1 /* Copyright (c) 2011-2012, The Linux Foundation. All rights reserved.
2  *
3  * Description: CoreSight Embedded Trace Buffer driver
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License version 2 and
7  * only version 2 as published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  */
14 
15 #include <asm/local.h>
16 #include <linux/kernel.h>
17 #include <linux/init.h>
18 #include <linux/types.h>
19 #include <linux/device.h>
20 #include <linux/io.h>
21 #include <linux/err.h>
22 #include <linux/fs.h>
23 #include <linux/miscdevice.h>
24 #include <linux/uaccess.h>
25 #include <linux/slab.h>
26 #include <linux/spinlock.h>
27 #include <linux/pm_runtime.h>
28 #include <linux/seq_file.h>
29 #include <linux/coresight.h>
30 #include <linux/amba/bus.h>
31 #include <linux/clk.h>
32 #include <linux/circ_buf.h>
33 #include <linux/mm.h>
34 #include <linux/perf_event.h>
35 
36 
37 #include "coresight-priv.h"
38 
39 #define ETB_RAM_DEPTH_REG	0x004
40 #define ETB_STATUS_REG		0x00c
41 #define ETB_RAM_READ_DATA_REG	0x010
42 #define ETB_RAM_READ_POINTER	0x014
43 #define ETB_RAM_WRITE_POINTER	0x018
44 #define ETB_TRG			0x01c
45 #define ETB_CTL_REG		0x020
46 #define ETB_RWD_REG		0x024
47 #define ETB_FFSR		0x300
48 #define ETB_FFCR		0x304
49 #define ETB_ITMISCOP0		0xee0
50 #define ETB_ITTRFLINACK		0xee4
51 #define ETB_ITTRFLIN		0xee8
52 #define ETB_ITATBDATA0		0xeeC
53 #define ETB_ITATBCTR2		0xef0
54 #define ETB_ITATBCTR1		0xef4
55 #define ETB_ITATBCTR0		0xef8
56 
57 /* register description */
58 /* STS - 0x00C */
59 #define ETB_STATUS_RAM_FULL	BIT(0)
60 /* CTL - 0x020 */
61 #define ETB_CTL_CAPT_EN		BIT(0)
62 /* FFCR - 0x304 */
63 #define ETB_FFCR_EN_FTC		BIT(0)
64 #define ETB_FFCR_FON_MAN	BIT(6)
65 #define ETB_FFCR_STOP_FI	BIT(12)
66 #define ETB_FFCR_STOP_TRIGGER	BIT(13)
67 
68 #define ETB_FFCR_BIT		6
69 #define ETB_FFSR_BIT		1
70 #define ETB_FRAME_SIZE_WORDS	4
71 
72 /**
73  * struct etb_drvdata - specifics associated to an ETB component
74  * @base:	memory mapped base address for this component.
75  * @dev:	the device entity associated to this component.
76  * @atclk:	optional clock for the core parts of the ETB.
77  * @csdev:	component vitals needed by the framework.
78  * @miscdev:	specifics to handle "/dev/xyz.etb" entry.
79  * @spinlock:	only one at a time pls.
80  * @reading:	synchronise user space access to etb buffer.
81  * @mode:	this ETB is being used.
82  * @buf:	area of memory where ETB buffer content gets sent.
83  * @buffer_depth: size of @buf.
84  * @trigger_cntr: amount of words to store after a trigger.
