xref: /linux/drivers/firmware/arm_scmi/reset.c (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * System Control and Management Interface (SCMI) Reset Protocol
4  *
5  * Copyright (C) 2019-2022 ARM Ltd.
6  */
7 
8 #define pr_fmt(fmt) "SCMI Notifications RESET - " fmt
9 
10 #include <linux/module.h>
11 #include <linux/scmi_protocol.h>
12 
13 #include "protocols.h"
14 #include "notify.h"
15 
16 /* Updated only after ALL the mandatory features for that version are merged */
17 #define SCMI_PROTOCOL_SUPPORTED_VERSION		0x30001
18 
19 enum scmi_reset_protocol_cmd {
20 	RESET_DOMAIN_ATTRIBUTES = 0x3,
21 	RESET = 0x4,
22 	RESET_NOTIFY = 0x5,
23 	RESET_DOMAIN_NAME_GET = 0x6,
24 };
25 
26 #define NUM_RESET_DOMAIN_MASK	0xffff
27 #define RESET_NOTIFY_ENABLE	BIT(0)
28 
29 struct scmi_msg_resp_reset_domain_attributes {
30 	__le32 attributes;
31 #define SUPPORTS_ASYNC_RESET(x)		((x) & BIT(31))
32 #define SUPPORTS_NOTIFY_RESET(x)	((x) & BIT(30))
33 #define SUPPORTS_EXTENDED_NAMES(x)	((x) & BIT(29))
34 	__le32 latency;
35 	u8 name[SCMI_SHORT_NAME_MAX_SIZE];
36 };
37 
38 struct scmi_msg_reset_domain_reset {
39 	__le32 domain_id;
40 	__le32 flags;
41 #define AUTONOMOUS_RESET	BIT(0)
42 #define EXPLICIT_RESET_ASSERT	BIT(1)
43 #define ASYNCHRONOUS_RESET	BIT(2)
44 	__le32 reset_state;
45 #define ARCH_COLD_RESET		0
46 };
47 
48 struct scmi_msg_reset_notify {
49 	__le32 id;
50 	__le32 event_control;
51 #define RESET_TP_NOTIFY_ALL	BIT(0)
52 };
53 
54 struct scmi_reset_issued_notify_payld {
55 	__le32 agent_id;
56 	__le32 domain_id;
57 	__le32 reset_state;
58 };
59 
60 struct reset_dom_info {
61 	bool async_reset;
62 	bool reset_notify;
63 	u32 latency_us;
64 	char name[SCMI_MAX_STR_SIZE];
65 };
66 
67 struct scmi_reset_info {
68 	u32 version;
69 	int num_domains;
70 	bool notify_reset_cmd;
71 	struct reset_dom_info *dom_info;
72 };
73 
74 static int scmi_reset_attributes_get(const struct scmi_protocol_handle *ph,
75 				     struct scmi_reset_info *pi)
76 {
77 	int ret;
78 	struct scmi_xfer *t;
79 	u32 attr;
80 
81 	ret = ph->xops->xfer_get_init(ph, PROTOCOL_ATTRIBUTES,
82 				      0, sizeof(attr), &t);
83 	if (ret)
84 		return ret;
85 
86 	ret = ph->xops->do_xfer(ph, t);
87 	if (!ret) {
88 		attr = get_unaligned_le32(t->rx.buf);
89 		pi->num_domains = attr & NUM_RESET_DOMAIN_MASK;
90 	}
91 
92 	ph->xops->xfer_put(ph, t);
93 
94 	if (!ret)
95 		if (!ph->hops->protocol_msg_check(ph, RESET_NOTIFY, NULL))
96 			pi->notify_reset_cmd = true;
97 
98 	return ret;
99 }
100 
101 static int
102 scmi_reset_domain_attributes_get(const struct scmi_protocol_handle *ph,
103 				 struct scmi_reset_info *pinfo,
104 				 u32 domain, u32 version)
105 {
106 	int ret;
107 	u32 attributes;
108 	struct scmi_xfer *t;
109 	struct scmi_msg_resp_reset_domain_attributes *attr;
110 	struct reset_dom_info *dom_info = pinfo->dom_info + domain;
111 
112 	ret = ph->xops->xfer_get_init(ph, RESET_DOMAIN_ATTRIBUTES,
113 				      sizeof(domain), sizeof(*attr), &t);
114 	if (ret)
115 		return ret;
116 
117 	put_unaligned_le32(domain, t->tx.buf);
118 	attr = t->rx.buf;
119 
120 	ret = ph->xops->do_xfer(ph, t);
121 	if (!ret) {
122 		attributes = le32_to_cpu(attr->attributes);
123 
124 		dom_info->async_reset = SUPPORTS_ASYNC_RESET(attributes);
125 		if (pinfo->notify_reset_cmd)
126 			dom_info->reset_notify =
127 				SUPPORTS_NOTIFY_RESET(attributes);
128 		dom_info->latency_us = le32_to_cpu(attr->latency);
129 		if (dom_info->latency_us == U32_MAX)
130 			dom_info->latency_us = 0;
131 		strscpy(dom_info->name, attr->name, SCMI_SHORT_NAME_MAX_SIZE);
132 	}
133 
134 	ph->xops->xfer_put(ph, t);
135 
136 	/*
137 	 * If supported overwrite short name with the extended one;
138 	 * on error just carry on and use already provided short name.
