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
15enum 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
26struct scmi_msg_resp_clock_protocol_attributes {
27	__le16 num_clocks;
28	u8 max_async_req;
29	u8 reserved;
30};
31
32struct 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
42struct scmi_clock_set_config {
43	__le32 id;
44	__le32 attributes;
45};
46
47struct scmi_msg_clock_describe_rates {
48	__le32 id;
49	__le32 rate_index;
50};
51
52struct 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
68struct 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
79struct scmi_msg_resp_set_rate_complete {
80	__le32 id;
81	__le32 rate_low;
82	__le32 rate_high;
83};
84
85struct scmi_msg_clock_rate_notify {
86	__le32 clk_id;
87	__le32 notify_enable;
88};
89
90struct scmi_clock_rate_notify_payld {
91	__le32 agent_id;
92	__le32 clock_id;
93	__le32 rate_low;
94	__le32 rate_high;
95};
96
97struct 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
105static enum scmi_clock_protocol_cmd evt_2_cmd[] = {
106	CLOCK_RATE_NOTIFY,
107	CLOCK_RATE_CHANGE_REQUESTED_NOTIFY,
108};
109
110static int
111scmi_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
135static 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
184static 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
196struct scmi_clk_ipriv {
197	struct device *dev;
198	u32 clk_id;
199	struct scmi_clock_info *clk;
200};
201
202static 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
214static int
215iter_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
253static int
254iter_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
287static int
288scmi_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
327static int
328scmi_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
349static 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
396static int
397scmi_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
421static 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
426static 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
431static 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
437static 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
443static 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
450static const struct scmi_clock_info *
451scmi_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
466static 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
477static 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
498static 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
515static 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
537static 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
547static 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
560static 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
566static 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
573static 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
611static 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
619DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(clock, scmi_clock)
620