xref: /linux/drivers/hwtracing/coresight/coresight-stm.c (revision 90d32e92011eaae8e70a9169b4e7acf4ca8f9d3a)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2015-2016, The Linux Foundation. All rights reserved.
4  *
5  * Description: CoreSight System Trace Macrocell driver
6  *
7  * Initial implementation by Pratik Patel
8  * (C) 2014-2015 Pratik Patel <pratikp@codeaurora.org>
9  *
10  * Serious refactoring, code cleanup and upgrading to the Coresight upstream
11  * framework by Mathieu Poirier
12  * (C) 2015-2016 Mathieu Poirier <mathieu.poirier@linaro.org>
13  *
14  * Guaranteed timing and support for various packet type coming from the
15  * generic STM API by Chunyan Zhang
16  * (C) 2015-2016 Chunyan Zhang <zhang.chunyan@linaro.org>
17  */
18 #include <asm/local.h>
19 #include <linux/acpi.h>
20 #include <linux/amba/bus.h>
21 #include <linux/bitmap.h>
22 #include <linux/clk.h>
23 #include <linux/coresight.h>
24 #include <linux/coresight-stm.h>
25 #include <linux/err.h>
26 #include <linux/kernel.h>
27 #include <linux/moduleparam.h>
28 #include <linux/of_address.h>
29 #include <linux/perf_event.h>
30 #include <linux/pm_runtime.h>
31 #include <linux/stm.h>
32 #include <linux/platform_device.h>
33 
34 #include "coresight-priv.h"
35 #include "coresight-trace-id.h"
36 
37 #define STMDMASTARTR			0xc04
38 #define STMDMASTOPR			0xc08
39 #define STMDMASTATR			0xc0c
40 #define STMDMACTLR			0xc10
41 #define STMDMAIDR			0xcfc
42 #define STMHEER				0xd00
43 #define STMHETER			0xd20
44 #define STMHEBSR			0xd60
45 #define STMHEMCR			0xd64
46 #define STMHEMASTR			0xdf4
47 #define STMHEFEAT1R			0xdf8
48 #define STMHEIDR			0xdfc
49 #define STMSPER				0xe00
50 #define STMSPTER			0xe20
51 #define STMPRIVMASKR			0xe40
52 #define STMSPSCR			0xe60
53 #define STMSPMSCR			0xe64
54 #define STMSPOVERRIDER			0xe68
55 #define STMSPMOVERRIDER			0xe6c
56 #define STMSPTRIGCSR			0xe70
57 #define STMTCSR				0xe80
58 #define STMTSSTIMR			0xe84
59 #define STMTSFREQR			0xe8c
60 #define STMSYNCR			0xe90
61 #define STMAUXCR			0xe94
62 #define STMSPFEAT1R			0xea0
63 #define STMSPFEAT2R			0xea4
64 #define STMSPFEAT3R			0xea8
65 #define STMITTRIGGER			0xee8
66 #define STMITATBDATA0			0xeec
67 #define STMITATBCTR2			0xef0
68 #define STMITATBID			0xef4
69 #define STMITATBCTR0			0xef8
70 
71 #define STM_32_CHANNEL			32
72 #define BYTES_PER_CHANNEL		256
73 #define STM_TRACE_BUF_SIZE		4096
74 #define STM_SW_MASTER_END		127
75 
76 /* Register bit definition */
77 #define STMTCSR_BUSY_BIT		23
78 /* Reserve the first 10 channels for kernel usage */
79 #define STM_CHANNEL_OFFSET		0
80 
81 enum stm_pkt_type {
82 	STM_PKT_TYPE_DATA	= 0x98,
83 	STM_PKT_TYPE_FLAG	= 0xE8,
84 	STM_PKT_TYPE_TRIG	= 0xF8,
85 };
86 
87 #define stm_channel_addr(drvdata, ch)	(drvdata->chs.base +	\
88 					(ch * BYTES_PER_CHANNEL))
89 #define stm_channel_off(type, opts)	(type & ~opts)
90 
91 static int boot_nr_channel;
92 
93 /*
94  * Not really modular but using module_param is the easiest way to
95  * remain consistent with existing use cases for now.
96  */
97 module_param_named(
98 	boot_nr_channel, boot_nr_channel, int, S_IRUGO
99 );
100 
101 /*
102  * struct channel_space - central management entity for extended ports
103  * @base:		memory mapped base address where channels start.
104  * @phys:		physical base address of channel region.
105  * @guaraneed:		is the channel delivery guaranteed.
106  */
107 struct channel_space {
108 	void __iomem		*base;
109 	phys_addr_t		phys;
110 	unsigned long		*guaranteed;
111 };
112 
113 DEFINE_CORESIGHT_DEVLIST(stm_devs, "stm");
114 
115 /**
116  * struct stm_drvdata - specifics associated to an STM component
117  * @base:		memory mapped base address for this component.
118  * @atclk:		optional clock for the core parts of the STM.
119  * @pclk:		APB clock if present, otherwise NULL
120  * @csdev:		component vitals needed by the framework.
