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  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#include <asm/local.h>
 37
 38#include "coresight-priv.h"
 39
 40#define ETB_RAM_DEPTH_REG	0x004
 41#define ETB_STATUS_REG		0x00c
 42#define ETB_RAM_READ_DATA_REG	0x010
 43#define ETB_RAM_READ_POINTER	0x014
 44#define ETB_RAM_WRITE_POINTER	0x018
 45#define ETB_TRG			0x01c
 46#define ETB_CTL_REG		0x020
 47#define ETB_RWD_REG		0x024
 48#define ETB_FFSR		0x300
 49#define ETB_FFCR		0x304
 50#define ETB_ITMISCOP0		0xee0
 51#define ETB_ITTRFLINACK		0xee4
 52#define ETB_ITTRFLIN		0xee8
 53#define ETB_ITATBDATA0		0xeeC
 54#define ETB_ITATBCTR2		0xef0
 55#define ETB_ITATBCTR1		0xef4
 56#define ETB_ITATBCTR0		0xef8
 57
 58/* register description */
 59/* STS - 0x00C */
 60#define ETB_STATUS_RAM_FULL	BIT(0)
 61/* CTL - 0x020 */
 62#define ETB_CTL_CAPT_EN		BIT(0)
 63/* FFCR - 0x304 */
 64#define ETB_FFCR_EN_FTC		BIT(0)
 65#define ETB_FFCR_FON_MAN	BIT(6)
 66#define ETB_FFCR_STOP_FI	BIT(12)
 67#define ETB_FFCR_STOP_TRIGGER	BIT(13)
 68
 69#define ETB_FFCR_BIT		6
 70#define ETB_FFSR_BIT		1
 71#define ETB_FRAME_SIZE_WORDS	4
 72
 73/**
 74 * struct cs_buffer - keep track of a recording session' specifics
 75 * @cur:	index of the current buffer
 76 * @nr_pages:	max number of pages granted to us
 77 * @offset:	offset within the current buffer
 78 * @data_size:	how much we collected in this run
 79 * @lost:	other than zero if we had a HW buffer wrap around
 80 * @snapshot:	is this run in snapshot mode
 81 * @data_pages:	a handle the ring buffer
 82 */
 83struct cs_buffers {
 84	unsigned int		cur;
 85	unsigned int		nr_pages;
 86	unsigned long		offset;
 87	local_t			data_size;
 88	local_t			lost;
 89	bool			snapshot;
 90	void			**data_pages;
 91};
 92
 93/**
 94 * struct etb_drvdata - specifics associated to an ETB component
 95 * @base:	memory mapped base address for this component.
 96 * @dev:	the device entity associated to this component.
 97 * @atclk:	optional clock for the core parts of the ETB.
 98 * @csdev:	component vitals needed by the framework.
 99 * @miscdev:	specifics to handle "/dev/xyz.etb" entry.
100 * @spinlock:	only one at a time pls.
101 * @reading:	synchronise user space access to etb buffer.
102 * @mode:	this ETB is being used.
103 * @buf:	area of memory where ETB buffer content gets sent.
104 * @buffer_depth: size of @buf.
105 * @trigger_cntr: amount of words to store after a trigger.
