xref: /openbmc/linux/drivers/greybus/svc.c (revision fb574682)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * SVC Greybus driver.
4  *
5  * Copyright 2015 Google Inc.
6  * Copyright 2015 Linaro Ltd.
7  */
8 
9 #include <linux/debugfs.h>
10 #include <linux/workqueue.h>
11 #include <linux/greybus.h>
12 
13 #define SVC_INTF_EJECT_TIMEOUT		9000
14 #define SVC_INTF_ACTIVATE_TIMEOUT	6000
15 #define SVC_INTF_RESUME_TIMEOUT		3000
16 
17 struct gb_svc_deferred_request {
18 	struct work_struct work;
19 	struct gb_operation *operation;
20 };
21 
22 static int gb_svc_queue_deferred_request(struct gb_operation *operation);
23 
24 static ssize_t endo_id_show(struct device *dev,
25 			    struct device_attribute *attr, char *buf)
26 {
27 	struct gb_svc *svc = to_gb_svc(dev);
28 
29 	return sprintf(buf, "0x%04x\n", svc->endo_id);
30 }
31 static DEVICE_ATTR_RO(endo_id);
32 
33 static ssize_t ap_intf_id_show(struct device *dev,
34 			       struct device_attribute *attr, char *buf)
35 {
36 	struct gb_svc *svc = to_gb_svc(dev);
37 
38 	return sprintf(buf, "%u\n", svc->ap_intf_id);
39 }
40 static DEVICE_ATTR_RO(ap_intf_id);
41 
42 // FIXME
43 // This is a hack, we need to do this "right" and clean the interface up
44 // properly, not just forcibly yank the thing out of the system and hope for the
45 // best.  But for now, people want their modules to come out without having to
46 // throw the thing to the ground or get out a screwdriver.
47 static ssize_t intf_eject_store(struct device *dev,
48 				struct device_attribute *attr, const char *buf,
49 				size_t len)
50 {
51 	struct gb_svc *svc = to_gb_svc(dev);
52 	unsigned short intf_id;
53 	int ret;
54 
55 	ret = kstrtou16(buf, 10, &intf_id);
56 	if (ret < 0)
57 		return ret;
58 
59 	dev_warn(dev, "Forcibly trying to eject interface %d\n", intf_id);
60 
61 	ret = gb_svc_intf_eject(svc, intf_id);
62 	if (ret < 0)
63 		return ret;
64 
65 	return len;
66 }
67 static DEVICE_ATTR_WO(intf_eject);
68 
69 static ssize_t watchdog_show(struct device *dev, struct device_attribute *attr,
70 			     char *buf)
71 {
72 	struct gb_svc *svc = to_gb_svc(dev);
73 
74 	return sprintf(buf, "%s\n",
75 		       gb_svc_watchdog_enabled(svc) ? "enabled" : "disabled");
76 }
77 
78 static ssize_t watchdog_store(struct device *dev,
79 			      struct device_attribute *attr, const char *buf,
80 			      size_t len)
81 {
82 	struct gb_svc *svc = to_gb_svc(dev);
83 	int retval;
84 	bool user_request;
85 
86 	retval = strtobool(buf, &user_request);
87 	if (retval)
88 		return retval;
89 
90 	if (user_request)
91 		retval = gb_svc_watchdog_enable(svc);
92 	else
93 		retval = gb_svc_watchdog_disable(svc);
94 	if (retval)
95 		return retval;
96 	return len;
97 }
98 static DEVICE_ATTR_RW(watchdog);
99 
100 static ssize_t watchdog_action_show(struct device *dev,
101 				    struct device_attribute *attr, char *buf)
102 {
103 	struct gb_svc *svc = to_gb_svc(dev);
104 
105 	if (svc->action == GB_SVC_WATCHDOG_BITE_PANIC_KERNEL)
106 		return sprintf(buf, "panic\n");
107 	else if (svc->action == GB_SVC_WATCHDOG_BITE_RESET_UNIPRO)
108 		return sprintf(buf, "reset\n");
109 
110 	return -EINVAL;
111 }
112 
113 static ssize_t watchdog_action_store(struct device *dev,
114 				     struct device_attribute *attr,
115 				     const char *buf, size_t len)
116 {
117 	struct gb_svc *svc = to_gb_svc(dev);
118 
119 	if (sysfs_streq(buf, "panic"))
120 		svc->action = GB_SVC_WATCHDOG_BITE_PANIC_KERNEL;
121 	else if (sysfs_streq(buf, "reset"))
122 		svc->action = GB_SVC_WATCHDOG_BITE_RESET_UNIPRO;
123 	else
124 		return -EINVAL;
125 
126 	return len;
127 }
128 static DEVICE_ATTR_RW(watchdog_action);
129 
130 static int gb_svc_pwrmon_rail_count_get(struct gb_svc *svc, u8 *value)
131 {
132 	struct gb_svc_pwrmon_rail_count_get_response response;
133 	int ret;
134 
135 	ret = gb_operation_sync(svc->connection,
136 				GB_SVC_TYPE_PWRMON_RAIL_COUNT_GET, NULL, 0,
137 				&response, sizeof(response));
138 	if (ret) {
139 		dev_err(&svc->dev, "failed to get rail count: %d\n", ret);
140 		return ret;
141 	}
142 
143 	*value = response.rail_count;
144 
145 	return 0;
146 }
147 
148 static int gb_svc_pwrmon_rail_names_get(struct gb_svc *svc,
149 		struct gb_svc_pwrmon_rail_names_get_response *response,
150 		size_t bufsize)
151 {
152 	int ret;
153 
154 	ret = gb_operation_sync(svc->connection,
155 				GB_SVC_TYPE_PWRMON_RAIL_NAMES_GET, NULL, 0,
156 				response, bufsize);
157 	if (ret) {
158 		dev_err(&svc->dev, "failed to get rail names: %d\n", ret);
159 		return ret;
160 	}
161 
162 	if (response->status != GB_SVC_OP_SUCCESS) {
163 		dev_err(&svc->dev,
164 			"SVC error while getting rail names: %u\n",
165 			response->status);
166 		return -EREMOTEIO;
167 	}
168 
169 	return 0;
170 }
171 
172 static int gb_svc_pwrmon_sample_get(struct gb_svc *svc, u8 rail_id,
173 				    u8 measurement_type, u32 *value)
174 {
175 	struct gb_svc_pwrmon_sample_get_request request;
176 	struct gb_svc_pwrmon_sample_get_response response;
177 	int ret;
178 
179 	request.rail_id = rail_id;
180 	request.measurement_type = measurement_type;
181 
182 	ret = gb_operation_sync(svc->connection, GB_SVC_TYPE_PWRMON_SAMPLE_GET,
183 				&request, sizeof(request),
184 				&response, sizeof(response));
185 	if (ret) {
186 		dev_err(&svc->dev, "failed to get rail sample: %d\n", ret);
187 		return ret;
188 	}
189 
190 	if (response.result) {
191 		dev_err(&svc->dev,