139 	 */
140 	if (!ret && PROTOCOL_REV_MAJOR(version) >= 0x3 &&
141 	    SUPPORTS_EXTENDED_NAMES(attributes))
142 		ph->hops->extended_name_get(ph, RESET_DOMAIN_NAME_GET, domain,
143 					    NULL, dom_info->name,
144 					    SCMI_MAX_STR_SIZE);
145 
146 	return ret;
147 }
148 
149 static int scmi_reset_num_domains_get(const struct scmi_protocol_handle *ph)
150 {
151 	struct scmi_reset_info *pi = ph->get_priv(ph);
152 
153 	return pi->num_domains;
154 }
155 
156 static const char *
157 scmi_reset_name_get(const struct scmi_protocol_handle *ph, u32 domain)
158 {
159 	struct scmi_reset_info *pi = ph->get_priv(ph);
160 
161 	struct reset_dom_info *dom = pi->dom_info + domain;
162 
163 	return dom->name;
164 }
165 
166 static int scmi_reset_latency_get(const struct scmi_protocol_handle *ph,
167 				  u32 domain)
168 {
169 	struct scmi_reset_info *pi = ph->get_priv(ph);
170 	struct reset_dom_info *dom = pi->dom_info + domain;
171 
172 	return dom->latency_us;
173 }
174 
175 static int scmi_domain_reset(const struct scmi_protocol_handle *ph, u32 domain,
176 			     u32 flags, u32 state)
177 {
178 	int ret;
179 	struct scmi_xfer *t;
180 	struct scmi_msg_reset_domain_reset *dom;
181 	struct scmi_reset_info *pi = ph->get_priv(ph);
182 	struct reset_dom_info *rdom;
183 
184 	if (domain >= pi->num_domains)
185 		return -EINVAL;
186 
187 	rdom = pi->dom_info + domain;
188 	if (rdom->async_reset && flags & AUTONOMOUS_RESET)
189 		flags |= ASYNCHRONOUS_RESET;
190 
191 	ret = ph->xops->xfer_get_init(ph, RESET, sizeof(*dom), 0, &t);
192 	if (ret)
193 		return ret;
194 
195 	dom = t->tx.buf;
196 	dom->domain_id = cpu_to_le32(domain);
197 	dom->flags = cpu_to_le32(flags);
198 	dom->reset_state = cpu_to_le32(state);
199 
200 	if (flags & ASYNCHRONOUS_RESET)
201 		ret = ph->xops->do_xfer_with_response(ph, t);
202 	else
203 		ret = ph->xops->do_xfer(ph, t);
204 
205 	ph->xops->xfer_put(ph, t);
206 	return ret;
207 }
208 
209 static int scmi_reset_domain_reset(const struct scmi_protocol_handle *ph,
210 				   u32 domain)
211 {
212 	return scmi_domain_reset(ph, domain, AUTONOMOUS_RESET,
213 				 ARCH_COLD_RESET);
214 }
215 
216 static int
217 scmi_reset_domain_assert(const struct scmi_protocol_handle *ph, u32 domain)
218 {
219 	return scmi_domain_reset(ph, domain, EXPLICIT_RESET_ASSERT,
220 				 ARCH_COLD_RESET);
221 }
222 
223 static int
224 scmi_reset_domain_deassert(const struct scmi_protocol_handle *ph, u32 domain)
225 {
226 	return scmi_domain_reset(ph, domain, 0, ARCH_COLD_RESET);
227 }
228 
229 static const struct scmi_reset_proto_ops reset_proto_ops = {
230 	.num_domains_get = scmi_reset_num_domains_get,
231 	.name_get = scmi_reset_name_get,
232 	.latency_get = scmi_reset_latency_get,
233 	.reset = scmi_reset_domain_reset,
234 	.assert = scmi_reset_domain_assert,
235 	.deassert = scmi_reset_domain_deassert,
236 };
237 
238 static bool scmi_reset_notify_supported(const struct scmi_protocol_handle *ph,
239 					u8 evt_id, u32 src_id)
240 {
241 	struct reset_dom_info *dom;
242 	struct scmi_reset_info *pi = ph->get_priv(ph);
243 
244 	if (evt_id != SCMI_EVENT_RESET_ISSUED || src_id >= pi->num_domains)
245 		return false;
246 
247 	dom = pi->dom_info + src_id;
248 
249 	return dom->reset_notify;
250 }
251 
252 static int scmi_reset_notify(const struct scmi_protocol_handle *ph,
253 			     u32 domain_id, bool enable)
254 {
255 	int ret;
256 	u32 evt_cntl = enable ? RESET_TP_NOTIFY_ALL : 0;
257 	struct scmi_xfer *t;
258 	struct scmi_msg_reset_notify *cfg;
259 
260 	ret = ph->xops->xfer_get_init(ph, RESET_NOTIFY, sizeof(*cfg), 0, &t);
261 	if (ret)
