xref: /openbmc/qemu/hw/misc/npcm7xx_pwm.c (revision a8dc82ce)
1 /*
2  * Nuvoton NPCM7xx PWM Module
3  *
4  * Copyright 2020 Google LLC
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms of the GNU General Public License as published by the
8  * Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful, but WITHOUT
12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14  * for more details.
15  */
16 
17 #include "qemu/osdep.h"
18 #include "hw/irq.h"
19 #include "hw/qdev-clock.h"
20 #include "hw/qdev-properties.h"
21 #include "hw/misc/npcm7xx_pwm.h"
22 #include "hw/registerfields.h"
23 #include "migration/vmstate.h"
24 #include "qemu/bitops.h"
25 #include "qemu/error-report.h"
26 #include "qemu/log.h"
27 #include "qemu/module.h"
28 #include "qemu/units.h"
29 #include "trace.h"
30 
31 REG32(NPCM7XX_PWM_PPR, 0x00);
32 REG32(NPCM7XX_PWM_CSR, 0x04);
33 REG32(NPCM7XX_PWM_PCR, 0x08);
34 REG32(NPCM7XX_PWM_CNR0, 0x0c);
35 REG32(NPCM7XX_PWM_CMR0, 0x10);
36 REG32(NPCM7XX_PWM_PDR0, 0x14);
37 REG32(NPCM7XX_PWM_CNR1, 0x18);
38 REG32(NPCM7XX_PWM_CMR1, 0x1c);
39 REG32(NPCM7XX_PWM_PDR1, 0x20);
40 REG32(NPCM7XX_PWM_CNR2, 0x24);
41 REG32(NPCM7XX_PWM_CMR2, 0x28);
42 REG32(NPCM7XX_PWM_PDR2, 0x2c);
43 REG32(NPCM7XX_PWM_CNR3, 0x30);
44 REG32(NPCM7XX_PWM_CMR3, 0x34);
45 REG32(NPCM7XX_PWM_PDR3, 0x38);
46 REG32(NPCM7XX_PWM_PIER, 0x3c);
47 REG32(NPCM7XX_PWM_PIIR, 0x40);
48 REG32(NPCM7XX_PWM_PWDR0, 0x44);
49 REG32(NPCM7XX_PWM_PWDR1, 0x48);
50 REG32(NPCM7XX_PWM_PWDR2, 0x4c);
51 REG32(NPCM7XX_PWM_PWDR3, 0x50);
52 
53 /* Register field definitions. */
54 #define NPCM7XX_PPR(rv, index)      extract32((rv), npcm7xx_ppr_base[index], 8)
55 #define NPCM7XX_CSR(rv, index)      extract32((rv), npcm7xx_csr_base[index], 3)
56 #define NPCM7XX_CH(rv, index)       extract32((rv), npcm7xx_ch_base[index], 4)
57 #define NPCM7XX_CH_EN               BIT(0)
58 #define NPCM7XX_CH_INV              BIT(2)
59 #define NPCM7XX_CH_MOD              BIT(3)
60 
61 #define NPCM7XX_MAX_CMR             65535
62 #define NPCM7XX_MAX_CNR             65535
63 
64 /* Offset of each PWM channel's prescaler in the PPR register. */
65 static const int npcm7xx_ppr_base[] = { 0, 0, 8, 8 };
66 /* Offset of each PWM channel's clock selector in the CSR register. */
67 static const int npcm7xx_csr_base[] = { 0, 4, 8, 12 };
68 /* Offset of each PWM channel's control variable in the PCR register. */
69 static const int npcm7xx_ch_base[] = { 0, 8, 12, 16 };
70 
71 static uint32_t npcm7xx_pwm_calculate_freq(NPCM7xxPWM *p)
72 {
73     uint32_t ppr;
74     uint32_t csr;
75     uint32_t freq;
76 
77     if (!p->running) {
78         return 0;
79     }
80 
81     csr = NPCM7XX_CSR(p->module->csr, p->index);
82     ppr = NPCM7XX_PPR(p->module->ppr, p->index);
83     freq = clock_get_hz(p->module->clock);
84     freq /= ppr + 1;
85     /* csr can only be 0~4 */
86     if (csr > 4) {
87         qemu_log_mask(LOG_GUEST_ERROR,
88                       "%s: invalid csr value %u\n",
89                       __func__, csr);
90         csr = 4;
91     }
92     /* freq won't be changed if csr == 4. */