192 			"UniPro error while getting rail power sample (%d %d): %d\n",
193 			rail_id, measurement_type, response.result);
194 		switch (response.result) {
195 		case GB_SVC_PWRMON_GET_SAMPLE_INVAL:
196 			return -EINVAL;
197 		case GB_SVC_PWRMON_GET_SAMPLE_NOSUPP:
198 			return -ENOMSG;
199 		default:
200 			return -EREMOTEIO;
201 		}
202 	}
203 
204 	*value = le32_to_cpu(response.measurement);
205 
206 	return 0;
207 }
208 
209 int gb_svc_pwrmon_intf_sample_get(struct gb_svc *svc, u8 intf_id,
210 				  u8 measurement_type, u32 *value)
211 {
212 	struct gb_svc_pwrmon_intf_sample_get_request request;
213 	struct gb_svc_pwrmon_intf_sample_get_response response;
214 	int ret;
215 
216 	request.intf_id = intf_id;
217 	request.measurement_type = measurement_type;
218 
219 	ret = gb_operation_sync(svc->connection,
220 				GB_SVC_TYPE_PWRMON_INTF_SAMPLE_GET,
221 				&request, sizeof(request),
222 				&response, sizeof(response));
223 	if (ret) {
224 		dev_err(&svc->dev, "failed to get intf sample: %d\n", ret);
225 		return ret;
226 	}
227 
228 	if (response.result) {
229 		dev_err(&svc->dev,
230 			"UniPro error while getting intf power sample (%d %d): %d\n",
231 			intf_id, measurement_type, response.result);
232 		switch (response.result) {
233 		case GB_SVC_PWRMON_GET_SAMPLE_INVAL:
234 			return -EINVAL;
235 		case GB_SVC_PWRMON_GET_SAMPLE_NOSUPP:
236 			return -ENOMSG;
237 		default:
238 			return -EREMOTEIO;
239 		}
240 	}
241 
242 	*value = le32_to_cpu(response.measurement);
243 
244 	return 0;
245 }
246 
247 static struct attribute *svc_attrs[] = {
248 	&dev_attr_endo_id.attr,
249 	&dev_attr_ap_intf_id.attr,
250 	&dev_attr_intf_eject.attr,
251 	&dev_attr_watchdog.attr,
252 	&dev_attr_watchdog_action.attr,
253 	NULL,
254 };
255 ATTRIBUTE_GROUPS(svc);
256 
257 int gb_svc_intf_device_id(struct gb_svc *svc, u8 intf_id, u8 device_id)
258 {
259 	struct gb_svc_intf_device_id_request request;
260 
261 	request.intf_id = intf_id;
262 	request.device_id = device_id;
263 
264 	return gb_operation_sync(svc->connection, GB_SVC_TYPE_INTF_DEVICE_ID,
265 				 &request, sizeof(request), NULL, 0);
266 }
267 
268 int gb_svc_intf_eject(struct gb_svc *svc, u8 intf_id)
269 {
270 	struct gb_svc_intf_eject_request request;
271 	int ret;
272 
273 	request.intf_id = intf_id;
274 
275 	/*
276 	 * The pulse width for module release in svc is long so we need to
277 	 * increase the timeout so the operation will not return to soon.
278 	 */
279 	ret = gb_operation_sync_timeout(svc->connection,
280 					GB_SVC_TYPE_INTF_EJECT, &request,
281 					sizeof(request), NULL, 0,
282 					SVC_INTF_EJECT_TIMEOUT);
283 	if (ret) {
284 		dev_err(&svc->dev, "failed to eject interface %u\n", intf_id);
285 		return ret;
286 	}
287 
288 	return 0;
289 }
290 
291 int gb_svc_intf_vsys_set(struct gb_svc *svc, u8 intf_id, bool enable)
292 {
293 	struct gb_svc_intf_vsys_request request;
294 	struct gb_svc_intf_vsys_response response;
295 	int type, ret;
296 
297 	request.intf_id = intf_id;
298 
299 	if (enable)
300 		type = GB_SVC_TYPE_INTF_VSYS_ENABLE;
301 	else
302 		type = GB_SVC_TYPE_INTF_VSYS_DISABLE;
303 
304 	ret = gb_operation_sync(svc->connection, type,
305 				&request, sizeof(request),
306 				&response, sizeof(response));
307 	if (ret < 0)
308 		return ret;
309 	if (response.result_code != GB_SVC_INTF_VSYS_OK)
310 		return -EREMOTEIO;
311 	return 0;
312 }
313 
314 int gb_svc_intf_refclk_set(struct gb_svc *svc, u8 intf_id, bool enable)
315 {
316 	struct gb_svc_intf_refclk_request request;
317 	struct gb_svc_intf_refclk_response response;
318 	int type, ret;
319 
320 	request.intf_id = intf_id;
321 
322 	if (enable)
323 		type = GB_SVC_TYPE_INTF_REFCLK_ENABLE;
324 	else
325 		type = GB_SVC_TYPE_INTF_REFCLK_DISABLE;
326 
327 	ret = gb_operation_sync(svc->connection, type,
328 				&request, sizeof(request),
329 				&response, sizeof(response));
330 	if (ret < 0)
331 		return ret;
332 	if (response.result_code != GB_SVC_INTF_REFCLK_OK)
333 		return -EREMOTEIO;
334 	return 0;
335 }
336 
337 int gb_svc_intf_unipro_set(struct gb_svc *svc, u8 intf_id, bool enable)
338 {
339 	struct gb_svc_intf_unipro_request request;
340 	struct gb_svc_intf_unipro_response response;
341 	int type, ret;
342 
343 	request.intf_id = intf_id;
344 
345 	if (enable)
346 		type = GB_SVC_TYPE_INTF_UNIPRO_ENABLE;
347 	else
348 		type = GB_SVC_TYPE_INTF_UNIPRO_DISABLE;
349 
350 	ret = gb_operation_sync(svc->connection, type,
351 				&request, sizeof(request),
352 				&response, sizeof(response));
353 	if (ret < 0)
354 		return ret;
355 	if (response.result_code != GB_SVC_INTF_UNIPRO_OK)
356 		return -EREMOTEIO;
357 	return 0;
358 }
359 
360 int gb_svc_intf_activate(struct gb_svc *svc, u8 intf_id, u8 *intf_type)
361 {
362 	struct gb_svc_intf_activate_request request;
363 	struct gb_svc_intf_activate_response response;
364 	int ret;
365 
366 	request.intf_id = intf_id;
367 
368 	ret = gb_operation_sync_timeout(svc->connection,
369 					GB_SVC_TYPE_INTF_ACTIVATE,
370 					&request, sizeof(request),
371 					&response, sizeof(response),
372 					SVC_INTF_ACTIVATE_TIMEOUT);
373 	if (ret < 0)
374 		return ret;
375 	if (response.status != GB_SVC_OP_SUCCESS) {
376 		dev_err(&svc->dev, "failed to activate interface %u: %u\n",
377 			intf_id, response.status);
378 		return -EREMOTEIO;
379 	}
380 
381 	*intf_type = response.intf_type;
382 
383 	return 0;
384 }
385 
386 int gb_svc_intf_resume(struct gb_svc *svc, u8 intf_id)
387 {
