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1// SPDX-License-Identifier: GPL-2.02/*3 * Copyright (c) 2011-2012, The Linux Foundation. All rights reserved.4 *5 * Description: CoreSight Embedded Trace Buffer driver6 */7 8#include <linux/atomic.h>9#include <linux/kernel.h>10#include <linux/init.h>11#include <linux/types.h>12#include <linux/device.h>13#include <linux/io.h>14#include <linux/err.h>15#include <linux/fs.h>16#include <linux/miscdevice.h>17#include <linux/uaccess.h>18#include <linux/slab.h>19#include <linux/spinlock.h>20#include <linux/pm_runtime.h>21#include <linux/seq_file.h>22#include <linux/coresight.h>23#include <linux/amba/bus.h>24#include <linux/clk.h>25#include <linux/circ_buf.h>26#include <linux/mm.h>27#include <linux/perf_event.h>28 29 30#include "coresight-priv.h"31#include "coresight-etm-perf.h"32 33#define ETB_RAM_DEPTH_REG 0x00434#define ETB_STATUS_REG 0x00c35#define ETB_RAM_READ_DATA_REG 0x01036#define ETB_RAM_READ_POINTER 0x01437#define ETB_RAM_WRITE_POINTER 0x01838#define ETB_TRG 0x01c39#define ETB_CTL_REG 0x02040#define ETB_RWD_REG 0x02441#define ETB_FFSR 0x30042#define ETB_FFCR 0x30443#define ETB_ITMISCOP0 0xee044#define ETB_ITTRFLINACK 0xee445#define ETB_ITTRFLIN 0xee846#define ETB_ITATBDATA0 0xeeC47#define ETB_ITATBCTR2 0xef048#define ETB_ITATBCTR1 0xef449#define ETB_ITATBCTR0 0xef850 51/* register description */52/* STS - 0x00C */53#define ETB_STATUS_RAM_FULL BIT(0)54/* CTL - 0x020 */55#define ETB_CTL_CAPT_EN BIT(0)56/* FFCR - 0x304 */57#define ETB_FFCR_EN_FTC BIT(0)58#define ETB_FFCR_FON_MAN BIT(6)59#define ETB_FFCR_STOP_FI BIT(12)60#define ETB_FFCR_STOP_TRIGGER BIT(13)61 62#define ETB_FFCR_BIT 663#define ETB_FFSR_BIT 164#define ETB_FRAME_SIZE_WORDS 465 66DEFINE_CORESIGHT_DEVLIST(etb_devs, "etb");67 68/**69 * struct etb_drvdata - specifics associated to an ETB component70 * @base: memory mapped base address for this component.71 * @atclk: optional clock for the core parts of the ETB.72 * @csdev: component vitals needed by the framework.73 * @miscdev: specifics to handle "/dev/xyz.etb" entry.74 * @spinlock: only one at a time pls.75 * @reading: synchronise user space access to etb buffer.76 * @pid: Process ID of the process being monitored by the session77 * that is using this component.78 * @buf: area of memory where ETB buffer content gets sent.79 * @buffer_depth: size of @buf.80 * @trigger_cntr: amount of words to store after a trigger.81 */82struct etb_drvdata {83 void __iomem *base;84 struct clk *atclk;85 struct coresight_device *csdev;86 struct miscdevice miscdev;87 spinlock_t spinlock;88 local_t reading;89 pid_t pid;90 u8 *buf;91 u32 buffer_depth;92 u32 trigger_cntr;93};94 95static int etb_set_buffer(struct coresight_device *csdev,96 struct perf_output_handle *handle);97 98static inline unsigned int etb_get_buffer_depth(struct etb_drvdata *drvdata)99{100 return readl_relaxed(drvdata->base + ETB_RAM_DEPTH_REG);101}102 103static void __etb_enable_hw(struct etb_drvdata *drvdata)104{105 int i;106 u32 depth;107 108 CS_UNLOCK(drvdata->base);109 110 depth = drvdata->buffer_depth;111 /* reset write RAM pointer address */112 writel_relaxed(0x0, drvdata->base + ETB_RAM_WRITE_POINTER);113 /* clear entire RAM buffer */114 for (i = 0; i < depth; i++)115 writel_relaxed(0x0, drvdata->base + ETB_RWD_REG);116 117 /* reset