121  * @spinlock:		only one at a time pls.
122  * @chs:		the channels accociated to this STM.
123  * @stm:		structure associated to the generic STM interface.
124  * @traceid:		value of the current ID for this component.
125  * @write_bytes:	Maximus bytes this STM can write at a time.
126  * @stmsper:		settings for register STMSPER.
127  * @stmspscr:		settings for register STMSPSCR.
128  * @numsp:		the total number of stimulus port support by this STM.
129  * @stmheer:		settings for register STMHEER.
130  * @stmheter:		settings for register STMHETER.
131  * @stmhebsr:		settings for register STMHEBSR.
132  */
133 struct stm_drvdata {
134 	void __iomem		*base;
135 	struct clk		*atclk;
136 	struct clk		*pclk;
137 	struct coresight_device	*csdev;
138 	spinlock_t		spinlock;
139 	struct channel_space	chs;
140 	struct stm_data		stm;
141 	u8			traceid;
142 	u32			write_bytes;
143 	u32			stmsper;
144 	u32			stmspscr;
145 	u32			numsp;
146 	u32			stmheer;
147 	u32			stmheter;
148 	u32			stmhebsr;
149 };
150 
151 static void stm_hwevent_enable_hw(struct stm_drvdata *drvdata)
152 {
153 	CS_UNLOCK(drvdata->base);
154 
155 	writel_relaxed(drvdata->stmhebsr, drvdata->base + STMHEBSR);
156 	writel_relaxed(drvdata->stmheter, drvdata->base + STMHETER);
157 	writel_relaxed(drvdata->stmheer, drvdata->base + STMHEER);
158 	writel_relaxed(0x01 |	/* Enable HW event tracing */
159 		       0x04,	/* Error detection on event tracing */
160 		       drvdata->base + STMHEMCR);
161 
162 	CS_LOCK(drvdata->base);
163 }
164 
165 static void stm_port_enable_hw(struct stm_drvdata *drvdata)
166 {
167 	CS_UNLOCK(drvdata->base);
168 	/* ATB trigger enable on direct writes to TRIG locations */
169 	writel_relaxed(0x10,
170 		       drvdata->base + STMSPTRIGCSR);
171 	writel_relaxed(drvdata->stmspscr, drvdata->base + STMSPSCR);
172 	writel_relaxed(drvdata->stmsper, drvdata->base + STMSPER);
173 
174 	CS_LOCK(drvdata->base);
175 }
176 
177 static void stm_enable_hw(struct stm_drvdata *drvdata)
178 {
179 	if (drvdata->stmheer)
180 		stm_hwevent_enable_hw(drvdata);
181 
182 	stm_port_enable_hw(drvdata);
183 
184 	CS_UNLOCK(drvdata->base);
185 
186 	/* 4096 byte between synchronisation packets */
187 	writel_relaxed(0xFFF, drvdata->base + STMSYNCR);
188 	writel_relaxed((drvdata->traceid << 16 | /* trace id */
189 			0x02 |			 /* timestamp enable */
190 			0x01),			 /* global STM enable */
191 			drvdata->base + STMTCSR);
192 
193 	CS_LOCK(drvdata->base);
194 }
195 
196 static int stm_enable(struct coresight_device *csdev, struct perf_event *event,
197 		      enum cs_mode mode)
198 {
199 	struct stm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
200 
201 	if (mode != CS_MODE_SYSFS)
202 		return -EINVAL;
203 
204 	if (!coresight_take_mode(csdev, mode)) {
205 		/* Someone is already using the tracer */
206 		return -EBUSY;
207 	}
208 
209 	pm_runtime_get_sync(csdev->dev.parent);
210 
211 	spin_lock(&drvdata->spinlock);
212 	stm_enable_hw(drvdata);
213 	spin_unlock(&drvdata->spinlock);
214 
215 	dev_dbg(&csdev->dev, "STM tracing enabled\n");
216 	return 0;
217 }
218 
219 static void stm_hwevent_disable_hw(struct stm_drvdata *drvdata)
220 {
221 	CS_UNLOCK(drvdata->base);
222 
223 	writel_relaxed(0x0, drvdata->base + STMHEMCR);
224 	writel_relaxed(0x0, drvdata->base + STMHEER);
225 	writel_relaxed(0x0, drvdata->base + STMHETER);
226 
227 	CS_LOCK(drvdata->base);
228 }
229 
230 static void stm_port_disable_hw(struct stm_drvdata *drvdata)
231 {
232 	CS_UNLOCK(drvdata->base);
233 
234 	writel_relaxed(0x0, drvdata->base + STMSPER);
235 	writel_relaxed(0x0, drvdata->base + STMSPTRIGCSR);
236 
237 	CS_LOCK(drvdata->base);
238 }
239 
240 static void stm_disable_hw(struct stm_drvdata *drvdata)
241 {
242 	u32 val;
243 
244 	CS_UNLOCK(drvdata->base);
245 
246 	val = readl_relaxed(drvdata->base + STMTCSR);
247 	val &= ~0x1; /* clear global STM enable [0] */
248 	writel_relaxed(val, drvdata->base + STMTCSR);
249 
250 	CS_LOCK(drvdata->base);
251 
252 	stm_port_disable_hw(drvdata);
253 	if (drvdata->stmheer)
254 		stm_hwevent_disable_hw(drvdata);
255 }
256 
257 static void stm_disable(struct coresight_device *csdev,
258 			struct perf_event *event)
259 {
260 	struct stm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
261 	struct csdev_access *csa = &csdev->access;
262 
263 	/*
264 	 * For as long as the tracer isn't disabled another entity can't
265 	 * change its status.  As such we can read the status here without
266 	 * fearing it will change under us.