388 	struct gb_svc_intf_resume_request request;
389 	struct gb_svc_intf_resume_response response;
390 	int ret;
391 
392 	request.intf_id = intf_id;
393 
394 	ret = gb_operation_sync_timeout(svc->connection,
395 					GB_SVC_TYPE_INTF_RESUME,
396 					&request, sizeof(request),
397 					&response, sizeof(response),
398 					SVC_INTF_RESUME_TIMEOUT);
399 	if (ret < 0) {
400 		dev_err(&svc->dev, "failed to send interface resume %u: %d\n",
401 			intf_id, ret);
402 		return ret;
403 	}
404 
405 	if (response.status != GB_SVC_OP_SUCCESS) {
406 		dev_err(&svc->dev, "failed to resume interface %u: %u\n",
407 			intf_id, response.status);
408 		return -EREMOTEIO;
409 	}
410 
411 	return 0;
412 }
413 
414 int gb_svc_dme_peer_get(struct gb_svc *svc, u8 intf_id, u16 attr, u16 selector,
415 			u32 *value)
416 {
417 	struct gb_svc_dme_peer_get_request request;
418 	struct gb_svc_dme_peer_get_response response;
419 	u16 result;
420 	int ret;
421 
422 	request.intf_id = intf_id;
423 	request.attr = cpu_to_le16(attr);
424 	request.selector = cpu_to_le16(selector);
425 
426 	ret = gb_operation_sync(svc->connection, GB_SVC_TYPE_DME_PEER_GET,
427 				&request, sizeof(request),
428 				&response, sizeof(response));
429 	if (ret) {
430 		dev_err(&svc->dev, "failed to get DME attribute (%u 0x%04x %u): %d\n",
431 			intf_id, attr, selector, ret);
432 		return ret;
433 	}
434 
435 	result = le16_to_cpu(response.result_code);
436 	if (result) {
437 		dev_err(&svc->dev, "UniPro error while getting DME attribute (%u 0x%04x %u): %u\n",
438 			intf_id, attr, selector, result);
439 		return -EREMOTEIO;
440 	}
441 
442 	if (value)
443 		*value = le32_to_cpu(response.attr_value);
444 
445 	return 0;
446 }
447 
448 int gb_svc_dme_peer_set(struct gb_svc *svc, u8 intf_id, u16 attr, u16 selector,
449 			u32 value)
450 {
451 	struct gb_svc_dme_peer_set_request request;
452 	struct gb_svc_dme_peer_set_response response;
453 	u16 result;
454 	int ret;
455 
456 	request.intf_id = intf_id;
457 	request.attr = cpu_to_le16(attr);
458 	request.selector = cpu_to_le16(selector);
459 	request.value = cpu_to_le32(value);
460 
461 	ret = gb_operation_sync(svc->connection, GB_SVC_TYPE_DME_PEER_SET,
462 				&request, sizeof(request),
463 				&response, sizeof(response));
464 	if (ret) {
465 		dev_err(&svc->dev, "failed to set DME attribute (%u 0x%04x %u %u): %d\n",
466 			intf_id, attr, selector, value, ret);
467 		return ret;
468 	}
469 
470 	result = le16_to_cpu(response.result_code);
471 	if (result) {
472 		dev_err(&svc->dev, "UniPro error while setting DME attribute (%u 0x%04x %u %u): %u\n",
473 			intf_id, attr, selector, value, result);
474 		return -EREMOTEIO;
475 	}
476 
477 	return 0;
478 }
479 
480 int gb_svc_connection_create(struct gb_svc *svc,
481 			     u8 intf1_id, u16 cport1_id,
482 			     u8 intf2_id, u16 cport2_id,
483 			     u8 cport_flags)
484 {
485 	struct gb_svc_conn_create_request request;
486 
487 	request.intf1_id = intf1_id;
488 	request.cport1_id = cpu_to_le16(cport1_id);
489 	request.intf2_id = intf2_id;
490 	request.cport2_id = cpu_to_le16(cport2_id);
491 	request.tc = 0;		/* TC0 */
492 	request.flags = cport_flags;
493 
494 	return gb_operation_sync(svc->connection, GB_SVC_TYPE_CONN_CREATE,
495 				 &request, sizeof(request), NULL, 0);
496 }
497 
498 void gb_svc_connection_destroy(struct gb_svc *svc, u8 intf1_id, u16 cport1_id,
499 			       u8 intf2_id, u16 cport2_id)
500 {
501 	struct gb_svc_conn_destroy_request request;
502 	struct gb_connection *connection = svc->connection;
503 	int ret;
504 
505 	request.intf1_id = intf1_id;
506 	request.cport1_id = cpu_to_le16(cport1_id);
507 	request.intf2_id = intf2_id;
508 	request.cport2_id = cpu_to_le16(cport2_id);
509 
510 	ret = gb_operation_sync(connection, GB_SVC_TYPE_CONN_DESTROY,
511 				&request, sizeof(request), NULL, 0);
512 	if (ret) {
513 		dev_err(&svc->dev, "failed to destroy connection (%u:%u %u:%u): %d\n",
514 			intf1_id, cport1_id, intf2_id, cport2_id, ret);
515 	}
516 }
517 
518 /* Creates bi-directional routes between the devices */
519 int gb_svc_route_create(struct gb_svc *svc, u8 intf1_id, u8 dev1_id,
520 			u8 intf2_id, u8 dev2_id)
521 {
522 	struct gb_svc_route_create_request request;
523 
524 	request.intf1_id = intf1_id;
525 	request.dev1_id = dev1_id;
526 	request.intf2_id = intf2_id;
527 	request.dev2_id = dev2_id;
528 
529 	return gb_operation_sync(svc->connection, GB_SVC_TYPE_ROUTE_CREATE,
530 				 &request, sizeof(request), NULL, 0);
531 }
532 
533 /* Destroys bi-directional routes between the devices */
534 void gb_svc_route_destroy(struct gb_svc *svc, u8 intf1_id, u8 intf2_id)
535 {
536 	struct gb_svc_route_destroy_request request;
537 	int ret;
538 
539 	request.intf1_id = intf1_id;
540 	request.intf2_id = intf2_id;
541 
542 	ret = gb_operation_sync(svc->connection, GB_SVC_TYPE_ROUTE_DESTROY,
543 				&request, sizeof(request), NULL, 0);
544 	if (ret) {
545 		dev_err(&svc->dev, "failed to destroy route (%u %u): %d\n",
546 			intf1_id, intf2_id, ret);
547 	}
548 }
549 
550 int gb_svc_intf_set_power_mode(struct gb_svc *svc, u8 intf_id, u8 hs_series,
551 			       u8 tx_mode, u8 tx_gear, u8 tx_nlanes,
552 			       u8 tx_amplitude, u8 tx_hs_equalizer,
553 			       u8 rx_mode, u8 rx_gear, u8 rx_nlanes,
554 			       u8 flags, u32 quirks,
555 			       struct gb_svc_l2_timer_cfg *local,
556 			       struct gb_svc_l2_timer_cfg *remote)
557 {
