drivers/hwtracing/coresight/coresight-etb10.c

   1 /* Copyright (c) 2011-2012, The Linux Foundation. All rights reserved.
   2  *
   3  * This program is free software; you can redistribute it and/or modify
   4  * it under the terms of the GNU General Public License version 2 and
   5  * only version 2 as published by the Free Software Foundation.
   6  *
   7  * This program is distributed in the hope that it will be useful,
   8  * but WITHOUT ANY WARRANTY; without even the implied warranty of
   9  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  10  * GNU General Public License for more details.
  11  */
  12
  13 #include <asm/local.h>
  14 #include <linux/kernel.h>
  15 #include <linux/module.h>
  16 #include <linux/init.h>
  17 #include <linux/types.h>
  18 #include <linux/device.h>
  19 #include <linux/io.h>
  20 #include <linux/err.h>
  21 #include <linux/fs.h>
  22 #include <linux/miscdevice.h>
  23 #include <linux/uaccess.h>
  24 #include <linux/slab.h>
  25 #include <linux/spinlock.h>
  26 #include <linux/pm_runtime.h>
  27 #include <linux/seq_file.h>
  28 #include <linux/coresight.h>
  29 #include <linux/amba/bus.h>
  30 #include <linux/clk.h>
  31 #include <linux/circ_buf.h>
  32 #include <linux/mm.h>
  33 #include <linux/perf_event.h>
  34
  35 #include <asm/local.h>
  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 cs_buffer - keep track of a recording session' specifics
  74  * @cur:        index of the current buffer
  75  * @nr_pages:   max number of pages granted to us
  76  * @offset:     offset within the current buffer
  77  * @data_size:  how much we collected in this run
  78  * @lost:       other than zero if we had a HW buffer wrap around
  79  * @snapshot:   is this run in snapshot mode
  80  * @data_pages: a handle the ring buffer
  81  */
  82 struct cs_buffers {
  83         unsigned int            cur;
  84         unsigned int            nr_pages;
  85         unsigned long           offset;
  86         local_t                 data_size;
  87         local_t                 lost;
  88         bool                    snapshot;
  89         void                    **data_pages;
  90 };
  91
  92 /**
  93  * struct etb_drvdata - specifics associated to an ETB component
  94  * @base:       memory mapped base address for this component.
  95  * @dev:        the device entity associated to this component.
  96  * @atclk:      optional clock for the core parts of the ETB.
  97  * @csdev:      component vitals needed by the framework.
  98  * @miscdev:    specifics to handle "/dev/xyz.etb" entry.
  99  * @spinlock:   only one at a time pls.
 100  * @reading:    synchronise user space access to etb buffer.
 101  * @mode:       this ETB is being used.
 102  * @buf:        area of memory where ETB buffer content gets sent.
 103  * @buffer_depth: size of @buf.
 104  * @trigger_cntr: amount of words to store after a trigger.
 105  */
 106 struct etb_drvdata {
 107         void __iomem            *base;
 108         struct device           *dev;
 109         struct clk              *atclk;
 110         struct coresight_device *csdev;
 111         struct miscdevice       miscdev;
 112         spinlock_t              spinlock;
 113         local_t                 reading;
 114         local_t                 mode;
 115         u8                      *buf;
 116         u32                     buffer_depth;
 117         u32                     trigger_cntr;
 118 };
 119
 120 static unsigned int etb_get_buffer_depth(struct etb_drvdata *drvdata)
 121 {
 122         u32 depth = 0;
 123
 124         pm_runtime_get_sync(drvdata->dev);
 125
 126         /* RO registers don't need locking */
 127         depth = readl_relaxed(drvdata->base + ETB_RAM_DEPTH_REG);
 128
 129         pm_runtime_put(drvdata->dev);
 130         return depth;
 131 }
 132
 133 static void etb_enable_hw(struct etb_drvdata *drvdata)
 134 {
 135         int i;
 136         u32 depth;
 137
 138         CS_UNLOCK(drvdata->base);
 139
 140         depth = drvdata->buffer_depth;
 141         /* reset write RAM pointer address */
 142         writel_relaxed(0x0, drvdata->base + ETB_RAM_WRITE_POINTER);
 143         /* clear entire RAM buffer */
 144         for (i = 0; i < depth; i++)
 145                 writel_relaxed(0x0, drvdata->base + ETB_RWD_REG);
 146
 147         /* reset write RAM pointer address */
 148         writel_relaxed(0x0, drvdata->base + ETB_RAM_WRITE_POINTER);
 149         /* reset read RAM pointer address */
 150         writel_relaxed(0x0, drvdata->base + ETB_RAM_READ_POINTER);
 151
 152         writel_relaxed(drvdata->trigger_cntr, drvdata->base + ETB_TRG);
 153         writel_relaxed(ETB_FFCR_EN_FTC | ETB_FFCR_STOP_TRIGGER,
 154                        drvdata->base + ETB_FFCR);
 155         /* ETB trace capture enable */
 156         writel_relaxed(ETB_CTL_CAPT_EN, drvdata->base + ETB_CTL_REG);
 157
 158         CS_LOCK(drvdata->base);
 159 }
 160
 161 static int etb_enable(struct coresight_device *csdev, u32 mode)
 162 {
 163         u32 val;
 164         unsigned long flags;
 165         struct etb_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
 166
 167         val = local_cmpxchg(&drvdata->mode,
 168                             CS_MODE_DISABLED, mode);
 169         /*
 170          * When accessing from Perf, a HW buffer can be handled
 171          * by a single trace entity.  In sysFS mode many tracers
 172          * can be logging to the same HW buffer.
