1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2018 Linaro Limited, All rights reserved.
4  * Author: Mike Leach <mike.leach@linaro.org>
5  */
6 
7 #include <linux/amba/bus.h>
8 #include <linux/atomic.h>
9 #include <linux/bits.h>
10 #include <linux/coresight.h>
11 #include <linux/cpu_pm.h>
12 #include <linux/cpuhotplug.h>
13 #include <linux/device.h>
14 #include <linux/io.h>
15 #include <linux/kernel.h>
16 #include <linux/list.h>
17 #include <linux/mutex.h>
18 #include <linux/pm_runtime.h>
19 #include <linux/property.h>
20 #include <linux/spinlock.h>
21 
22 #include "coresight-priv.h"
23 #include "coresight-cti.h"
24 
25 /**
26  * CTI devices can be associated with a PE, or be connected to CoreSight
27  * hardware. We have a list of all CTIs irrespective of CPU bound or
28  * otherwise.
29  *
30  * We assume that the non-CPU CTIs are always powered as we do with sinks etc.
31  *
32  * We leave the client to figure out if all the CTIs are interconnected with
33  * the same CTM, in general this is the case but does not always have to be.
34  */
35 
36 /* net of CTI devices connected via CTM */
37 static LIST_HEAD(ect_net);
38 
39 /* protect the list */
40 static DEFINE_MUTEX(ect_mutex);
41 
42 #define csdev_to_cti_drvdata(csdev)	\
43 	dev_get_drvdata(csdev->dev.parent)
44 
45 /* power management handling */
46 static int nr_cti_cpu;
47 
48 /* quick lookup list for CPU bound CTIs when power handling */
49 static struct cti_drvdata *cti_cpu_drvdata[NR_CPUS];
50 
51 /*
52  * CTI naming. CTI bound to cores will have the name cti_cpu<N> where
53  * N is the CPU ID. System CTIs will have the name cti_sys<I> where I
54  * is an index allocated by order of discovery.
55  *
56  * CTI device name list - for CTI not bound to cores.
57  */
58 DEFINE_CORESIGHT_DEVLIST(cti_sys_devs, "cti_sys");
59 
60 /* write set of regs to hardware - call with spinlock claimed */
61 void cti_write_all_hw_regs(struct cti_drvdata *drvdata)
62 {
63 	struct cti_config *config = &drvdata->config;
64 	int i;
65 
66 	CS_UNLOCK(drvdata->base);
67 
68 	/* disable CTI before writing registers */
69 	writel_relaxed(0, drvdata->base + CTICONTROL);
70 
71 	/* write the CTI trigger registers */
72 	for (i = 0; i < config->nr_trig_max; i++) {
73 		writel_relaxed(config->ctiinen[i], drvdata->base + CTIINEN(i));
74 		writel_relaxed(config->ctiouten[i],
75 			       drvdata->base + CTIOUTEN(i));
76 	}
77 
78 	/* other regs */
79 	writel_relaxed(config->ctigate, drvdata->base + CTIGATE);
80 	writel_relaxed(config->asicctl, drvdata->base + ASICCTL);
81 	writel_relaxed(config->ctiappset, drvdata->base + CTIAPPSET);
82 
83 	/* re-enable CTI */
84 	writel_relaxed(1, drvdata->base + CTICONTROL);
85 
86 	CS_LOCK(drvdata->base);
87 }
88 
89 /* write regs to hardware and enable */
90 static int cti_enable_hw(struct cti_drvdata *drvdata)
91 {
92 	struct cti_config *config = &drvdata->config;
93 	unsigned long flags;
94 	int rc = 0;
95 
96 	spin_lock_irqsave(&drvdata->spinlock, flags);
97 
98 	/* no need to do anything if enabled or unpowered*/
99 	if (config->hw_enabled || !config->hw_powered)
100 		goto cti_state_unchanged;
101 
102 	/* claim the device */
103 	rc = coresight_claim_device(drvdata->csdev);
104 	if (rc)
105 		goto cti_err_not_enabled;
106 
107 	cti_write_all_hw_regs(drvdata);
108 
109 	config->hw_enabled = true;
110 	drvdata->config.enable_req_count++;
111 	spin_unlock_irqrestore(&drvdata->spinlock, flags);
112 	return rc;
113 
114 cti_state_unchanged:
115 	drvdata->config.enable_req_count++;
116 
117 	/* cannot enable due to error */
118 cti_err_not_enabled:
119 	spin_unlock_irqrestore(&drvdata->spinlock, flags);
120 	return rc;
121 }
122 
123 /* re-enable CTI on CPU when using CPU hotplug */