85  */
86 struct etb_drvdata {
87 	void __iomem		*base;
88 	struct device		*dev;
89 	struct clk		*atclk;
90 	struct coresight_device	*csdev;
91 	struct miscdevice	miscdev;
92 	spinlock_t		spinlock;
93 	local_t			reading;
94 	local_t			mode;
95 	u8			*buf;
96 	u32			buffer_depth;
97 	u32			trigger_cntr;
98 };
99 
100 static unsigned int etb_get_buffer_depth(struct etb_drvdata *drvdata)
101 {
102 	u32 depth = 0;
103 
104 	pm_runtime_get_sync(drvdata->dev);
105 
106 	/* RO registers don't need locking */
107 	depth = readl_relaxed(drvdata->base + ETB_RAM_DEPTH_REG);
108 
109 	pm_runtime_put(drvdata->dev);
110 	return depth;
111 }
112 
113 static void etb_enable_hw(struct etb_drvdata *drvdata)
114 {
115 	int i;
116 	u32 depth;
117 
118 	CS_UNLOCK(drvdata->base);
119 
120 	depth = drvdata->buffer_depth;
121 	/* reset write RAM pointer address */
122 	writel_relaxed(0x0, drvdata->base + ETB_RAM_WRITE_POINTER);
123 	/* clear entire RAM buffer */
124 	for (i = 0; i < depth; i++)
125 		writel_relaxed(0x0, drvdata->base + ETB_RWD_REG);
126 
127 	/* reset write RAM pointer address */
128 	writel_relaxed(0x0, drvdata->base + ETB_RAM_WRITE_POINTER);
129 	/* reset read RAM pointer address */
130 	writel_relaxed(0x0, drvdata->base + ETB_RAM_READ_POINTER);
131 
132 	writel_relaxed(drvdata->trigger_cntr, drvdata->base + ETB_TRG);
133 	writel_relaxed(ETB_FFCR_EN_FTC | ETB_FFCR_STOP_TRIGGER,
134 		       drvdata->base + ETB_FFCR);
135 	/* ETB trace capture enable */
136 	writel_relaxed(ETB_CTL_CAPT_EN, drvdata->base + ETB_CTL_REG);
137 
138 	CS_LOCK(drvdata->base);
139 }
140 
141 static int etb_enable(struct coresight_device *csdev, u32 mode)
142 {
143 	u32 val;
144 	unsigned long flags;
145 	struct etb_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
146 
147 	val = local_cmpxchg(&drvdata->mode,
148 			    CS_MODE_DISABLED, mode);
149 	/*
150 	 * When accessing from Perf, a HW buffer can be handled
151 	 * by a single trace entity.  In sysFS mode many tracers
152 	 * can be logging to the same HW buffer.
153 	 */
154 	if (val == CS_MODE_PERF)
155 		return -EBUSY;
156 
157 	/* Nothing to do, the tracer is already enabled. */
158 	if (val == CS_MODE_SYSFS)
159 		goto out;
160 
161 	spin_lock_irqsave(&drvdata->spinlock, flags);
162 	etb_enable_hw(drvdata);
163 	spin_unlock_irqrestore(&drvdata->spinlock, flags);
164 
165 out:
166 	dev_info(drvdata->dev, "ETB enabled\n");
167 	return 0;
168 }
169 
170 static void etb_disable_hw(struct etb_drvdata *drvdata)
171 {
172 	u32 ffcr;
173 
174 	CS_UNLOCK(drvdata->base);
175 
176 	ffcr = readl_relaxed(drvdata->base + ETB_FFCR);
177 	/* stop formatter when a stop has completed */
178 	ffcr |= ETB_FFCR_STOP_FI;
179 	writel_relaxed(ffcr, drvdata->base + ETB_FFCR);
180 	/* manually generate a flush of the system */
181 	ffcr |= ETB_FFCR_FON_MAN;
182 	writel_relaxed(ffcr, drvdata->base + ETB_FFCR);
183 
184 	if (coresight_timeout(drvdata->base, ETB_FFCR, ETB_FFCR_BIT, 0)) {
185 		dev_err(drvdata->dev,
186 		"timeout while waiting for completion of Manual Flush\n");
187 	}
188 
189 	/* disable trace capture */
190 	writel_relaxed(0x0, drvdata->base + ETB_CTL_REG);
191 
192 	if (coresight_timeout(drvdata->base, ETB_FFSR, ETB_FFSR_BIT, 1)) {
193 		dev_err(drvdata->dev,
194 			"timeout while waiting for Formatter to Stop\n");
195 	}
196 
197 	CS_LOCK(drvdata->base);
198 }
199 
200 static void etb_dump_hw(struct etb_drvdata *drvdata)
201 {
202 	bool lost = false;
203 	int i;
204 	u8 *buf_ptr;
205 	const u32 *barrier;
206 	u32 read_data, depth;
207 	u32 read_ptr, write_ptr;
208 	u32 frame_off, frame_endoff;
209 
210 	CS_UNLOCK(drvdata->base);
211 