106 */
107struct etb_drvdata {
108	void __iomem		*base;
109	struct device		*dev;
110	struct clk		*atclk;
111	struct coresight_device	*csdev;
112	struct miscdevice	miscdev;
113	spinlock_t		spinlock;
114	local_t			reading;
115	local_t			mode;
116	u8			*buf;
117	u32			buffer_depth;
118	u32			trigger_cntr;
119};
120
121static unsigned int etb_get_buffer_depth(struct etb_drvdata *drvdata)
122{
123	u32 depth = 0;
124
125	pm_runtime_get_sync(drvdata->dev);
126
127	/* RO registers don't need locking */
128	depth = readl_relaxed(drvdata->base + ETB_RAM_DEPTH_REG);
129
130	pm_runtime_put(drvdata->dev);
131	return depth;
132}
133
134static void etb_enable_hw(struct etb_drvdata *drvdata)
135{
136	int i;
137	u32 depth;
138
139	CS_UNLOCK(drvdata->base);
140
141	depth = drvdata->buffer_depth;
142	/* reset write RAM pointer address */
143	writel_relaxed(0x0, drvdata->base + ETB_RAM_WRITE_POINTER);
144	/* clear entire RAM buffer */
145	for (i = 0; i < depth; i++)
146		writel_relaxed(0x0, drvdata->base + ETB_RWD_REG);
147
148	/* reset write RAM pointer address */
149	writel_relaxed(0x0, drvdata->base + ETB_RAM_WRITE_POINTER);
150	/* reset read RAM pointer address */
151	writel_relaxed(0x0, drvdata->base + ETB_RAM_READ_POINTER);
152
153	writel_relaxed(drvdata->trigger_cntr, drvdata->base + ETB_TRG);
154	writel_relaxed(ETB_FFCR_EN_FTC | ETB_FFCR_STOP_TRIGGER,
155		       drvdata->base + ETB_FFCR);
156	/* ETB trace capture enable */
157	writel_relaxed(ETB_CTL_CAPT_EN, drvdata->base + ETB_CTL_REG);
158
159	CS_LOCK(drvdata->base);
160}
161
162static int etb_enable(struct coresight_device *csdev, u32 mode)
163{
164	u32 val;
165	unsigned long flags;
166	struct etb_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
167
168	val = local_cmpxchg(&drvdata->mode,
169			    CS_MODE_DISABLED, mode);
170	/*
171	 * When accessing from Perf, a HW buffer can be handled
172	 * by a single trace entity.  In sysFS mode many tracers
173	 * can be logging to the same HW buffer.
174	 */
175	if (val == CS_MODE_PERF)
176		return -EBUSY;
177
178	/* Nothing to do, the tracer is already enabled. */
179	if (val == CS_MODE_SYSFS)
180		goto out;
181
182	spin_lock_irqsave(&drvdata->spinlock, flags);
183	etb_enable_hw(drvdata);
184	spin_unlock_irqrestore(&drvdata->spinlock, flags);
185
186out:
187	dev_info(drvdata->dev, "ETB enabled\n");
188	return 0;
189}
190
191static void etb_disable_hw(struct etb_drvdata *drvdata)
192{
193	u32 ffcr;
194
195	CS_UNLOCK(drvdata->base);
196
197	ffcr = readl_relaxed(drvdata->base + ETB_FFCR);
198	/* stop formatter when a stop has completed */
199	ffcr |= ETB_FFCR_STOP_FI;
200	writel_relaxed(ffcr, drvdata->base + ETB_FFCR);
201	/* manually generate a flush of the system */
202	ffcr |= ETB_FFCR_FON_MAN;
203	writel_relaxed(ffcr, drvdata->base + ETB_FFCR);
204
205	if (coresight_timeout(drvdata->base, ETB_FFCR, ETB_FFCR_BIT, 0)) {
206		dev_err(drvdata->dev,
207			"timeout observed when probing at offset %#x\n",
208			ETB_FFCR);
209	}
210
211	/* disable trace capture */
212	writel_relaxed(0x0, drvdata->base + ETB_CTL_REG);
213
214	if (coresight_timeout(drvdata->base, ETB_FFSR, ETB_FFSR_BIT, 1)) {
215		dev_err(drvdata->dev,
216			"timeout observed when probing at offset %#x\n",
217			ETB_FFCR);
218	}
219
220	CS_LOCK(drvdata->base);
221}
222
223static void etb_dump_hw(struct etb_drvdata *drvdata)
224{
225	int i;
226	u8 *buf_ptr;
227	u32 read_data, depth;
228	u32 read_ptr, write_ptr;
229	u32 frame_off, frame_endoff;
230
231	CS_UNLOCK(drvdata->base);
232