558 	struct gb_svc_intf_set_pwrm_request request;
559 	struct gb_svc_intf_set_pwrm_response response;
560 	int ret;
561 	u16 result_code;
562 
563 	memset(&request, 0, sizeof(request));
564 
565 	request.intf_id = intf_id;
566 	request.hs_series = hs_series;
567 	request.tx_mode = tx_mode;
568 	request.tx_gear = tx_gear;
569 	request.tx_nlanes = tx_nlanes;
570 	request.tx_amplitude = tx_amplitude;
571 	request.tx_hs_equalizer = tx_hs_equalizer;
572 	request.rx_mode = rx_mode;
573 	request.rx_gear = rx_gear;
574 	request.rx_nlanes = rx_nlanes;
575 	request.flags = flags;
576 	request.quirks = cpu_to_le32(quirks);
577 	if (local)
578 		request.local_l2timerdata = *local;
579 	if (remote)
580 		request.remote_l2timerdata = *remote;
581 
582 	ret = gb_operation_sync(svc->connection, GB_SVC_TYPE_INTF_SET_PWRM,
583 				&request, sizeof(request),
584 				&response, sizeof(response));
585 	if (ret < 0)
586 		return ret;
587 
588 	result_code = response.result_code;
589 	if (result_code != GB_SVC_SETPWRM_PWR_LOCAL) {
590 		dev_err(&svc->dev, "set power mode = %d\n", result_code);
591 		return -EIO;
592 	}
593 
594 	return 0;
595 }
596 EXPORT_SYMBOL_GPL(gb_svc_intf_set_power_mode);
597 
598 int gb_svc_intf_set_power_mode_hibernate(struct gb_svc *svc, u8 intf_id)
599 {
600 	struct gb_svc_intf_set_pwrm_request request;
601 	struct gb_svc_intf_set_pwrm_response response;
602 	int ret;
603 	u16 result_code;
604 
605 	memset(&request, 0, sizeof(request));
606 
607 	request.intf_id = intf_id;
608 	request.hs_series = GB_SVC_UNIPRO_HS_SERIES_A;
609 	request.tx_mode = GB_SVC_UNIPRO_HIBERNATE_MODE;
610 	request.rx_mode = GB_SVC_UNIPRO_HIBERNATE_MODE;
611 
612 	ret = gb_operation_sync(svc->connection, GB_SVC_TYPE_INTF_SET_PWRM,
613 				&request, sizeof(request),
614 				&response, sizeof(response));
615 	if (ret < 0) {
616 		dev_err(&svc->dev,
617 			"failed to send set power mode operation to interface %u: %d\n",
618 			intf_id, ret);
619 		return ret;
620 	}
621 
622 	result_code = response.result_code;
623 	if (result_code != GB_SVC_SETPWRM_PWR_OK) {
624 		dev_err(&svc->dev,
625 			"failed to hibernate the link for interface %u: %u\n",
626 			intf_id, result_code);
627 		return -EIO;
628 	}
629 
630 	return 0;
631 }
632 
633 int gb_svc_ping(struct gb_svc *svc)
634 {
635 	return gb_operation_sync_timeout(svc->connection, GB_SVC_TYPE_PING,
636 					 NULL, 0, NULL, 0,
637 					 GB_OPERATION_TIMEOUT_DEFAULT * 2);
638 }
639 
640 static int gb_svc_version_request(struct gb_operation *op)
641 {
642 	struct gb_connection *connection = op->connection;
643 	struct gb_svc *svc = gb_connection_get_data(connection);
644 	struct gb_svc_version_request *request;
645 	struct gb_svc_version_response *response;
646 
647 	if (op->request->payload_size < sizeof(*request)) {
648 		dev_err(&svc->dev, "short version request (%zu < %zu)\n",
649 			op->request->payload_size,
650 			sizeof(*request));
651 		return -EINVAL;
652 	}
653 
654 	request = op->request->payload;
655 
656 	if (request->major > GB_SVC_VERSION_MAJOR) {
657 		dev_warn(&svc->dev, "unsupported major version (%u > %u)\n",
658 			 request->major, GB_SVC_VERSION_MAJOR);
659 		return -ENOTSUPP;
660 	}
661 
662 	svc->protocol_major = request->major;
663 	svc->protocol_minor = request->minor;
664 
665 	if (!gb_operation_response_alloc(op, sizeof(*response), GFP_KERNEL))
666 		return -ENOMEM;
667 
668 	response = op->response->payload;
669 	response->major = svc->protocol_major;
670 	response->minor = svc->protocol_minor;
671 
672 	return 0;
673 }
674 
675 static ssize_t pwr_debugfs_voltage_read(struct file *file, char __user *buf,
676 					size_t len, loff_t *offset)
677 {
678 	struct svc_debugfs_pwrmon_rail *pwrmon_rails =
679 		file_inode(file)->i_private;
680 	struct gb_svc *svc = pwrmon_rails->svc;
681 	int ret, desc;
682 	u32 value;
683 	char buff[16];
684 
685 	ret = gb_svc_pwrmon_sample_get(svc, pwrmon_rails->id,
686 				       GB_SVC_PWRMON_TYPE_VOL, &value);
687 	if (ret) {
688 		dev_err(&svc->dev,
689 			"failed to get voltage sample %u: %d\n",
690 			pwrmon_rails->id, ret);
691 		return ret;
692 	}
693 
694 	desc = scnprintf(buff, sizeof(buff), "%u\n", value);
695 
696 	return simple_read_from_buffer(buf, len, offset, buff, desc);
697 }
698 
699 static ssize_t pwr_debugfs_current_read(struct file *file, char __user *buf,
700 					size_t len, loff_t *offset)
701 {
702 	struct svc_debugfs_pwrmon_rail *pwrmon_rails =
703 		file_inode(file)->i_private;
704 	struct gb_svc *svc = pwrmon_rails->svc;
705 	int ret, desc;
706 	u32 value;
707 	char buff[16];
708 
709 	ret = gb_svc_pwrmon_sample_get(svc, pwrmon_rails->id,
710 				       GB_SVC_PWRMON_TYPE_CURR, &value);
711 	if (ret) {
712 		dev_err(&svc->dev,
713 			"failed to get current sample %u: %d\n",
714 			pwrmon_rails->id, ret);
715 		return ret;
716 	}
717 
718 	desc = scnprintf(buff, sizeof(buff), "%u\n", value);
719 
720 	return simple_read_from_buffer(buf, len, offset, buff, desc);
721 }
722 
723 static ssize_t pwr_debugfs_power_read(struct file *file, char __user *buf,
724 				      size_t len, loff_t *offset)
725 {
726 	struct svc_debugfs_pwrmon_rail *pwrmon_rails =
727 		file_inode(file)->i_private;
728 	struct gb_svc *svc = pwrmon_rails->svc;
729 	int ret, desc;
730 	u32 value;
731 	char buff[16];
732 
733 	ret = gb_svc_pwrmon_sample_get(svc, pwrmon_rails->id,
734 				       GB_SVC_PWRMON_TYPE_PWR, &value);
735 	if (ret) {
736 		dev_err(&svc->dev, "failed to get power sample %u: %d\n",