124 static void cti_cpuhp_enable_hw(struct cti_drvdata *drvdata)
125 {
126 	struct cti_config *config = &drvdata->config;
127 
128 	spin_lock(&drvdata->spinlock);
129 	config->hw_powered = true;
130 
131 	/* no need to do anything if no enable request */
132 	if (!drvdata->config.enable_req_count)
133 		goto cti_hp_not_enabled;
134 
135 	/* try to claim the device */
136 	if (coresight_claim_device(drvdata->csdev))
137 		goto cti_hp_not_enabled;
138 
139 	cti_write_all_hw_regs(drvdata);
140 	config->hw_enabled = true;
141 	spin_unlock(&drvdata->spinlock);
142 	return;
143 
144 	/* did not re-enable due to no claim / no request */
145 cti_hp_not_enabled:
146 	spin_unlock(&drvdata->spinlock);
147 }
148 
149 /* disable hardware */
150 static int cti_disable_hw(struct cti_drvdata *drvdata)
151 {
152 	struct cti_config *config = &drvdata->config;
153 	struct coresight_device *csdev = drvdata->csdev;
154 	int ret = 0;
155 
156 	spin_lock(&drvdata->spinlock);
157 
158 	/* don't allow negative refcounts, return an error */
159 	if (!drvdata->config.enable_req_count) {
160 		ret = -EINVAL;
161 		goto cti_not_disabled;
162 	}
163 
164 	/* check refcount - disable on 0 */
165 	if (--drvdata->config.enable_req_count > 0)
166 		goto cti_not_disabled;
167 
168 	/* no need to do anything if disabled or cpu unpowered */
169 	if (!config->hw_enabled || !config->hw_powered)
170 		goto cti_not_disabled;
171 
172 	CS_UNLOCK(drvdata->base);
173 
174 	/* disable CTI */
175 	writel_relaxed(0, drvdata->base + CTICONTROL);
176 	config->hw_enabled = false;
177 
178 	coresight_disclaim_device_unlocked(csdev);
179 	CS_LOCK(drvdata->base);
180 	spin_unlock(&drvdata->spinlock);
181 	return ret;
182 
183 	/* not disabled this call */
184 cti_not_disabled:
185 	spin_unlock(&drvdata->spinlock);
186 	return ret;
187 }
188 
189 void cti_write_single_reg(struct cti_drvdata *drvdata, int offset, u32 value)
190 {
191 	CS_UNLOCK(drvdata->base);
192 	writel_relaxed(value, drvdata->base + offset);
193 	CS_LOCK(drvdata->base);
194 }
195 
196 void cti_write_intack(struct device *dev, u32 ackval)
197 {
198 	struct cti_drvdata *drvdata = dev_get_drvdata(dev->parent);
199 	struct cti_config *config = &drvdata->config;
200 
201 	spin_lock(&drvdata->spinlock);
202 	/* write if enabled */
203 	if (cti_active(config))
204 		cti_write_single_reg(drvdata, CTIINTACK, ackval);
205 	spin_unlock(&drvdata->spinlock);
206 }
207 
208 /*
209  * Look at the HW DEVID register for some of the HW settings.
210  * DEVID[15:8] - max number of in / out triggers.
211  */
212 #define CTI_DEVID_MAXTRIGS(devid_val) ((int) BMVAL(devid_val, 8, 15))
213 
214 /* DEVID[19:16] - number of CTM channels */
215 #define CTI_DEVID_CTMCHANNELS(devid_val) ((int) BMVAL(devid_val, 16, 19))
216 
217 static void cti_set_default_config(struct device *dev,
218 				   struct cti_drvdata *drvdata)
219 {
220 	struct cti_config *config = &drvdata->config;
221 	u32 devid;
222 
223 	devid = readl_relaxed(drvdata->base + CORESIGHT_DEVID);
224 	config->nr_trig_max = CTI_DEVID_MAXTRIGS(devid);
225 
226 	/*
227 	 * no current hardware should exceed this, but protect the driver
228 	 * in case of fault / out of spec hw
229 	 */
230 	if (config->nr_trig_max > CTIINOUTEN_MAX) {
231 		dev_warn_once(dev,
232 			"Limiting HW MaxTrig value(%d) to driver max(%d)\n",
233 			config->nr_trig_max, CTIINOUTEN_MAX);
234 		config->nr_trig_max = CTIINOUTEN_MAX;
235 	}
236 
237 	config->nr_ctm_channels = CTI_DEVID_CTMCHANNELS(devid);
238 
239 	/* Most regs default to 0 as zalloc'ed except...*/
240 	config->trig_filter_enable = true;
241 	config->ctigate = GENMASK(config->nr_ctm_channels - 1, 0);
242 	config->enable_req_count = 0;
243 }
244 
245 /*
246  * Add a connection entry to the list of connections for this
247  * CTI device.
