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