267 	 */
268 	if (coresight_get_mode(csdev) == CS_MODE_SYSFS) {
269 		spin_lock(&drvdata->spinlock);
270 		stm_disable_hw(drvdata);
271 		spin_unlock(&drvdata->spinlock);
272 
273 		/* Wait until the engine has completely stopped */
274 		coresight_timeout(csa, STMTCSR, STMTCSR_BUSY_BIT, 0);
275 
276 		pm_runtime_put(csdev->dev.parent);
277 
278 		coresight_set_mode(csdev, CS_MODE_DISABLED);
279 		dev_dbg(&csdev->dev, "STM tracing disabled\n");
280 	}
281 }
282 
283 static const struct coresight_ops_source stm_source_ops = {
284 	.enable		= stm_enable,
285 	.disable	= stm_disable,
286 };
287 
288 static const struct coresight_ops stm_cs_ops = {
289 	.source_ops	= &stm_source_ops,
290 };
291 
292 static inline bool stm_addr_unaligned(const void *addr, u8 write_bytes)
293 {
294 	return ((unsigned long)addr & (write_bytes - 1));
295 }
296 
297 static void stm_send(void __iomem *addr, const void *data,
298 		     u32 size, u8 write_bytes)
299 {
300 	u8 paload[8];
301 
302 	if (stm_addr_unaligned(data, write_bytes)) {
303 		memcpy(paload, data, size);
304 		data = paload;
305 	}
306 
307 	/* now we are 64bit/32bit aligned */
308 	switch (size) {
309 #ifdef CONFIG_64BIT
310 	case 8:
311 		writeq_relaxed(*(u64 *)data, addr);
312 		break;
313 #endif
314 	case 4:
315 		writel_relaxed(*(u32 *)data, addr);
316 		break;
317 	case 2:
318 		writew_relaxed(*(u16 *)data, addr);
319 		break;
320 	case 1:
321 		writeb_relaxed(*(u8 *)data, addr);
322 		break;
323 	default:
324 		break;
325 	}
326 }
327 
328 static int stm_generic_link(struct stm_data *stm_data,
329 			    unsigned int master,  unsigned int channel)
330 {
331 	struct stm_drvdata *drvdata = container_of(stm_data,
332 						   struct stm_drvdata, stm);
333 	if (!drvdata || !drvdata->csdev)
334 		return -EINVAL;
335 
336 	return coresight_enable_sysfs(drvdata->csdev);
337 }
338 
339 static void stm_generic_unlink(struct stm_data *stm_data,
340 			       unsigned int master,  unsigned int channel)
341 {
342 	struct stm_drvdata *drvdata = container_of(stm_data,
343 						   struct stm_drvdata, stm);
344 	if (!drvdata || !drvdata->csdev)
345 		return;
346 
347 	coresight_disable_sysfs(drvdata->csdev);
348 }
349 
350 static phys_addr_t
351 stm_mmio_addr(struct stm_data *stm_data, unsigned int master,
352 	      unsigned int channel, unsigned int nr_chans)
353 {
354 	struct stm_drvdata *drvdata = container_of(stm_data,
355 						   struct stm_drvdata, stm);
356 	phys_addr_t addr;
357 
358 	addr = drvdata->chs.phys + channel * BYTES_PER_CHANNEL;
359 
360 	if (offset_in_page(addr) ||
361 	    offset_in_page(nr_chans * BYTES_PER_CHANNEL))
362 		return 0;
363 
364 	return addr;
365 }
366 
367 static long stm_generic_set_options(struct stm_data *stm_data,
368 				    unsigned int master,
369 				    unsigned int channel,
370 				    unsigned int nr_chans,
371 				    unsigned long options)
372 {
373 	struct stm_drvdata *drvdata = container_of(stm_data,
374 						   struct stm_drvdata, stm);
375 	if (!(drvdata && coresight_get_mode(drvdata->csdev)))
376 		return -EINVAL;
377 
378 	if (channel >= drvdata->numsp)
379 		return -EINVAL;
380 
381 	switch (options) {
382 	case STM_OPTION_GUARANTEED:
383 		set_bit(channel, drvdata->chs.guaranteed);
384 		break;
385 
386 	case STM_OPTION_INVARIANT:
387 		clear_bit(channel, drvdata->chs.guaranteed);
388 		break;
389 
390 	default:
391 		return -EINVAL;
392 	}
393 
394 	return 0;
395 }
396 
397 static ssize_t notrace stm_generic_packet(struct stm_data *stm_data,
398 				  unsigned int master,
399 				  unsigned int channel,
400 				  unsigned int packet,
401 				  unsigned int flags,
402 				  unsigned int size,
403 				  const unsigned char *payload)
404 {
405 	void __iomem *ch_addr;
406 	struct stm_drvdata *drvdata = container_of(stm_data,
407 						   struct stm_drvdata, stm);
408 	unsigned int stm_flags;
409 
410 	if (!(drvdata && coresight_get_mode(drvdata->csdev)))
411 		return -EACCES;
412 
413 	if (channel >= drvdata->numsp)
414 		return -EINVAL;
415 
416 	ch_addr = stm_channel_addr(drvdata, channel);
417 
418 	stm_flags = (flags & STP_PACKET_TIMESTAMPED) ?