 173          */
 174         if (val == CS_MODE_PERF)
 175                 return -EBUSY;
 176
 177         /* Nothing to do, the tracer is already enabled. */
 178         if (val == CS_MODE_SYSFS)
 179                 goto out;
 180
 181         spin_lock_irqsave(&drvdata->spinlock, flags);
 182         etb_enable_hw(drvdata);
 183         spin_unlock_irqrestore(&drvdata->spinlock, flags);
 184
 185 out:
 186         dev_info(drvdata->dev, "ETB enabled\n");
 187         return 0;
 188 }
 189
 190 static void etb_disable_hw(struct etb_drvdata *drvdata)
 191 {
 192         u32 ffcr;
 193
 194         CS_UNLOCK(drvdata->base);
 195
 196         ffcr = readl_relaxed(drvdata->base + ETB_FFCR);
 197         /* stop formatter when a stop has completed */
 198         ffcr |= ETB_FFCR_STOP_FI;
 199         writel_relaxed(ffcr, drvdata->base + ETB_FFCR);
 200         /* manually generate a flush of the system */
 201         ffcr |= ETB_FFCR_FON_MAN;
 202         writel_relaxed(ffcr, drvdata->base + ETB_FFCR);
 203
 204         if (coresight_timeout(drvdata->base, ETB_FFCR, ETB_FFCR_BIT, 0)) {
 205                 dev_err(drvdata->dev,
 206                         "timeout observed when probing at offset %#x\n",
 207                         ETB_FFCR);
 208         }
 209
 210         /* disable trace capture */
 211         writel_relaxed(0x0, drvdata->base + ETB_CTL_REG);
 212
 213         if (coresight_timeout(drvdata->base, ETB_FFSR, ETB_FFSR_BIT, 1)) {
 214                 dev_err(drvdata->dev,
 215                         "timeout observed when probing at offset %#x\n",
 216                         ETB_FFCR);
 217         }
 218
 219         CS_LOCK(drvdata->base);
 220 }
 221
 222 static void etb_dump_hw(struct etb_drvdata *drvdata)
 223 {
 224         int i;
 225         u8 *buf_ptr;
 226         u32 read_data, depth;
 227         u32 read_ptr, write_ptr;
 228         u32 frame_off, frame_endoff;
 229
 230         CS_UNLOCK(drvdata->base);
 231
 232         read_ptr = readl_relaxed(drvdata->base + ETB_RAM_READ_POINTER);
 233         write_ptr = readl_relaxed(drvdata->base + ETB_RAM_WRITE_POINTER);
 234
 235         frame_off = write_ptr % ETB_FRAME_SIZE_WORDS;
 236         frame_endoff = ETB_FRAME_SIZE_WORDS - frame_off;
 237         if (frame_off) {
 238                 dev_err(drvdata->dev,
 239                         "write_ptr: %lu not aligned to formatter frame size\n",
 240                         (unsigned long)write_ptr);
 241                 dev_err(drvdata->dev, "frameoff: %lu, frame_endoff: %lu\n",
 242                         (unsigned long)frame_off, (unsigned long)frame_endoff);
 243                 write_ptr += frame_endoff;
 244         }
 245
 246         if ((readl_relaxed(drvdata->base + ETB_STATUS_REG)
 247                       & ETB_STATUS_RAM_FULL) == 0)
 248                 writel_relaxed(0x0, drvdata->base + ETB_RAM_READ_POINTER);
 249         else
 250                 writel_relaxed(write_ptr, drvdata->base + ETB_RAM_READ_POINTER);
 251
 252         depth = drvdata->buffer_depth;
 253         buf_ptr = drvdata->buf;
 254         for (i = 0; i < depth; i++) {
 255                 read_data = readl_relaxed(drvdata->base +
 256                                           ETB_RAM_READ_DATA_REG);
 257                 *buf_ptr++ = read_data >> 0;
 258                 *buf_ptr++ = read_data >> 8;
 259                 *buf_ptr++ = read_data >> 16;
 260                 *buf_ptr++ = read_data >> 24;
 261         }
 262
 263         if (frame_off) {
 264                 buf_ptr -= (frame_endoff * 4);
 265                 for (i = 0; i < frame_endoff; i++) {
