drivers/hwtracing/coresight/coresight-etb10.c

   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  */
  83 struct 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  */
 107 struct 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
 121 static 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
 134 static 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
 162 static 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
 186 out:
 187         dev_info(drvdata->dev, "ETB enabled\n");
 188         return 0;
 189 }
 190
 191 static 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
 223 static 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
 279 static 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
 294 static 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
 315 static void etb_free_buffer(void *config)
 316 {
 317         struct cs_buffers *buf = config;
 318
 319         kfree(buf);
 320 }
 321
 322 static 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
 344 static 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
 375 static 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
 498 static 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
 508 static const struct coresight_ops etb_cs_ops = {
 509         .sink_ops       = &etb_sink_ops,
 510 };
 511
 512 static 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
 527 static 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
 539 static 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
 564 static 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
 574 static 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
 582 #define coresight_etb10_simple_func(name, offset)                       \
 583         coresight_simple_func(struct etb_drvdata, name, offset)
 584
 585 coresight_etb10_simple_func(rdp, ETB_RAM_DEPTH_REG);
 586 coresight_etb10_simple_func(sts, ETB_STATUS_REG);
 587 coresight_etb10_simple_func(rrp, ETB_RAM_READ_POINTER);
 588 coresight_etb10_simple_func(rwp, ETB_RAM_WRITE_POINTER);
 589 coresight_etb10_simple_func(trg, ETB_TRG);
 590 coresight_etb10_simple_func(ctl, ETB_CTL_REG);
 591 coresight_etb10_simple_func(ffsr, ETB_FFSR);
 592 coresight_etb10_simple_func(ffcr, ETB_FFCR);
 593
 594 static struct attribute *coresight_etb_mgmt_attrs[] = {
 595         &dev_attr_rdp.attr,
 596         &dev_attr_sts.attr,
 597         &dev_attr_rrp.attr,
 598         &dev_attr_rwp.attr,
 599         &dev_attr_trg.attr,
 600         &dev_attr_ctl.attr,
 601         &dev_attr_ffsr.attr,
 602         &dev_attr_ffcr.attr,
 603         NULL,
 604 };
 605
 606 static ssize_t trigger_cntr_show(struct device *dev,
 607                             struct device_attribute *attr, char *buf)
 608 {
 609         struct etb_drvdata *drvdata = dev_get_drvdata(dev->parent);
 610         unsigned long val = drvdata->trigger_cntr;
 611
 612         return sprintf(buf, "%#lx\n", val);
 613 }
 614
 615 static ssize_t trigger_cntr_store(struct device *dev,
 616                              struct device_attribute *attr,
 617                              const char *buf, size_t size)
 618 {
 619         int ret;
 620         unsigned long val;
 621         struct etb_drvdata *drvdata = dev_get_drvdata(dev->parent);
 622
 623         ret = kstrtoul(buf, 16, &val);
 624         if (ret)
 625                 return ret;
 626
 627         drvdata->trigger_cntr = val;
 628         return size;
 629 }
 630 static DEVICE_ATTR_RW(trigger_cntr);
 631
 632 static struct attribute *coresight_etb_attrs[] = {
 633         &dev_attr_trigger_cntr.attr,
 634         NULL,
 635 };
 636
 637 static const struct attribute_group coresight_etb_group = {
 638         .attrs = coresight_etb_attrs,
 639 };
 640
 641 static const struct attribute_group coresight_etb_mgmt_group = {
 642         .attrs = coresight_etb_mgmt_attrs,
 643         .name = "mgmt",
 644 };
 645
 646 const struct attribute_group *coresight_etb_groups[] = {
 647         &coresight_etb_group,
 648         &coresight_etb_mgmt_group,
 649         NULL,
 650 };
 651
 652 static int etb_probe(struct amba_device *adev, const struct amba_id *id)
 653 {
 654         int ret;
 655         void __iomem *base;
 656         struct device *dev = &adev->dev;