419 			STM_FLAG_TIMESTAMPED : 0;
420 	stm_flags |= test_bit(channel, drvdata->chs.guaranteed) ?
421 			   STM_FLAG_GUARANTEED : 0;
422 
423 	if (size > drvdata->write_bytes)
424 		size = drvdata->write_bytes;
425 	else
426 		size = rounddown_pow_of_two(size);
427 
428 	switch (packet) {
429 	case STP_PACKET_FLAG:
430 		ch_addr += stm_channel_off(STM_PKT_TYPE_FLAG, stm_flags);
431 
432 		/*
433 		 * The generic STM core sets a size of '0' on flag packets.
434 		 * As such send a flag packet of size '1' and tell the
435 		 * core we did so.
436 		 */
437 		stm_send(ch_addr, payload, 1, drvdata->write_bytes);
438 		size = 1;
439 		break;
440 
441 	case STP_PACKET_DATA:
442 		stm_flags |= (flags & STP_PACKET_MARKED) ? STM_FLAG_MARKED : 0;
443 		ch_addr += stm_channel_off(STM_PKT_TYPE_DATA, stm_flags);
444 		stm_send(ch_addr, payload, size,
445 				drvdata->write_bytes);
446 		break;
447 
448 	default:
449 		return -ENOTSUPP;
450 	}
451 
452 	return size;
453 }
454 
455 static ssize_t hwevent_enable_show(struct device *dev,
456 				   struct device_attribute *attr, char *buf)
457 {
458 	struct stm_drvdata *drvdata = dev_get_drvdata(dev->parent);
459 	unsigned long val = drvdata->stmheer;
460 
461 	return scnprintf(buf, PAGE_SIZE, "%#lx\n", val);
462 }
463 
464 static ssize_t hwevent_enable_store(struct device *dev,
465 				    struct device_attribute *attr,
466 				    const char *buf, size_t size)
467 {
468 	struct stm_drvdata *drvdata = dev_get_drvdata(dev->parent);
469 	unsigned long val;
470 	int ret = 0;
471 
472 	ret = kstrtoul(buf, 16, &val);
473 	if (ret)
474 		return -EINVAL;
475 
476 	drvdata->stmheer = val;
477 	/* HW event enable and trigger go hand in hand */
478 	drvdata->stmheter = val;
479 
480 	return size;
481 }
482 static DEVICE_ATTR_RW(hwevent_enable);
483 
484 static ssize_t hwevent_select_show(struct device *dev,
485 				   struct device_attribute *attr, char *buf)
486 {
487 	struct stm_drvdata *drvdata = dev_get_drvdata(dev->parent);
488 	unsigned long val = drvdata->stmhebsr;
489 
490 	return scnprintf(buf, PAGE_SIZE, "%#lx\n", val);
491 }
492 
493 static ssize_t hwevent_select_store(struct device *dev,
494 				    struct device_attribute *attr,
495 				    const char *buf, size_t size)
496 {
497 	struct stm_drvdata *drvdata = dev_get_drvdata(dev->parent);
498 	unsigned long val;
499 	int ret = 0;
500 
501 	ret = kstrtoul(buf, 16, &val);
502 	if (ret)
503 		return -EINVAL;
504 
505 	drvdata->stmhebsr = val;
506 
507 	return size;
508 }
509 static DEVICE_ATTR_RW(hwevent_select);
510 
511 static ssize_t port_select_show(struct device *dev,
512 				struct device_attribute *attr, char *buf)
513 {
514 	struct stm_drvdata *drvdata = dev_get_drvdata(dev->parent);
515 	unsigned long val;
516 
517 	if (!coresight_get_mode(drvdata->csdev)) {
518 		val = drvdata->stmspscr;
519 	} else {
520 		spin_lock(&drvdata->spinlock);
521 		val = readl_relaxed(drvdata->base + STMSPSCR);
522 		spin_unlock(&drvdata->spinlock);
523 	}
524 
525 	return scnprintf(buf, PAGE_SIZE, "%#lx\n", val);
526 }
527 
528 static ssize_t port_select_store(struct device *dev,
529 				 struct device_attribute *attr,
530 				 const char *buf, size_t size)
531 {
532 	struct stm_drvdata *drvdata = dev_get_drvdata(dev->parent);
533 	unsigned long val, stmsper;
534 	int ret = 0;
535 
536 	ret = kstrtoul(buf, 16, &val);
537 	if (ret)
538 		return ret;
539 
540 	spin_lock(&drvdata->spinlock);
541 	drvdata->stmspscr = val;
542 
543 	if (coresight_get_mode(drvdata->csdev)) {
544 		CS_UNLOCK(drvdata->base);
