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path: root/drivers/hwtracing/coresight/coresight-etb10.c
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Diffstat (limited to 'drivers/hwtracing/coresight/coresight-etb10.c')
-rw-r--r--drivers/hwtracing/coresight/coresight-etb10.c863
1 files changed, 863 insertions, 0 deletions
diff --git a/drivers/hwtracing/coresight/coresight-etb10.c b/drivers/hwtracing/coresight/coresight-etb10.c
new file mode 100644
index 0000000000..fa80039e08
--- /dev/null
+++ b/drivers/hwtracing/coresight/coresight-etb10.c
@@ -0,0 +1,863 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2011-2012, The Linux Foundation. All rights reserved.
+ *
+ * Description: CoreSight Embedded Trace Buffer driver
+ */
+
+#include <linux/atomic.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/err.h>
+#include <linux/fs.h>
+#include <linux/miscdevice.h>
+#include <linux/uaccess.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/pm_runtime.h>
+#include <linux/seq_file.h>
+#include <linux/coresight.h>
+#include <linux/amba/bus.h>
+#include <linux/clk.h>
+#include <linux/circ_buf.h>
+#include <linux/mm.h>
+#include <linux/perf_event.h>
+
+
+#include "coresight-priv.h"
+#include "coresight-etm-perf.h"
+
+#define ETB_RAM_DEPTH_REG 0x004
+#define ETB_STATUS_REG 0x00c
+#define ETB_RAM_READ_DATA_REG 0x010
+#define ETB_RAM_READ_POINTER 0x014
+#define ETB_RAM_WRITE_POINTER 0x018
+#define ETB_TRG 0x01c
+#define ETB_CTL_REG 0x020
+#define ETB_RWD_REG 0x024
+#define ETB_FFSR 0x300
+#define ETB_FFCR 0x304
+#define ETB_ITMISCOP0 0xee0
+#define ETB_ITTRFLINACK 0xee4
+#define ETB_ITTRFLIN 0xee8
+#define ETB_ITATBDATA0 0xeeC
+#define ETB_ITATBCTR2 0xef0
+#define ETB_ITATBCTR1 0xef4
+#define ETB_ITATBCTR0 0xef8
+
+/* register description */
+/* STS - 0x00C */
+#define ETB_STATUS_RAM_FULL BIT(0)
+/* CTL - 0x020 */
+#define ETB_CTL_CAPT_EN BIT(0)
+/* FFCR - 0x304 */
+#define ETB_FFCR_EN_FTC BIT(0)
+#define ETB_FFCR_FON_MAN BIT(6)
+#define ETB_FFCR_STOP_FI BIT(12)
+#define ETB_FFCR_STOP_TRIGGER BIT(13)
+
+#define ETB_FFCR_BIT 6
+#define ETB_FFSR_BIT 1
+#define ETB_FRAME_SIZE_WORDS 4
+
+DEFINE_CORESIGHT_DEVLIST(etb_devs, "etb");
+
+/**
+ * struct etb_drvdata - specifics associated to an ETB component
+ * @base: memory mapped base address for this component.
+ * @atclk: optional clock for the core parts of the ETB.
+ * @csdev: component vitals needed by the framework.
+ * @miscdev: specifics to handle "/dev/xyz.etb" entry.
+ * @spinlock: only one at a time pls.
+ * @reading: synchronise user space access to etb buffer.
+ * @pid: Process ID of the process being monitored by the session
+ * that is using this component.
+ * @buf: area of memory where ETB buffer content gets sent.
+ * @mode: this ETB is being used.
+ * @buffer_depth: size of @buf.
+ * @trigger_cntr: amount of words to store after a trigger.