 657         struct coresight_platform_data *pdata = NULL;
 658         struct etb_drvdata *drvdata;
 659         struct resource *res = &adev->res;
 660         struct coresight_desc *desc;
 661         struct device_node *np = adev->dev.of_node;
 662
 663         if (np) {
 664                 pdata = of_get_coresight_platform_data(dev, np);
 665                 if (IS_ERR(pdata))
 666                         return PTR_ERR(pdata);
 667                 adev->dev.platform_data = pdata;
 668         }
 669
 670         drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
 671         if (!drvdata)
 672                 return -ENOMEM;
 673
 674         drvdata->dev = &adev->dev;
 675         drvdata->atclk = devm_clk_get(&adev->dev, "atclk"); /* optional */
 676         if (!IS_ERR(drvdata->atclk)) {
 677                 ret = clk_prepare_enable(drvdata->atclk);
 678                 if (ret)
 679                         return ret;
 680         }
 681         dev_set_drvdata(dev, drvdata);
 682
 683         /* validity for the resource is already checked by the AMBA core */
 684         base = devm_ioremap_resource(dev, res);
 685         if (IS_ERR(base))
 686                 return PTR_ERR(base);
 687
 688         drvdata->base = base;
 689
 690         spin_lock_init(&drvdata->spinlock);
 691
 692         drvdata->buffer_depth = etb_get_buffer_depth(drvdata);
 693         pm_runtime_put(&adev->dev);
 694
 695         if (drvdata->buffer_depth & 0x80000000)
 696                 return -EINVAL;
 697
 698         drvdata->buf = devm_kzalloc(dev,
 699                                     drvdata->buffer_depth * 4, GFP_KERNEL);
 700         if (!drvdata->buf) {
 701                 dev_err(dev, "Failed to allocate %u bytes for buffer data\n",
 702                         drvdata->buffer_depth * 4);
 703                 return -ENOMEM;
 704         }
 705
 706         desc = devm_kzalloc(dev, sizeof(*desc), GFP_KERNEL);
 707         if (!desc)
 708                 return -ENOMEM;
 709
 710         desc->type = CORESIGHT_DEV_TYPE_SINK;
 711         desc->subtype.sink_subtype = CORESIGHT_DEV_SUBTYPE_SINK_BUFFER;
 712         desc->ops = &etb_cs_ops;
 713         desc->pdata = pdata;
 714         desc->dev = dev;
 715         desc->groups = coresight_etb_groups;
 716         drvdata->csdev = coresight_register(desc);
 717         if (IS_ERR(drvdata->csdev))
 718                 return PTR_ERR(drvdata->csdev);
 719
 720         drvdata->miscdev.name = pdata->name;
 721         drvdata->miscdev.minor = MISC_DYNAMIC_MINOR;
 722         drvdata->miscdev.fops = &etb_fops;
 723         ret = misc_register(&drvdata->miscdev);
 724         if (ret)
 725                 goto err_misc_register;
 726
 727         dev_info(dev, "ETB initialized\n");
 728         return 0;
 729
 730 err_misc_register:
 731         coresight_unregister(drvdata->csdev);
 732         return ret;
 733 }
 734
 735 #ifdef CONFIG_PM
 736 static int etb_runtime_suspend(struct device *dev)
 737 {
 738         struct etb_drvdata *drvdata = dev_get_drvdata(dev);
 739
 740         if (drvdata && !IS_ERR(drvdata->atclk))
 741                 clk_disable_unprepare(drvdata->atclk);
 742
 743         return 0;
 744 }
 745
 746 static int etb_runtime_resume(struct device *dev)
 747 {
 748         struct etb_drvdata *drvdata = dev_get_drvdata(dev);
 749
 750         if (drvdata && !IS_ERR(drvdata->atclk))
 751                 clk_prepare_enable(drvdata->atclk);
 752
 753         return 0;
 754 }
 755 #endif
 756
 757 static const struct dev_pm_ops etb_dev_pm_ops = {
 758         SET_RUNTIME_PM_OPS(etb_runtime_suspend, etb_runtime_resume, NULL)
 759 };
 760
 761 static struct amba_id etb_ids[] = {
 762         {
 763                 .id     = 0x0003b907,
 764                 .mask   = 0x0003ffff,
 765         },
 766         { 0, 0},
 767 };
 768
 769 static struct amba_driver etb_driver = {
 770         .drv = {
 771                 .name   = "coresight-etb10",
 772                 .owner  = THIS_MODULE,
 773                 .pm     = &etb_dev_pm_ops,
 774                 .suppress_bind_attrs = true,
 775
 776         },
 777         .probe          = etb_probe,
 778         .id_table       = etb_ids,
 779 };
 780 builtin_amba_driver(etb_driver);