write RAM pointer address */118 writel_relaxed(0x0, drvdata->base + ETB_RAM_WRITE_POINTER);119 /* reset read RAM pointer address */120 writel_relaxed(0x0, drvdata->base + ETB_RAM_READ_POINTER);121 122 writel_relaxed(drvdata->trigger_cntr, drvdata->base + ETB_TRG);123 writel_relaxed(ETB_FFCR_EN_FTC | ETB_FFCR_STOP_TRIGGER,124 drvdata->base + ETB_FFCR);125 /* ETB trace capture enable */126 writel_relaxed(ETB_CTL_CAPT_EN, drvdata->base + ETB_CTL_REG);127 128 CS_LOCK(drvdata->base);129}130 131static int etb_enable_hw(struct etb_drvdata *drvdata)132{133 int rc = coresight_claim_device(drvdata->csdev);134 135 if (rc)136 return rc;137 138 __etb_enable_hw(drvdata);139 return 0;140}141 142static int etb_enable_sysfs(struct coresight_device *csdev)143{144 int ret = 0;145 unsigned long flags;146 struct etb_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);147 148 spin_lock_irqsave(&drvdata->spinlock, flags);149 150 /* Don't messup with perf sessions. */151 if (coresight_get_mode(csdev) == CS_MODE_PERF) {152 ret = -EBUSY;153 goto out;154 }155 156 if (coresight_get_mode(csdev) == CS_MODE_DISABLED) {157 ret = etb_enable_hw(drvdata);158 if (ret)159 goto out;160 161 coresight_set_mode(csdev, CS_MODE_SYSFS);162 }163 164 csdev->refcnt++;165out:166 spin_unlock_irqrestore(&drvdata->spinlock, flags);167 return ret;168}169 170static int etb_enable_perf(struct coresight_device *csdev, void *data)171{172 int ret = 0;173 pid_t pid;174 unsigned long flags;175 struct etb_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);176 struct perf_output_handle *handle = data;177 struct cs_buffers *buf = etm_perf_sink_config(handle);178 179 spin_lock_irqsave(&drvdata->spinlock, flags);180 181 /* No need to continue if the component is already in used by sysFS. */182 if (coresight_get_mode(drvdata->csdev) == CS_MODE_SYSFS) {183 ret = -EBUSY;184 goto out;185 }186 187 /* Get a handle on the pid of the process to monitor */188 pid = buf->pid;189 190 if (drvdata->pid != -1 && drvdata->pid != pid) {191 ret = -EBUSY;192 goto out;193 }194 195 /*196 * No HW configuration is needed if the sink is already in197 * use for this session.198 */199 if (drvdata->pid == pid) {200 csdev->refcnt++;201 goto out;202 }203 204 /*205 * We don't have an internal state to clean up if we fail to setup206 * the perf buffer. So we can perform the step before we turn the207 * ETB on and leave without cleaning up.208 */209 ret = etb_set_buffer(csdev, handle);210 if (ret)211 goto out;212 213 ret = etb_enable_hw(drvdata);214 if (!ret) {215 /* Associate with monitored process. */216 drvdata->pid = pid;217 coresight_set_mode(drvdata->csdev, CS_MODE_PERF);218 csdev->refcnt++;219 }220 221out:222 spin_unlock_irqrestore(&drvdata->spinlock, flags);223 return ret;224}225 226static int etb_enable(struct coresight_device *csdev, enum cs_mode mode,227 void *data)228{229 int ret;230 231 switch (mode) {232 case CS_MODE_SYSFS:233 ret = etb_enable_sysfs(csdev);234 break;235 case CS_MODE_PERF:236 ret = etb_enable_perf(csdev, data);237 break;238 default:239 ret = -EINVAL;240 break;241 }242 243 if (ret)244 return ret;245 246 dev_dbg(&csdev->dev, "ETB enabled\n");247 return 0;248}249 250static void __etb_disable_hw(struct etb_drvdata *drvdata)251{252 u32 ffcr;253 struct device *dev = &drvdata->csdev->dev;254 struct csdev_access *csa = &drvdata->csdev->access;255 256 CS_UNLOCK(drvdata->base);257 258 ffcr = readl_relaxed(drvdata->base + ETB_FFCR);259 /* stop formatter when a stop has completed */260 ffcr |= ETB_FFCR_STOP_FI;261 writel_relaxed(ffcr, drvdata->base + ETB_FFCR);262 /* manually generate a flush of the system */263 ffcr |= ETB_FFCR_FON_MAN;264 writel_relaxed(ffcr, drvdata->base + ETB_FFCR);265 266 if (coresight_timeout(csa, ETB_FFCR, ETB_FFCR_BIT, 0)) {267 dev_err(dev,268 "timeout while waiting for completion of Manual Flush\n");269 }270 271 /* disable trace capture */272 writel_relaxed(0x0, drvdata->base + ETB_CTL_REG);273 274 if (coresight_timeout(csa, ETB_FFSR, ETB_FFSR_BIT, 1)) {275 dev_err(dev,276 "timeout while waiting for Formatter to Stop\n");277 }278 279 CS_LOCK(drvdata->base);280}281 282static void etb_dump_hw(struct etb_drvdata *drvdata)283{284 bool lost = false;285 int i;286 u8 *buf_ptr;287 u32 read_data, depth;288 u32 read_ptr, write_ptr;289 u32 frame_off, frame_endoff;290 struct device *dev = &drvdata->csdev->dev;291 292 CS_UNLOCK(drvdata->base);293 294 read_ptr = readl_relaxed(drvdata->base + ETB_RAM_READ_POINTER);295 write_ptr = readl_relaxed(drvdata->base + ETB_RAM_WRITE_POINTER);296 297 frame_off = write_ptr % ETB_FRAME_SIZE_WORDS;298 frame_endoff = ETB_FRAME_SIZE_WORDS - frame_off;299 if (frame_off) {300 dev_err(dev,301 "write_ptr: %lu not aligned to formatter frame size\n",302 (unsigned long)write_ptr);303 dev_err(dev, "frameoff: %lu, frame_endoff: %lu\n",304 (unsigned long)frame_off, (unsigned long)frame_endoff);305 write_ptr += frame_endoff;306 }307 308 if ((readl_relaxed(drvdata->base + ETB_STATUS_REG)309 & ETB_STATUS_RAM_FULL) == 0) {310 writel_relaxed(0x0, drvdata->base + ETB_RAM_READ_POINTER);311 } else {312 writel_relaxed(write_ptr, drvdata->base + ETB_RAM_READ_POINTER);313 lost = true;314 }315 316 depth = drvdata->buffer_depth;317 buf_ptr = drvdata->buf;318 for (i = 0; i < depth; i++) {319 read_data = readl_relaxed(drvdata->base +320 ETB_RAM_READ_DATA_REG);321 *(u32 *)buf_ptr = read_data;322 buf_ptr += 4;323 }324 325 if (lost)326 coresight_insert_barrier_packet(drvdata->buf);327 328 if (frame_off) {329 buf_ptr -= (frame_endoff * 4);330 for (i = 0; i < frame_endoff; i++) {331 *buf_ptr++ = 0x0;332 *buf_ptr++ = 0x0;333 *buf_ptr++ = 0x0;334 *buf_ptr++ = 0x0;335 }336 }337 338 writel_relaxed(read_ptr, drvdata->base + ETB_RAM_READ_POINTER);339 340 CS_LOCK(drvdata->base);341}342 343static void etb_disable_hw(struct etb_drvdata *drvdata)344{345 __etb_disable_hw(drvdata);346 etb_dump_hw(drvdata);347 coresight_disclaim_device(drvdata->csdev);348}349 350static int etb_disable(struct coresight_device *csdev)351{352 struct etb_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);353 unsigned long flags;354 355 spin_lock_irqsave(&drvdata->spinlock, flags);356 357 csdev->refcnt--;358 if (csdev->refcnt) {359 spin_unlock_irqrestore(&drvdata->spinlock, flags);360 return -EBUSY;361 }362 363 /* Complain if we (somehow) got out of sync */364 WARN_ON_ONCE(coresight_get_mode(csdev) == CS_MODE_DISABLED);365 etb_disable_hw(drvdata);366 /* Dissociate from monitored process. */367 drvdata->pid = -1;368 coresight_set_mode(csdev, CS_MODE_DISABLED);369 spin_unlock_irqrestore(&drvdata->spinlock, flags);370 371 dev_dbg(&csdev->dev, "ETB disabled\n");372 return 0;373}374 