93     if (csr < 4) {
94         freq >>= csr + 1;
95     }
96 
97     return freq / (p->cnr + 1);
98 }
99 
100 static uint32_t npcm7xx_pwm_calculate_duty(NPCM7xxPWM *p)
101 {
102     uint32_t duty;
103 
104     if (p->running) {
105         if (p->cnr == 0) {
106             duty = 0;
107         } else if (p->cmr >= p->cnr) {
108             duty = NPCM7XX_PWM_MAX_DUTY;
109         } else {
110             duty = (uint64_t)NPCM7XX_PWM_MAX_DUTY * (p->cmr + 1) / (p->cnr + 1);
111         }
112     } else {
113         duty = 0;
114     }
115 
116     if (p->inverted) {
117         duty = NPCM7XX_PWM_MAX_DUTY - duty;
118     }
119 
120     return duty;
121 }
122 
123 static void npcm7xx_pwm_update_freq(NPCM7xxPWM *p)
124 {
125     uint32_t freq = npcm7xx_pwm_calculate_freq(p);
126 
127     if (freq != p->freq) {
128         trace_npcm7xx_pwm_update_freq(DEVICE(p->module)->canonical_path,
129                                       p->index, p->freq, freq);
130         p->freq = freq;
131     }
132 }
133 
134 static void npcm7xx_pwm_update_duty(NPCM7xxPWM *p)
135 {
136     uint32_t duty = npcm7xx_pwm_calculate_duty(p);
137 
138     if (duty != p->duty) {
139         trace_npcm7xx_pwm_update_duty(DEVICE(p->module)->canonical_path,
140                                       p->index, p->duty, duty);
141         p->duty = duty;
142     }
143 }
144 
145 static void npcm7xx_pwm_update_output(NPCM7xxPWM *p)
146 {
147     npcm7xx_pwm_update_freq(p);
148     npcm7xx_pwm_update_duty(p);
149 }
150 
151 static void npcm7xx_pwm_write_ppr(NPCM7xxPWMState *s, uint32_t new_ppr)
152 {
153     int i;
154     uint32_t old_ppr = s->ppr;
155 
156     QEMU_BUILD_BUG_ON(ARRAY_SIZE(npcm7xx_ppr_base) != NPCM7XX_PWM_PER_MODULE);
157     s->ppr = new_ppr;
158     for (i = 0; i < NPCM7XX_PWM_PER_MODULE; ++i) {
159         if (NPCM7XX_PPR(old_ppr, i) != NPCM7XX_PPR(new_ppr, i)) {
160             npcm7xx_pwm_update_freq(&s->pwm[i]);
161         }
162     }
163 }
164 
165 static void npcm7xx_pwm_write_csr(NPCM7xxPWMState *s, uint32_t new_csr)
166 {
167     int i;
168     uint32_t old_csr = s->csr;
169 
170     QEMU_BUILD_BUG_ON(ARRAY_SIZE(npcm7xx_csr_base) != NPCM7XX_PWM_PER_MODULE);
171     s->csr = new_csr;
172     for (i = 0; i < NPCM7XX_PWM_PER_MODULE; ++i) {
173         if (NPCM7XX_CSR(old_csr, i) != NPCM7XX_CSR(new_csr, i)) {
174             npcm7xx_pwm_update_freq(&s->pwm[i]);
175         }
176     }
177 }
178 
179 static void npcm7xx_pwm_write_pcr(NPCM7xxPWMState *s, uint32_t new_pcr)
180 {
181     int i;
182     bool inverted;
183     uint32_t pcr;
184     NPCM7xxPWM *p;
185 
186     s->pcr = new_pcr;
187     QEMU_BUILD_BUG_ON(ARRAY_SIZE(npcm7xx_ch_base) != NPCM7XX_PWM_PER_MODULE);
188     for (i = 0; i < NPCM7XX_PWM_PER_MODULE; ++i) {
189         p = &s->pwm[i];
190         pcr = NPCM7XX_CH(new_pcr, i);
191         inverted = pcr & NPCM7XX_CH_INV;
192 
193         /*
194          * We only run a PWM channel with toggle mode. Single-shot mode does not
195          * generate frequency and duty-cycle values.