212 	read_ptr = readl_relaxed(drvdata->base + ETB_RAM_READ_POINTER);
213 	write_ptr = readl_relaxed(drvdata->base + ETB_RAM_WRITE_POINTER);
214 
215 	frame_off = write_ptr % ETB_FRAME_SIZE_WORDS;
216 	frame_endoff = ETB_FRAME_SIZE_WORDS - frame_off;
217 	if (frame_off) {
218 		dev_err(drvdata->dev,
219 			"write_ptr: %lu not aligned to formatter frame size\n",
220 			(unsigned long)write_ptr);
221 		dev_err(drvdata->dev, "frameoff: %lu, frame_endoff: %lu\n",
222 			(unsigned long)frame_off, (unsigned long)frame_endoff);
223 		write_ptr += frame_endoff;
224 	}
225 
226 	if ((readl_relaxed(drvdata->base + ETB_STATUS_REG)
227 		      & ETB_STATUS_RAM_FULL) == 0) {
228 		writel_relaxed(0x0, drvdata->base + ETB_RAM_READ_POINTER);
229 	} else {
230 		writel_relaxed(write_ptr, drvdata->base + ETB_RAM_READ_POINTER);
231 		lost = true;
232 	}
233 
234 	depth = drvdata->buffer_depth;
235 	buf_ptr = drvdata->buf;
236 	barrier = barrier_pkt;
237 	for (i = 0; i < depth; i++) {
238 		read_data = readl_relaxed(drvdata->base +
239 					  ETB_RAM_READ_DATA_REG);
240 		if (lost && *barrier) {
241 			read_data = *barrier;
242 			barrier++;
243 		}
244 
245 		*(u32 *)buf_ptr = read_data;
246 		buf_ptr += 4;
247 	}
248 
249 	if (frame_off) {
250 		buf_ptr -= (frame_endoff * 4);
251 		for (i = 0; i < frame_endoff; i++) {
252 			*buf_ptr++ = 0x0;
253 			*buf_ptr++ = 0x0;
254 			*buf_ptr++ = 0x0;
255 			*buf_ptr++ = 0x0;
256 		}
257 	}
258 
259 	writel_relaxed(read_ptr, drvdata->base + ETB_RAM_READ_POINTER);
260 
261 	CS_LOCK(drvdata->base);
262 }
263 
264 static void etb_disable(struct coresight_device *csdev)
265 {
266 	struct etb_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
267 	unsigned long flags;
268 
269 	spin_lock_irqsave(&drvdata->spinlock, flags);
270 	etb_disable_hw(drvdata);
271 	etb_dump_hw(drvdata);
272 	spin_unlock_irqrestore(&drvdata->spinlock, flags);
273 
274 	local_set(&drvdata->mode, CS_MODE_DISABLED);
275 
276 	dev_info(drvdata->dev, "ETB disabled\n");
277 }
278 
279 static void *etb_alloc_buffer(struct coresight_device *csdev, int cpu,
280 			      void **pages, int nr_pages, bool overwrite)
281 {
282 	int node;
283 	struct cs_buffers *buf;
284 
285 	if (cpu == -1)
286 		cpu = smp_processor_id();
287 	node = cpu_to_node(cpu);
288 
289 	buf = kzalloc_node(sizeof(struct cs_buffers), GFP_KERNEL, node);
290 	if (!buf)
291 		return NULL;
292 
293 	buf->snapshot = overwrite;
294 	buf->nr_pages = nr_pages;
295 	buf->data_pages = pages;
296 
297 	return buf;
298 }
299 
300 static void etb_free_buffer(void *config)
301 {
302 	struct cs_buffers *buf = config;
303 
304 	kfree(buf);
305 }
306 
307 static int etb_set_buffer(struct coresight_device *csdev,
308 			  struct perf_output_handle *handle,
309 			  void *sink_config)
310 {
311 	int ret = 0;
312 	unsigned long head;
313 	struct cs_buffers *buf = sink_config;
314 
315 	/* wrap head around to the amount of space we have */
316 	head = handle->head & ((buf->nr_pages << PAGE_SHIFT) - 1);
317 
318 	/* find the page to write to */
319 	buf->cur = head / PAGE_SIZE;
320 
321 	/* and offset within that page */
322 	buf->offset = head % PAGE_SIZE;
323 
324 	local_set(&buf->data_size, 0);
325 
326 	return ret;
327 }
328 
329 static unsigned long etb_reset_buffer(struct coresight_device *csdev,
330 				      struct perf_output_handle *handle,
331 				      void *sink_config)
332 {
333 	unsigned long size = 0;
334 	struct cs_buffers *buf = sink_config;
335 
336 	if (buf) {
337 		/*
338 		 * In snapshot mode ->data_size holds the new address of the
339 		 * ring buffer's head.  The size itself is the whole address
340 		 * range since we want the latest information.