 266                         *buf_ptr++ = 0x0;
 267                         *buf_ptr++ = 0x0;
 268                         *buf_ptr++ = 0x0;
 269                         *buf_ptr++ = 0x0;
 270                 }
 271         }
 272
 273         writel_relaxed(read_ptr, drvdata->base + ETB_RAM_READ_POINTER);
 274
 275         CS_LOCK(drvdata->base);
 276 }
 277
 278 static void etb_disable(struct coresight_device *csdev)
 279 {
 280         struct etb_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
 281         unsigned long flags;
 282
 283         spin_lock_irqsave(&drvdata->spinlock, flags);
 284         etb_disable_hw(drvdata);
 285         etb_dump_hw(drvdata);
 286         spin_unlock_irqrestore(&drvdata->spinlock, flags);
 287
 288         local_set(&drvdata->mode, CS_MODE_DISABLED);
 289
 290         dev_info(drvdata->dev, "ETB disabled\n");
 291 }
 292
 293 static void *etb_alloc_buffer(struct coresight_device *csdev, int cpu,
 294                               void **pages, int nr_pages, bool overwrite)
 295 {
 296         int node;
 297         struct cs_buffers *buf;
 298
 299         if (cpu == -1)
 300                 cpu = smp_processor_id();
 301         node = cpu_to_node(cpu);
 302
 303         buf = kzalloc_node(sizeof(struct cs_buffers), GFP_KERNEL, node);
 304         if (!buf)
 305                 return NULL;
 306
 307         buf->snapshot = overwrite;
 308         buf->nr_pages = nr_pages;
 309         buf->data_pages = pages;
 310
 311         return buf;
 312 }
 313
 314 static void etb_free_buffer(void *config)
 315 {
 316         struct cs_buffers *buf = config;
 317
 318         kfree(buf);
 319 }
 320
 321 static int etb_set_buffer(struct coresight_device *csdev,
 322                           struct perf_output_handle *handle,
 323                           void *sink_config)
 324 {
 325         int ret = 0;
 326         unsigned long head;
 327         struct cs_buffers *buf = sink_config;
 328
 329         /* wrap head around to the amount of space we have */
 330         head = handle->head & ((buf->nr_pages << PAGE_SHIFT) - 1);
 331
 332         /* find the page to write to */
 333         buf->cur = head / PAGE_SIZE;
 334
 335         /* and offset within that page */
 336         buf->offset = head % PAGE_SIZE;
 337
 338         local_set(&buf->data_size, 0);
 339
 340         return ret;
 341 }
 342
 343 static unsigned long etb_reset_buffer(struct coresight_device *csdev,
 344                                       struct perf_output_handle *handle,
 345                                       void *sink_config, bool *lost)
 346 {
 347         unsigned long size = 0;
 348         struct cs_buffers *buf = sink_config;
 349
 350         if (buf) {
 351                 /*
 352                  * In snapshot mode ->data_size holds the new address of the
 353                  * ring buffer's head.  The size itself is the whole address
 354                  * range since we want the latest information.
 355                  */
 356                 if (buf->snapshot)
 357                         handle->head = local_xchg(&buf->data_size,
 358                                                   buf->nr_pages << PAGE_SHIFT);
 359
 360                 /*
 361                  * Tell the tracer PMU how much we got in this run and if
 362                  * something went wrong along the way.  Nobody else can use
 363                  * this cs_buffers instance until we are done.  As such
 364                  * resetting parameters here and squaring off with the ring
 365                  * buffer API in the tracer PMU is fine.