248  */
249 int cti_add_connection_entry(struct device *dev, struct cti_drvdata *drvdata,
250 			     struct cti_trig_con *tc,
251 			     struct coresight_device *csdev,
252 			     const char *assoc_dev_name)
253 {
254 	struct cti_device *cti_dev = &drvdata->ctidev;
255 
256 	tc->con_dev = csdev;
257 	/*
258 	 * Prefer actual associated CS device dev name to supplied value -
259 	 * which is likely to be node name / other conn name.
260 	 */
261 	if (csdev)
262 		tc->con_dev_name = dev_name(&csdev->dev);
263 	else if (assoc_dev_name != NULL) {
264 		tc->con_dev_name = devm_kstrdup(dev,
265 						assoc_dev_name, GFP_KERNEL);
266 		if (!tc->con_dev_name)
267 			return -ENOMEM;
268 	}
269 	list_add_tail(&tc->node, &cti_dev->trig_cons);
270 	cti_dev->nr_trig_con++;
271 
272 	/* add connection usage bit info to overall info */
273 	drvdata->config.trig_in_use |= tc->con_in->used_mask;
274 	drvdata->config.trig_out_use |= tc->con_out->used_mask;
275 
276 	return 0;
277 }
278 
279 /* create a trigger connection with appropriately sized signal groups */
280 struct cti_trig_con *cti_allocate_trig_con(struct device *dev, int in_sigs,
281 					   int out_sigs)
282 {
283 	struct cti_trig_con *tc = NULL;
284 	struct cti_trig_grp *in = NULL, *out = NULL;
285 
286 	tc = devm_kzalloc(dev, sizeof(struct cti_trig_con), GFP_KERNEL);
287 	if (!tc)
288 		return tc;
289 
290 	in = devm_kzalloc(dev,
291 			  offsetof(struct cti_trig_grp, sig_types[in_sigs]),
292 			  GFP_KERNEL);
293 	if (!in)
294 		return NULL;
295 
296 	out = devm_kzalloc(dev,
297 			   offsetof(struct cti_trig_grp, sig_types[out_sigs]),
298 			   GFP_KERNEL);
299 	if (!out)
300 		return NULL;
301 
302 	tc->con_in = in;
303 	tc->con_out = out;
304 	tc->con_in->nr_sigs = in_sigs;
305 	tc->con_out->nr_sigs = out_sigs;
306 	return tc;
307 }
308 
309 /*
310  * Add a default connection if nothing else is specified.
311  * single connection based on max in/out info, no assoc device
312  */
313 int cti_add_default_connection(struct device *dev, struct cti_drvdata *drvdata)
314 {
315 	int ret = 0;
316 	int n_trigs = drvdata->config.nr_trig_max;
317 	u32 n_trig_mask = GENMASK(n_trigs - 1, 0);
318 	struct cti_trig_con *tc = NULL;
319 
320 	/*
321 	 * Assume max trigs for in and out,
322 	 * all used, default sig types allocated
323 	 */
324 	tc = cti_allocate_trig_con(dev, n_trigs, n_trigs);
325 	if (!tc)
326 		return -ENOMEM;
327 
328 	tc->con_in->used_mask = n_trig_mask;
329 	tc->con_out->used_mask = n_trig_mask;
330 	ret = cti_add_connection_entry(dev, drvdata, tc, NULL, "default");
331 	return ret;
332 }
333 
334 /** cti channel api **/
335 /* attach/detach channel from trigger - write through if enabled. */
336 int cti_channel_trig_op(struct device *dev, enum cti_chan_op op,
337 			enum cti_trig_dir direction, u32 channel_idx,
338 			u32 trigger_idx)
339 {
340 	struct cti_drvdata *drvdata = dev_get_drvdata(dev->parent);
341 	struct cti_config *config = &drvdata->config;
342 	u32 trig_bitmask;
343 	u32 chan_bitmask;
344 	u32 reg_value;
345 	int reg_offset;
346 
347 	/* ensure indexes in range */
348 	if ((channel_idx >= config->nr_ctm_channels) ||
349 	   (trigger_idx >= config->nr_trig_max))
350 		return -EINVAL;
351 
352 	trig_bitmask = BIT(trigger_idx);
353 
354 	/* ensure registered triggers and not out filtered */
355 	if (direction == CTI_TRIG_IN)	{
356 		if (!(trig_bitmask & config->trig_in_use))
357 			return -EINVAL;
358 	} else {
359 		if (!(trig_bitmask & config->trig_out_use))
360 			return -EINVAL;
361 
362 		if ((config->trig_filter_enable) &&
363 		    (config->trig_out_filter & trig_bitmask))
364 			return -EINVAL;
365 	}
366 
367 	/* update the local register values */
368 	chan_bitmask = BIT(channel_idx);
369 	reg_offset = (direction == CTI_TRIG_IN ? CTIINEN(trigger_idx) :
370 		      CTIOUTEN(trigger_idx));
371 
372 	spin_lock(&drvdata->spinlock);
373 