375static void *etb_alloc_buffer(struct coresight_device *csdev,376 struct perf_event *event, void **pages,377 int nr_pages, bool overwrite)378{379 int node;380 struct cs_buffers *buf;381 382 node = (event->cpu == -1) ? NUMA_NO_NODE : cpu_to_node(event->cpu);383 384 buf = kzalloc_node(sizeof(struct cs_buffers), GFP_KERNEL, node);385 if (!buf)386 return NULL;387 388 buf->pid = task_pid_nr(event->owner);389 buf->snapshot = overwrite;390 buf->nr_pages = nr_pages;391 buf->data_pages = pages;392 393 return buf;394}395 396static void etb_free_buffer(void *config)397{398 struct cs_buffers *buf = config;399 400 kfree(buf);401}402 403static int etb_set_buffer(struct coresight_device *csdev,404 struct perf_output_handle *handle)405{406 int ret = 0;407 unsigned long head;408 struct cs_buffers *buf = etm_perf_sink_config(handle);409 410 if (!buf)411 return -EINVAL;412 413 /* wrap head around to the amount of space we have */414 head = handle->head & ((buf->nr_pages << PAGE_SHIFT) - 1);415 416 /* find the page to write to */417 buf->cur = head / PAGE_SIZE;418 419 /* and offset within that page */420 buf->offset = head % PAGE_SIZE;421 422 local_set(&buf->data_size, 0);423 424 return ret;425}426 427static unsigned long etb_update_buffer(struct coresight_device *csdev,428 struct perf_output_handle *handle,429 void *sink_config)430{431 bool lost = false;432 int i, cur;433 u8 *buf_ptr;434 const u32 *barrier;435 u32 read_ptr, write_ptr, capacity;436 u32 status, read_data;437 unsigned long offset, to_read = 0, flags;438 struct cs_buffers *buf = sink_config;439 struct etb_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);440 441 if (!buf)442 return 0;443 444 capacity = drvdata->buffer_depth * ETB_FRAME_SIZE_WORDS;445 446 spin_lock_irqsave(&drvdata->spinlock, flags);447 448 /* Don't do anything if another tracer is using this sink */449 if (csdev->refcnt != 1)450 goto out;451 452 __etb_disable_hw(drvdata);453 CS_UNLOCK(drvdata->base);454 455 /* unit is in words, not bytes */456 read_ptr = readl_relaxed(drvdata->base + ETB_RAM_READ_POINTER);457 write_ptr = readl_relaxed(drvdata->base + ETB_RAM_WRITE_POINTER);458 459 /*460 * Entries should be aligned to the frame size. If they are not461 * go back to the last alignment point to give decoding tools a462 * chance to fix things.463 */464 if (write_ptr % ETB_FRAME_SIZE_WORDS) {465 dev_err(&csdev->dev,466 "write_ptr: %lu not aligned to formatter frame size\n",467 (unsigned long)write_ptr);468 469 write_ptr &= ~(ETB_FRAME_SIZE_WORDS - 1);470 lost = true;471 }472 473 /*474 * Get a hold of the status register and see if a wrap around475 * has occurred. If so adjust things accordingly. Otherwise476 * start at the beginning and go until the write pointer has477 * been reached.478 */479 status = readl_relaxed(drvdata->base + ETB_STATUS_REG);480 if (status & ETB_STATUS_RAM_FULL) {481 lost = true;482 to_read = capacity;483 read_ptr = write_ptr;484 } else {485 to_read = CIRC_CNT(write_ptr, read_ptr, drvdata->buffer_depth);486 to_read *= ETB_FRAME_SIZE_WORDS;487 }488 489 /*490 * Make sure we don't overwrite data that hasn't been consumed yet.491 * It is entirely possible that the HW buffer has more data than the492 * ring buffer can currently handle. If so adjust the start address493 * to take only the last traces.494 *495 * In snapshot