196          */
197         if ((pcr & NPCM7XX_CH_EN) && (pcr & NPCM7XX_CH_MOD)) {
198             if (p->running) {
199                 /* Re-run this PWM channel if inverted changed. */
200                 if (p->inverted ^ inverted) {
201                     p->inverted = inverted;
202                     npcm7xx_pwm_update_duty(p);
203                 }
204             } else {
205                 /* Run this PWM channel. */
206                 p->running = true;
207                 p->inverted = inverted;
208                 npcm7xx_pwm_update_output(p);
209             }
210         } else {
211             /* Clear this PWM channel. */
212             p->running = false;
213             p->inverted = inverted;
214             npcm7xx_pwm_update_output(p);
215         }
216     }
217 
218 }
219 
220 static hwaddr npcm7xx_cnr_index(hwaddr offset)
221 {
222     switch (offset) {
223     case A_NPCM7XX_PWM_CNR0:
224         return 0;
225     case A_NPCM7XX_PWM_CNR1:
226         return 1;
227     case A_NPCM7XX_PWM_CNR2:
228         return 2;
229     case A_NPCM7XX_PWM_CNR3:
230         return 3;
231     default:
232         g_assert_not_reached();
233     }
234 }
235 
236 static hwaddr npcm7xx_cmr_index(hwaddr offset)
237 {
238     switch (offset) {
239     case A_NPCM7XX_PWM_CMR0:
240         return 0;
241     case A_NPCM7XX_PWM_CMR1:
242         return 1;
243     case A_NPCM7XX_PWM_CMR2:
244         return 2;
245     case A_NPCM7XX_PWM_CMR3:
246         return 3;
247     default:
248         g_assert_not_reached();
249     }
250 }
251 
252 static hwaddr npcm7xx_pdr_index(hwaddr offset)
253 {
254     switch (offset) {
255     case A_NPCM7XX_PWM_PDR0:
256         return 0;
257     case A_NPCM7XX_PWM_PDR1:
258         return 1;
259     case A_NPCM7XX_PWM_PDR2:
260         return 2;
261     case A_NPCM7XX_PWM_PDR3:
262         return 3;
263     default:
264         g_assert_not_reached();
265     }
266 }
267 
268 static hwaddr npcm7xx_pwdr_index(hwaddr offset)
269 {
270     switch (offset) {
271     case A_NPCM7XX_PWM_PWDR0:
272         return 0;
273     case A_NPCM7XX_PWM_PWDR1:
274         return 1;
275     case A_NPCM7XX_PWM_PWDR2:
276         return 2;
277     case A_NPCM7XX_PWM_PWDR3:
278         return 3;
279     default:
280         g_assert_not_reached();
281     }
282 }
283 
284 static uint64_t npcm7xx_pwm_read(void *opaque, hwaddr offset, unsigned size)
285 {
286     NPCM7xxPWMState *s = opaque;
287     uint64_t value = 0;
288 
289     switch (offset) {
290     case A_NPCM7XX_PWM_CNR0:
291     case A_NPCM7XX_PWM_CNR1:
292     case A_NPCM7XX_PWM_CNR2:
293     case A_NPCM7XX_PWM_CNR3:
294         value = s->pwm[npcm7xx_cnr_index(offset)].cnr;
295         break;
296 
297     case A_NPCM7XX_PWM_CMR0:
298     case A_NPCM7XX_PWM_CMR1:
299     case A_NPCM7XX_PWM_CMR2:
300     case A_NPCM7XX_PWM_CMR3:
