1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * System Control and Management Interface (SCMI) Clock Protocol
4 *
5 * Copyright (C) 2018-2022 ARM Ltd.
6 */
7
8 #include <linux/module.h>
9 #include <linux/limits.h>
10 #include <linux/sort.h>
11
12 #include "protocols.h"
13 #include "notify.h"
14
15 enum scmi_clock_protocol_cmd {
16 CLOCK_ATTRIBUTES = 0x3,
17 CLOCK_DESCRIBE_RATES = 0x4,
18 CLOCK_RATE_SET = 0x5,
19 CLOCK_RATE_GET = 0x6,
20 CLOCK_CONFIG_SET = 0x7,
21 CLOCK_NAME_GET = 0x8,
22 CLOCK_RATE_NOTIFY = 0x9,
23 CLOCK_RATE_CHANGE_REQUESTED_NOTIFY = 0xA,
24 };
25
26 struct scmi_msg_resp_clock_protocol_attributes {
27 __le16 num_clocks;
28 u8 max_async_req;
29 u8 reserved;
30 };
31
32 struct scmi_msg_resp_clock_attributes {
33 __le32 attributes;
34 #define CLOCK_ENABLE BIT(0)
35 #define SUPPORTS_RATE_CHANGED_NOTIF(x) ((x) & BIT(31))
36 #define SUPPORTS_RATE_CHANGE_REQUESTED_NOTIF(x) ((x) & BIT(30))
37 #define SUPPORTS_EXTENDED_NAMES(x) ((x) & BIT(29))
38 u8 name[SCMI_SHORT_NAME_MAX_SIZE];
39 __le32 clock_enable_latency;
40 };
41
42 struct scmi_clock_set_config {
43 __le32 id;
44 __le32 attributes;
45 };
46
47 struct scmi_msg_clock_describe_rates {
48 __le32 id;
49 __le32 rate_index;
50 };
51
52 struct scmi_msg_resp_clock_describe_rates {
53 __le32 num_rates_flags;
54 #define NUM_RETURNED(x) ((x) & 0xfff)
55 #define RATE_DISCRETE(x) !((x) & BIT(12))
56 #define NUM_REMAINING(x) ((x) >> 16)
57 struct {
58 __le32 value_low;
59 __le32 value_high;
60 } rate[];
61 #define RATE_TO_U64(X) \
62 ({ \
63 typeof(X) x = (X); \
64 le32_to_cpu((x).value_low) | (u64)le32_to_cpu((x).value_high) << 32; \
65 })
66 };
67
68 struct scmi_clock_set_rate {
69 __le32 flags;
70 #define CLOCK_SET_ASYNC BIT(0)
71 #define CLOCK_SET_IGNORE_RESP BIT(1)
72 #define CLOCK_SET_ROUND_UP BIT(2)
73 #define CLOCK_SET_ROUND_AUTO BIT(3)
74 __le32 id;
75 __le32 value_low;
76 __le32 value_high;
77 };
78
79 struct scmi_msg_resp_set_rate_complete {
80 __le32 id;
81 __le32 rate_low;
82 __le32 rate_high;
83 };
84
85 struct scmi_msg_clock_rate_notify {
86 __le32 clk_id;
87 __le32 notify_enable;
88 };
89
90 struct scmi_clock_rate_notify_payld {
91 __le32 agent_id;
92 __le32 clock_id;
93 __le32 rate_low;
94 __le32 rate_high;
95 };
96
97 struct clock_info {
98 u32 version;
99 int num_clocks;
100 int max_async_req;
101 atomic_t cur_async_req;
102 struct scmi_clock_info *clk;
103 };
104
105 static enum scmi_clock_protocol_cmd evt_2_cmd[] = {
106 CLOCK_RATE_NOTIFY,
107 CLOCK_RATE_CHANGE_REQUESTED_NOTIFY,
108 };
109
110 static int
scmi_clock_protocol_attributes_get(const struct scmi_protocol_handle * ph,struct clock_info * ci)111 scmi_clock_protocol_attributes_get(const struct scmi_protocol_handle *ph,
112 struct clock_info *ci)
113 {
114 int ret;
115 struct scmi_xfer *t;
116 struct scmi_msg_resp_clock_protocol_attributes *attr;
117
118 ret = ph->xops->xfer_get_init(ph, PROTOCOL_ATTRIBUTES,
119 0, sizeof(*attr), &t);
120 if (ret)
121 return ret;
122
123 attr = t->rx.buf;
124
125 ret = ph->xops->do_xfer(ph, t);
126 if (!ret) {
127 ci->num_clocks = le16_to_cpu(attr->num_clocks);
128 ci->max_async_req = attr->max_async_req;
129 }
130
131 ph->xops->xfer_put(ph, t);
132 return ret;
133 }
134
scmi_clock_attributes_get(const struct scmi_protocol_handle * ph,u32 clk_id,struct scmi_clock_info * clk,u32 version)135 static int scmi_clock_attributes_get(const struct scmi_protocol_handle *ph,