262 		return ret;
263 
264 	cfg = t->tx.buf;
265 	cfg->id = cpu_to_le32(domain_id);
266 	cfg->event_control = cpu_to_le32(evt_cntl);
267 
268 	ret = ph->xops->do_xfer(ph, t);
269 
270 	ph->xops->xfer_put(ph, t);
271 	return ret;
272 }
273 
274 static int scmi_reset_set_notify_enabled(const struct scmi_protocol_handle *ph,
275 					 u8 evt_id, u32 src_id, bool enable)
276 {
277 	int ret;
278 
279 	ret = scmi_reset_notify(ph, src_id, enable);
280 	if (ret)
281 		pr_debug("FAIL_ENABLED - evt[%X] dom[%d] - ret:%d\n",
282 			 evt_id, src_id, ret);
283 
284 	return ret;
285 }
286 
287 static void *
288 scmi_reset_fill_custom_report(const struct scmi_protocol_handle *ph,
289 			      u8 evt_id, ktime_t timestamp,
290 			      const void *payld, size_t payld_sz,
291 			      void *report, u32 *src_id)
292 {
293 	const struct scmi_reset_issued_notify_payld *p = payld;
294 	struct scmi_reset_issued_report *r = report;
295 
296 	if (evt_id != SCMI_EVENT_RESET_ISSUED || sizeof(*p) != payld_sz)
297 		return NULL;
298 
299 	r->timestamp = timestamp;
300 	r->agent_id = le32_to_cpu(p->agent_id);
301 	r->domain_id = le32_to_cpu(p->domain_id);
302 	r->reset_state = le32_to_cpu(p->reset_state);
303 	*src_id = r->domain_id;
304 
305 	return r;
306 }
307 
308 static int scmi_reset_get_num_sources(const struct scmi_protocol_handle *ph)
309 {
310 	struct scmi_reset_info *pinfo = ph->get_priv(ph);
311 
312 	if (!pinfo)
313 		return -EINVAL;
314 
315 	return pinfo->num_domains;
316 }
317 
318 static const struct scmi_event reset_events[] = {
319 	{
320 		.id = SCMI_EVENT_RESET_ISSUED,
321 		.max_payld_sz = sizeof(struct scmi_reset_issued_notify_payld),
322 		.max_report_sz = sizeof(struct scmi_reset_issued_report),
323 	},
324 };
325 
326 static const struct scmi_event_ops reset_event_ops = {
327 	.is_notify_supported = scmi_reset_notify_supported,
328 	.get_num_sources = scmi_reset_get_num_sources,
329 	.set_notify_enabled = scmi_reset_set_notify_enabled,
330 	.fill_custom_report = scmi_reset_fill_custom_report,
331 };
332 
333 static const struct scmi_protocol_events reset_protocol_events = {
334 	.queue_sz = SCMI_PROTO_QUEUE_SZ,
335 	.ops = &reset_event_ops,
336 	.evts = reset_events,
337 	.num_events = ARRAY_SIZE(reset_events),
338 };
339 
340 static int scmi_reset_protocol_init(const struct scmi_protocol_handle *ph)
341 {
342 	int domain, ret;
343 	u32 version;
344 	struct scmi_reset_info *pinfo;
345 
346 	ret = ph->xops->version_get(ph, &version);
347 	if (ret)
348 		return ret;
349 
350 	dev_dbg(ph->dev, "Reset Version %d.%d\n",
351 		PROTOCOL_REV_MAJOR(version), PROTOCOL_REV_MINOR(version));
352 
353 	pinfo = devm_kzalloc(ph->dev, sizeof(*pinfo), GFP_KERNEL);
354 	if (!pinfo)
355 		return -ENOMEM;
356 
357 	ret = scmi_reset_attributes_get(ph, pinfo);
358 	if (ret)
359 		return ret;
360 
361 	pinfo->dom_info = devm_kcalloc(ph->dev, pinfo->num_domains,
362 				       sizeof(*pinfo->dom_info), GFP_KERNEL);
363 	if (!pinfo->dom_info)
364 		return -ENOMEM;
365 
366 	for (domain = 0; domain < pinfo->num_domains; domain++)
367 		scmi_reset_domain_attributes_get(ph, pinfo, domain, version);
368 
369 	pinfo->version = version;
370 	return ph->set_priv(ph, pinfo, version);
371 }
372 
373 static const struct scmi_protocol scmi_reset = {
374 	.id = SCMI_PROTOCOL_RESET,
375 	.owner = THIS_MODULE,
376 	.instance_init = &scmi_reset_protocol_init,
377 	.ops = &reset_proto_ops,
378 	.events = &reset_protocol_events,
379 	.supported_version = SCMI_PROTOCOL_SUPPORTED_VERSION,
380 };
381 
382 DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(reset, scmi_reset)
383