233	read_ptr = readl_relaxed(drvdata->base + ETB_RAM_READ_POINTER);
234	write_ptr = readl_relaxed(drvdata->base + ETB_RAM_WRITE_POINTER);
235
236	frame_off = write_ptr % ETB_FRAME_SIZE_WORDS;
237	frame_endoff = ETB_FRAME_SIZE_WORDS - frame_off;
238	if (frame_off) {
239		dev_err(drvdata->dev,
240			"write_ptr: %lu not aligned to formatter frame size\n",
241			(unsigned long)write_ptr);
242		dev_err(drvdata->dev, "frameoff: %lu, frame_endoff: %lu\n",
243			(unsigned long)frame_off, (unsigned long)frame_endoff);
244		write_ptr += frame_endoff;
245	}
246
247	if ((readl_relaxed(drvdata->base + ETB_STATUS_REG)
248		      & ETB_STATUS_RAM_FULL) == 0)
249		writel_relaxed(0x0, drvdata->base + ETB_RAM_READ_POINTER);
250	else
251		writel_relaxed(write_ptr, drvdata->base + ETB_RAM_READ_POINTER);
252
253	depth = drvdata->buffer_depth;
254	buf_ptr = drvdata->buf;
255	for (i = 0; i < depth; i++) {
256		read_data = readl_relaxed(drvdata->base +
257					  ETB_RAM_READ_DATA_REG);
258		*buf_ptr++ = read_data >> 0;
259		*buf_ptr++ = read_data >> 8;
260		*buf_ptr++ = read_data >> 16;
261		*buf_ptr++ = read_data >> 24;
262	}
263
264	if (frame_off) {
265		buf_ptr -= (frame_endoff * 4);
266		for (i = 0; i < frame_endoff; i++) {
267			*buf_ptr++ = 0x0;
268			*buf_ptr++ = 0x0;
269			*buf_ptr++ = 0x0;
270			*buf_ptr++ = 0x0;
271		}
272	}
273
274	writel_relaxed(read_ptr, drvdata->base + ETB_RAM_READ_POINTER);
275
276	CS_LOCK(drvdata->base);
277}
278
279static void etb_disable(struct coresight_device *csdev)
280{
281	struct etb_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
282	unsigned long flags;
283
284	spin_lock_irqsave(&drvdata->spinlock, flags);
285	etb_disable_hw(drvdata);
286	etb_dump_hw(drvdata);
287	spin_unlock_irqrestore(&drvdata->spinlock, flags);
288
289	local_set(&drvdata->mode, CS_MODE_DISABLED);
290
291	dev_info(drvdata->dev, "ETB disabled\n");
292}
293
294static void *etb_alloc_buffer(struct coresight_device *csdev, int cpu,
295			      void **pages, int nr_pages, bool overwrite)
296{
297	int node;
298	struct cs_buffers *buf;
299
300	if (cpu == -1)
301		cpu = smp_processor_id();
302	node = cpu_to_node(cpu);
303
304	buf = kzalloc_node(sizeof(struct cs_buffers), GFP_KERNEL, node);
305	if (!buf)
306		return NULL;
307
308	buf->snapshot = overwrite;
309	buf->nr_pages = nr_pages;
310	buf->data_pages = pages;
311
312	return buf;
313}
314
315static void etb_free_buffer(void *config)
316{
317	struct cs_buffers *buf = config;
318
319	kfree(buf);
320}
321
322static int etb_set_buffer(struct coresight_device *csdev,
323			  struct perf_output_handle *handle,
324			  void *sink_config)
325{
326	int ret = 0;
327	unsigned long head;
328	struct cs_buffers *buf = sink_config;
329
330	/* wrap head around to the amount of space we have */
331	head = handle->head & ((buf->nr_pages << PAGE_SHIFT) - 1);
332
333	/* find the page to write to */
334	buf->cur = head / PAGE_SIZE;
335
336	/* and offset within that page */
337	buf->offset = head % PAGE_SIZE;
338
339	local_set(&buf->data_size, 0);
340
341	return ret;
342}
343
344static unsigned long etb_reset_buffer(struct coresight_device *csdev,
345				      struct perf_output_handle *handle,
346				      void *sink_config, bool *lost)
347{
348	unsigned long size = 0;
349	struct cs_buffers *buf = sink_config;
350
351	if (buf) {
352		/*
353		 * In snapshot mode ->data_size holds the new address of the
354		 * ring buffer's head.  The size itself is the whole address
355		 * range since we want the latest information.