+ */
+struct etb_drvdata {
+ void __iomem *base;
+ struct clk *atclk;
+ struct coresight_device *csdev;
+ struct miscdevice miscdev;
+ spinlock_t spinlock;
+ local_t reading;
+ pid_t pid;
+ u8 *buf;
+ u32 mode;
+ u32 buffer_depth;
+ u32 trigger_cntr;
+};
+
+static int etb_set_buffer(struct coresight_device *csdev,
+ struct perf_output_handle *handle);
+
+static inline unsigned int etb_get_buffer_depth(struct etb_drvdata *drvdata)
+{
+ return readl_relaxed(drvdata->base + ETB_RAM_DEPTH_REG);
+}
+
+static void __etb_enable_hw(struct etb_drvdata *drvdata)
+{
+ int i;
+ u32 depth;
+
+ CS_UNLOCK(drvdata->base);
+
+ depth = drvdata->buffer_depth;
+ /* reset write RAM pointer address */
+ writel_relaxed(0x0, drvdata->base + ETB_RAM_WRITE_POINTER);
+ /* clear entire RAM buffer */
+ for (i = 0; i < depth; i++)
+ writel_relaxed(0x0, drvdata->base + ETB_RWD_REG);
+
+ /* reset write RAM pointer address */
+ writel_relaxed(0x0, drvdata->base + ETB_RAM_WRITE_POINTER);
+ /* reset read RAM pointer address */
+ writel_relaxed(0x0, drvdata->base + ETB_RAM_READ_POINTER);
+
+ writel_relaxed(drvdata->trigger_cntr, drvdata->base + ETB_TRG);
+ writel_relaxed(ETB_FFCR_EN_FTC | ETB_FFCR_STOP_TRIGGER,
+ drvdata->base + ETB_FFCR);
+ /* ETB trace capture enable */
+ writel_relaxed(ETB_CTL_CAPT_EN, drvdata->base + ETB_CTL_REG);
+
+ CS_LOCK(drvdata->base);
+}
+
+static int etb_enable_hw(struct etb_drvdata *drvdata)
+{
+ int rc = coresight_claim_device(drvdata->csdev);
+
+ if (rc)
+ return rc;
+
+ __etb_enable_hw(drvdata);
+ return 0;
+}
+
+static int etb_enable_sysfs(struct coresight_device *csdev)
+{
+ int ret = 0;
+ unsigned long flags;
+ struct etb_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+
+ spin_lock_irqsave(&drvdata->spinlock, flags);
+
+ /* Don't messup with perf sessions. */
+ if (drvdata->mode == CS_MODE_PERF) {
+ ret = -EBUSY;
+ goto out;
+ }
+
+ if (drvdata->mode == CS_MODE_DISABLED) {
+ ret = etb_enable_hw(drvdata);
+ if (ret)
+ goto out;
+
+ drvdata->mode = CS_MODE_SYSFS;
+ }
+
+ atomic_inc(&csdev->refcnt);
+out:
+ spin_unlock_irqrestore(&drvdata->spinlock, flags);
+ return ret;
+}
+
+static int etb_enable_perf(struct coresight_device *csdev, void *data)
+{
+ int ret = 0;
+ pid_t pid;
+ unsigned long flags;
+ struct etb_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+ struct perf_output_handle *handle = data;
+ struct cs_buffers *buf = etm_perf_sink_config(handle);
+
+ spin_lock_irqsave(&drvdata->spinlock, flags);
+
+ /* No need to continue if the component is already in used by sysFS. */
+ if (drvdata->mode == CS_MODE_SYSFS) {
+ ret = -EBUSY;
+ goto out;
+ }
+
+ /* Get a handle on the pid of the process to monitor */
+ pid = buf->pid;
+
+ if (drvdata->pid != -1 && drvdata->pid != pid) {
+ ret = -EBUSY;
+ goto out;
+ }
+
+ /*
+ * No HW configuration is needed if the sink is already in
+ * use for this session.
+ */
+ if (drvdata->pid == pid) {
+ atomic_inc(&csdev->refcnt);
+ goto out;
+ }
+
+ /*
+ * We don't have an internal state to clean up if we fail to setup
+ * the perf buffer. So we can perform the step before we turn the
+ * ETB on and leave without cleaning up.