374 	/* read - modify write - the trigger / channel enable value */
375 	reg_value = direction == CTI_TRIG_IN ? config->ctiinen[trigger_idx] :
376 		     config->ctiouten[trigger_idx];
377 	if (op == CTI_CHAN_ATTACH)
378 		reg_value |= chan_bitmask;
379 	else
380 		reg_value &= ~chan_bitmask;
381 
382 	/* write local copy */
383 	if (direction == CTI_TRIG_IN)
384 		config->ctiinen[trigger_idx] = reg_value;
385 	else
386 		config->ctiouten[trigger_idx] = reg_value;
387 
388 	/* write through if enabled */
389 	if (cti_active(config))
390 		cti_write_single_reg(drvdata, reg_offset, reg_value);
391 	spin_unlock(&drvdata->spinlock);
392 	return 0;
393 }
394 
395 int cti_channel_gate_op(struct device *dev, enum cti_chan_gate_op op,
396 			u32 channel_idx)
397 {
398 	struct cti_drvdata *drvdata = dev_get_drvdata(dev->parent);
399 	struct cti_config *config = &drvdata->config;
400 	u32 chan_bitmask;
401 	u32 reg_value;
402 	int err = 0;
403 
404 	if (channel_idx >= config->nr_ctm_channels)
405 		return -EINVAL;
406 
407 	chan_bitmask = BIT(channel_idx);
408 
409 	spin_lock(&drvdata->spinlock);
410 	reg_value = config->ctigate;
411 	switch (op) {
412 	case CTI_GATE_CHAN_ENABLE:
413 		reg_value |= chan_bitmask;
414 		break;
415 
416 	case CTI_GATE_CHAN_DISABLE:
417 		reg_value &= ~chan_bitmask;
418 		break;
419 
420 	default:
421 		err = -EINVAL;
422 		break;
423 	}
424 	if (err == 0) {
425 		config->ctigate = reg_value;
426 		if (cti_active(config))
427 			cti_write_single_reg(drvdata, CTIGATE, reg_value);
428 	}
429 	spin_unlock(&drvdata->spinlock);
430 	return err;
431 }
432 
433 int cti_channel_setop(struct device *dev, enum cti_chan_set_op op,
434 		      u32 channel_idx)
435 {
436 	struct cti_drvdata *drvdata = dev_get_drvdata(dev->parent);
437 	struct cti_config *config = &drvdata->config;
438 	u32 chan_bitmask;
439 	u32 reg_value;
440 	u32 reg_offset;
441 	int err = 0;
442 
443 	if (channel_idx >= config->nr_ctm_channels)
444 		return -EINVAL;
445 
446 	chan_bitmask = BIT(channel_idx);
447 
448 	spin_lock(&drvdata->spinlock);
449 	reg_value = config->ctiappset;
450 	switch (op) {
451 	case CTI_CHAN_SET:
452 		config->ctiappset |= chan_bitmask;
453 		reg_value  = config->ctiappset;
454 		reg_offset = CTIAPPSET;
455 		break;
456 
457 	case CTI_CHAN_CLR:
458 		config->ctiappset &= ~chan_bitmask;
459 		reg_value = chan_bitmask;
460 		reg_offset = CTIAPPCLEAR;
461 		break;
462 
463 	case CTI_CHAN_PULSE:
464 		config->ctiappset &= ~chan_bitmask;
465 		reg_value = chan_bitmask;
466 		reg_offset = CTIAPPPULSE;
467 		break;
468 
469 	default:
470 		err = -EINVAL;
471 		break;
472 	}
473 
474 	if ((err == 0) && cti_active(config))
475 		cti_write_single_reg(drvdata, reg_offset, reg_value);
476 	spin_unlock(&drvdata->spinlock);
477 
478 	return err;
479 }
480 
481 static bool cti_add_sysfs_link(struct cti_drvdata *drvdata,
482 			       struct cti_trig_con *tc)
483 {
484 	struct coresight_sysfs_link link_info;
485 	int link_err = 0;
486 
487 	link_info.orig = drvdata->csdev;
488 	link_info.orig_name = tc->con_dev_name;
489 	link_info.target = tc->con_dev;
490 	link_info.target_name = dev_name(&drvdata->csdev->dev);
491 
492 	link_err = coresight_add_sysfs_link(&link_info);
493 	if (link_err)
494 		dev_warn(&drvdata->csdev->dev,
495 			 "Failed to set CTI sysfs link %s<=>%s\n",
496 			 link_info.orig_name, link_info.target_name);
497 	return !link_err;
498 }
499 
500 static void cti_remove_sysfs_link(struct cti_drvdata *drvdata,
501 				  struct cti_trig_con *tc)
502 {
503 	struct coresight_sysfs_link link_info;
504 
505 	link_info.orig = drvdata->csdev;
506 	link_info.orig_name = tc->con_dev_name;
507 	link_info.target = tc->con_dev;
508 	link_info.target_name = dev_name(&drvdata->csdev->dev);
509 	coresight_remove_sysfs_link(&link_info);
510 }
511 
512 /*
513  * Look for a matching connection device name in the list of connections.