356		 */
357		if (buf->snapshot)
358			handle->head = local_xchg(&buf->data_size,
359						  buf->nr_pages << PAGE_SHIFT);
360
361		/*
362		 * Tell the tracer PMU how much we got in this run and if
363		 * something went wrong along the way.  Nobody else can use
364		 * this cs_buffers instance until we are done.  As such
365		 * resetting parameters here and squaring off with the ring
366		 * buffer API in the tracer PMU is fine.
367		 */
368		*lost = !!local_xchg(&buf->lost, 0);
369		size = local_xchg(&buf->data_size, 0);
370	}
371
372	return size;
373}
374
375static void etb_update_buffer(struct coresight_device *csdev,
376			      struct perf_output_handle *handle,
377			      void *sink_config)
378{
379	int i, cur;
380	u8 *buf_ptr;
381	u32 read_ptr, write_ptr, capacity;
382	u32 status, read_data, to_read;
383	unsigned long offset;
384	struct cs_buffers *buf = sink_config;
385	struct etb_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
386
387	if (!buf)
388		return;
389
390	capacity = drvdata->buffer_depth * ETB_FRAME_SIZE_WORDS;
391
392	CS_UNLOCK(drvdata->base);
393	etb_disable_hw(drvdata);
394
395	/* unit is in words, not bytes */
396	read_ptr = readl_relaxed(drvdata->base + ETB_RAM_READ_POINTER);
397	write_ptr = readl_relaxed(drvdata->base + ETB_RAM_WRITE_POINTER);
398
399	/*
400	 * Entries should be aligned to the frame size.  If they are not
401	 * go back to the last alignement point to give decoding tools a
402	 * chance to fix things.
403	 */
404	if (write_ptr % ETB_FRAME_SIZE_WORDS) {
405		dev_err(drvdata->dev,
406			"write_ptr: %lu not aligned to formatter frame size\n",
407			(unsigned long)write_ptr);
408
409		write_ptr &= ~(ETB_FRAME_SIZE_WORDS - 1);
410		local_inc(&buf->lost);
411	}
412
413	/*
414	 * Get a hold of the status register and see if a wrap around
415	 * has occurred.  If so adjust things accordingly.  Otherwise
416	 * start at the beginning and go until the write pointer has
417	 * been reached.
418	 */
419	status = readl_relaxed(drvdata->base + ETB_STATUS_REG);
420	if (status & ETB_STATUS_RAM_FULL) {
421		local_inc(&buf->lost);
422		to_read = capacity;
423		read_ptr = write_ptr;
424	} else {
425		to_read = CIRC_CNT(write_ptr, read_ptr, drvdata->buffer_depth);
426		to_read *= ETB_FRAME_SIZE_WORDS;
427	}
428
429	/*
430	 * Make sure we don't overwrite data that hasn't been consumed yet.
431	 * It is entirely possible that the HW buffer has more data than the
432	 * ring buffer can currently handle.  If so adjust the start address
433	 * to take only the last traces.
434	 *
435	 * In snapshot mode we are looking to get the latest traces only and as
436	 * such, we don't care about not overwriting data that hasn't been
437	 * processed by user space.
438	 */
439	if (!buf->snapshot && to_read > handle->size) {
440		u32 mask = ~(ETB_FRAME_SIZE_WORDS - 1);
441
442		/* The new read pointer must be frame size aligned */
443		to_read -= handle->size & mask;
444		/*
445		 * Move the RAM read pointer up, keeping in mind that
446		 * everything is in frame size units.