136 u32 clk_id, struct scmi_clock_info *clk,
137 u32 version)
138 {
139 int ret;
140 u32 attributes;
141 struct scmi_xfer *t;
142 struct scmi_msg_resp_clock_attributes *attr;
143
144 ret = ph->xops->xfer_get_init(ph, CLOCK_ATTRIBUTES,
145 sizeof(clk_id), sizeof(*attr), &t);
146 if (ret)
147 return ret;
148
149 put_unaligned_le32(clk_id, t->tx.buf);
150 attr = t->rx.buf;
151
152 ret = ph->xops->do_xfer(ph, t);
153 if (!ret) {
154 u32 latency = 0;
155 attributes = le32_to_cpu(attr->attributes);
156 strscpy(clk->name, attr->name, SCMI_SHORT_NAME_MAX_SIZE);
157 /* clock_enable_latency field is present only since SCMI v3.1 */
158 if (PROTOCOL_REV_MAJOR(version) >= 0x2)
159 latency = le32_to_cpu(attr->clock_enable_latency);
160 clk->enable_latency = latency ? : U32_MAX;
161 }
162
163 ph->xops->xfer_put(ph, t);
164
165 /*
166 * If supported overwrite short name with the extended one;
167 * on error just carry on and use already provided short name.
168 */
169 if (!ret && PROTOCOL_REV_MAJOR(version) >= 0x2) {
170 if (SUPPORTS_EXTENDED_NAMES(attributes))
171 ph->hops->extended_name_get(ph, CLOCK_NAME_GET, clk_id,
172 clk->name,
173 SCMI_MAX_STR_SIZE);
174
175 if (SUPPORTS_RATE_CHANGED_NOTIF(attributes))
176 clk->rate_changed_notifications = true;
177 if (SUPPORTS_RATE_CHANGE_REQUESTED_NOTIF(attributes))
178 clk->rate_change_requested_notifications = true;
179 }
180
181 return ret;
182 }
183
rate_cmp_func(const void * _r1,const void * _r2)184 static int rate_cmp_func(const void *_r1, const void *_r2)
185 {
186 const u64 *r1 = _r1, *r2 = _r2;
187
188 if (*r1 < *r2)
189 return -1;
190 else if (*r1 == *r2)
191 return 0;
192 else
193 return 1;
194 }
195
196 struct scmi_clk_ipriv {
197 struct device *dev;
198 u32 clk_id;
199 struct scmi_clock_info *clk;
200 };
201
iter_clk_describe_prepare_message(void * message,const unsigned int desc_index,const void * priv)202 static void iter_clk_describe_prepare_message(void *message,
203 const unsigned int desc_index,
204 const void *priv)
205 {
206 struct scmi_msg_clock_describe_rates *msg = message;
207 const struct scmi_clk_ipriv *p = priv;
208
209 msg->id = cpu_to_le32(p->clk_id);
210 /* Set the number of rates to be skipped/already read */
211 msg->rate_index = cpu_to_le32(desc_index);
212 }
213
214 static int
iter_clk_describe_update_state(struct scmi_iterator_state * st,const void * response,void * priv)215 iter_clk_describe_update_state(struct scmi_iterator_state *st,
216 const void *response, void *priv)
217 {
218 u32 flags;
219 struct scmi_clk_ipriv *p = priv;
220 const struct scmi_msg_resp_clock_describe_rates *r = response;
221
222 flags = le32_to_cpu(r->num_rates_flags);
223 st->num_remaining = NUM_REMAINING(flags);
224 st->num_returned = NUM_RETURNED(flags);
225 p->clk->rate_discrete = RATE_DISCRETE(flags);
226
227 /* Warn about out of spec replies ... */
228 if (!p->clk->rate_discrete &&
229 (st->num_returned != 3 || st->num_remaining != 0)) {
230 dev_warn(p->dev,
231 "Out-of-spec CLOCK_DESCRIBE_RATES reply for %s - returned:%d remaining:%d rx_len:%zd\n",
232 p->clk->name, st->num_returned, st->num_remaining,
233 st->rx_len);
234
235 /*
236 * A known quirk: a triplet is returned but num_returned != 3
237 * Check for a safe payload size and fix.