 366                  */
 367                 *lost = !!local_xchg(&buf->lost, 0);
 368                 size = local_xchg(&buf->data_size, 0);
 369         }
 370
 371         return size;
 372 }
 373
 374 static void etb_update_buffer(struct coresight_device *csdev,
 375                               struct perf_output_handle *handle,
 376                               void *sink_config)
 377 {
 378         int i, cur;
 379         u8 *buf_ptr;
 380         u32 read_ptr, write_ptr, capacity;
 381         u32 status, read_data, to_read;
 382         unsigned long offset;
 383         struct cs_buffers *buf = sink_config;
 384         struct etb_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
 385
 386         if (!buf)
 387                 return;
 388
 389         capacity = drvdata->buffer_depth * ETB_FRAME_SIZE_WORDS;
 390
 391         CS_UNLOCK(drvdata->base);
 392         etb_disable_hw(drvdata);
 393
 394         /* unit is in words, not bytes */
 395         read_ptr = readl_relaxed(drvdata->base + ETB_RAM_READ_POINTER);
 396         write_ptr = readl_relaxed(drvdata->base + ETB_RAM_WRITE_POINTER);
 397
 398         /*
 399          * Entries should be aligned to the frame size.  If they are not
 400          * go back to the last alignement point to give decoding tools a
 401          * chance to fix things.
 402          */
 403         if (write_ptr % ETB_FRAME_SIZE_WORDS) {
 404                 dev_err(drvdata->dev,
 405                         "write_ptr: %lu not aligned to formatter frame size\n",
 406                         (unsigned long)write_ptr);
 407
 408                 write_ptr &= ~(ETB_FRAME_SIZE_WORDS - 1);
 409                 local_inc(&buf->lost);
 410         }
 411
 412         /*
 413          * Get a hold of the status register and see if a wrap around
 414          * has occurred.  If so adjust things accordingly.  Otherwise
 415          * start at the beginning and go until the write pointer has
 416          * been reached.
 417          */
 418         status = readl_relaxed(drvdata->base + ETB_STATUS_REG);
 419         if (status & ETB_STATUS_RAM_FULL) {
 420                 local_inc(&buf->lost);
 421                 to_read = capacity;
 422                 read_ptr = write_ptr;
 423         } else {
 424                 to_read = CIRC_CNT(write_ptr, read_ptr, drvdata->buffer_depth);
 425                 to_read *= ETB_FRAME_SIZE_WORDS;
 426         }
 427
 428         /*
 429          * Make sure we don't overwrite data that hasn't been consumed yet.
 430          * It is entirely possible that the HW buffer has more data than the
 431          * ring buffer can currently handle.  If so adjust the start address
 432          * to take only the last traces.
 433          *
 434          * In snapshot mode we are looking to get the latest traces only and as
 435          * such, we don't care about not overwriting data that hasn't been
 436          * processed by user space.
 437          */
 438         if (!buf->snapshot && to_read > handle->size) {
 439                 u32 mask = ~(ETB_FRAME_SIZE_WORDS - 1);
 440
 441                 /* The new read pointer must be frame size aligned */
 442                 to_read -= handle->size & mask;
 443                 /*
 444                  * Move the RAM read pointer up, keeping in mind that
 445                  * everything is in frame size units.