+ */
+ ret = etb_set_buffer(csdev, handle);
+ if (ret)
+ goto out;
+
+ ret = etb_enable_hw(drvdata);
+ if (!ret) {
+ /* Associate with monitored process. */
+ drvdata->pid = pid;
+ drvdata->mode = CS_MODE_PERF;
+ atomic_inc(&csdev->refcnt);
+ }
+
+out:
+ spin_unlock_irqrestore(&drvdata->spinlock, flags);
+ return ret;
+}
+
+static int etb_enable(struct coresight_device *csdev, enum cs_mode mode,
+ void *data)
+{
+ int ret;
+
+ switch (mode) {
+ case CS_MODE_SYSFS:
+ ret = etb_enable_sysfs(csdev);
+ break;
+ case CS_MODE_PERF:
+ ret = etb_enable_perf(csdev, data);
+ break;
+ default:
+ ret = -EINVAL;
+ break;
+ }
+
+ if (ret)
+ return ret;
+
+ dev_dbg(&csdev->dev, "ETB enabled\n");
+ return 0;
+}
+
+static void __etb_disable_hw(struct etb_drvdata *drvdata)
+{
+ u32 ffcr;
+ struct device *dev = &drvdata->csdev->dev;
+ struct csdev_access *csa = &drvdata->csdev->access;
+
+ CS_UNLOCK(drvdata->base);
+
+ ffcr = readl_relaxed(drvdata->base + ETB_FFCR);
+ /* stop formatter when a stop has completed */
+ ffcr |= ETB_FFCR_STOP_FI;
+ writel_relaxed(ffcr, drvdata->base + ETB_FFCR);
+ /* manually generate a flush of the system */
+ ffcr |= ETB_FFCR_FON_MAN;
+ writel_relaxed(ffcr, drvdata->base + ETB_FFCR);
+
+ if (coresight_timeout(csa, ETB_FFCR, ETB_FFCR_BIT, 0)) {
+ dev_err(dev,
+ "timeout while waiting for completion of Manual Flush\n");
+ }
+
+ /* disable trace capture */
+ writel_relaxed(0x0, drvdata->base + ETB_CTL_REG);
+
+ if (coresight_timeout(csa, ETB_FFSR, ETB_FFSR_BIT, 1)) {
+ dev_err(dev,
+ "timeout while waiting for Formatter to Stop\n");
+ }
+
+ CS_LOCK(drvdata->base);
+}
+
+static void etb_dump_hw(struct etb_drvdata *drvdata)
+{
+ bool lost = false;
+ int i;
+ u8 *buf_ptr;
+ u32 read_data, depth;
+ u32 read_ptr, write_ptr;
+ u32 frame_off, frame_endoff;
+ struct device *dev = &drvdata->csdev->dev;
+
+ CS_UNLOCK(drvdata->base);
+
+ read_ptr = readl_relaxed(drvdata->base + ETB_RAM_READ_POINTER);
+ write_ptr = readl_relaxed(drvdata->base + ETB_RAM_WRITE_POINTER);
+
+ frame_off = write_ptr % ETB_FRAME_SIZE_WORDS;
+ frame_endoff = ETB_FRAME_SIZE_WORDS - frame_off;
+ if (frame_off) {
+ dev_err(dev,
+ "write_ptr: %lu not aligned to formatter frame size\n",
+ (unsigned long)write_ptr);
+ dev_err(dev, "frameoff: %lu, frame_endoff: %lu\n",
+ (unsigned long)frame_off, (unsigned long)frame_endoff);
+ write_ptr += frame_endoff;
+ }
+
+ if ((readl_relaxed(drvdata->base + ETB_STATUS_REG)
+ & ETB_STATUS_RAM_FULL) == 0) {
+ writel_relaxed(0x0, drvdata->base + ETB_RAM_READ_POINTER);
+ } else {
+ writel_relaxed(write_ptr, drvdata->base + ETB_RAM_READ_POINTER);
+ lost = true;
+ }
+
+ depth = drvdata->buffer_depth;
+ buf_ptr = drvdata->buf;
+ for (i = 0; i < depth; i++) {
+ read_data = readl_relaxed(drvdata->base +
+ ETB_RAM_READ_DATA_REG);
+ *(u32 *)buf_ptr = read_data;
+ buf_ptr += 4;
+ }
+
+ if (lost)
+ coresight_insert_barrier_packet(drvdata->buf);
+
+ if (frame_off) {
+ buf_ptr -= (frame_endoff * 4);
+ for (i = 0; i < frame_endoff; i++) {
+ *buf_ptr++ = 0x0;
+ *buf_ptr++ = 0x0;
+ *buf_ptr++ = 0x0;
+ *buf_ptr++ = 0x0;
+ }
+ }
+
+ writel_relaxed(read_ptr, drvdata->base + ETB_RAM_READ_POINTER);
+
+ CS_LOCK(drvdata->base);
+}
+
+static void etb_disable_hw(struct etb_drvdata *drvdata)
+{
+ __etb_disable_hw(drvdata);
+ etb_dump_hw(drvdata);
+ coresight_disclaim_device(drvdata->csdev);
+}
+
+static int etb_disable(struct coresight_device *csdev)
+{
+ struct etb_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+ unsigned long flags;
+