238 */
239 if (st->num_returned != 3 && st->num_remaining == 0 &&
240 st->rx_len == sizeof(*r) + sizeof(__le32) * 2 * 3) {
241 st->num_returned = 3;
242 st->num_remaining = 0;
243 } else {
244 dev_err(p->dev,
245 "Cannot fix out-of-spec reply !\n");
246 return -EPROTO;
247 }
248 }
249
250 return 0;
251 }
252
253 static int
iter_clk_describe_process_response(const struct scmi_protocol_handle * ph,const void * response,struct scmi_iterator_state * st,void * priv)254 iter_clk_describe_process_response(const struct scmi_protocol_handle *ph,
255 const void *response,
256 struct scmi_iterator_state *st, void *priv)
257 {
258 int ret = 0;
259 struct scmi_clk_ipriv *p = priv;
260 const struct scmi_msg_resp_clock_describe_rates *r = response;
261
262 if (!p->clk->rate_discrete) {
263 switch (st->desc_index + st->loop_idx) {
264 case 0:
265 p->clk->range.min_rate = RATE_TO_U64(r->rate[0]);
266 break;
267 case 1:
268 p->clk->range.max_rate = RATE_TO_U64(r->rate[1]);
269 break;
270 case 2:
271 p->clk->range.step_size = RATE_TO_U64(r->rate[2]);
272 break;
273 default:
274 ret = -EINVAL;
275 break;
276 }
277 } else {
278 u64 *rate = &p->clk->list.rates[st->desc_index + st->loop_idx];
279
280 *rate = RATE_TO_U64(r->rate[st->loop_idx]);
281 p->clk->list.num_rates++;
282 }
283
284 return ret;
285 }
286
287 static int
scmi_clock_describe_rates_get(const struct scmi_protocol_handle * ph,u32 clk_id,struct scmi_clock_info * clk)288 scmi_clock_describe_rates_get(const struct scmi_protocol_handle *ph, u32 clk_id,
289 struct scmi_clock_info *clk)
290 {
291 int ret;
292 void *iter;
293 struct scmi_iterator_ops ops = {
294 .prepare_message = iter_clk_describe_prepare_message,
295 .update_state = iter_clk_describe_update_state,
296 .process_response = iter_clk_describe_process_response,
297 };
298 struct scmi_clk_ipriv cpriv = {
299 .clk_id = clk_id,
300 .clk = clk,
301 .dev = ph->dev,
302 };
303
304 iter = ph->hops->iter_response_init(ph, &ops, SCMI_MAX_NUM_RATES,
305 CLOCK_DESCRIBE_RATES,
306 sizeof(struct scmi_msg_clock_describe_rates),
307 &cpriv);
308 if (IS_ERR(iter))
309 return PTR_ERR(iter);
310
311 ret = ph->hops->iter_response_run(iter);
312 if (ret)
313 return ret;
314
315 if (!clk->rate_discrete) {
316 dev_dbg(ph->dev, "Min %llu Max %llu Step %llu Hz\n",
317 clk->range.min_rate, clk->range.max_rate,
318 clk->range.step_size);
319 } else if (clk->list.num_rates) {
320 sort(clk->list.rates, clk->list.num_rates,
321 sizeof(clk->list.rates[0]), rate_cmp_func, NULL);
322 }
323
324 return ret;
325 }
326
327 static int
scmi_clock_rate_get(const struct scmi_protocol_handle * ph,u32 clk_id,u64 * value)328 scmi_clock_rate_get(const struct scmi_protocol_handle *ph,
329 u32 clk_id, u64 *value)
330 {
331 int ret;
332 struct scmi_xfer *t;
333
334 ret = ph->xops->xfer_get_init(ph, CLOCK_RATE_GET,
335 sizeof(__le32), sizeof(u64), &t);
336 if (ret)
337 return ret;
338