447		 */
448		read_ptr = (write_ptr + drvdata->buffer_depth) -
449					to_read / ETB_FRAME_SIZE_WORDS;
450		/* Wrap around if need be*/
451		read_ptr &= ~(drvdata->buffer_depth - 1);
452		/* let the decoder know we've skipped ahead */
453		local_inc(&buf->lost);
454	}
455
456	/* finally tell HW where we want to start reading from */
457	writel_relaxed(read_ptr, drvdata->base + ETB_RAM_READ_POINTER);
458
459	cur = buf->cur;
460	offset = buf->offset;
461	for (i = 0; i < to_read; i += 4) {
462		buf_ptr = buf->data_pages[cur] + offset;
463		read_data = readl_relaxed(drvdata->base +
464					  ETB_RAM_READ_DATA_REG);
465		*buf_ptr++ = read_data >> 0;
466		*buf_ptr++ = read_data >> 8;
467		*buf_ptr++ = read_data >> 16;
468		*buf_ptr++ = read_data >> 24;
469
470		offset += 4;
471		if (offset >= PAGE_SIZE) {
472			offset = 0;
473			cur++;
474			/* wrap around at the end of the buffer */
475			cur &= buf->nr_pages - 1;
476		}
477	}
478
479	/* reset ETB buffer for next run */
480	writel_relaxed(0x0, drvdata->base + ETB_RAM_READ_POINTER);
481	writel_relaxed(0x0, drvdata->base + ETB_RAM_WRITE_POINTER);
482
483	/*
484	 * In snapshot mode all we have to do is communicate to
485	 * perf_aux_output_end() the address of the current head.  In full
486	 * trace mode the same function expects a size to move rb->aux_head
487	 * forward.
488	 */
489	if (buf->snapshot)
490		local_set(&buf->data_size, (cur * PAGE_SIZE) + offset);
491	else
492		local_add(to_read, &buf->data_size);
493
494	etb_enable_hw(drvdata);
495	CS_LOCK(drvdata->base);
496}
497
498static const struct coresight_ops_sink etb_sink_ops = {
499	.enable		= etb_enable,
500	.disable	= etb_disable,
501	.alloc_buffer	= etb_alloc_buffer,
502	.free_buffer	= etb_free_buffer,
503	.set_buffer	= etb_set_buffer,
504	.reset_buffer	= etb_reset_buffer,
505	.update_buffer	= etb_update_buffer,
506};
507
508static const struct coresight_ops etb_cs_ops = {
509	.sink_ops	= &etb_sink_ops,
510};
511
512static void etb_dump(struct etb_drvdata *drvdata)
513{
514	unsigned long flags;
515
516	spin_lock_irqsave(&drvdata->spinlock, flags);
517	if (local_read(&drvdata->mode) == CS_MODE_SYSFS) {
518		etb_disable_hw(drvdata);
519		etb_dump_hw(drvdata);
520		etb_enable_hw(drvdata);
521	}
522	spin_unlock_irqrestore(&drvdata->spinlock, flags);
523
524	dev_info(drvdata->dev, "ETB dumped\n");
525}
526
527static int etb_open(struct inode *inode, struct file *file)
528{
529	struct etb_drvdata *drvdata = container_of(file->private_data,
530						   struct etb_drvdata, miscdev);
531
532	if (local_cmpxchg(&drvdata->reading, 0, 1))
533		return -EBUSY;
534
535	dev_dbg(drvdata->dev, "%s: successfully opened\n", __func__);
536	return 0;
537}
538
539static ssize_t etb_read(struct file *file, char __user *data,
540				size_t len, loff_t *ppos)
541{
542	u32 depth;
543	struct etb_drvdata *drvdata = container_of(file->private_data,
544						   struct etb_drvdata, miscdev);
545
546	etb_dump(drvdata);
547
548	depth = drvdata->buffer_depth;
549	if (*ppos + len > depth * 4)
550		len = depth * 4 - *ppos;
551
552	if (copy_to_user(data, drvdata->buf + *ppos, len)) {
553		dev_dbg(drvdata->dev, "%s: copy_to_user failed\n", __func__);
554		return -EFAULT;