514  * If found then swap in the csdev name, set trig con association pointer
515  * and return found.
516  */
517 static bool
518 cti_match_fixup_csdev(struct cti_device *ctidev, const char *node_name,
519 		      struct coresight_device *csdev)
520 {
521 	struct cti_trig_con *tc;
522 	struct cti_drvdata *drvdata = container_of(ctidev, struct cti_drvdata,
523 						   ctidev);
524 
525 	list_for_each_entry(tc, &ctidev->trig_cons, node) {
526 		if (tc->con_dev_name) {
527 			if (!strcmp(node_name, tc->con_dev_name)) {
528 				/* match: so swap in csdev name & dev */
529 				tc->con_dev_name = dev_name(&csdev->dev);
530 				tc->con_dev = csdev;
531 				/* try to set sysfs link */
532 				if (cti_add_sysfs_link(drvdata, tc))
533 					return true;
534 				/* link failed - remove CTI reference */
535 				tc->con_dev = NULL;
536 				break;
537 			}
538 		}
539 	}
540 	return false;
541 }
542 
543 /*
544  * Search the cti list to add an associated CTI into the supplied CS device
545  * This will set the association if CTI declared before the CS device.
546  * (called from coresight_register() without coresight_mutex locked).
547  */
548 static void cti_add_assoc_to_csdev(struct coresight_device *csdev)
549 {
550 	struct cti_drvdata *ect_item;
551 	struct cti_device *ctidev;
552 	const char *node_name = NULL;
553 
554 	/* protect the list */
555 	mutex_lock(&ect_mutex);
556 
557 	/* exit if current is an ECT device.*/
558 	if ((csdev->type == CORESIGHT_DEV_TYPE_ECT) || list_empty(&ect_net))
559 		goto cti_add_done;
560 
561 	/* if we didn't find the csdev previously we used the fwnode name */
562 	node_name = cti_plat_get_node_name(dev_fwnode(csdev->dev.parent));
563 	if (!node_name)
564 		goto cti_add_done;
565 
566 	/* for each CTI in list... */
567 	list_for_each_entry(ect_item, &ect_net, node) {
568 		ctidev = &ect_item->ctidev;
569 		if (cti_match_fixup_csdev(ctidev, node_name, csdev)) {
570 			/*
571 			 * if we found a matching csdev then update the ECT
572 			 * association pointer for the device with this CTI.
573 			 */
574 			coresight_set_assoc_ectdev_mutex(csdev,
575 							 ect_item->csdev);
576 			break;
577 		}
578 	}
579 cti_add_done:
580 	mutex_unlock(&ect_mutex);
581 }
582 
583 /*
584  * Removing the associated devices is easier.
585  * A CTI will not have a value for csdev->ect_dev.
586  */
587 static void cti_remove_assoc_from_csdev(struct coresight_device *csdev)
588 {
589 	struct cti_drvdata *ctidrv;
590 	struct cti_trig_con *tc;
591 	struct cti_device *ctidev;
592 
593 	mutex_lock(&ect_mutex);
594 	if (csdev->ect_dev) {
595 		ctidrv = csdev_to_cti_drvdata(csdev->ect_dev);
596 		ctidev = &ctidrv->ctidev;
597 		list_for_each_entry(tc, &ctidev->trig_cons, node) {
598 			if (tc->con_dev == csdev) {
599 				cti_remove_sysfs_link(ctidrv, tc);
600 				tc->con_dev = NULL;
601 				break;
602 			}
603 		}
604 		csdev->ect_dev = NULL;
605 	}
606 	mutex_unlock(&ect_mutex);
607 }
608 
609 /*
610  * Operations to add and remove associated CTI.
611  * Register to coresight core driver as call back function.
612  */
613 static struct cti_assoc_op cti_assoc_ops = {
614 	.add = cti_add_assoc_to_csdev,
615 	.remove = cti_remove_assoc_from_csdev
616 };
617 
618 /*
619  * Update the cross references where the associated device was found
620  * while we were building the connection info. This will occur if the
621  * assoc device was registered before the CTI.