+ spin_lock_irqsave(&drvdata->spinlock, flags);
+
+ if (atomic_dec_return(&csdev->refcnt)) {
+ spin_unlock_irqrestore(&drvdata->spinlock, flags);
+ return -EBUSY;
+ }
+
+ /* Complain if we (somehow) got out of sync */
+ WARN_ON_ONCE(drvdata->mode == CS_MODE_DISABLED);
+ etb_disable_hw(drvdata);
+ /* Dissociate from monitored process. */
+ drvdata->pid = -1;
+ drvdata->mode = CS_MODE_DISABLED;
+ spin_unlock_irqrestore(&drvdata->spinlock, flags);
+
+ dev_dbg(&csdev->dev, "ETB disabled\n");
+ return 0;
+}
+
+static void *etb_alloc_buffer(struct coresight_device *csdev,
+ struct perf_event *event, void **pages,
+ int nr_pages, bool overwrite)
+{
+ int node;
+ struct cs_buffers *buf;
+
+ node = (event->cpu == -1) ? NUMA_NO_NODE : cpu_to_node(event->cpu);
+
+ buf = kzalloc_node(sizeof(struct cs_buffers), GFP_KERNEL, node);
+ if (!buf)
+ return NULL;
+
+ buf->pid = task_pid_nr(event->owner);
+ buf->snapshot = overwrite;
+ buf->nr_pages = nr_pages;
+ buf->data_pages = pages;
+
+ return buf;
+}
+
+static void etb_free_buffer(void *config)
+{
+ struct cs_buffers *buf = config;
+
+ kfree(buf);
+}
+
+static int etb_set_buffer(struct coresight_device *csdev,
+ struct perf_output_handle *handle)
+{
+ int ret = 0;
+ unsigned long head;
+ struct cs_buffers *buf = etm_perf_sink_config(handle);
+
+ if (!buf)
+ return -EINVAL;
+
+ /* wrap head around to the amount of space we have */
+ head = handle->head & ((buf->nr_pages << PAGE_SHIFT) - 1);
+
+ /* find the page to write to */
+ buf->cur = head / PAGE_SIZE;
+
+ /* and offset within that page */
+ buf->offset = head % PAGE_SIZE;
+
+ local_set(&buf->data_size, 0);
+
+ return ret;
+}
+
+static unsigned long etb_update_buffer(struct coresight_device *csdev,
+ struct perf_output_handle *handle,
+ void *sink_config)
+{
+ bool lost = false;
+ int i, cur;
+ u8 *buf_ptr;
+ const u32 *barrier;
+ u32 read_ptr, write_ptr, capacity;
+ u32 status, read_data;
+ unsigned long offset, to_read = 0, flags;
+ struct cs_buffers *buf = sink_config;
+ struct etb_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+
+ if (!buf)
+ return 0;
+
+ capacity = drvdata->buffer_depth * ETB_FRAME_SIZE_WORDS;
+
+ spin_lock_irqsave(&drvdata->spinlock, flags);
+
+ /* Don't do anything if another tracer is using this sink */
+ if (atomic_read(&csdev->refcnt) != 1)
+ goto out;
+
+ __etb_disable_hw(drvdata);
+ CS_UNLOCK(drvdata->base);
+
+ /* unit is in words, not bytes */
+ read_ptr = readl_relaxed(drvdata->base + ETB_RAM_READ_POINTER);
+ write_ptr = readl_relaxed(drvdata->base + ETB_RAM_WRITE_POINTER);
+
+ /*
+ * Entries should be aligned to the frame size. If they are not
+ * go back to the last alignment point to give decoding tools a
+ * chance to fix things.
+ */
+ if (write_ptr % ETB_FRAME_SIZE_WORDS) {
+ dev_err(&csdev->dev,
+ "write_ptr: %lu not aligned to formatter frame size\n",
+ (unsigned long)write_ptr);
+
+ write_ptr &= ~(ETB_FRAME_SIZE_WORDS - 1);
+ lost = true;
+ }
+
+ /*
+ * Get a hold of the status register and see if a wrap around
+ * has occurred. If so adjust things accordingly. Otherwise
+ * start at the beginning and go until the write pointer has
+ * been reached.
+ */
+ status = readl_relaxed(drvdata->base + ETB_STATUS_REG);
+ if (status & ETB_STATUS_RAM_FULL) {
+ lost = true;
+ to_read = capacity;
+ read_ptr = write_ptr;
+ } else {
+ to_read = CIRC_CNT(write_ptr, read_ptr, drvdata->buffer_depth);
+ to_read *= ETB_FRAME_SIZE_WORDS;
+ }
+
+ /*
+ * Make sure we don't overwrite data that hasn't been consumed yet.