555	}
556
557	*ppos += len;
558
559	dev_dbg(drvdata->dev, "%s: %zu bytes copied, %d bytes left\n",
560		__func__, len, (int)(depth * 4 - *ppos));
561	return len;
562}
563
564static int etb_release(struct inode *inode, struct file *file)
565{
566	struct etb_drvdata *drvdata = container_of(file->private_data,
567						   struct etb_drvdata, miscdev);
568	local_set(&drvdata->reading, 0);
569
570	dev_dbg(drvdata->dev, "%s: released\n", __func__);
571	return 0;
572}
573
574static const struct file_operations etb_fops = {
575	.owner		= THIS_MODULE,
576	.open		= etb_open,
577	.read		= etb_read,
578	.release	= etb_release,
579	.llseek		= no_llseek,
580};
581
582static ssize_t status_show(struct device *dev,
583			   struct device_attribute *attr, char *buf)
584{
585	unsigned long flags;
586	u32 etb_rdr, etb_sr, etb_rrp, etb_rwp;
587	u32 etb_trg, etb_cr, etb_ffsr, etb_ffcr;
588	struct etb_drvdata *drvdata = dev_get_drvdata(dev->parent);
589
590	pm_runtime_get_sync(drvdata->dev);
591	spin_lock_irqsave(&drvdata->spinlock, flags);
592	CS_UNLOCK(drvdata->base);
593
594	etb_rdr = readl_relaxed(drvdata->base + ETB_RAM_DEPTH_REG);
595	etb_sr = readl_relaxed(drvdata->base + ETB_STATUS_REG);
596	etb_rrp = readl_relaxed(drvdata->base + ETB_RAM_READ_POINTER);
597	etb_rwp = readl_relaxed(drvdata->base + ETB_RAM_WRITE_POINTER);
598	etb_trg = readl_relaxed(drvdata->base + ETB_TRG);
599	etb_cr = readl_relaxed(drvdata->base + ETB_CTL_REG);
600	etb_ffsr = readl_relaxed(drvdata->base + ETB_FFSR);
601	etb_ffcr = readl_relaxed(drvdata->base + ETB_FFCR);
602
603	CS_LOCK(drvdata->base);
604	spin_unlock_irqrestore(&drvdata->spinlock, flags);
605
606	pm_runtime_put(drvdata->dev);
607
608	return sprintf(buf,
609		       "Depth:\t\t0x%x\n"
610		       "Status:\t\t0x%x\n"
611		       "RAM read ptr:\t0x%x\n"
612		       "RAM wrt ptr:\t0x%x\n"
613		       "Trigger cnt:\t0x%x\n"
614		       "Control:\t0x%x\n"
615		       "Flush status:\t0x%x\n"
616		       "Flush ctrl:\t0x%x\n",
617		       etb_rdr, etb_sr, etb_rrp, etb_rwp,
618		       etb_trg, etb_cr, etb_ffsr, etb_ffcr);
619
620	return -EINVAL;
621}
622static DEVICE_ATTR_RO(status);
623
624static ssize_t trigger_cntr_show(struct device *dev,
625			    struct device_attribute *attr, char *buf)
626{
627	struct etb_drvdata *drvdata = dev_get_drvdata(dev->parent);
628	unsigned long val = drvdata->trigger_cntr;
629
630	return sprintf(buf, "%#lx\n", val);
631}
632
633static ssize_t trigger_cntr_store(struct device *dev,
634			     struct device_attribute *attr,
635			     const char *buf, size_t size)
636{
637	int ret;
638	unsigned long val;
639	struct etb_drvdata *drvdata = dev_get_drvdata(dev->parent);
640
641	ret = kstrtoul(buf, 16, &val);
642	if (ret)
643		return ret;
644
645	drvdata->trigger_cntr = val;
646	return size;
647}
648static DEVICE_ATTR_RW(trigger_cntr);
649
650static struct attribute *coresight_etb_attrs[] = {
651	&dev_attr_trigger_cntr.attr,
652	&dev_attr_status.attr,
653	NULL,
654};
655ATTRIBUTE_GROUPS(coresight_etb);
656
657static int etb_probe(struct amba_device *adev, const struct amba_id *id)
658{
659	int ret;
660	void __iomem *base;
661	struct device *dev = &adev->dev;
662	struct coresight_platform_data *pdata = NULL;