 446                  */
 447                 read_ptr = (write_ptr + drvdata->buffer_depth) -
 448                                         to_read / ETB_FRAME_SIZE_WORDS;
 449                 /* Wrap around if need be*/
 450                 read_ptr &= ~(drvdata->buffer_depth - 1);
 451                 /* let the decoder know we've skipped ahead */
 452                 local_inc(&buf->lost);
 453         }
 454
 455         /* finally tell HW where we want to start reading from */
 456         writel_relaxed(read_ptr, drvdata->base + ETB_RAM_READ_POINTER);
 457
 458         cur = buf->cur;
 459         offset = buf->offset;
 460         for (i = 0; i < to_read; i += 4) {
 461                 buf_ptr = buf->data_pages[cur] + offset;
 462                 read_data = readl_relaxed(drvdata->base +
 463                                           ETB_RAM_READ_DATA_REG);
 464                 *buf_ptr++ = read_data >> 0;
 465                 *buf_ptr++ = read_data >> 8;
 466                 *buf_ptr++ = read_data >> 16;
 467                 *buf_ptr++ = read_data >> 24;
 468
 469                 offset += 4;
 470                 if (offset >= PAGE_SIZE) {
 471                         offset = 0;
 472                         cur++;
 473                         /* wrap around at the end of the buffer */
 474                         cur &= buf->nr_pages - 1;
 475                 }
 476         }
 477
 478         /* reset ETB buffer for next run */
 479         writel_relaxed(0x0, drvdata->base + ETB_RAM_READ_POINTER);
 480         writel_relaxed(0x0, drvdata->base + ETB_RAM_WRITE_POINTER);
 481
 482         /*
 483          * In snapshot mode all we have to do is communicate to
 484          * perf_aux_output_end() the address of the current head.  In full
 485          * trace mode the same function expects a size to move rb->aux_head
 486          * forward.
 487          */
 488         if (buf->snapshot)
 489                 local_set(&buf->data_size, (cur * PAGE_SIZE) + offset);
 490         else
 491                 local_add(to_read, &buf->data_size);
 492
 493         etb_enable_hw(drvdata);
 494         CS_LOCK(drvdata->base);
 495 }
 496
 497 static const struct coresight_ops_sink etb_sink_ops = {
 498         .enable         = etb_enable,
 499         .disable        = etb_disable,
 500         .alloc_buffer   = etb_alloc_buffer,
 501         .free_buffer    = etb_free_buffer,
 502         .set_buffer     = etb_set_buffer,
 503         .reset_buffer   = etb_reset_buffer,
 504         .update_buffer  = etb_update_buffer,
 505 };
 506
 507 static const struct coresight_ops etb_cs_ops = {
 508         .sink_ops       = &etb_sink_ops,
 509 };
 510
 511 static void etb_dump(struct etb_drvdata *drvdata)
 512 {
 513         unsigned long flags;
 514
 515         spin_lock_irqsave(&drvdata->spinlock, flags);
 516         if (local_read(&drvdata->mode) == CS_MODE_SYSFS) {
 517                 etb_disable_hw(drvdata);
 518                 etb_dump_hw(drvdata);
 519                 etb_enable_hw(drvdata);
 520         }
 521         spin_unlock_irqrestore(&drvdata->spinlock, flags);
 522
 523         dev_info(drvdata->dev, "ETB dumped\n");
 524 }
 525
 526 static int etb_open(struct inode *inode, struct file *file)
 527 {
 528         struct etb_drvdata *drvdata = container_of(file->private_data,
 529                                                    struct etb_drvdata, miscdev);
 530
 531         if (local_cmpxchg(&drvdata->reading, 0, 1))
 532                 return -EBUSY;
 533
 534         dev_dbg(drvdata->dev, "%s: successfully opened\n", __func__);
 535         return 0;
 536 }
 537
 538 static ssize_t etb_read(struct file *file, char __user *data,
 539                                 size_t len, loff_t *ppos)
 540 {
 541         u32 depth;
 542         struct etb_drvdata *drvdata = container_of(file->private_data,
 543                                                    struct etb_drvdata, miscdev);
 544
 545         etb_dump(drvdata);
 546
 547         depth = drvdata->buffer_depth;
 548         if (*ppos + len > depth * 4)
 549                 len = depth * 4 - *ppos;
 550
 551         if (copy_to_user(data, drvdata->buf + *ppos, len)) {