mode we are looking to get the latest traces only and as496 * such, we don't care about not overwriting data that hasn't been497 * processed by user space.498 */499 if (!buf->snapshot && to_read > handle->size) {500 u32 mask = ~(ETB_FRAME_SIZE_WORDS - 1);501 502 /* The new read pointer must be frame size aligned */503 to_read = handle->size & mask;504 /*505 * Move the RAM read pointer up, keeping in mind that506 * everything is in frame size units.507 */508 read_ptr = (write_ptr + drvdata->buffer_depth) -509 to_read / ETB_FRAME_SIZE_WORDS;510 /* Wrap around if need be*/511 if (read_ptr > (drvdata->buffer_depth - 1))512 read_ptr -= drvdata->buffer_depth;513 /* let the decoder know we've skipped ahead */514 lost = true;515 }516 517 /*518 * Don't set the TRUNCATED flag in snapshot mode because 1) the519 * captured buffer is expected to be truncated and 2) a full buffer520 * prevents the event from being re-enabled by the perf core,521 * resulting in stale data being send to user space.522 */523 if (!buf->snapshot && lost)524 perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED);525 526 /* finally tell HW where we want to start reading from */527 writel_relaxed(read_ptr, drvdata->base + ETB_RAM_READ_POINTER);528 529 cur = buf->cur;530 offset = buf->offset;531 barrier = coresight_barrier_pkt;532 533 for (i = 0; i < to_read; i += 4) {534 buf_ptr = buf->data_pages[cur] + offset;535 read_data = readl_relaxed(drvdata->base +536 ETB_RAM_READ_DATA_REG);537 if (lost && i < CORESIGHT_BARRIER_PKT_SIZE) {538 read_data = *barrier;539 barrier++;540 }541 542 *(u32 *)buf_ptr = read_data;543 buf_ptr += 4;544 545 offset += 4;546 if (offset >= PAGE_SIZE) {547 offset = 0;548 cur++;549 /* wrap around at the end of the buffer */550 cur &= buf->nr_pages - 1;551 }552 }553 554 /* reset ETB buffer for next run */555 writel_relaxed(0x0, drvdata->base + ETB_RAM_READ_POINTER);556 writel_relaxed(0x0, drvdata->base + ETB_RAM_WRITE_POINTER);557 558 /*559 * In snapshot mode we simply increment the head by the number of byte560 * that were written. User space will figure out how many bytes to get561 * from the AUX buffer based on the position of the head.562 */563 if (buf->snapshot)564 handle->head += to_read;565 566 __etb_enable_hw(drvdata);567 CS_LOCK(drvdata->base);568out:569 spin_unlock_irqrestore(&drvdata->spinlock, flags);570 571 return to_read;572}573 574static const struct coresight_ops_sink etb_sink_ops = {575 .enable = etb_enable,576 .disable = etb_disable,577 .alloc_buffer = etb_alloc_buffer,578 .free_buffer = etb_free_buffer,579 .update_buffer = etb_update_buffer,580};581 582static const struct coresight_ops etb_cs_ops = {583 .sink_ops = &etb_sink_ops,584};585 586static void etb_dump(struct etb_drvdata *drvdata)587{588 unsigned long flags;589 590 spin_lock_irqsave(&drvdata->spinlock, flags);591 if (coresight_get_mode(drvdata->csdev) == CS_MODE_SYSFS) {592 __etb_disable_hw(drvdata);593 etb_dump_hw(drvdata);594 __etb_enable_hw(drvdata);595 }596 spin_unlock_irqrestore(&drvdata->spinlock, flags);597 598 dev_dbg(&drvdata->csdev->dev, "ETB dumped\n");599}600 601static int etb_open(struct inode *inode, struct file *file)602{603 struct etb_drvdata *drvdata = container_of(file->private_data,604 struct etb_drvdata, miscdev);605 606 if (local_cmpxchg(&drvdata->reading, 0, 1))607 