341 		 */
342 		if (buf->snapshot)
343 			handle->head = local_xchg(&buf->data_size,
344 						  buf->nr_pages << PAGE_SHIFT);
345 
346 		/*
347 		 * Tell the tracer PMU how much we got in this run and if
348 		 * something went wrong along the way.  Nobody else can use
349 		 * this cs_buffers instance until we are done.  As such
350 		 * resetting parameters here and squaring off with the ring
351 		 * buffer API in the tracer PMU is fine.
352 		 */
353 		size = local_xchg(&buf->data_size, 0);
354 	}
355 
356 	return size;
357 }
358 
359 static void etb_update_buffer(struct coresight_device *csdev,
360 			      struct perf_output_handle *handle,
361 			      void *sink_config)
362 {
363 	bool lost = false;
364 	int i, cur;
365 	u8 *buf_ptr;
366 	const u32 *barrier;
367 	u32 read_ptr, write_ptr, capacity;
368 	u32 status, read_data, to_read;
369 	unsigned long offset;
370 	struct cs_buffers *buf = sink_config;
371 	struct etb_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
372 
373 	if (!buf)
374 		return;
375 
376 	capacity = drvdata->buffer_depth * ETB_FRAME_SIZE_WORDS;
377 
378 	etb_disable_hw(drvdata);
379 	CS_UNLOCK(drvdata->base);
380 
381 	/* unit is in words, not bytes */
382 	read_ptr = readl_relaxed(drvdata->base + ETB_RAM_READ_POINTER);
383 	write_ptr = readl_relaxed(drvdata->base + ETB_RAM_WRITE_POINTER);
384 
385 	/*
386 	 * Entries should be aligned to the frame size.  If they are not
387 	 * go back to the last alignment point to give decoding tools a
388 	 * chance to fix things.
389 	 */
390 	if (write_ptr % ETB_FRAME_SIZE_WORDS) {
391 		dev_err(drvdata->dev,
392 			"write_ptr: %lu not aligned to formatter frame size\n",
393 			(unsigned long)write_ptr);
394 
395 		write_ptr &= ~(ETB_FRAME_SIZE_WORDS - 1);
396 		lost = true;
397 	}
398 
399 	/*
400 	 * Get a hold of the status register and see if a wrap around
401 	 * has occurred.  If so adjust things accordingly.  Otherwise
402 	 * start at the beginning and go until the write pointer has
403 	 * been reached.
404 	 */
405 	status = readl_relaxed(drvdata->base + ETB_STATUS_REG);
406 	if (status & ETB_STATUS_RAM_FULL) {
407 		lost = true;
408 		to_read = capacity;
409 		read_ptr = write_ptr;
410 	} else {
411 		to_read = CIRC_CNT(write_ptr, read_ptr, drvdata->buffer_depth);
412 		to_read *= ETB_FRAME_SIZE_WORDS;
413 	}
414 
415 	/*
416 	 * Make sure we don't overwrite data that hasn't been consumed yet.
417 	 * It is entirely possible that the HW buffer has more data than the
418 	 * ring buffer can currently handle.  If so adjust the start address
419 	 * to take only the last traces.
420 	 *
421 	 * In snapshot mode we are looking to get the latest traces only and as
422 	 * such, we don't care about not overwriting data that hasn't been
423 	 * processed by user space.
424 	 */
425 	if (!buf->snapshot && to_read > handle->size) {
426 		u32 mask = ~(ETB_FRAME_SIZE_WORDS - 1);
427 
428 		/* The new read pointer must be frame size aligned */
429 		to_read = handle->size & mask;
430 		/*
431 		 * Move the RAM read pointer up, keeping in mind that
432 		 * everything is in frame size units.