301         value = s->pwm[npcm7xx_cmr_index(offset)].cmr;
302         break;
303 
304     case A_NPCM7XX_PWM_PDR0:
305     case A_NPCM7XX_PWM_PDR1:
306     case A_NPCM7XX_PWM_PDR2:
307     case A_NPCM7XX_PWM_PDR3:
308         value = s->pwm[npcm7xx_pdr_index(offset)].pdr;
309         break;
310 
311     case A_NPCM7XX_PWM_PWDR0:
312     case A_NPCM7XX_PWM_PWDR1:
313     case A_NPCM7XX_PWM_PWDR2:
314     case A_NPCM7XX_PWM_PWDR3:
315         value = s->pwm[npcm7xx_pwdr_index(offset)].pwdr;
316         break;
317 
318     case A_NPCM7XX_PWM_PPR:
319         value = s->ppr;
320         break;
321 
322     case A_NPCM7XX_PWM_CSR:
323         value = s->csr;
324         break;
325 
326     case A_NPCM7XX_PWM_PCR:
327         value = s->pcr;
328         break;
329 
330     case A_NPCM7XX_PWM_PIER:
331         value = s->pier;
332         break;
333 
334     case A_NPCM7XX_PWM_PIIR:
335         value = s->piir;
336         break;
337 
338     default:
339         qemu_log_mask(LOG_GUEST_ERROR,
340                       "%s: invalid offset 0x%04" HWADDR_PRIx "\n",
341                       __func__, offset);
342         break;
343     }
344 
345     trace_npcm7xx_pwm_read(DEVICE(s)->canonical_path, offset, value);
346     return value;
347 }
348 
349 static void npcm7xx_pwm_write(void *opaque, hwaddr offset,
350                                 uint64_t v, unsigned size)
351 {
352     NPCM7xxPWMState *s = opaque;
353     NPCM7xxPWM *p;
354     uint32_t value = v;
355 
356     trace_npcm7xx_pwm_write(DEVICE(s)->canonical_path, offset, value);
357     switch (offset) {
358     case A_NPCM7XX_PWM_CNR0:
359     case A_NPCM7XX_PWM_CNR1:
360     case A_NPCM7XX_PWM_CNR2:
361     case A_NPCM7XX_PWM_CNR3:
362         p = &s->pwm[npcm7xx_cnr_index(offset)];
363         if (value > NPCM7XX_MAX_CNR) {
364             qemu_log_mask(LOG_GUEST_ERROR,
365                           "%s: invalid cnr value: %u", __func__, value);
366             p->cnr = NPCM7XX_MAX_CNR;
367         } else {
368             p->cnr = value;
369         }
370         npcm7xx_pwm_update_output(p);
371         break;
372 
373     case A_NPCM7XX_PWM_CMR0:
374     case A_NPCM7XX_PWM_CMR1:
375     case A_NPCM7XX_PWM_CMR2:
376     case A_NPCM7XX_PWM_CMR3:
377         p = &s->pwm[npcm7xx_cmr_index(offset)];
378         if (value > NPCM7XX_MAX_CMR) {
379             qemu_log_mask(LOG_GUEST_ERROR,
380                           "%s: invalid cmr value: %u", __func__, value);
381             p->cmr = NPCM7XX_MAX_CMR;
382         } else {
383             p->cmr = value;
384         }
385         npcm7xx_pwm_update_output(p);
386         break;
387 
388     case A_NPCM7XX_PWM_PDR0:
389     case A_NPCM7XX_PWM_PDR1:
390     case A_NPCM7XX_PWM_PDR2:
391     case A_NPCM7XX_PWM_PDR3:
392         qemu_log_mask(LOG_GUEST_ERROR,
393                       "%s: register @ 0x%04" HWADDR_PRIx " is read-only\n",