return -EBUSY;608 609 dev_dbg(&drvdata->csdev->dev, "%s: successfully opened\n", __func__);610 return 0;611}612 613static ssize_t etb_read(struct file *file, char __user *data,614 size_t len, loff_t *ppos)615{616 u32 depth;617 struct etb_drvdata *drvdata = container_of(file->private_data,618 struct etb_drvdata, miscdev);619 struct device *dev = &drvdata->csdev->dev;620 621 etb_dump(drvdata);622 623 depth = drvdata->buffer_depth;624 if (*ppos + len > depth * 4)625 len = depth * 4 - *ppos;626 627 if (copy_to_user(data, drvdata->buf + *ppos, len)) {628 dev_dbg(dev,629 "%s: copy_to_user failed\n", __func__);630 return -EFAULT;631 }632 633 *ppos += len;634 635 dev_dbg(dev, "%s: %zu bytes copied, %d bytes left\n",636 __func__, len, (int)(depth * 4 - *ppos));637 return len;638}639 640static int etb_release(struct inode *inode, struct file *file)641{642 struct etb_drvdata *drvdata = container_of(file->private_data,643 struct etb_drvdata, miscdev);644 local_set(&drvdata->reading, 0);645 646 dev_dbg(&drvdata->csdev->dev, "%s: released\n", __func__);647 return 0;648}649 650static const struct file_operations etb_fops = {651 .owner = THIS_MODULE,652 .open = etb_open,653 .read = etb_read,654 .release = etb_release,655};656 657static struct attribute *coresight_etb_mgmt_attrs[] = {658 coresight_simple_reg32(rdp, ETB_RAM_DEPTH_REG),659 coresight_simple_reg32(sts, ETB_STATUS_REG),660 coresight_simple_reg32(rrp, ETB_RAM_READ_POINTER),661 coresight_simple_reg32(rwp, ETB_RAM_WRITE_POINTER),662 coresight_simple_reg32(trg, ETB_TRG),663 coresight_simple_reg32(ctl, ETB_CTL_REG),664 coresight_simple_reg32(ffsr, ETB_FFSR),665 coresight_simple_reg32(ffcr, ETB_FFCR),666 NULL,667};668 669static ssize_t trigger_cntr_show(struct device *dev,670 struct device_attribute *attr, char *buf)671{672 struct etb_drvdata *drvdata = dev_get_drvdata(dev->parent);673 unsigned long val = drvdata->trigger_cntr;674 675 return sprintf(buf, "%#lx\n", val);676}677 678static ssize_t trigger_cntr_store(struct device *dev,679 struct device_attribute *attr,680 const char *buf, size_t size)681{682 int ret;683 unsigned long val;684 struct etb_drvdata *drvdata = dev_get_drvdata(dev->parent);685 686 ret = kstrtoul(buf, 16, &val);687 if (ret)688 return ret;689 690 drvdata->trigger_cntr = val;691 return size;692}693static DEVICE_ATTR_RW(trigger_cntr);694 695static struct attribute *coresight_etb_attrs[] = {696 &dev_attr_trigger_cntr.attr,697 NULL,698};699 700static const struct attribute_group coresight_etb_group = {701 .attrs = coresight_etb_attrs,702};703 704static const struct attribute_group coresight_etb_mgmt_group = {705 .attrs = coresight_etb_mgmt_attrs,706 .name = "mgmt",707};708 709static const struct attribute_group *coresight_etb_groups[] = {710 &coresight_etb_group,711 &coresight_etb_mgmt_group,712 NULL,713};714 715static int etb_probe(struct amba_device *adev, const struct amba_id *id)716{717 int ret;718 void __iomem *base;719 struct device *dev = &adev->dev;720 struct coresight_platform_data *pdata = NULL;721 struct etb_drvdata *drvdata;722 struct resource *res = &adev->res;723 struct coresight_desc desc = { 0 };724 725 desc.name = coresight_alloc_device_name(&etb_devs, dev);726 if (!desc.name)727 return -ENOMEM;728 729 drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);730 if (!drvdata)731 