545 		/* Process as per ARM's TRM recommendation */
546 		stmsper = readl_relaxed(drvdata->base + STMSPER);
547 		writel_relaxed(0x0, drvdata->base + STMSPER);
548 		writel_relaxed(drvdata->stmspscr, drvdata->base + STMSPSCR);
549 		writel_relaxed(stmsper, drvdata->base + STMSPER);
550 		CS_LOCK(drvdata->base);
551 	}
552 	spin_unlock(&drvdata->spinlock);
553 
554 	return size;
555 }
556 static DEVICE_ATTR_RW(port_select);
557 
558 static ssize_t port_enable_show(struct device *dev,
559 				struct device_attribute *attr, char *buf)
560 {
561 	struct stm_drvdata *drvdata = dev_get_drvdata(dev->parent);
562 	unsigned long val;
563 
564 	if (!coresight_get_mode(drvdata->csdev)) {
565 		val = drvdata->stmsper;
566 	} else {
567 		spin_lock(&drvdata->spinlock);
568 		val = readl_relaxed(drvdata->base + STMSPER);
569 		spin_unlock(&drvdata->spinlock);
570 	}
571 
572 	return scnprintf(buf, PAGE_SIZE, "%#lx\n", val);
573 }
574 
575 static ssize_t port_enable_store(struct device *dev,
576 				 struct device_attribute *attr,
577 				 const char *buf, size_t size)
578 {
579 	struct stm_drvdata *drvdata = dev_get_drvdata(dev->parent);
580 	unsigned long val;
581 	int ret = 0;
582 
583 	ret = kstrtoul(buf, 16, &val);
584 	if (ret)
585 		return ret;
586 
587 	spin_lock(&drvdata->spinlock);
588 	drvdata->stmsper = val;
589 
590 	if (coresight_get_mode(drvdata->csdev)) {
591 		CS_UNLOCK(drvdata->base);
592 		writel_relaxed(drvdata->stmsper, drvdata->base + STMSPER);
593 		CS_LOCK(drvdata->base);
594 	}
595 	spin_unlock(&drvdata->spinlock);
596 
597 	return size;
598 }
599 static DEVICE_ATTR_RW(port_enable);
600 
601 static ssize_t traceid_show(struct device *dev,
602 			    struct device_attribute *attr, char *buf)
603 {
604 	unsigned long val;
605 	struct stm_drvdata *drvdata = dev_get_drvdata(dev->parent);
606 
607 	val = drvdata->traceid;
608 	return sprintf(buf, "%#lx\n", val);
609 }
610 static DEVICE_ATTR_RO(traceid);
611 
612 static struct attribute *coresight_stm_attrs[] = {
613 	&dev_attr_hwevent_enable.attr,
614 	&dev_attr_hwevent_select.attr,
615 	&dev_attr_port_enable.attr,
616 	&dev_attr_port_select.attr,
617 	&dev_attr_traceid.attr,
618 	NULL,
619 };
620 
621 static struct attribute *coresight_stm_mgmt_attrs[] = {
622 	coresight_simple_reg32(tcsr, STMTCSR),
623 	coresight_simple_reg32(tsfreqr, STMTSFREQR),
624 	coresight_simple_reg32(syncr, STMSYNCR),
625 	coresight_simple_reg32(sper, STMSPER),
626 	coresight_simple_reg32(spter, STMSPTER),
627 	coresight_simple_reg32(privmaskr, STMPRIVMASKR),
628 	coresight_simple_reg32(spscr, STMSPSCR),
629 	coresight_simple_reg32(spmscr, STMSPMSCR),
630 	coresight_simple_reg32(spfeat1r, STMSPFEAT1R),
631 	coresight_simple_reg32(spfeat2r, STMSPFEAT2R),
632 	coresight_simple_reg32(spfeat3r, STMSPFEAT3R),
633 	coresight_simple_reg32(devid, CORESIGHT_DEVID),
634 	NULL,
635 };
636 
637 static const struct attribute_group coresight_stm_group = {
638 	.attrs = coresight_stm_attrs,
639 };
640 
641 static const struct attribute_group coresight_stm_mgmt_group = {
642 	.attrs = coresight_stm_mgmt_attrs,
643 	.name = "mgmt",
644 };
645 
646 static const struct attribute_group *coresight_stm_groups[] = {
647 	&coresight_stm_group,
648 	&coresight_stm_mgmt_group,
649 	NULL,
650 };
651 
652 #ifdef CONFIG_OF
653 static int of_stm_get_stimulus_area(struct device *dev, struct resource *res)
654 {
655 	const char *name = NULL;
656 	int index = 0, found = 0;
657 	struct device_node *np = dev->of_node;
658 
659 	while (!of_property_read_string_index(np, "reg-names", index, &name)) {