433 		 */
434 		read_ptr = (write_ptr + drvdata->buffer_depth) -
435 					to_read / ETB_FRAME_SIZE_WORDS;
436 		/* Wrap around if need be*/
437 		if (read_ptr > (drvdata->buffer_depth - 1))
438 			read_ptr -= drvdata->buffer_depth;
439 		/* let the decoder know we've skipped ahead */
440 		lost = true;
441 	}
442 
443 	if (lost)
444 		perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED);
445 
446 	/* finally tell HW where we want to start reading from */
447 	writel_relaxed(read_ptr, drvdata->base + ETB_RAM_READ_POINTER);
448 
449 	cur = buf->cur;
450 	offset = buf->offset;
451 	barrier = barrier_pkt;
452 
453 	for (i = 0; i < to_read; i += 4) {
454 		buf_ptr = buf->data_pages[cur] + offset;
455 		read_data = readl_relaxed(drvdata->base +
456 					  ETB_RAM_READ_DATA_REG);
457 		if (lost && *barrier) {
458 			read_data = *barrier;
459 			barrier++;
460 		}
461 
462 		*(u32 *)buf_ptr = read_data;
463 		buf_ptr += 4;
464 
465 		offset += 4;
466 		if (offset >= PAGE_SIZE) {
467 			offset = 0;
468 			cur++;
469 			/* wrap around at the end of the buffer */
470 			cur &= buf->nr_pages - 1;
471 		}
472 	}
473 
474 	/* reset ETB buffer for next run */
475 	writel_relaxed(0x0, drvdata->base + ETB_RAM_READ_POINTER);
476 	writel_relaxed(0x0, drvdata->base + ETB_RAM_WRITE_POINTER);
477 
478 	/*
479 	 * In snapshot mode all we have to do is communicate to
480 	 * perf_aux_output_end() the address of the current head.  In full
481 	 * trace mode the same function expects a size to move rb->aux_head
482 	 * forward.
483 	 */
484 	if (buf->snapshot)
485 		local_set(&buf->data_size, (cur * PAGE_SIZE) + offset);
486 	else
487 		local_add(to_read, &buf->data_size);
488 
489 	etb_enable_hw(drvdata);
490 	CS_LOCK(drvdata->base);
491 }
492 
493 static const struct coresight_ops_sink etb_sink_ops = {
494 	.enable		= etb_enable,
495 	.disable	= etb_disable,
496 	.alloc_buffer	= etb_alloc_buffer,
497 	.free_buffer	= etb_free_buffer,
498 	.set_buffer	= etb_set_buffer,
499 	.reset_buffer	= etb_reset_buffer,
500 	.update_buffer	= etb_update_buffer,
501 };
502 
503 static const struct coresight_ops etb_cs_ops = {
504 	.sink_ops	= &etb_sink_ops,
505 };
506 
507 static void etb_dump(struct etb_drvdata *drvdata)
508 {
509 	unsigned long flags;
510 
511 	spin_lock_irqsave(&drvdata->spinlock, flags);
512 	if (local_read(&drvdata->mode) == CS_MODE_SYSFS) {
513 		etb_disable_hw(drvdata);
514 		etb_dump_hw(drvdata);
515 		etb_enable_hw(drvdata);
516 	}
517 	spin_unlock_irqrestore(&drvdata->spinlock, flags);
518 
519 	dev_info(drvdata->dev, "ETB dumped\n");
520 }
521 
522 static int etb_open(struct inode *inode, struct file *file)
523 {
524 	struct etb_drvdata *drvdata = container_of(file->private_data,
525 						   struct etb_drvdata, miscdev);
526 
527 	if (local_cmpxchg(&drvdata->reading, 0, 1))
528 		return -EBUSY;
529 
530 	dev_dbg(drvdata->dev, "%s: successfully opened\n", __func__);
531 	return 0;
532 }
533 
534 static ssize_t etb_read(struct file *file, char __user *data,
535 				size_t len, loff_t *ppos)
536 {
537 	u32 depth;
538 	struct etb_drvdata *drvdata = container_of(file->private_data,