622  */
623 static void cti_update_conn_xrefs(struct cti_drvdata *drvdata)
624 {
625 	struct cti_trig_con *tc;
626 	struct cti_device *ctidev = &drvdata->ctidev;
627 
628 	list_for_each_entry(tc, &ctidev->trig_cons, node) {
629 		if (tc->con_dev) {
630 			/* if we can set the sysfs link */
631 			if (cti_add_sysfs_link(drvdata, tc))
632 				/* set the CTI/csdev association */
633 				coresight_set_assoc_ectdev_mutex(tc->con_dev,
634 							 drvdata->csdev);
635 			else
636 				/* otherwise remove reference from CTI */
637 				tc->con_dev = NULL;
638 		}
639 	}
640 }
641 
642 static void cti_remove_conn_xrefs(struct cti_drvdata *drvdata)
643 {
644 	struct cti_trig_con *tc;
645 	struct cti_device *ctidev = &drvdata->ctidev;
646 
647 	list_for_each_entry(tc, &ctidev->trig_cons, node) {
648 		if (tc->con_dev) {
649 			coresight_set_assoc_ectdev_mutex(tc->con_dev,
650 							 NULL);
651 			cti_remove_sysfs_link(drvdata, tc);
652 			tc->con_dev = NULL;
653 		}
654 	}
655 }
656 
657 /** cti PM callbacks **/
658 static int cti_cpu_pm_notify(struct notifier_block *nb, unsigned long cmd,
659 			     void *v)
660 {
661 	struct cti_drvdata *drvdata;
662 	struct coresight_device *csdev;
663 	unsigned int cpu = smp_processor_id();
664 	int notify_res = NOTIFY_OK;
665 
666 	if (!cti_cpu_drvdata[cpu])
667 		return NOTIFY_OK;
668 
669 	drvdata = cti_cpu_drvdata[cpu];
670 	csdev = drvdata->csdev;
671 
672 	if (WARN_ON_ONCE(drvdata->ctidev.cpu != cpu))
673 		return NOTIFY_BAD;
674 
675 	spin_lock(&drvdata->spinlock);
676 
677 	switch (cmd) {
678 	case CPU_PM_ENTER:
679 		/* CTI regs all static - we have a copy & nothing to save */
680 		drvdata->config.hw_powered = false;
681 		if (drvdata->config.hw_enabled)
682 			coresight_disclaim_device(csdev);
683 		break;
684 
685 	case CPU_PM_ENTER_FAILED:
686 		drvdata->config.hw_powered = true;
687 		if (drvdata->config.hw_enabled) {
688 			if (coresight_claim_device(csdev))
689 				drvdata->config.hw_enabled = false;
690 		}
691 		break;
692 
693 	case CPU_PM_EXIT:
694 		/* write hardware registers to re-enable. */
695 		drvdata->config.hw_powered = true;
696 		drvdata->config.hw_enabled = false;
697 
698 		/* check enable reference count to enable HW */
699 		if (drvdata->config.enable_req_count) {
700 			/* check we can claim the device as we re-power */
701 			if (coresight_claim_device(csdev))
702 				goto cti_notify_exit;
703 
704 			drvdata->config.hw_enabled = true;
705 			cti_write_all_hw_regs(drvdata);
706 		}
707 		break;
708 
709 	default:
710 		notify_res = NOTIFY_DONE;
711 		break;
712 	}
713 
714 cti_notify_exit:
715 	spin_unlock(&drvdata->spinlock);
716 	return notify_res;
717 }
718 
719 static struct notifier_block cti_cpu_pm_nb = {
720 	.notifier_call = cti_cpu_pm_notify,
721 };
722 
723 /* CPU HP handlers */
724 static int cti_starting_cpu(unsigned int cpu)
725 {
726 	struct cti_drvdata *drvdata = cti_cpu_drvdata[cpu];
727 
728 	if (!drvdata)
729 		return 0;
730 
731 	cti_cpuhp_enable_hw(drvdata);
732 	return 0;
733 }
734 
735 static int cti_dying_cpu(unsigned int cpu)
736 {
737 	struct cti_drvdata *drvdata = cti_cpu_drvdata[cpu];
738 
739 	if (!drvdata)
740 		return 0;
741 
742 	spin_lock(&drvdata->spinlock);
743 	drvdata->config.hw_powered = false;
744 	if (drvdata->config.hw_enabled)
745 		coresight_disclaim_device(drvdata->csdev);
746 	spin_unlock(&drvdata->spinlock);
747 	return 0;
748 }
749 
750 static int cti_pm_setup(struct cti_drvdata *drvdata)
751 {
752 	int ret;
753 
754 	if (drvdata->ctidev.cpu == -1)
755 		return 0;
756 
757 	if (nr_cti_cpu)
758 		goto done;
759 
760 	cpus_read_lock();