339 put_unaligned_le32(clk_id, t->tx.buf);
340
341 ret = ph->xops->do_xfer(ph, t);
342 if (!ret)
343 *value = get_unaligned_le64(t->rx.buf);
344
345 ph->xops->xfer_put(ph, t);
346 return ret;
347 }
348
scmi_clock_rate_set(const struct scmi_protocol_handle * ph,u32 clk_id,u64 rate)349 static int scmi_clock_rate_set(const struct scmi_protocol_handle *ph,
350 u32 clk_id, u64 rate)
351 {
352 int ret;
353 u32 flags = 0;
354 struct scmi_xfer *t;
355 struct scmi_clock_set_rate *cfg;
356 struct clock_info *ci = ph->get_priv(ph);
357
358 ret = ph->xops->xfer_get_init(ph, CLOCK_RATE_SET, sizeof(*cfg), 0, &t);
359 if (ret)
360 return ret;
361
362 if (ci->max_async_req &&
363 atomic_inc_return(&ci->cur_async_req) < ci->max_async_req)
364 flags |= CLOCK_SET_ASYNC;
365
366 cfg = t->tx.buf;
367 cfg->flags = cpu_to_le32(flags);
368 cfg->id = cpu_to_le32(clk_id);
369 cfg->value_low = cpu_to_le32(rate & 0xffffffff);
370 cfg->value_high = cpu_to_le32(rate >> 32);
371
372 if (flags & CLOCK_SET_ASYNC) {
373 ret = ph->xops->do_xfer_with_response(ph, t);
374 if (!ret) {
375 struct scmi_msg_resp_set_rate_complete *resp;
376
377 resp = t->rx.buf;
378 if (le32_to_cpu(resp->id) == clk_id)
379 dev_dbg(ph->dev,
380 "Clk ID %d set async to %llu\n", clk_id,
381 get_unaligned_le64(&resp->rate_low));
382 else
383 ret = -EPROTO;
384 }
385 } else {
386 ret = ph->xops->do_xfer(ph, t);
387 }
388
389 if (ci->max_async_req)
390 atomic_dec(&ci->cur_async_req);
391
392 ph->xops->xfer_put(ph, t);
393 return ret;
394 }
395
396 static int
scmi_clock_config_set(const struct scmi_protocol_handle * ph,u32 clk_id,u32 config,bool atomic)397 scmi_clock_config_set(const struct scmi_protocol_handle *ph, u32 clk_id,
398 u32 config, bool atomic)
399 {
400 int ret;
401 struct scmi_xfer *t;
402 struct scmi_clock_set_config *cfg;
403
404 ret = ph->xops->xfer_get_init(ph, CLOCK_CONFIG_SET,
405 sizeof(*cfg), 0, &t);
406 if (ret)
407 return ret;
408
409 t->hdr.poll_completion = atomic;
410
411 cfg = t->tx.buf;
412 cfg->id = cpu_to_le32(clk_id);
413 cfg->attributes = cpu_to_le32(config);
414
415 ret = ph->xops->do_xfer(ph, t);
416
417 ph->xops->xfer_put(ph, t);
418 return ret;
419 }
420
scmi_clock_enable(const struct scmi_protocol_handle * ph,u32 clk_id)421 static int scmi_clock_enable(const struct scmi_protocol_handle *ph, u32 clk_id)
422 {
423 return scmi_clock_config_set(ph, clk_id, CLOCK_ENABLE, false);
424 }
425
scmi_clock_disable(const struct scmi_protocol_handle * ph,u32 clk_id)426 static int scmi_clock_disable(const struct scmi_protocol_handle *ph, u32 clk_id)
427 {
428 return scmi_clock_config_set(ph, clk_id, 0, false);
429 }
430
scmi_clock_enable_atomic(const struct scmi_protocol_handle * ph,u32 clk_id)431 static int scmi_clock_enable_atomic(const struct scmi_protocol_handle *ph,
432 u32 clk_id)
433 {
434 return scmi_clock_config_set(ph, clk_id, CLOCK_ENABLE, true);
435 }
436