660 		if (strcmp("stm-stimulus-base", name)) {
661 			index++;
662 			continue;
663 		}
664 
665 		/* We have a match and @index is where it's at */
666 		found = 1;
667 		break;
668 	}
669 
670 	if (!found)
671 		return -EINVAL;
672 
673 	return of_address_to_resource(np, index, res);
674 }
675 #else
676 static inline int of_stm_get_stimulus_area(struct device *dev,
677 					   struct resource *res)
678 {
679 	return -ENOENT;
680 }
681 #endif
682 
683 #ifdef CONFIG_ACPI
684 static int acpi_stm_get_stimulus_area(struct device *dev, struct resource *res)
685 {
686 	int rc;
687 	bool found_base = false;
688 	struct resource_entry *rent;
689 	LIST_HEAD(res_list);
690 
691 	struct acpi_device *adev = ACPI_COMPANION(dev);
692 
693 	rc = acpi_dev_get_resources(adev, &res_list, NULL, NULL);
694 	if (rc < 0)
695 		return rc;
696 
697 	/*
698 	 * The stimulus base for STM device must be listed as the second memory
699 	 * resource, followed by the programming base address as described in
700 	 * "Section 2.3 Resources" in ACPI for CoreSightTM 1.0 Platform Design
701 	 * document (DEN0067).
702 	 */
703 	rc = -ENOENT;
704 	list_for_each_entry(rent, &res_list, node) {
705 		if (resource_type(rent->res) != IORESOURCE_MEM)
706 			continue;
707 		if (found_base) {
708 			*res = *rent->res;
709 			rc = 0;
710 			break;
711 		}
712 
713 		found_base = true;
714 	}
715 
716 	acpi_dev_free_resource_list(&res_list);
717 	return rc;
718 }
719 #else
720 static inline int acpi_stm_get_stimulus_area(struct device *dev,
721 					     struct resource *res)
722 {
723 	return -ENOENT;
724 }
725 #endif
726 
727 static int stm_get_stimulus_area(struct device *dev, struct resource *res)
728 {
729 	struct fwnode_handle *fwnode = dev_fwnode(dev);
730 
731 	if (is_of_node(fwnode))
732 		return of_stm_get_stimulus_area(dev, res);
733 	else if (is_acpi_node(fwnode))
734 		return acpi_stm_get_stimulus_area(dev, res);
735 	return -ENOENT;
736 }
737 
738 static u32 stm_fundamental_data_size(struct stm_drvdata *drvdata)
739 {
740 	u32 stmspfeat2r;
741 
742 	if (!IS_ENABLED(CONFIG_64BIT))
743 		return 4;
744 
745 	stmspfeat2r = readl_relaxed(drvdata->base + STMSPFEAT2R);
746 
747 	/*
748 	 * bit[15:12] represents the fundamental data size
749 	 * 0 - 32-bit data
750 	 * 1 - 64-bit data
751 	 */
752 	return BMVAL(stmspfeat2r, 12, 15) ? 8 : 4;
753 }
754 
755 static u32 stm_num_stimulus_port(struct stm_drvdata *drvdata)
756 {
757 	u32 numsp;
758 
759 	numsp = readl_relaxed(drvdata->base + CORESIGHT_DEVID);
760 	/*
761 	 * NUMPS in STMDEVID is 17 bit long and if equal to 0x0,
762 	 * 32 stimulus ports are supported.
763 	 */
764 	numsp &= 0x1ffff;
765 	if (!numsp)
766 		numsp = STM_32_CHANNEL;
767 	return numsp;
768 }
769 
770 static void stm_init_default_data(struct stm_drvdata *drvdata)
771 {
772 	/* Don't use port selection */
773 	drvdata->stmspscr = 0x0;
774 	/*
775 	 * Enable all channel regardless of their number.  When port
776 	 * selection isn't used (see above) STMSPER applies to all
777 	 * 32 channel group available, hence setting all 32 bits to 1
778 	 */
779 	drvdata->stmsper = ~0x0;
780 
781 	/* Set invariant transaction timing on all channels */
782 	bitmap_clear(drvdata->chs.guaranteed, 0, drvdata->numsp);
783 }
784 
785 static void stm_init_generic_data(struct stm_drvdata *drvdata,
786 				  const char *name)
787 {
788 	drvdata->stm.name = name;
789 
790 	/*
791 	 * MasterIDs are assigned at HW design phase. As such the core is
792 	 * using a single master for interaction with this device.