394                       __func__, offset);
395         break;
396 
397     case A_NPCM7XX_PWM_PWDR0:
398     case A_NPCM7XX_PWM_PWDR1:
399     case A_NPCM7XX_PWM_PWDR2:
400     case A_NPCM7XX_PWM_PWDR3:
401         qemu_log_mask(LOG_UNIMP,
402                      "%s: register @ 0x%04" HWADDR_PRIx " is not implemented\n",
403                      __func__, offset);
404         break;
405 
406     case A_NPCM7XX_PWM_PPR:
407         npcm7xx_pwm_write_ppr(s, value);
408         break;
409 
410     case A_NPCM7XX_PWM_CSR:
411         npcm7xx_pwm_write_csr(s, value);
412         break;
413 
414     case A_NPCM7XX_PWM_PCR:
415         npcm7xx_pwm_write_pcr(s, value);
416         break;
417 
418     case A_NPCM7XX_PWM_PIER:
419         qemu_log_mask(LOG_UNIMP,
420                      "%s: register @ 0x%04" HWADDR_PRIx " is not implemented\n",
421                      __func__, offset);
422         break;
423 
424     case A_NPCM7XX_PWM_PIIR:
425         qemu_log_mask(LOG_UNIMP,
426                      "%s: register @ 0x%04" HWADDR_PRIx " is not implemented\n",
427                      __func__, offset);
428         break;
429 
430     default:
431         qemu_log_mask(LOG_GUEST_ERROR,
432                       "%s: invalid offset 0x%04" HWADDR_PRIx "\n",
433                       __func__, offset);
434         break;
435     }
436 }
437 
438 static const struct MemoryRegionOps npcm7xx_pwm_ops = {
439     .read       = npcm7xx_pwm_read,
440     .write      = npcm7xx_pwm_write,
441     .endianness = DEVICE_LITTLE_ENDIAN,
442     .valid      = {
443         .min_access_size        = 4,
444         .max_access_size        = 4,
445         .unaligned              = false,
446     },
447 };
448 
449 static void npcm7xx_pwm_enter_reset(Object *obj, ResetType type)
450 {
451     NPCM7xxPWMState *s = NPCM7XX_PWM(obj);
452     int i;
453 
454     for (i = 0; i < NPCM7XX_PWM_PER_MODULE; i++) {
455         NPCM7xxPWM *p = &s->pwm[i];
456 
457         p->cnr = 0x00000000;
458         p->cmr = 0x00000000;
459         p->pdr = 0x00000000;
460         p->pwdr = 0x00000000;
461     }
462 
463     s->ppr = 0x00000000;
464     s->csr = 0x00000000;
465     s->pcr = 0x00000000;
466     s->pier = 0x00000000;
467     s->piir = 0x00000000;
468 }
469 
470 static void npcm7xx_pwm_hold_reset(Object *obj)
471 {
472     NPCM7xxPWMState *s = NPCM7XX_PWM(obj);
473     int i;
474 
475     for (i = 0; i < NPCM7XX_PWM_PER_MODULE; i++) {
476         qemu_irq_lower(s->pwm[i].irq);
477     }
478 }
479 
480 static void npcm7xx_pwm_init(Object *obj)
481 {
482     NPCM7xxPWMState *s = NPCM7XX_PWM(obj);
483     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
484     int i;
485 
486     for (i = 0; i < NPCM7XX_PWM_PER_MODULE; i++) {
487         NPCM7xxPWM *p = &s->pwm[i];
488         p->module = s;
489         p->index = i;