scmi_clock_disable_atomic(const struct scmi_protocol_handle * ph,u32 clk_id)437 static int scmi_clock_disable_atomic(const struct scmi_protocol_handle *ph,
438 u32 clk_id)
439 {
440 return scmi_clock_config_set(ph, clk_id, 0, true);
441 }
442
scmi_clock_count_get(const struct scmi_protocol_handle * ph)443 static int scmi_clock_count_get(const struct scmi_protocol_handle *ph)
444 {
445 struct clock_info *ci = ph->get_priv(ph);
446
447 return ci->num_clocks;
448 }
449
450 static const struct scmi_clock_info *
scmi_clock_info_get(const struct scmi_protocol_handle * ph,u32 clk_id)451 scmi_clock_info_get(const struct scmi_protocol_handle *ph, u32 clk_id)
452 {
453 struct scmi_clock_info *clk;
454 struct clock_info *ci = ph->get_priv(ph);
455
456 if (clk_id >= ci->num_clocks)
457 return NULL;
458
459 clk = ci->clk + clk_id;
460 if (!clk->name[0])
461 return NULL;
462
463 return clk;
464 }
465
466 static const struct scmi_clk_proto_ops clk_proto_ops = {
467 .count_get = scmi_clock_count_get,
468 .info_get = scmi_clock_info_get,
469 .rate_get = scmi_clock_rate_get,
470 .rate_set = scmi_clock_rate_set,
471 .enable = scmi_clock_enable,
472 .disable = scmi_clock_disable,
473 .enable_atomic = scmi_clock_enable_atomic,
474 .disable_atomic = scmi_clock_disable_atomic,
475 };
476
scmi_clk_rate_notify(const struct scmi_protocol_handle * ph,u32 clk_id,int message_id,bool enable)477 static int scmi_clk_rate_notify(const struct scmi_protocol_handle *ph,
478 u32 clk_id, int message_id, bool enable)
479 {
480 int ret;
481 struct scmi_xfer *t;
482 struct scmi_msg_clock_rate_notify *notify;
483
484 ret = ph->xops->xfer_get_init(ph, message_id, sizeof(*notify), 0, &t);
485 if (ret)
486 return ret;
487
488 notify = t->tx.buf;
489 notify->clk_id = cpu_to_le32(clk_id);
490 notify->notify_enable = enable ? cpu_to_le32(BIT(0)) : 0;
491
492 ret = ph->xops->do_xfer(ph, t);
493
494 ph->xops->xfer_put(ph, t);
495 return ret;
496 }
497
scmi_clk_set_notify_enabled(const struct scmi_protocol_handle * ph,u8 evt_id,u32 src_id,bool enable)498 static int scmi_clk_set_notify_enabled(const struct scmi_protocol_handle *ph,
499 u8 evt_id, u32 src_id, bool enable)
500 {
501 int ret, cmd_id;
502
503 if (evt_id >= ARRAY_SIZE(evt_2_cmd))
504 return -EINVAL;
505
506 cmd_id = evt_2_cmd[evt_id];
507 ret = scmi_clk_rate_notify(ph, src_id, cmd_id, enable);
508 if (ret)
509 pr_debug("FAIL_ENABLED - evt[%X] dom[%d] - ret:%d\n",
510 evt_id, src_id, ret);
511
512 return ret;
513 }
514
scmi_clk_fill_custom_report(const struct scmi_protocol_handle * ph,u8 evt_id,ktime_t timestamp,const void * payld,size_t payld_sz,void * report,u32 * src_id)515 static void *scmi_clk_fill_custom_report(const struct scmi_protocol_handle *ph,
516 u8 evt_id, ktime_t timestamp,
517 const void *payld, size_t payld_sz,
518 void *report, u32 *src_id)
519 {
520 const struct scmi_clock_rate_notify_payld *p = payld;
521 struct scmi_clock_rate_notif_report *r = report;
522