+ * It is entirely possible that the HW buffer has more data than the
+ * ring buffer can currently handle. If so adjust the start address
+ * to take only the last traces.
+ *
+ * In snapshot mode we are looking to get the latest traces only and as
+ * such, we don't care about not overwriting data that hasn't been
+ * processed by user space.
+ */
+ if (!buf->snapshot && to_read > handle->size) {
+ u32 mask = ~(ETB_FRAME_SIZE_WORDS - 1);
+
+ /* The new read pointer must be frame size aligned */
+ to_read = handle->size & mask;
+ /*
+ * Move the RAM read pointer up, keeping in mind that
+ * everything is in frame size units.
+ */
+ read_ptr = (write_ptr + drvdata->buffer_depth) -
+ to_read / ETB_FRAME_SIZE_WORDS;
+ /* Wrap around if need be*/
+ if (read_ptr > (drvdata->buffer_depth - 1))
+ read_ptr -= drvdata->buffer_depth;
+ /* let the decoder know we've skipped ahead */
+ lost = true;
+ }
+
+ /*
+ * Don't set the TRUNCATED flag in snapshot mode because 1) the
+ * captured buffer is expected to be truncated and 2) a full buffer
+ * prevents the event from being re-enabled by the perf core,
+ * resulting in stale data being send to user space.
+ */
+ if (!buf->snapshot && lost)
+ perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED);
+
+ /* finally tell HW where we want to start reading from */
+ writel_relaxed(read_ptr, drvdata->base + ETB_RAM_READ_POINTER);
+
+ cur = buf->cur;
+ offset = buf->offset;
+ barrier = coresight_barrier_pkt;
+
+ for (i = 0; i < to_read; i += 4) {
+ buf_ptr = buf->data_pages[cur] + offset;
+ read_data = readl_relaxed(drvdata->base +
+ ETB_RAM_READ_DATA_REG);
+ if (lost && i < CORESIGHT_BARRIER_PKT_SIZE) {
+ read_data = *barrier;
+ barrier++;
+ }
+
+ *(u32 *)buf_ptr = read_data;
+ buf_ptr += 4;
+
+ offset += 4;
+ if (offset >= PAGE_SIZE) {
+ offset = 0;
+ cur++;
+ /* wrap around at the end of the buffer */
+ cur &= buf->nr_pages - 1;
+ }
+ }
+
+ /* reset ETB buffer for next run */
+ writel_relaxed(0x0, drvdata->base + ETB_RAM_READ_POINTER);
+ writel_relaxed(0x0, drvdata->base + ETB_RAM_WRITE_POINTER);
+
+ /*
+ * In snapshot mode we simply increment the head by the number of byte
+ * that were written. User space will figure out how many bytes to get
+ * from the AUX buffer based on the position of the head.
+ */
+ if (buf->snapshot)
+ handle->head += to_read;
+
+ __etb_enable_hw(drvdata);
+ CS_LOCK(drvdata->base);
+out:
+ spin_unlock_irqrestore(&drvdata->spinlock, flags);
+
+ return to_read;
+}
+
+static const struct coresight_ops_sink etb_sink_ops = {
+ .enable = etb_enable,
+ .disable = etb_disable,
+ .alloc_buffer = etb_alloc_buffer,
+ .free_buffer = etb_free_buffer,
+ .update_buffer = etb_update_buffer,
+};
+
+static const struct coresight_ops etb_cs_ops = {
+ .sink_ops = &etb_sink_ops,
+};
+
+static void etb_dump(struct etb_drvdata *drvdata)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&drvdata->spinlock, flags);
+ if (drvdata->mode == CS_MODE_SYSFS) {
+ __etb_disable_hw(drvdata);
+ etb_dump_hw(drvdata);
+ __etb_enable_hw(drvdata);
+ }
+ spin_unlock_irqrestore(&drvdata->spinlock, flags);
+
+ dev_dbg(&drvdata->csdev->dev, "ETB dumped\n");
+}
+
+static int etb_open(struct inode *inode, struct file *file)
+{
