3) == 3)				/* IDLEMODE */
359             fprintf(stderr, "%s: illegal IDLEMODE value in TIOCP_CFG\n",
360                             __func__);
361         if (value & 2)						/* SOFTRESET */
362             omap_gp_timer_reset(s);
363         break;
364 
365     case 0x18:	/* TISR */
366         if (value & GPT_TCAR_IT)
367             s->capt_num = 0;
368         if (s->status && !(s->status &= ~value))
369             qemu_irq_lower(s->irq);
370         break;
371 
372     case 0x1c:	/* TIER */
373         s->it_ena = value & 7;
374         break;
375 
376     case 0x20:	/* TWER */
377         s->wu_ena = value & 7;
378         break;
379 
380     case 0x24:	/* TCLR */
381         omap_gp_timer_sync(s);
382         s->inout = (value >> 14) & 1;
383         s->capt2 = (value >> 13) & 1;
384         s->pt = (value >> 12) & 1;
385         s->trigger = (value >> 10) & 3;
386         if (s->capture == gpt_capture_none &&
387                         ((value >> 8) & 3) != gpt_capture_none)
388             s->capt_num = 0;
389         s->capture = (value >> 8) & 3;
390         s->scpwm = (value >> 7) & 1;
391         s->ce = (value >> 6) & 1;
392         s->pre = (value >> 5) & 1;
393         s->ptv = (value >> 2) & 7;
394         s->ar = (value >> 1) & 1;
395         s->st = (value >> 0) & 1;
396         if (s->inout && s->trigger != gpt_trigger_none)
397             fprintf(stderr, "%s: GP timer pin must be an output "
398                             "for this trigger mode\n", __func__);
399         if (!s->inout && s->capture != gpt_capture_none)
400             fprintf(stderr, "%s: GP timer pin must be an input "
401                             "for this capture mode\n", __func__);
402         if (s->trigger == gpt_trigger_none)
403             omap_gp_timer_out(s, s->scpwm);
404         /* TODO: make sure this doesn't overflow 32-bits */
405         s->ticks_per_sec = NANOSECONDS_PER_SECOND << (s->pre ? s->ptv + 1 : 0);
406         omap_gp_timer_update(s);
407         break;
408 
409     case 0x28:	/* TCRR */
410         s->time = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
411         s->val = value;
412         omap_gp_timer_update(s);
413         break;
414 
415     case 0x2c:	/* TLDR */
416         s->load_val = value;
417         break;
418 
419     case 0x30:	/* TTGR */
420         s->time = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
421         s->val = s->load_val;
422         omap_gp_timer_update(s);
423         break;
424 
425     case 0x38:	/* TMAR */
426         omap_gp_timer_sync(s);
427         s->match_val = value;
428         omap_gp_timer_update(s);
429         break;
430 
431     case 0x40:	/* TSICR */
432         s->posted = (value >> 2) & 1;
433         if (value & 2)	/* How much exactly are we supposed to reset? */
434             omap_gp_timer_reset(s);
435         break;
436 
437     default:
438         OMAP_BAD_REG(addr);
439     }
440 }
441 
442 static void omap_gp_timer_writeh(void *opaque, hwaddr addr, uint32_t value)
443 {
444     struct omap_gp_timer_s *s = opaque;
445 
446     if (addr & 2)
447         omap_gp_timer_write(opaque, addr, (value << 16) | s->writeh);
448     else
449         s->writeh = (uint16_t) value;
450 }
451 
452 static uint64_t omap_gp_timer_readfn(void *opaque, hwaddr addr,
453                                      unsigned size)
454 {
455     switch (size) {
456     case 1:
457         return omap_badwidth_read32(opaque, addr);
458     case 2:
459         return omap_gp_timer_readh(opaque, addr);
460     case 4:
461         return omap_gp_timer_readw(opaque, addr);
462     default:
463         g_assert_not_reached();
464     }
465 }
466 
467 static void omap_gp_timer_writefn(void *opaque, hwaddr addr,
468                                   uint64_t value, unsigned size)
469 {
470     switch (size) {
471     case 1:
472         omap_badwidth_write32(opaque, addr, value);
473         break;
474     case 2:
475         omap_gp_timer_writeh(opaque, addr, value);
476         break;
477     case 4:
478         omap_gp_timer_write(opaque, addr, value);
479         break;
480     default:
481         g_assert_not_reached();
482     }
483 }
484 
485 static const MemoryRegionOps omap_gp_timer_ops = {
486     .read = omap_gp_timer_readfn,
487     .write = omap_gp_timer_writefn,
488     .valid.min_access_size = 1,
489     .valid.max_access_size = 4,
490     .endianness = DEVICE_NATIVE_ENDIAN,
491 };
492 
493 struct omap_gp_timer_s *omap_gp_timer_init(struct omap_target_agent_s *ta,
494                 qemu_irq irq, omap_clk fclk, omap_clk iclk)
495 {
496     struct omap_gp_timer_s *s = g_new0(struct omap_gp_timer_s, 1);
497 
498     s->ta = ta;
499     s->irq = irq;
500     s->clk = fclk;
501     s->timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, omap_gp_timer_tick, s);
502     s->match = timer_new_ns(QEMU_CLOCK_VIRTUAL, omap_gp_timer_match, s);
503     s->in = qemu_allocate_irq(omap_gp_timer_input, s, 0);
504     omap_gp_timer_reset(s);
505     omap_gp_timer_clk_setup(s);
506 
507     memory_region_init_io(&s->iomem, NULL, &omap_gp_timer_ops, s, "omap.gptimer",
508                           omap_l4_region_size(ta, 0));
509     omap_l4_attach(ta, 0, &s->iomem);
510 
511     return s;
512 }
513