793 	 */
794 	drvdata->stm.sw_start = 1;
795 	drvdata->stm.sw_end = 1;
796 	drvdata->stm.hw_override = true;
797 	drvdata->stm.sw_nchannels = drvdata->numsp;
798 	drvdata->stm.sw_mmiosz = BYTES_PER_CHANNEL;
799 	drvdata->stm.packet = stm_generic_packet;
800 	drvdata->stm.mmio_addr = stm_mmio_addr;
801 	drvdata->stm.link = stm_generic_link;
802 	drvdata->stm.unlink = stm_generic_unlink;
803 	drvdata->stm.set_options = stm_generic_set_options;
804 }
805 
806 static const struct amba_id stm_ids[];
807 
808 static char *stm_csdev_name(struct coresight_device *csdev)
809 {
810 	u32 stm_pid = coresight_get_pid(&csdev->access);
811 	void *uci_data = coresight_get_uci_data_from_amba(stm_ids, stm_pid);
812 
813 	return uci_data ? (char *)uci_data : "STM";
814 }
815 
816 static int __stm_probe(struct device *dev, struct resource *res)
817 {
818 	int ret, trace_id;
819 	void __iomem *base;
820 	struct coresight_platform_data *pdata = NULL;
821 	struct stm_drvdata *drvdata;
822 	struct resource ch_res;
823 	struct coresight_desc desc = { 0 };
824 
825 	desc.name = coresight_alloc_device_name(&stm_devs, dev);
826 	if (!desc.name)
827 		return -ENOMEM;
828 
829 	drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
830 	if (!drvdata)
831 		return -ENOMEM;
832 
833 	drvdata->atclk = devm_clk_get(dev, "atclk"); /* optional */
834 	if (!IS_ERR(drvdata->atclk)) {
835 		ret = clk_prepare_enable(drvdata->atclk);
836 		if (ret)
837 			return ret;
838 	}
839 
840 	drvdata->pclk = coresight_get_enable_apb_pclk(dev);
841 	if (IS_ERR(drvdata->pclk))
842 		return -ENODEV;
843 	dev_set_drvdata(dev, drvdata);
844 
845 	base = devm_ioremap_resource(dev, res);
846 	if (IS_ERR(base))
847 		return PTR_ERR(base);
848 	drvdata->base = base;
849 	desc.access = CSDEV_ACCESS_IOMEM(base);
850 
851 	ret = stm_get_stimulus_area(dev, &ch_res);
852 	if (ret)
853 		return ret;
854 	drvdata->chs.phys = ch_res.start;
855 
856 	base = devm_ioremap_resource(dev, &ch_res);
857 	if (IS_ERR(base))
858 		return PTR_ERR(base);
859 	drvdata->chs.base = base;
860 
861 	drvdata->write_bytes = stm_fundamental_data_size(drvdata);
862 
863 	if (boot_nr_channel)
864 		drvdata->numsp = boot_nr_channel;
865 	else
866 		drvdata->numsp = stm_num_stimulus_port(drvdata);
867 
868 	drvdata->chs.guaranteed = devm_bitmap_zalloc(dev, drvdata->numsp,
869 						     GFP_KERNEL);
870 	if (!drvdata->chs.guaranteed)
871 		return -ENOMEM;
872 
873 	spin_lock_init(&drvdata->spinlock);
874 
875 	stm_init_default_data(drvdata);
876 	stm_init_generic_data(drvdata, desc.name);
877 
878 	if (stm_register_device(dev, &drvdata->stm, THIS_MODULE)) {
879 		dev_info(dev,
880 			 "%s : stm_register_device failed, probing deferred\n",
881 			 desc.name);
882 		return -EPROBE_DEFER;
883 	}
884 
885 	pdata = coresight_get_platform_data(dev);
886 	if (IS_ERR(pdata)) {
887 		ret = PTR_ERR(pdata);
888 		goto stm_unregister;
889 	}
890 	dev->platform_data = pdata;
891 
892 	desc.type = CORESIGHT_DEV_TYPE_SOURCE;
893 	desc.subtype.source_subtype = CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE;
894 	desc.ops = &stm_cs_ops;
895 	desc.pdata = pdata;
896 	desc.dev = dev;
897 	desc.groups = coresight_stm_groups;
898 	drvdata->csdev = coresight_register(&desc);
899 	if (IS_ERR(drvdata->csdev)) {
900 		ret = PTR_ERR(drvdata->csdev);
901 		goto stm_unregister;
902 	}
903 
904 	trace_id = coresight_trace_id_get_system_id();
905 	if (trace_id < 0) {
906 		ret = trace_id;
907 		goto cs_unregister;
908 	}
909 	drvdata->traceid = (u8)trace_id;
910 
911 	dev_info(&drvdata->csdev->dev, "%s initialized\n",
912 		 stm_csdev_name(drvdata->csdev));
913 	return 0;
914 
915 cs_unregister:
916 	coresight_unregister(drvdata->csdev);
917 
918 stm_unregister:
919 	stm_unregister_device(&drvdata->stm);
920 	return ret;