+ struct etb_drvdata *drvdata = container_of(file->private_data,
+ struct etb_drvdata, miscdev);
+
+ if (local_cmpxchg(&drvdata->reading, 0, 1))
+ return -EBUSY;
+
+ dev_dbg(&drvdata->csdev->dev, "%s: successfully opened\n", __func__);
+ return 0;
+}
+
+static ssize_t etb_read(struct file *file, char __user *data,
+ size_t len, loff_t *ppos)
+{
+ u32 depth;
+ struct etb_drvdata *drvdata = container_of(file->private_data,
+ struct etb_drvdata, miscdev);
+ struct device *dev = &drvdata->csdev->dev;
+
+ etb_dump(drvdata);
+
+ depth = drvdata->buffer_depth;
+ if (*ppos + len > depth * 4)
+ len = depth * 4 - *ppos;
+
+ if (copy_to_user(data, drvdata->buf + *ppos, len)) {
+ dev_dbg(dev,
+ "%s: copy_to_user failed\n", __func__);
+ return -EFAULT;
+ }
+
+ *ppos += len;
+
+ dev_dbg(dev, "%s: %zu bytes copied, %d bytes left\n",
+ __func__, len, (int)(depth * 4 - *ppos));
+ return len;
+}
+
+static int etb_release(struct inode *inode, struct file *file)
+{
+ struct etb_drvdata *drvdata = container_of(file->private_data,
+ struct etb_drvdata, miscdev);
+ local_set(&drvdata->reading, 0);
+
+ dev_dbg(&drvdata->csdev->dev, "%s: released\n", __func__);
+ return 0;
+}
+
+static const struct file_operations etb_fops = {
+ .owner = THIS_MODULE,
+ .open = etb_open,
+ .read = etb_read,
+ .release = etb_release,
+ .llseek = no_llseek,
+};
+
+static struct attribute *coresight_etb_mgmt_attrs[] = {
+ coresight_simple_reg32(rdp, ETB_RAM_DEPTH_REG),
+ coresight_simple_reg32(sts, ETB_STATUS_REG),
+ coresight_simple_reg32(rrp, ETB_RAM_READ_POINTER),
+ coresight_simple_reg32(rwp, ETB_RAM_WRITE_POINTER),
+ coresight_simple_reg32(trg, ETB_TRG),
+ coresight_simple_reg32(ctl, ETB_CTL_REG),
+ coresight_simple_reg32(ffsr, ETB_FFSR),
+ coresight_simple_reg32(ffcr, ETB_FFCR),
+ NULL,
+};
+
+static ssize_t trigger_cntr_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct etb_drvdata *drvdata = dev_get_drvdata(dev->parent);
+ unsigned long val = drvdata->trigger_cntr;
+
+ return sprintf(buf, "%#lx\n", val);
+}
+
+static ssize_t trigger_cntr_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t size)
+{
+ int ret;
+ unsigned long val;
+ struct etb_drvdata *drvdata = dev_get_drvdata(dev->parent);
+
+ ret = kstrtoul(buf, 16, &val);
+ if (ret)
+ return ret;
+
+ drvdata->trigger_cntr = val;
+ return size;
+}
+static DEVICE_ATTR_RW(trigger_cntr);
+
+static struct attribute *coresight_etb_attrs[] = {
+ &dev_attr_trigger_cntr.attr,
+ NULL,
+};
+
+static const struct attribute_group coresight_etb_group = {
+ .attrs = coresight_etb_attrs,
+};
+
+static const struct attribute_group coresight_etb_mgmt_group = {
+ .attrs = coresight_etb_mgmt_attrs,
+ .name = "mgmt",
+};
+
+static const struct attribute_group *coresight_etb_groups[] = {
+ &coresight_etb_group,
+ &coresight_etb_mgmt_group,
+ NULL,
+};
+
+static int etb_probe(struct amba_device *adev, const struct amba_id *id)
+{
+ int ret;
+ void __iomem *base;
+ struct device *dev = &adev->dev;
+ struct coresight_platform_data *pdata = NULL;
+ struct etb_drvdata *drvdata;
+ struct resource *res = &adev->res;
+ struct coresight_desc desc = { 0 };
+
+ desc.name = coresight_alloc_device_name(&etb_devs, dev);
+ if (!desc.name)
+ return -ENOMEM;
+
+ drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
+ if (!drvdata)
+ return -ENOMEM;
+
+ drvdata->atclk = devm_clk_get(&adev->dev, "atclk"); /* optional */
+ if (!IS_ERR(drvdata->atclk)) {
+ ret = clk_prepare_enable(drvdata->atclk);
+ if (ret)
+ return ret;
+ }
+ dev_set_drvdata(dev, drvdata);
+
+ /* validity for the resource is already checked by the AMBA core */
+ base = devm_ioremap_resource(dev, res);
+ if (IS_ERR(base))
+ return PTR_ERR(base);
+
+ drvdata->base = base;
+ desc.access = CSDEV_ACCESS_IOMEM(base);
+
+ spin_lock_init(&drvdata->spinlock);
+
+ drvdata->buffer_depth = etb_get_buffer_depth(drvdata);
+
+ if (drvdata->buffer_depth & 0x80000000)
+ return -EINVAL;
+
+ drvdata->buf = devm_kcalloc(dev,
+ drvdata->buffer_depth, 4, GFP_KERNEL);
+ if (!drvdata->buf)
+ return -ENOMEM;
+
+ /* This device is not associated with a session */
+ drvdata->pid = -1;
+
+ pdata = coresight_get_platform_data(dev);
+ if (IS_ERR(pdata))
+ return PTR_ERR(pdata);
+ adev->dev.platform_data = pdata;
+
+ desc.type = CORESIGHT_DEV_TYPE_SINK;
+ desc.subtype.sink_subtype = CORESIGHT_DEV_SUBTYPE_SINK_BUFFER;
+ desc.ops = &etb_cs_ops;
+ desc.pdata = pdata;
+ desc.dev = dev;
+ desc.groups = coresight_etb_groups;
+ drvdata->csdev = coresight_register(&desc);
+ if (IS_ERR(drvdata->csdev))
+ return PTR_ERR(drvdata->csdev);
+
+ drvdata->miscdev.name = desc.name;
+ drvdata->miscdev.minor = MISC_DYNAMIC_MINOR;
+ drvdata->miscdev.fops = &etb_fops;
+ ret = misc_register(&drvdata->miscdev);
+ if (ret)
+ goto err_misc_register;
+
+ pm_runtime_put(&adev->dev);
+ return 0;
+
+err_misc_register:
+ coresight_unregister(drvdata->csdev);
+ return ret;
+}
+
+static void etb_remove(struct amba_device *adev)
+{
+ struct etb_drvdata *drvdata = dev_get_drvdata(&adev->dev);
+
+ /*
+ * Since misc_open() holds a refcount on the f_ops, which is
+ * etb fops in this case, device is there until last file
+ * handler to this device is closed.
+ */
+ misc_deregister(&drvdata->miscdev);
+ coresight_unregister(drvdata->csdev);
+}
+
+#ifdef CONFIG_PM
+static int etb_runtime_suspend(struct device *dev)
+{
+ struct etb_drvdata *drvdata = dev_get_drvdata(dev);
+
+ if (drvdata && !IS_ERR(drvdata->atclk))
+ clk_disable_unprepare(drvdata->atclk);
+
+ return 0;
+}
+
+static int etb_runtime_resume(struct device *dev)
+{
+ struct etb_drvdata *drvdata = dev_get_drvdata(dev);
+
+ if (drvdata && !IS_ERR(drvdata->atclk))
+ clk_prepare_enable(drvdata->atclk);
+
+ return 0;
+}
+#endif
+
+static const struct dev_pm_ops etb_dev_pm_ops = {
+ SET_RUNTIME_PM_OPS(etb_runtime_suspend, etb_runtime_resume, NULL)
+};
+
+static const struct amba_id etb_ids[] = {
+ {
+ .id = 0x000bb907,
+ .mask = 0x000fffff,
+ },
+ { 0, 0},
+};
+
+MODULE_DEVICE_TABLE(amba, etb_ids);
+
+static struct amba_driver etb_driver = {
+ .drv = {
+ .name = "coresight-etb10",
+ .owner = THIS_MODULE,
+ .pm = &etb_dev_pm_ops,
+ .suppress_bind_attrs = true,
+
+ },
+ .probe = etb_probe,
+ .remove = etb_remove,
+ .id_table = etb_ids,
+};
+
+module_amba_driver(etb_driver);
+
+MODULE_AUTHOR("Pratik Patel <pratikp@codeaurora.org>");
+MODULE_AUTHOR("Mathieu Poirier <mathieu.poirier@linaro.org>");
+MODULE_DESCRIPTION("Arm CoreSight Embedded Trace Buffer driver");
+MODULE_LICENSE("GPL v2");