539 						   struct etb_drvdata, miscdev);
540 
541 	etb_dump(drvdata);
542 
543 	depth = drvdata->buffer_depth;
544 	if (*ppos + len > depth * 4)
545 		len = depth * 4 - *ppos;
546 
547 	if (copy_to_user(data, drvdata->buf + *ppos, len)) {
548 		dev_dbg(drvdata->dev, "%s: copy_to_user failed\n", __func__);
549 		return -EFAULT;
550 	}
551 
552 	*ppos += len;
553 
554 	dev_dbg(drvdata->dev, "%s: %zu bytes copied, %d bytes left\n",
555 		__func__, len, (int)(depth * 4 - *ppos));
556 	return len;
557 }
558 
559 static int etb_release(struct inode *inode, struct file *file)
560 {
561 	struct etb_drvdata *drvdata = container_of(file->private_data,
562 						   struct etb_drvdata, miscdev);
563 	local_set(&drvdata->reading, 0);
564 
565 	dev_dbg(drvdata->dev, "%s: released\n", __func__);
566 	return 0;
567 }
568 
569 static const struct file_operations etb_fops = {
570 	.owner		= THIS_MODULE,
571 	.open		= etb_open,
572 	.read		= etb_read,
573 	.release	= etb_release,
574 	.llseek		= no_llseek,
575 };
576 
577 #define coresight_etb10_reg(name, offset)		\
578 	coresight_simple_reg32(struct etb_drvdata, name, offset)
579 
580 coresight_etb10_reg(rdp, ETB_RAM_DEPTH_REG);
581 coresight_etb10_reg(sts, ETB_STATUS_REG);
582 coresight_etb10_reg(rrp, ETB_RAM_READ_POINTER);
583 coresight_etb10_reg(rwp, ETB_RAM_WRITE_POINTER);
584 coresight_etb10_reg(trg, ETB_TRG);
585 coresight_etb10_reg(ctl, ETB_CTL_REG);
586 coresight_etb10_reg(ffsr, ETB_FFSR);
587 coresight_etb10_reg(ffcr, ETB_FFCR);
588 
589 static struct attribute *coresight_etb_mgmt_attrs[] = {
590 	&dev_attr_rdp.attr,
591 	&dev_attr_sts.attr,
592 	&dev_attr_rrp.attr,
593 	&dev_attr_rwp.attr,
594 	&dev_attr_trg.attr,
595 	&dev_attr_ctl.attr,
596 	&dev_attr_ffsr.attr,
597 	&dev_attr_ffcr.attr,
598 	NULL,
599 };
600 
601 static ssize_t trigger_cntr_show(struct device *dev,
602 			    struct device_attribute *attr, char *buf)
603 {
604 	struct etb_drvdata *drvdata = dev_get_drvdata(dev->parent);
605 	unsigned long val = drvdata->trigger_cntr;
606 
607 	return sprintf(buf, "%#lx\n", val);
608 }
609 
610 static ssize_t trigger_cntr_store(struct device *dev,
611 			     struct device_attribute *attr,
612 			     const char *buf, size_t size)
613 {
614 	int ret;
615 	unsigned long val;
616 	struct etb_drvdata *drvdata = dev_get_drvdata(dev->parent);
617 
618 	ret = kstrtoul(buf, 16, &val);
619 	if (ret)
620 		return ret;
621 
622 	drvdata->trigger_cntr = val;
623 	return size;
624 }
625 static DEVICE_ATTR_RW(trigger_cntr);
626 
627 static struct attribute *coresight_etb_attrs[] = {
628 	&dev_attr_trigger_cntr.attr,
629 	NULL,
630 };
631 
632 static const struct attribute_group coresight_etb_group = {
633 	.attrs = coresight_etb_attrs,
634 };
635 
636 static const struct attribute_group coresight_etb_mgmt_group = {
637 	.attrs = coresight_etb_mgmt_attrs,
638 	.name = "mgmt",
639 };
640 
641 const struct attribute_group *coresight_etb_groups[] = {
642 	&coresight_etb_group,
643 	&coresight_etb_mgmt_group,
644 	NULL,
645 };
646 
647 static int etb_probe(struct amba_device *adev, const struct amba_id *id)
648 {
649 	int ret;
650 	void __iomem *base;