 552                 dev_dbg(drvdata->dev, "%s: copy_to_user failed\n", __func__);
 553                 return -EFAULT;
 554         }
 555
 556         *ppos += len;
 557
 558         dev_dbg(drvdata->dev, "%s: %zu bytes copied, %d bytes left\n",
 559                 __func__, len, (int)(depth * 4 - *ppos));
 560         return len;
 561 }
 562
 563 static int etb_release(struct inode *inode, struct file *file)
 564 {
 565         struct etb_drvdata *drvdata = container_of(file->private_data,
 566                                                    struct etb_drvdata, miscdev);
 567         local_set(&drvdata->reading, 0);
 568
 569         dev_dbg(drvdata->dev, "%s: released\n", __func__);
 570         return 0;
 571 }
 572
 573 static const struct file_operations etb_fops = {
 574         .owner          = THIS_MODULE,
 575         .open           = etb_open,
 576         .read           = etb_read,
 577         .release        = etb_release,
 578         .llseek         = no_llseek,
 579 };
 580
 581 static ssize_t status_show(struct device *dev,
 582                            struct device_attribute *attr, char *buf)
 583 {
 584         unsigned long flags;
 585         u32 etb_rdr, etb_sr, etb_rrp, etb_rwp;
 586         u32 etb_trg, etb_cr, etb_ffsr, etb_ffcr;
 587         struct etb_drvdata *drvdata = dev_get_drvdata(dev->parent);
 588
 589         pm_runtime_get_sync(drvdata->dev);
 590         spin_lock_irqsave(&drvdata->spinlock, flags);
 591         CS_UNLOCK(drvdata->base);
 592
 593         etb_rdr = readl_relaxed(drvdata->base + ETB_RAM_DEPTH_REG);
 594         etb_sr = readl_relaxed(drvdata->base + ETB_STATUS_REG);
 595         etb_rrp = readl_relaxed(drvdata->base + ETB_RAM_READ_POINTER);
 596         etb_rwp = readl_relaxed(drvdata->base + ETB_RAM_WRITE_POINTER);
 597         etb_trg = readl_relaxed(drvdata->base + ETB_TRG);
 598         etb_cr = readl_relaxed(drvdata->base + ETB_CTL_REG);
 599         etb_ffsr = readl_relaxed(drvdata->base + ETB_FFSR);
 600         etb_ffcr = readl_relaxed(drvdata->base + ETB_FFCR);
 601
 602         CS_LOCK(drvdata->base);
 603         spin_unlock_irqrestore(&drvdata->spinlock, flags);
 604
 605         pm_runtime_put(drvdata->dev);
 606
 607         return sprintf(buf,
 608                        "Depth:\t\t0x%x\n"
 609                        "Status:\t\t0x%x\n"
 610                        "RAM read ptr:\t0x%x\n"
 611                        "RAM wrt ptr:\t0x%x\n"
 612                        "Trigger cnt:\t0x%x\n"
 613                        "Control:\t0x%x\n"
 614                        "Flush status:\t0x%x\n"
 615                        "Flush ctrl:\t0x%x\n",
 616                        etb_rdr, etb_sr, etb_rrp, etb_rwp,
 617                        etb_trg, etb_cr, etb_ffsr, etb_ffcr);
 618
 619         return -EINVAL;
 620 }
 621 static DEVICE_ATTR_RO(status);
 622
 623 static ssize_t trigger_cntr_show(struct device *dev,
 624                             struct device_attribute *attr, char *buf)
 625 {
 626         struct etb_drvdata *drvdata = dev_get_drvdata(dev->parent);
 627         unsigned long val = drvdata->trigger_cntr;
 628
 629         return sprintf(buf, "%#lx\n", val);
 630 }
 631
 632 static ssize_t trigger_cntr_store(struct device *dev,
 633                              struct device_attribute *attr,
 634                              const char *buf, size_t size)
 635 {
 636         int ret;
 637         unsigned long val;
 638         struct etb_drvdata *drvdata = dev_get_drvdata(dev->parent);
 639
 640         ret = kstrtoul(buf, 16, &val);
 641         if (ret)
 642                 return ret;
 643
 644         drvdata->trigger_cntr = val;
 645         return size;
 646 }
 647 static DEVICE_ATTR_RW(trigger_cntr);
 648
 649 static struct attribute *coresight_etb_attrs[] = {
 650         &dev_attr_trigger_cntr.attr,
 651         &dev_attr_status.attr,
 652         NULL,
 653 };
 654 ATTRIBUTE_GROUPS(coresight_etb);
 655
 656 static int etb_probe(struct amba_device *adev, const struct amba_id *id)
 657 {
 658         int ret;
 659         void __iomem *base;
 660         struct device *dev = &adev->dev;
 661         struct coresight_platform_data *pdata = NULL;
 662         struct etb_drvdata *drvdata;
 663         struct resource *res = &adev->res;