737 			pwrmon_rails->id, ret);
738 		return ret;
739 	}
740 
741 	desc = scnprintf(buff, sizeof(buff), "%u\n", value);
742 
743 	return simple_read_from_buffer(buf, len, offset, buff, desc);
744 }
745 
746 static const struct file_operations pwrmon_debugfs_voltage_fops = {
747 	.read		= pwr_debugfs_voltage_read,
748 };
749 
750 static const struct file_operations pwrmon_debugfs_current_fops = {
751 	.read		= pwr_debugfs_current_read,
752 };
753 
754 static const struct file_operations pwrmon_debugfs_power_fops = {
755 	.read		= pwr_debugfs_power_read,
756 };
757 
758 static void gb_svc_pwrmon_debugfs_init(struct gb_svc *svc)
759 {
760 	int i;
761 	size_t bufsize;
762 	struct dentry *dent;
763 	struct gb_svc_pwrmon_rail_names_get_response *rail_names;
764 	u8 rail_count;
765 
766 	dent = debugfs_create_dir("pwrmon", svc->debugfs_dentry);
767 	if (IS_ERR_OR_NULL(dent))
768 		return;
769 
770 	if (gb_svc_pwrmon_rail_count_get(svc, &rail_count))
771 		goto err_pwrmon_debugfs;
772 
773 	if (!rail_count || rail_count > GB_SVC_PWRMON_MAX_RAIL_COUNT)
774 		goto err_pwrmon_debugfs;
775 
776 	bufsize = sizeof(*rail_names) +
777 		GB_SVC_PWRMON_RAIL_NAME_BUFSIZE * rail_count;
778 
779 	rail_names = kzalloc(bufsize, GFP_KERNEL);
780 	if (!rail_names)
781 		goto err_pwrmon_debugfs;
782 
783 	svc->pwrmon_rails = kcalloc(rail_count, sizeof(*svc->pwrmon_rails),
784 				    GFP_KERNEL);
785 	if (!svc->pwrmon_rails)
786 		goto err_pwrmon_debugfs_free;
787 
788 	if (gb_svc_pwrmon_rail_names_get(svc, rail_names, bufsize))
789 		goto err_pwrmon_debugfs_free;
790 
791 	for (i = 0; i < rail_count; i++) {
792 		struct dentry *dir;
793 		struct svc_debugfs_pwrmon_rail *rail = &svc->pwrmon_rails[i];
794 		char fname[GB_SVC_PWRMON_RAIL_NAME_BUFSIZE];
795 
796 		snprintf(fname, sizeof(fname), "%s",
797 			 (char *)&rail_names->name[i]);
798 
799 		rail->id = i;
800 		rail->svc = svc;
801 
802 		dir = debugfs_create_dir(fname, dent);
803 		debugfs_create_file("voltage_now", 0444, dir, rail,
804 				    &pwrmon_debugfs_voltage_fops);
805 		debugfs_create_file("current_now", 0444, dir, rail,
806 				    &pwrmon_debugfs_current_fops);
807 		debugfs_create_file("power_now", 0444, dir, rail,
808 				    &pwrmon_debugfs_power_fops);
809 	}
810 
811 	kfree(rail_names);
812 	return;
813 
814 err_pwrmon_debugfs_free:
815 	kfree(rail_names);
816 	kfree(svc->pwrmon_rails);
817 	svc->pwrmon_rails = NULL;
818 
819 err_pwrmon_debugfs:
820 	debugfs_remove(dent);
821 }
822 
823 static void gb_svc_debugfs_init(struct gb_svc *svc)
824 {
825 	svc->debugfs_dentry = debugfs_create_dir(dev_name(&svc->dev),
826 						 gb_debugfs_get());
827 	gb_svc_pwrmon_debugfs_init(svc);
828 }
829 
830 static void gb_svc_debugfs_exit(struct gb_svc *svc)
831 {
832 	debugfs_remove_recursive(svc->debugfs_dentry);
833 	kfree(svc->pwrmon_rails);
834 	svc->pwrmon_rails = NULL;
835 }
836 
837 static int gb_svc_hello(struct gb_operation *op)
838 {
839 	struct gb_connection *connection = op->connection;
840 	struct gb_svc *svc = gb_connection_get_data(connection);
841 	struct gb_svc_hello_request *hello_request;
842 	int ret;
843 
844 	if (op->request->payload_size < sizeof(*hello_request)) {
845 		dev_warn(&svc->dev, "short hello request (%zu < %zu)\n",
846 			 op->request->payload_size,
847 			 sizeof(*hello_request));
848 		return -EINVAL;
849 	}
850 
851 	hello_request = op->request->payload;
852 	svc->endo_id = le16_to_cpu(hello_request->endo_id);
853 	svc->ap_intf_id = hello_request->interface_id;
854 
855 	ret = device_add(&svc->dev);
856 	if (ret) {
857 		dev_err(&svc->dev, "failed to register svc device: %d\n", ret);
858 		return ret;
859 	}
860 
861 	ret = gb_svc_watchdog_create(svc);
862 	if (ret) {
863 		dev_err(&svc->dev, "failed to create watchdog: %d\n", ret);
864 		goto err_unregister_device;
865 	}
866 
867 	gb_svc_debugfs_init(svc);
868 
869 	return gb_svc_queue_deferred_request(op);
870 
871 err_unregister_device:
872 	gb_svc_watchdog_destroy(svc);
873 	device_del(&svc->dev);
874 	return ret;
875 }
876 
877 static struct gb_interface *gb_svc_interface_lookup(struct gb_svc *svc,
878 						    u8 intf_id)
879 {
880 	struct gb_host_device *hd = svc->hd;
881 	struct gb_module *module;
882 	size_t num_interfaces;
883 	u8 module_id;
884 
885 	list_for_each_entry(module, &hd->modules, hd_node) {
886 		module_id = module->module_id;
887 		num_interfaces = module->num_interfaces;
888 
889 		if (intf_id >= module_id &&
890 		    intf_id < module_id + num_interfaces) {
891 			return module->interfaces[intf_id - module_id];
892 		}
893 	}
894 
895 	return NULL;
896 }
897 
898 static struct gb_module *gb_svc_module_lookup(struct gb_svc *svc, u8 module_id)
899 {
900 	struct gb_host_device *hd = svc->hd;
901 	struct gb_module *module;
902 
903 	list_for_each_entry(module, &hd->modules, hd_node) {
904 		if (module->module_id == module_id)
905 			return module;
906 	}
907 
908 	return NULL;
909 }
910 
911 static void gb_svc_process_hello_deferred(struct gb_operation *operation)
912 {
913 	struct gb_connection *connection = operation->connection;
914 	struct gb_svc *svc = gb_connection_get_data(connection);
915 	int ret;
916 
917 	/*
918 	 * XXX This is a hack/work-around to reconfigure the APBridgeA-Switch
919 	 * link to PWM G2, 1 Lane, Slow Auto, so that it has sufficient
920 	 * bandwidth for 3 audio streams plus boot-over-UniPro of a hot-plugged
921 	 * module.