651 	struct device *dev = &adev->dev;
652 	struct coresight_platform_data *pdata = NULL;
653 	struct etb_drvdata *drvdata;
654 	struct resource *res = &adev->res;
655 	struct coresight_desc desc = { 0 };
656 	struct device_node *np = adev->dev.of_node;
657 
658 	if (np) {
659 		pdata = of_get_coresight_platform_data(dev, np);
660 		if (IS_ERR(pdata))
661 			return PTR_ERR(pdata);
662 		adev->dev.platform_data = pdata;
663 	}
664 
665 	drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
666 	if (!drvdata)
667 		return -ENOMEM;
668 
669 	drvdata->dev = &adev->dev;
670 	drvdata->atclk = devm_clk_get(&adev->dev, "atclk"); /* optional */
671 	if (!IS_ERR(drvdata->atclk)) {
672 		ret = clk_prepare_enable(drvdata->atclk);
673 		if (ret)
674 			return ret;
675 	}
676 	dev_set_drvdata(dev, drvdata);
677 
678 	/* validity for the resource is already checked by the AMBA core */
679 	base = devm_ioremap_resource(dev, res);
680 	if (IS_ERR(base))
681 		return PTR_ERR(base);
682 
683 	drvdata->base = base;
684 
685 	spin_lock_init(&drvdata->spinlock);
686 
687 	drvdata->buffer_depth = etb_get_buffer_depth(drvdata);
688 	pm_runtime_put(&adev->dev);
689 
690 	if (drvdata->buffer_depth & 0x80000000)
691 		return -EINVAL;
692 
693 	drvdata->buf = devm_kzalloc(dev,
694 				    drvdata->buffer_depth * 4, GFP_KERNEL);
695 	if (!drvdata->buf)
696 		return -ENOMEM;
697 
698 	desc.type = CORESIGHT_DEV_TYPE_SINK;
699 	desc.subtype.sink_subtype = CORESIGHT_DEV_SUBTYPE_SINK_BUFFER;
700 	desc.ops = &etb_cs_ops;
701 	desc.pdata = pdata;
702 	desc.dev = dev;
703 	desc.groups = coresight_etb_groups;
704 	drvdata->csdev = coresight_register(&desc);
705 	if (IS_ERR(drvdata->csdev))
706 		return PTR_ERR(drvdata->csdev);
707 
708 	drvdata->miscdev.name = pdata->name;
709 	drvdata->miscdev.minor = MISC_DYNAMIC_MINOR;
710 	drvdata->miscdev.fops = &etb_fops;
711 	ret = misc_register(&drvdata->miscdev);
712 	if (ret)
713 		goto err_misc_register;
714 
715 	return 0;
716 
717 err_misc_register:
718 	coresight_unregister(drvdata->csdev);
719 	return ret;
720 }
721 
722 #ifdef CONFIG_PM
723 static int etb_runtime_suspend(struct device *dev)
724 {
725 	struct etb_drvdata *drvdata = dev_get_drvdata(dev);
726 
727 	if (drvdata && !IS_ERR(drvdata->atclk))
728 		clk_disable_unprepare(drvdata->atclk);
729 
730 	return 0;
731 }
732 
733 static int etb_runtime_resume(struct device *dev)
734 {
735 	struct etb_drvdata *drvdata = dev_get_drvdata(dev);
736 
737 	if (drvdata && !IS_ERR(drvdata->atclk))
738 		clk_prepare_enable(drvdata->atclk);
739 
740 	return 0;
741 }
742 #endif
743 
744 static const struct dev_pm_ops etb_dev_pm_ops = {
745 	SET_RUNTIME_PM_OPS(etb_runtime_suspend, etb_runtime_resume, NULL)
746 };
747 
748 static const struct amba_id etb_ids[] = {
749 	{
750 		.id	= 0x000bb907,
751 		.mask	= 0x000fffff,
752 	},
753 	{ 0, 0},
754 };
755 
756 static struct amba_driver etb_driver = {
757 	.drv = {
758 		.name	= "coresight-etb10",
759 		.owner	= THIS_MODULE,
760 		.pm	= &etb_dev_pm_ops,
761 		.suppress_bind_attrs = true,
762 
763 	},
764 	.probe		= etb_probe,
765 	.id_table	= etb_ids,
766 };
767 builtin_amba_driver(etb_driver);
768