 664         struct coresight_desc *desc;
 665         struct device_node *np = adev->dev.of_node;
 666
 667         if (np) {
 668                 pdata = of_get_coresight_platform_data(dev, np);
 669                 if (IS_ERR(pdata))
 670                         return PTR_ERR(pdata);
 671                 adev->dev.platform_data = pdata;
 672         }
 673
 674         drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
 675         if (!drvdata)
 676                 return -ENOMEM;
 677
 678         drvdata->dev = &adev->dev;
 679         drvdata->atclk = devm_clk_get(&adev->dev, "atclk"); /* optional */
 680         if (!IS_ERR(drvdata->atclk)) {
 681                 ret = clk_prepare_enable(drvdata->atclk);
 682                 if (ret)
 683                         return ret;
 684         }
 685         dev_set_drvdata(dev, drvdata);
 686
 687         /* validity for the resource is already checked by the AMBA core */
 688         base = devm_ioremap_resource(dev, res);
 689         if (IS_ERR(base))
 690                 return PTR_ERR(base);
 691
 692         drvdata->base = base;
 693
 694         spin_lock_init(&drvdata->spinlock);
 695
 696         drvdata->buffer_depth = etb_get_buffer_depth(drvdata);
 697         pm_runtime_put(&adev->dev);
 698
 699         if (drvdata->buffer_depth & 0x80000000)
 700                 return -EINVAL;
 701
 702         drvdata->buf = devm_kzalloc(dev,
 703                                     drvdata->buffer_depth * 4, GFP_KERNEL);
 704         if (!drvdata->buf) {
 705                 dev_err(dev, "Failed to allocate %u bytes for buffer data\n",
 706                         drvdata->buffer_depth * 4);
 707                 return -ENOMEM;
 708         }
 709
 710         desc = devm_kzalloc(dev, sizeof(*desc), GFP_KERNEL);
 711         if (!desc)
 712                 return -ENOMEM;
 713
 714         desc->type = CORESIGHT_DEV_TYPE_SINK;
 715         desc->subtype.sink_subtype = CORESIGHT_DEV_SUBTYPE_SINK_BUFFER;
 716         desc->ops = &etb_cs_ops;
 717         desc->pdata = pdata;
 718         desc->dev = dev;
 719         desc->groups = coresight_etb_groups;
 720         drvdata->csdev = coresight_register(desc);
 721         if (IS_ERR(drvdata->csdev))
 722                 return PTR_ERR(drvdata->csdev);
 723
 724         drvdata->miscdev.name = pdata->name;
 725         drvdata->miscdev.minor = MISC_DYNAMIC_MINOR;
 726         drvdata->miscdev.fops = &etb_fops;
 727         ret = misc_register(&drvdata->miscdev);
 728         if (ret)
 729                 goto err_misc_register;
 730
 731         dev_info(dev, "ETB initialized\n");
 732         return 0;
 733
 734 err_misc_register:
 735         coresight_unregister(drvdata->csdev);
 736         return ret;
 737 }
 738
 739 #ifdef CONFIG_PM
 740 static int etb_runtime_suspend(struct device *dev)
 741 {
 742         struct etb_drvdata *drvdata = dev_get_drvdata(dev);
 743
 744         if (drvdata && !IS_ERR(drvdata->atclk))
 745                 clk_disable_unprepare(drvdata->atclk);
 746
 747         return 0;
 748 }
 749
 750 static int etb_runtime_resume(struct device *dev)
 751 {
 752         struct etb_drvdata *drvdata = dev_get_drvdata(dev);
 753
 754         if (drvdata && !IS_ERR(drvdata->atclk))
 755                 clk_prepare_enable(drvdata->atclk);
 756
 757         return 0;
 758 }
 759 #endif
 760
 761 static const struct dev_pm_ops etb_dev_pm_ops = {
 762         SET_RUNTIME_PM_OPS(etb_runtime_suspend, etb_runtime_resume, NULL)
 763 };
 764
 765 static struct amba_id etb_ids[] = {
 766         {
 767                 .id     = 0x0003b907,
 768                 .mask   = 0x0003ffff,
 769         },
 770         { 0, 0},
 771 };
 772
 773 static struct amba_driver etb_driver = {
 774         .drv = {
 775                 .name   = "coresight-etb10",
 776                 .owner  = THIS_MODULE,
 777                 .pm     = &etb_dev_pm_ops,
 778                 .suppress_bind_attrs = true,
 779
 780         },
 781         .probe          = etb_probe,
 782         .id_table       = etb_ids,
 783 };
 784
 785 module_amba_driver(etb_driver);
 786
 787 MODULE_LICENSE("GPL v2");
 788 MODULE_DESCRIPTION("CoreSight Embedded Trace Buffer driver");