922 	 *
923 	 * The code should be removed once SW-2217, Heuristic for UniPro
924 	 * Power Mode Changes is resolved.
925 	 */
926 	ret = gb_svc_intf_set_power_mode(svc, svc->ap_intf_id,
927 					 GB_SVC_UNIPRO_HS_SERIES_A,
928 					 GB_SVC_UNIPRO_SLOW_AUTO_MODE,
929 					 2, 1,
930 					 GB_SVC_SMALL_AMPLITUDE,
931 					 GB_SVC_NO_DE_EMPHASIS,
932 					 GB_SVC_UNIPRO_SLOW_AUTO_MODE,
933 					 2, 1,
934 					 0, 0,
935 					 NULL, NULL);
936 
937 	if (ret)
938 		dev_warn(&svc->dev,
939 			 "power mode change failed on AP to switch link: %d\n",
940 			 ret);
941 }
942 
943 static void gb_svc_process_module_inserted(struct gb_operation *operation)
944 {
945 	struct gb_svc_module_inserted_request *request;
946 	struct gb_connection *connection = operation->connection;
947 	struct gb_svc *svc = gb_connection_get_data(connection);
948 	struct gb_host_device *hd = svc->hd;
949 	struct gb_module *module;
950 	size_t num_interfaces;
951 	u8 module_id;
952 	u16 flags;
953 	int ret;
954 
955 	/* The request message size has already been verified. */
956 	request = operation->request->payload;
957 	module_id = request->primary_intf_id;
958 	num_interfaces = request->intf_count;
959 	flags = le16_to_cpu(request->flags);
960 
961 	dev_dbg(&svc->dev, "%s - id = %u, num_interfaces = %zu, flags = 0x%04x\n",
962 		__func__, module_id, num_interfaces, flags);
963 
964 	if (flags & GB_SVC_MODULE_INSERTED_FLAG_NO_PRIMARY) {
965 		dev_warn(&svc->dev, "no primary interface detected on module %u\n",
966 			 module_id);
967 	}
968 
969 	module = gb_svc_module_lookup(svc, module_id);
970 	if (module) {
971 		dev_warn(&svc->dev, "unexpected module-inserted event %u\n",
972 			 module_id);
973 		return;
974 	}
975 
976 	module = gb_module_create(hd, module_id, num_interfaces);
977 	if (!module) {
978 		dev_err(&svc->dev, "failed to create module\n");
979 		return;
980 	}
981 
982 	ret = gb_module_add(module);
983 	if (ret) {
984 		gb_module_put(module);
985 		return;
986 	}
987 
988 	list_add(&module->hd_node, &hd->modules);
989 }
990 
991 static void gb_svc_process_module_removed(struct gb_operation *operation)
992 {
993 	struct gb_svc_module_removed_request *request;
994 	struct gb_connection *connection = operation->connection;
995 	struct gb_svc *svc = gb_connection_get_data(connection);
996 	struct gb_module *module;
997 	u8 module_id;
998 
999 	/* The request message size has already been verified. */
1000 	request = operation->request->payload;
1001 	module_id = request->primary_intf_id;
1002 
1003 	dev_dbg(&svc->dev, "%s - id = %u\n", __func__, module_id);
1004 
1005 	module = gb_svc_module_lookup(svc, module_id);
1006 	if (!module) {
1007 		dev_warn(&svc->dev, "unexpected module-removed event %u\n",
1008 			 module_id);
1009 		return;
1010 	}
1011 
1012 	module->disconnected = true;
1013 
1014 	gb_module_del(module);
1015 	list_del(&module->hd_node);
1016 	gb_module_put(module);
1017 }
1018 
1019 static void gb_svc_process_intf_oops(struct gb_operation *operation)
1020 {
1021 	struct gb_svc_intf_oops_request *request;
1022 	struct gb_connection *connection = operation->connection;
1023 	struct gb_svc *svc = gb_connection_get_data(connection);
1024 	struct gb_interface *intf;
1025 	u8 intf_id;
1026 	u8 reason;
1027 
1028 	/* The request message size has already been verified. */
1029 	request = operation->request->payload;
1030 	intf_id = request->intf_id;
1031 	reason = request->reason;
1032 
1033 	intf = gb_svc_interface_lookup(svc, intf_id);
1034 	if (!intf) {
1035 		dev_warn(&svc->dev, "unexpected interface-oops event %u\n",
1036 			 intf_id);
1037 		return;
1038 	}
1039 
1040 	dev_info(&svc->dev, "Deactivating interface %u, interface oops reason = %u\n",
1041 		 intf_id, reason);
1042 
1043 	mutex_lock(&intf->mutex);
1044 	intf->disconnected = true;
1045 	gb_interface_disable(intf);
1046 	gb_interface_deactivate(intf);
1047 	mutex_unlock(&intf->mutex);
1048 }
1049 
1050 static void gb_svc_process_intf_mailbox_event(struct gb_operation *operation)
1051 {
1052 	struct gb_svc_intf_mailbox_event_request *request;
1053 	struct gb_connection *connection = operation->connection;
1054 	struct gb_svc *svc = gb_connection_get_data(connection);
1055 	struct gb_interface *intf;
1056 	u8 intf_id;
1057 	u16 result_code;
1058 	u32 mailbox;
1059 
1060 	/* The request message size has already been verified. */
1061 	request = operation->request->payload;
1062 	intf_id = request->intf_id;
1063 	result_code = le16_to_cpu(request->result_code);
1064 	mailbox = le32_to_cpu(request->mailbox);
1065 
1066 	dev_dbg(&svc->dev, "%s - id = %u, result = 0x%04x, mailbox = 0x%08x\n",
1067 		__func__, intf_id, result_code, mailbox);
1068 
1069 	intf = gb_svc_interface_lookup(svc, intf_id);
1070 	if (!intf) {
1071 		dev_warn(&svc->dev, "unexpected mailbox event %u\n", intf_id);
1072 		return;
1073 	}
1074 
1075 	gb_interface_mailbox_event(intf, result_code, mailbox);
1076 }
1077 
1078 static void gb_svc_process_deferred_request(struct work_struct *work)