761 	ret = cpuhp_setup_state_nocalls_cpuslocked(
762 			CPUHP_AP_ARM_CORESIGHT_CTI_STARTING,
763 			"arm/coresight_cti:starting",
764 			cti_starting_cpu, cti_dying_cpu);
765 	if (ret) {
766 		cpus_read_unlock();
767 		return ret;
768 	}
769 
770 	ret = cpu_pm_register_notifier(&cti_cpu_pm_nb);
771 	cpus_read_unlock();
772 	if (ret) {
773 		cpuhp_remove_state_nocalls(CPUHP_AP_ARM_CORESIGHT_CTI_STARTING);
774 		return ret;
775 	}
776 
777 done:
778 	nr_cti_cpu++;
779 	cti_cpu_drvdata[drvdata->ctidev.cpu] = drvdata;
780 
781 	return 0;
782 }
783 
784 /* release PM registrations */
785 static void cti_pm_release(struct cti_drvdata *drvdata)
786 {
787 	if (drvdata->ctidev.cpu == -1)
788 		return;
789 
790 	cti_cpu_drvdata[drvdata->ctidev.cpu] = NULL;
791 	if (--nr_cti_cpu == 0) {
792 		cpu_pm_unregister_notifier(&cti_cpu_pm_nb);
793 		cpuhp_remove_state_nocalls(CPUHP_AP_ARM_CORESIGHT_CTI_STARTING);
794 	}
795 }
796 
797 /** cti ect operations **/
798 int cti_enable(struct coresight_device *csdev)
799 {
800 	struct cti_drvdata *drvdata = csdev_to_cti_drvdata(csdev);
801 
802 	return cti_enable_hw(drvdata);
803 }
804 
805 int cti_disable(struct coresight_device *csdev)
806 {
807 	struct cti_drvdata *drvdata = csdev_to_cti_drvdata(csdev);
808 
809 	return cti_disable_hw(drvdata);
810 }
811 
812 static const struct coresight_ops_ect cti_ops_ect = {
813 	.enable = cti_enable,
814 	.disable = cti_disable,
815 };
816 
817 static const struct coresight_ops cti_ops = {
818 	.ect_ops = &cti_ops_ect,
819 };
820 
821 /*
822  * Free up CTI specific resources
823  * called by dev->release, need to call down to underlying csdev release.
824  */
825 static void cti_device_release(struct device *dev)
826 {
827 	struct cti_drvdata *drvdata = dev_get_drvdata(dev->parent);
828 	struct cti_drvdata *ect_item, *ect_tmp;
829 
830 	mutex_lock(&ect_mutex);
831 	cti_pm_release(drvdata);
832 
833 	/* remove from the list */
834 	list_for_each_entry_safe(ect_item, ect_tmp, &ect_net, node) {
835 		if (ect_item == drvdata) {
836 			list_del(&ect_item->node);
837 			break;
838 		}
839 	}
840 	mutex_unlock(&ect_mutex);
841 
842 	if (drvdata->csdev_release)
843 		drvdata->csdev_release(dev);
844 }
845 static void cti_remove(struct amba_device *adev)
846 {
847 	struct cti_drvdata *drvdata = dev_get_drvdata(&adev->dev);
848 
849 	mutex_lock(&ect_mutex);
850 	cti_remove_conn_xrefs(drvdata);
851 	mutex_unlock(&ect_mutex);
852 
853 	coresight_unregister(drvdata->csdev);
854 }
855 
856 static int cti_probe(struct amba_device *adev, const struct amba_id *id)
857 {
858 	int ret = 0;
859 	void __iomem *base;
860 	struct device *dev = &adev->dev;
861 	struct cti_drvdata *drvdata = NULL;
862 	struct coresight_desc cti_desc;
863 	struct coresight_platform_data *pdata = NULL;
864 	struct resource *res = &adev->res;
865 
866 	/* driver data*/
867 	drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
868 	if (!drvdata)
869 		return -ENOMEM;
870 
871 	/* Validity for the resource is already checked by the AMBA core */
872 	base = devm_ioremap_resource(dev, res);
873 	if (IS_ERR(base))
874 		return PTR_ERR(base);
875 
876 	drvdata->base = base;
877 	cti_desc.access = CSDEV_ACCESS_IOMEM(base);
878 
879 	dev_set_drvdata(dev, drvdata);
880 
881 	/* default CTI device info  */
882 	drvdata->ctidev.cpu = -1;
883 	drvdata->ctidev.nr_trig_con = 0;
884 	drvdata->ctidev.ctm_id = 0;
885 	INIT_LIST_HEAD(&drvdata->ctidev.trig_cons);
886 
887 	spin_lock_init(&drvdata->spinlock);
888 
889 	/* initialise CTI driver config values */
890 	cti_set_default_config(dev, drvdata);
891 