663	struct etb_drvdata *drvdata;
664	struct resource *res = &adev->res;
665	struct coresight_desc *desc;
666	struct device_node *np = adev->dev.of_node;
667
668	if (np) {
669		pdata = of_get_coresight_platform_data(dev, np);
670		if (IS_ERR(pdata))
671			return PTR_ERR(pdata);
672		adev->dev.platform_data = pdata;
673	}
674
675	drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
676	if (!drvdata)
677		return -ENOMEM;
678
679	drvdata->dev = &adev->dev;
680	drvdata->atclk = devm_clk_get(&adev->dev, "atclk"); /* optional */
681	if (!IS_ERR(drvdata->atclk)) {
682		ret = clk_prepare_enable(drvdata->atclk);
683		if (ret)
684			return ret;
685	}
686	dev_set_drvdata(dev, drvdata);
687
688	/* validity for the resource is already checked by the AMBA core */
689	base = devm_ioremap_resource(dev, res);
690	if (IS_ERR(base))
691		return PTR_ERR(base);
692
693	drvdata->base = base;
694
695	spin_lock_init(&drvdata->spinlock);
696
697	drvdata->buffer_depth = etb_get_buffer_depth(drvdata);
698	pm_runtime_put(&adev->dev);
699
700	if (drvdata->buffer_depth & 0x80000000)
701		return -EINVAL;
702
703	drvdata->buf = devm_kzalloc(dev,
704				    drvdata->buffer_depth * 4, GFP_KERNEL);
705	if (!drvdata->buf) {
706		dev_err(dev, "Failed to allocate %u bytes for buffer data\n",
707			drvdata->buffer_depth * 4);
708		return -ENOMEM;
709	}
710
711	desc = devm_kzalloc(dev, sizeof(*desc), GFP_KERNEL);
712	if (!desc)
713		return -ENOMEM;
714
715	desc->type = CORESIGHT_DEV_TYPE_SINK;
716	desc->subtype.sink_subtype = CORESIGHT_DEV_SUBTYPE_SINK_BUFFER;
717	desc->ops = &etb_cs_ops;
718	desc->pdata = pdata;
719	desc->dev = dev;
720	desc->groups = coresight_etb_groups;
721	drvdata->csdev = coresight_register(desc);
722	if (IS_ERR(drvdata->csdev))
723		return PTR_ERR(drvdata->csdev);
724
725	drvdata->miscdev.name = pdata->name;
726	drvdata->miscdev.minor = MISC_DYNAMIC_MINOR;
727	drvdata->miscdev.fops = &etb_fops;
728	ret = misc_register(&drvdata->miscdev);
729	if (ret)
730		goto err_misc_register;
731
732	dev_info(dev, "ETB initialized\n");
733	return 0;
734
735err_misc_register:
736	coresight_unregister(drvdata->csdev);
737	return ret;
738}
739
740#ifdef CONFIG_PM
741static int etb_runtime_suspend(struct device *dev)
742{
743	struct etb_drvdata *drvdata = dev_get_drvdata(dev);
744
745	if (drvdata && !IS_ERR(drvdata->atclk))
746		clk_disable_unprepare(drvdata->atclk);
747
748	return 0;
749}
750
751static int etb_runtime_resume(struct device *dev)
752{
753	struct etb_drvdata *drvdata = dev_get_drvdata(dev);
754
755	if (drvdata && !IS_ERR(drvdata->atclk))
756		clk_prepare_enable(drvdata->atclk);
757
758	return 0;
759}
760#endif
761
762static const struct dev_pm_ops etb_dev_pm_ops = {
763	SET_RUNTIME_PM_OPS(etb_runtime_suspend, etb_runtime_resume, NULL)
764};
765
766static struct amba_id etb_ids[] = {
767	{
768		.id	= 0x0003b907,
769		.mask	= 0x0003ffff,
770	},
771	{ 0, 0},
772};
773
774static struct amba_driver etb_driver = {
775	.drv = {
776		.name	= "coresight-etb10",
777		.owner	= THIS_MODULE,
778		.pm	= &etb_dev_pm_ops,
779		.suppress_bind_attrs = true,
780
781	},
782	.probe		= etb_probe,
783	.id_table	= etb_ids,
784};
785builtin_amba_driver(etb_driver);