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