return -ENOMEM;732 733 drvdata->atclk = devm_clk_get(&adev->dev, "atclk"); /* optional */734 if (!IS_ERR(drvdata->atclk)) {735 ret = clk_prepare_enable(drvdata->atclk);736 if (ret)737 return ret;738 }739 dev_set_drvdata(dev, drvdata);740 741 /* validity for the resource is already checked by the AMBA core */742 base = devm_ioremap_resource(dev, res);743 if (IS_ERR(base))744 return PTR_ERR(base);745 746 drvdata->base = base;747 desc.access = CSDEV_ACCESS_IOMEM(base);748 749 spin_lock_init(&drvdata->spinlock);750 751 drvdata->buffer_depth = etb_get_buffer_depth(drvdata);752 753 if (drvdata->buffer_depth & 0x80000000)754 return -EINVAL;755 756 drvdata->buf = devm_kcalloc(dev,757 drvdata->buffer_depth, 4, GFP_KERNEL);758 if (!drvdata->buf)759 return -ENOMEM;760 761 /* This device is not associated with a session */762 drvdata->pid = -1;763 764 pdata = coresight_get_platform_data(dev);765 if (IS_ERR(pdata))766 return PTR_ERR(pdata);767 adev->dev.platform_data = pdata;768 769 desc.type = CORESIGHT_DEV_TYPE_SINK;770 desc.subtype.sink_subtype = CORESIGHT_DEV_SUBTYPE_SINK_BUFFER;771 desc.ops = &etb_cs_ops;772 desc.pdata = pdata;773 desc.dev = dev;774 desc.groups = coresight_etb_groups;775 drvdata->csdev = coresight_register(&desc);776 if (IS_ERR(drvdata->csdev))777 return PTR_ERR(drvdata->csdev);778 779 drvdata->miscdev.name = desc.name;780 drvdata->miscdev.minor = MISC_DYNAMIC_MINOR;781 drvdata->miscdev.fops = &etb_fops;782 ret = misc_register(&drvdata->miscdev);783 if (ret)784 goto err_misc_register;785 786 pm_runtime_put(&adev->dev);787 return 0;788 789err_misc_register:790 coresight_unregister(drvdata->csdev);791 return ret;792}793 794static void etb_remove(struct amba_device *adev)795{796 struct etb_drvdata *drvdata = dev_get_drvdata(&adev->dev);797 798 /*799 * Since misc_open() holds a refcount on the f_ops, which is800 * etb fops in this case, device is there until last file801 * handler to this device is closed.802 */803 misc_deregister(&drvdata->miscdev);804 coresight_unregister(drvdata->csdev);805}806 807#ifdef CONFIG_PM808static int etb_runtime_suspend(struct device *dev)809{810 struct etb_drvdata *drvdata = dev_get_drvdata(dev);811 812 if (drvdata && !IS_ERR(drvdata->atclk))813 clk_disable_unprepare(drvdata->atclk);814 815 return 0;816}817 818static int etb_runtime_resume(struct device *dev)819{820 struct etb_drvdata *drvdata = dev_get_drvdata(dev);821 822 if (drvdata && !IS_ERR(drvdata->atclk))823 clk_prepare_enable(drvdata->atclk);824 825 return 0;826}827#endif828 829static const struct dev_pm_ops etb_dev_pm_ops = {830 SET_RUNTIME_PM_OPS(etb_runtime_suspend, etb_runtime_resume, NULL)831};832 833static const struct amba_id etb_ids[] = {834 {835 .id = 0x000bb907,836 .mask = 0x000fffff,837 },838 { 0, 0, NULL },839};840 841MODULE_DEVICE_TABLE(amba, etb_ids);842 843static struct amba_driver etb_driver = {844 .drv = {845 .name = "coresight-etb10",846 .pm = &etb_dev_pm_ops,847 .suppress_bind_attrs = true,848 849 },850 .probe = etb_probe,851 .remove = etb_remove,852 .id_table = etb_ids,853};854 855module_amba_driver(etb_driver);856 857MODULE_AUTHOR("Pratik Patel <pratikp@codeaurora.org>");858MODULE_AUTHOR("Mathieu Poirier <mathieu.poirier@linaro.org>");859MODULE_DESCRIPTION("Arm CoreSight Embedded Trace Buffer driver");860MODULE_LICENSE("GPL v2");861