1079 {
1080 	struct gb_svc_deferred_request *dr;
1081 	struct gb_operation *operation;
1082 	struct gb_svc *svc;
1083 	u8 type;
1084 
1085 	dr = container_of(work, struct gb_svc_deferred_request, work);
1086 	operation = dr->operation;
1087 	svc = gb_connection_get_data(operation->connection);
1088 	type = operation->request->header->type;
1089 
1090 	switch (type) {
1091 	case GB_SVC_TYPE_SVC_HELLO:
1092 		gb_svc_process_hello_deferred(operation);
1093 		break;
1094 	case GB_SVC_TYPE_MODULE_INSERTED:
1095 		gb_svc_process_module_inserted(operation);
1096 		break;
1097 	case GB_SVC_TYPE_MODULE_REMOVED:
1098 		gb_svc_process_module_removed(operation);
1099 		break;
1100 	case GB_SVC_TYPE_INTF_MAILBOX_EVENT:
1101 		gb_svc_process_intf_mailbox_event(operation);
1102 		break;
1103 	case GB_SVC_TYPE_INTF_OOPS:
1104 		gb_svc_process_intf_oops(operation);
1105 		break;
1106 	default:
1107 		dev_err(&svc->dev, "bad deferred request type: 0x%02x\n", type);
1108 	}
1109 
1110 	gb_operation_put(operation);
1111 	kfree(dr);
1112 }
1113 
1114 static int gb_svc_queue_deferred_request(struct gb_operation *operation)
1115 {
1116 	struct gb_svc *svc = gb_connection_get_data(operation->connection);
1117 	struct gb_svc_deferred_request *dr;
1118 
1119 	dr = kmalloc(sizeof(*dr), GFP_KERNEL);
1120 	if (!dr)
1121 		return -ENOMEM;
1122 
1123 	gb_operation_get(operation);
1124 
1125 	dr->operation = operation;
1126 	INIT_WORK(&dr->work, gb_svc_process_deferred_request);
1127 
1128 	queue_work(svc->wq, &dr->work);
1129 
1130 	return 0;
1131 }
1132 
1133 static int gb_svc_intf_reset_recv(struct gb_operation *op)
1134 {
1135 	struct gb_svc *svc = gb_connection_get_data(op->connection);
1136 	struct gb_message *request = op->request;
1137 	struct gb_svc_intf_reset_request *reset;
1138 
1139 	if (request->payload_size < sizeof(*reset)) {
1140 		dev_warn(&svc->dev, "short reset request received (%zu < %zu)\n",
1141 			 request->payload_size, sizeof(*reset));
1142 		return -EINVAL;
1143 	}
1144 	reset = request->payload;
1145 
1146 	/* FIXME Reset the interface here */
1147 
1148 	return 0;
1149 }
1150 
1151 static int gb_svc_module_inserted_recv(struct gb_operation *op)
1152 {
1153 	struct gb_svc *svc = gb_connection_get_data(op->connection);
1154 	struct gb_svc_module_inserted_request *request;
1155 
1156 	if (op->request->payload_size < sizeof(*request)) {
1157 		dev_warn(&svc->dev, "short module-inserted request received (%zu < %zu)\n",
1158 			 op->request->payload_size, sizeof(*request));
1159 		return -EINVAL;
1160 	}
1161 
1162 	request = op->request->payload;
1163 
1164 	dev_dbg(&svc->dev, "%s - id = %u\n", __func__,
1165 		request->primary_intf_id);
1166 
1167 	return gb_svc_queue_deferred_request(op);
1168 }
1169 
1170 static int gb_svc_module_removed_recv(struct gb_operation *op)
1171 {
1172 	struct gb_svc *svc = gb_connection_get_data(op->connection);
1173 	struct gb_svc_module_removed_request *request;
1174 
1175 	if (op->request->payload_size < sizeof(*request)) {
1176 		dev_warn(&svc->dev, "short module-removed request received (%zu < %zu)\n",
1177 			 op->request->payload_size, sizeof(*request));
1178 		return -EINVAL;
1179 	}
1180 
1181 	request = op->request->payload;
1182 
1183 	dev_dbg(&svc->dev, "%s - id = %u\n", __func__,
1184 		request->primary_intf_id);
1185 
1186 	return gb_svc_queue_deferred_request(op);
1187 }
1188 
1189 static int gb_svc_intf_oops_recv(struct gb_operation *op)
1190 {
1191 	struct gb_svc *svc = gb_connection_get_data(op->connection);
1192 	struct gb_svc_intf_oops_request *request;
1193 
1194 	if (op->request->payload_size < sizeof(*request)) {
1195 		dev_warn(&svc->dev, "short intf-oops request received (%zu < %zu)\n",
1196 			 op->request->payload_size, sizeof(*request));
1197 		return -EINVAL;
1198 	}
1199 
1200 	return gb_svc_queue_deferred_request(op);
1201 }
1202 
1203 static int gb_svc_intf_mailbox_event_recv(struct gb_operation *op)
1204 {
1205 	struct gb_svc *svc = gb_connection_get_data(op->connection);
1206 	struct gb_svc_intf_mailbox_event_request *request;
1207 
1208 	if (op->request->payload_size < sizeof(*request)) {
1209 		dev_warn(&svc->dev, "short mailbox request received (%zu < %zu)\n",
1210 			 op->request->payload_size, sizeof(*request));
1211 		return -EINVAL;
1212 	}
1213 
1214 	request = op->request->payload;
1215 
1216 	dev_dbg(&svc->dev, "%s - id = %u\n", __func__, request->intf_id);
1217 
1218 	return gb_svc_queue_deferred_request(op);
1219 }
1220 
1221 static int gb_svc_request_handler(struct gb_operation *op)
1222 {
1223 	struct gb_connection *connection = op->connection;
1224 	struct gb_svc *svc = gb_connection_get_data(connection);
1225 	u8 type = op->type;
1226 	int ret = 0;
1227 
1228 	/*
1229 	 * SVC requests need to follow a specific order (at least initially) and
1230 	 * below code takes care of enforcing that. The expected order is:
1231 	 * - PROTOCOL_VERSION
1232 	 * - SVC_HELLO
1233 	 * - Any other request, but the earlier two.