921 }
922 
923 static int stm_probe(struct amba_device *adev, const struct amba_id *id)
924 {
925 	int ret;
926 
927 	ret = __stm_probe(&adev->dev, &adev->res);
928 	if (!ret)
929 		pm_runtime_put(&adev->dev);
930 
931 	return ret;
932 }
933 
934 static void __stm_remove(struct device *dev)
935 {
936 	struct stm_drvdata *drvdata = dev_get_drvdata(dev);
937 
938 	coresight_trace_id_put_system_id(drvdata->traceid);
939 	coresight_unregister(drvdata->csdev);
940 
941 	stm_unregister_device(&drvdata->stm);
942 }
943 
944 static void stm_remove(struct amba_device *adev)
945 {
946 	__stm_remove(&adev->dev);
947 }
948 
949 #ifdef CONFIG_PM
950 static int stm_runtime_suspend(struct device *dev)
951 {
952 	struct stm_drvdata *drvdata = dev_get_drvdata(dev);
953 
954 	if (drvdata && !IS_ERR(drvdata->atclk))
955 		clk_disable_unprepare(drvdata->atclk);
956 
957 	if (drvdata && !IS_ERR_OR_NULL(drvdata->pclk))
958 		clk_disable_unprepare(drvdata->pclk);
959 	return 0;
960 }
961 
962 static int stm_runtime_resume(struct device *dev)
963 {
964 	struct stm_drvdata *drvdata = dev_get_drvdata(dev);
965 
966 	if (drvdata && !IS_ERR(drvdata->atclk))
967 		clk_prepare_enable(drvdata->atclk);
968 
969 	if (drvdata && !IS_ERR_OR_NULL(drvdata->pclk))
970 		clk_prepare_enable(drvdata->pclk);
971 	return 0;
972 }
973 #endif
974 
975 static const struct dev_pm_ops stm_dev_pm_ops = {
976 	SET_RUNTIME_PM_OPS(stm_runtime_suspend, stm_runtime_resume, NULL)
977 };
978 
979 static const struct amba_id stm_ids[] = {
980 	CS_AMBA_ID_DATA(0x000bb962, "STM32"),
981 	CS_AMBA_ID_DATA(0x000bb963, "STM500"),
982 	{ 0, 0, NULL },
983 };
984 
985 MODULE_DEVICE_TABLE(amba, stm_ids);
986 
987 static struct amba_driver stm_driver = {
988 	.drv = {
989 		.name   = "coresight-stm",
990 		.pm	= &stm_dev_pm_ops,
991 		.suppress_bind_attrs = true,
992 	},
993 	.probe          = stm_probe,
994 	.remove         = stm_remove,
995 	.id_table	= stm_ids,
996 };
997 
998 static int stm_platform_probe(struct platform_device *pdev)
999 {
1000 	struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1001 	int ret = 0;
1002 
1003 	pm_runtime_get_noresume(&pdev->dev);
1004 	pm_runtime_set_active(&pdev->dev);
1005 	pm_runtime_enable(&pdev->dev);
1006 
1007 	ret = __stm_probe(&pdev->dev, res);
1008 	pm_runtime_put(&pdev->dev);
1009 	if (ret)
1010 		pm_runtime_disable(&pdev->dev);
1011 
1012 	return ret;
1013 }
1014 
1015 static void stm_platform_remove(struct platform_device *pdev)
1016 {
1017 	struct stm_drvdata *drvdata = dev_get_drvdata(&pdev->dev);
1018 
1019 	if (WARN_ON(!drvdata))
1020 		return;
1021 
1022 	__stm_remove(&pdev->dev);
1023 	pm_runtime_disable(&pdev->dev);
1024 	if (!IS_ERR_OR_NULL(drvdata->pclk))
1025 		clk_put(drvdata->pclk);
1026 }
1027 
1028 #ifdef CONFIG_ACPI
1029 static const struct acpi_device_id stm_acpi_ids[] = {
1030 	{"ARMHC502", 0, 0, 0}, /* ARM CoreSight STM */
1031 	{},
1032 };
1033 MODULE_DEVICE_TABLE(acpi, stm_acpi_ids);
1034 #endif
1035 
1036 static struct platform_driver stm_platform_driver = {
1037 	.probe	= stm_platform_probe,
1038 	.remove_new = stm_platform_remove,
1039 	.driver	= {
1040 		.name			= "coresight-stm-platform",
1041 		.acpi_match_table	= ACPI_PTR(stm_acpi_ids),
1042 		.suppress_bind_attrs	= true,
1043 		.pm			= &stm_dev_pm_ops,
1044 	},
1045 };
1046 
1047 static int __init stm_init(void)
1048 {
1049 	return coresight_init_driver("stm", &stm_driver, &stm_platform_driver);
1050 }
1051 
1052 static void __exit stm_exit(void)
1053 {
1054 	coresight_remove_driver(&stm_driver, &stm_platform_driver);
1055 }
1056 module_init(stm_init);
1057 module_exit(stm_exit);
1058 
1059 MODULE_AUTHOR("Pratik Patel <pratikp@codeaurora.org>");
1060 MODULE_DESCRIPTION("Arm CoreSight System Trace Macrocell driver");
1061 MODULE_LICENSE("GPL v2");
1062