892 	pdata = coresight_cti_get_platform_data(dev);
893 	if (IS_ERR(pdata)) {
894 		dev_err(dev, "coresight_cti_get_platform_data err\n");
895 		return  PTR_ERR(pdata);
896 	}
897 
898 	/* default to powered - could change on PM notifications */
899 	drvdata->config.hw_powered = true;
900 
901 	/* set up device name - will depend if cpu bound or otherwise */
902 	if (drvdata->ctidev.cpu >= 0)
903 		cti_desc.name = devm_kasprintf(dev, GFP_KERNEL, "cti_cpu%d",
904 					       drvdata->ctidev.cpu);
905 	else
906 		cti_desc.name = coresight_alloc_device_name(&cti_sys_devs, dev);
907 	if (!cti_desc.name)
908 		return -ENOMEM;
909 
910 	/* setup CPU power management handling for CPU bound CTI devices. */
911 	ret = cti_pm_setup(drvdata);
912 	if (ret)
913 		return ret;
914 
915 	/* create dynamic attributes for connections */
916 	ret = cti_create_cons_sysfs(dev, drvdata);
917 	if (ret) {
918 		dev_err(dev, "%s: create dynamic sysfs entries failed\n",
919 			cti_desc.name);
920 		goto pm_release;
921 	}
922 
923 	/* set up coresight component description */
924 	cti_desc.pdata = pdata;
925 	cti_desc.type = CORESIGHT_DEV_TYPE_ECT;
926 	cti_desc.subtype.ect_subtype = CORESIGHT_DEV_SUBTYPE_ECT_CTI;
927 	cti_desc.ops = &cti_ops;
928 	cti_desc.groups = drvdata->ctidev.con_groups;
929 	cti_desc.dev = dev;
930 	drvdata->csdev = coresight_register(&cti_desc);
931 	if (IS_ERR(drvdata->csdev)) {
932 		ret = PTR_ERR(drvdata->csdev);
933 		goto pm_release;
934 	}
935 
936 	/* add to list of CTI devices */
937 	mutex_lock(&ect_mutex);
938 	list_add(&drvdata->node, &ect_net);
939 	/* set any cross references */
940 	cti_update_conn_xrefs(drvdata);
941 	mutex_unlock(&ect_mutex);
942 
943 	/* set up release chain */
944 	drvdata->csdev_release = drvdata->csdev->dev.release;
945 	drvdata->csdev->dev.release = cti_device_release;
946 
947 	/* all done - dec pm refcount */
948 	pm_runtime_put(&adev->dev);
949 	dev_info(&drvdata->csdev->dev, "CTI initialized\n");
950 	return 0;
951 
952 pm_release:
953 	cti_pm_release(drvdata);
954 	return ret;
955 }
956 
957 static struct amba_cs_uci_id uci_id_cti[] = {
958 	{
959 		/*  CTI UCI data */
960 		.devarch	= 0x47701a14, /* CTI v2 */
961 		.devarch_mask	= 0xfff0ffff,
962 		.devtype	= 0x00000014, /* maj(0x4-debug) min(0x1-ECT) */
963 	}
964 };
965 
966 static const struct amba_id cti_ids[] = {
967 	CS_AMBA_ID(0x000bb906), /* Coresight CTI (SoC 400), C-A72, C-A57 */
968 	CS_AMBA_ID(0x000bb922), /* CTI - C-A8 */
969 	CS_AMBA_ID(0x000bb9a8), /* CTI - C-A53 */
970 	CS_AMBA_ID(0x000bb9aa), /* CTI - C-A73 */
971 	CS_AMBA_UCI_ID(0x000bb9da, uci_id_cti), /* CTI - C-A35 */
972 	CS_AMBA_UCI_ID(0x000bb9ed, uci_id_cti), /* Coresight CTI (SoC 600) */
973 	{ 0, 0},
974 };
975 
976 MODULE_DEVICE_TABLE(amba, cti_ids);
977 
978 static struct amba_driver cti_driver = {
979 	.drv = {
980 		.name	= "coresight-cti",
981 		.owner = THIS_MODULE,
982 		.suppress_bind_attrs = true,
983 	},
984 	.probe		= cti_probe,
985 	.remove		= cti_remove,
986 	.id_table	= cti_ids,
987 };
988 
989 static int __init cti_init(void)
990 {
991 	int ret;
992 
993 	ret = amba_driver_register(&cti_driver);
994 	if (ret)
995 		pr_info("Error registering cti driver\n");
996 	coresight_set_cti_ops(&cti_assoc_ops);
997 	return ret;
998 }
999 
1000 static void __exit cti_exit(void)
1001 {
1002 	coresight_remove_cti_ops();
1003 	amba_driver_unregister(&cti_driver);
1004 }
1005 
1006 module_init(cti_init);
1007 module_exit(cti_exit);
1008 
1009 MODULE_AUTHOR("Mike Leach <mike.leach@linaro.org>");
1010 MODULE_DESCRIPTION("Arm CoreSight CTI Driver");
1011 MODULE_LICENSE("GPL v2");
1012