523 if (sizeof(*p) != payld_sz ||
524 (evt_id != SCMI_EVENT_CLOCK_RATE_CHANGED &&
525 evt_id != SCMI_EVENT_CLOCK_RATE_CHANGE_REQUESTED))
526 return NULL;
527
528 r->timestamp = timestamp;
529 r->agent_id = le32_to_cpu(p->agent_id);
530 r->clock_id = le32_to_cpu(p->clock_id);
531 r->rate = get_unaligned_le64(&p->rate_low);
532 *src_id = r->clock_id;
533
534 return r;
535 }
536
scmi_clk_get_num_sources(const struct scmi_protocol_handle * ph)537 static int scmi_clk_get_num_sources(const struct scmi_protocol_handle *ph)
538 {
539 struct clock_info *ci = ph->get_priv(ph);
540
541 if (!ci)
542 return -EINVAL;
543
544 return ci->num_clocks;
545 }
546
547 static const struct scmi_event clk_events[] = {
548 {
549 .id = SCMI_EVENT_CLOCK_RATE_CHANGED,
550 .max_payld_sz = sizeof(struct scmi_clock_rate_notify_payld),
551 .max_report_sz = sizeof(struct scmi_clock_rate_notif_report),
552 },
553 {
554 .id = SCMI_EVENT_CLOCK_RATE_CHANGE_REQUESTED,
555 .max_payld_sz = sizeof(struct scmi_clock_rate_notify_payld),
556 .max_report_sz = sizeof(struct scmi_clock_rate_notif_report),
557 },
558 };
559
560 static const struct scmi_event_ops clk_event_ops = {
561 .get_num_sources = scmi_clk_get_num_sources,
562 .set_notify_enabled = scmi_clk_set_notify_enabled,
563 .fill_custom_report = scmi_clk_fill_custom_report,
564 };
565
566 static const struct scmi_protocol_events clk_protocol_events = {
567 .queue_sz = SCMI_PROTO_QUEUE_SZ,
568 .ops = &clk_event_ops,
569 .evts = clk_events,
570 .num_events = ARRAY_SIZE(clk_events),
571 };
572
scmi_clock_protocol_init(const struct scmi_protocol_handle * ph)573 static int scmi_clock_protocol_init(const struct scmi_protocol_handle *ph)
574 {
575 u32 version;
576 int clkid, ret;
577 struct clock_info *cinfo;
578
579 ret = ph->xops->version_get(ph, &version);
580 if (ret)
581 return ret;
582
583 dev_dbg(ph->dev, "Clock Version %d.%d\n",
584 PROTOCOL_REV_MAJOR(version), PROTOCOL_REV_MINOR(version));
585
586 cinfo = devm_kzalloc(ph->dev, sizeof(*cinfo), GFP_KERNEL);
587 if (!cinfo)
588 return -ENOMEM;
589
590 ret = scmi_clock_protocol_attributes_get(ph, cinfo);
591 if (ret)
592 return ret;
593
594 cinfo->clk = devm_kcalloc(ph->dev, cinfo->num_clocks,
595 sizeof(*cinfo->clk), GFP_KERNEL);
596 if (!cinfo->clk)
597 return -ENOMEM;
598
599 for (clkid = 0; clkid < cinfo->num_clocks; clkid++) {
600 struct scmi_clock_info *clk = cinfo->clk + clkid;
601
602 ret = scmi_clock_attributes_get(ph, clkid, clk, version);
603 if (!ret)
604 scmi_clock_describe_rates_get(ph, clkid, clk);
605 }
606
607 cinfo->version = version;
608 return ph->set_priv(ph, cinfo);
609 }
610
611 static const struct scmi_protocol scmi_clock = {
612 .id = SCMI_PROTOCOL_CLOCK,
613 .owner = THIS_MODULE,
614 .instance_init = &scmi_clock_protocol_init,
615 .ops = &clk_proto_ops,
616 .events = &clk_protocol_events,
617 };
618
619 DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(clock, scmi_clock)
620