1234 	 *
1235 	 * Incoming requests are guaranteed to be serialized and so we don't
1236 	 * need to protect 'state' for any races.
1237 	 */
1238 	switch (type) {
1239 	case GB_SVC_TYPE_PROTOCOL_VERSION:
1240 		if (svc->state != GB_SVC_STATE_RESET)
1241 			ret = -EINVAL;
1242 		break;
1243 	case GB_SVC_TYPE_SVC_HELLO:
1244 		if (svc->state != GB_SVC_STATE_PROTOCOL_VERSION)
1245 			ret = -EINVAL;
1246 		break;
1247 	default:
1248 		if (svc->state != GB_SVC_STATE_SVC_HELLO)
1249 			ret = -EINVAL;
1250 		break;
1251 	}
1252 
1253 	if (ret) {
1254 		dev_warn(&svc->dev, "unexpected request 0x%02x received (state %u)\n",
1255 			 type, svc->state);
1256 		return ret;
1257 	}
1258 
1259 	switch (type) {
1260 	case GB_SVC_TYPE_PROTOCOL_VERSION:
1261 		ret = gb_svc_version_request(op);
1262 		if (!ret)
1263 			svc->state = GB_SVC_STATE_PROTOCOL_VERSION;
1264 		return ret;
1265 	case GB_SVC_TYPE_SVC_HELLO:
1266 		ret = gb_svc_hello(op);
1267 		if (!ret)
1268 			svc->state = GB_SVC_STATE_SVC_HELLO;
1269 		return ret;
1270 	case GB_SVC_TYPE_INTF_RESET:
1271 		return gb_svc_intf_reset_recv(op);
1272 	case GB_SVC_TYPE_MODULE_INSERTED:
1273 		return gb_svc_module_inserted_recv(op);
1274 	case GB_SVC_TYPE_MODULE_REMOVED:
1275 		return gb_svc_module_removed_recv(op);
1276 	case GB_SVC_TYPE_INTF_MAILBOX_EVENT:
1277 		return gb_svc_intf_mailbox_event_recv(op);
1278 	case GB_SVC_TYPE_INTF_OOPS:
1279 		return gb_svc_intf_oops_recv(op);
1280 	default:
1281 		dev_warn(&svc->dev, "unsupported request 0x%02x\n", type);
1282 		return -EINVAL;
1283 	}
1284 }
1285 
1286 static void gb_svc_release(struct device *dev)
1287 {
1288 	struct gb_svc *svc = to_gb_svc(dev);
1289 
1290 	if (svc->connection)
1291 		gb_connection_destroy(svc->connection);
1292 	ida_destroy(&svc->device_id_map);
1293 	destroy_workqueue(svc->wq);
1294 	kfree(svc);
1295 }
1296 
1297 struct device_type greybus_svc_type = {
1298 	.name		= "greybus_svc",
1299 	.release	= gb_svc_release,
1300 };
1301 
1302 struct gb_svc *gb_svc_create(struct gb_host_device *hd)
1303 {
1304 	struct gb_svc *svc;
1305 
1306 	svc = kzalloc(sizeof(*svc), GFP_KERNEL);
1307 	if (!svc)
1308 		return NULL;
1309 
1310 	svc->wq = alloc_workqueue("%s:svc", WQ_UNBOUND, 1, dev_name(&hd->dev));
1311 	if (!svc->wq) {
1312 		kfree(svc);
1313 		return NULL;
1314 	}
1315 
1316 	svc->dev.parent = &hd->dev;
1317 	svc->dev.bus = &greybus_bus_type;
1318 	svc->dev.type = &greybus_svc_type;
1319 	svc->dev.groups = svc_groups;
1320 	svc->dev.dma_mask = svc->dev.parent->dma_mask;
1321 	device_initialize(&svc->dev);
1322 
1323 	dev_set_name(&svc->dev, "%d-svc", hd->bus_id);
1324 
1325 	ida_init(&svc->device_id_map);
1326 	svc->state = GB_SVC_STATE_RESET;
1327 	svc->hd = hd;
1328 
1329 	svc->connection = gb_connection_create_static(hd, GB_SVC_CPORT_ID,
1330 						      gb_svc_request_handler);
1331 	if (IS_ERR(svc->connection)) {
1332 		dev_err(&svc->dev, "failed to create connection: %ld\n",
1333 			PTR_ERR(svc->connection));
1334 		goto err_put_device;
1335 	}
1336 
1337 	gb_connection_set_data(svc->connection, svc);
1338 
1339 	return svc;
1340 
1341 err_put_device:
1342 	put_device(&svc->dev);
1343 	return NULL;
1344 }
1345 
1346 int gb_svc_add(struct gb_svc *svc)
1347 {
1348 	int ret;
1349 
1350 	/*
1351 	 * The SVC protocol is currently driven by the SVC, so the SVC device
1352 	 * is added from the connection request handler when enough
1353 	 * information has been received.
1354 	 */
1355 	ret = gb_connection_enable(svc->connection);
1356 	if (ret)
1357 		return ret;
1358 
1359 	return 0;
1360 }
1361 
1362 static void gb_svc_remove_modules(struct gb_svc *svc)
1363 {
1364 	struct gb_host_device *hd = svc->hd;
1365 	struct gb_module *module, *tmp;
1366 
1367 	list_for_each_entry_safe(module, tmp, &hd->modules, hd_node) {
1368 		gb_module_del(module);
1369 		list_del(&module->hd_node);
1370 		gb_module_put(module);
1371 	}
1372 }
1373 
1374 void gb_svc_del(struct gb_svc *svc)
1375 {
1376 	gb_connection_disable_rx(svc->connection);
1377 
1378 	/*
1379 	 * The SVC device may have been registered from the request handler.
1380 	 */
1381 	if (device_is_registered(&svc->dev)) {
1382 		gb_svc_debugfs_exit(svc);
1383 		gb_svc_watchdog_destroy(svc);
1384 		device_del(&svc->dev);
1385 	}
1386 
1387 	flush_workqueue(svc->wq);
1388 
1389 	gb_svc_remove_modules(svc);
1390 
1391 	gb_connection_disable(svc->connection);
1392 }
1393 
1394 void gb_svc_put(struct gb_svc *svc)
1395 {
1396 	put_device(&svc->dev);
1397 }
1398