490         sysbus_init_irq(sbd, &p->irq);
491     }
492 
493     memory_region_init_io(&s->iomem, obj, &npcm7xx_pwm_ops, s,
494                           TYPE_NPCM7XX_PWM, 4 * KiB);
495     sysbus_init_mmio(sbd, &s->iomem);
496     s->clock = qdev_init_clock_in(DEVICE(s), "clock", NULL, NULL);
497 
498     for (i = 0; i < NPCM7XX_PWM_PER_MODULE; ++i) {
499         object_property_add_uint32_ptr(obj, "freq[*]",
500                 &s->pwm[i].freq, OBJ_PROP_FLAG_READ);
501         object_property_add_uint32_ptr(obj, "duty[*]",
502                 &s->pwm[i].duty, OBJ_PROP_FLAG_READ);
503     }
504 }
505 
506 static const VMStateDescription vmstate_npcm7xx_pwm = {
507     .name = "npcm7xx-pwm",
508     .version_id = 0,
509     .minimum_version_id = 0,
510     .fields = (VMStateField[]) {
511         VMSTATE_BOOL(running, NPCM7xxPWM),
512         VMSTATE_BOOL(inverted, NPCM7xxPWM),
513         VMSTATE_UINT8(index, NPCM7xxPWM),
514         VMSTATE_UINT32(cnr, NPCM7xxPWM),
515         VMSTATE_UINT32(cmr, NPCM7xxPWM),
516         VMSTATE_UINT32(pdr, NPCM7xxPWM),
517         VMSTATE_UINT32(pwdr, NPCM7xxPWM),
518         VMSTATE_UINT32(freq, NPCM7xxPWM),
519         VMSTATE_UINT32(duty, NPCM7xxPWM),
520         VMSTATE_END_OF_LIST(),
521     },
522 };
523 
524 static const VMStateDescription vmstate_npcm7xx_pwm_module = {
525     .name = "npcm7xx-pwm-module",
526     .version_id = 0,
527     .minimum_version_id = 0,
528     .fields = (VMStateField[]) {
529         VMSTATE_CLOCK(clock, NPCM7xxPWMState),
530         VMSTATE_STRUCT_ARRAY(pwm, NPCM7xxPWMState,
531                              NPCM7XX_PWM_PER_MODULE, 0, vmstate_npcm7xx_pwm,
532                              NPCM7xxPWM),
533         VMSTATE_UINT32(ppr, NPCM7xxPWMState),
534         VMSTATE_UINT32(csr, NPCM7xxPWMState),
535         VMSTATE_UINT32(pcr, NPCM7xxPWMState),
536         VMSTATE_UINT32(pier, NPCM7xxPWMState),
537         VMSTATE_UINT32(piir, NPCM7xxPWMState),
538         VMSTATE_END_OF_LIST(),
539     },
540 };
541 
542 static void npcm7xx_pwm_class_init(ObjectClass *klass, void *data)
543 {
544     ResettableClass *rc = RESETTABLE_CLASS(klass);
545     DeviceClass *dc = DEVICE_CLASS(klass);
546 
547     dc->desc = "NPCM7xx PWM Controller";
548     dc->vmsd = &vmstate_npcm7xx_pwm_module;
549     rc->phases.enter = npcm7xx_pwm_enter_reset;
550     rc->phases.hold = npcm7xx_pwm_hold_reset;
551 }
552 
553 static const TypeInfo npcm7xx_pwm_info = {
554     .name               = TYPE_NPCM7XX_PWM,
555     .parent             = TYPE_SYS_BUS_DEVICE,
556     .instance_size      = sizeof(NPCM7xxPWMState),
557     .class_init         = npcm7xx_pwm_class_init,
558     .instance_init      = npcm7xx_pwm_init,
559 };
560 
561 static void npcm7xx_pwm_register_type(void)
562 {
563     type_register_static(&npcm7xx_pwm_info);
564 }
565 type_init(npcm7xx_pwm_register_type);
566