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path: root/drivers/coresight/coresight.c
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Diffstat (limited to 'drivers/coresight/coresight.c')
-rw-r--r--drivers/coresight/coresight.c717
1 files changed, 717 insertions, 0 deletions
diff --git a/drivers/coresight/coresight.c b/drivers/coresight/coresight.c
new file mode 100644
index 000000000000..6e0181f84425
--- /dev/null
+++ b/drivers/coresight/coresight.c
@@ -0,0 +1,717 @@
+/* Copyright (c) 2012, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/err.h>
+#include <linux/export.h>
+#include <linux/slab.h>
+#include <linux/mutex.h>
+#include <linux/clk.h>
+#include <linux/coresight.h>
+#include <linux/of_platform.h>
+#include <linux/delay.h>
+
+#include "coresight-priv.h"
+
+static DEFINE_MUTEX(coresight_mutex);
+
+static int coresight_id_match(struct device *dev, void *data)
+{
+ int trace_id, i_trace_id;
+ struct coresight_device *csdev, *i_csdev;
+
+ csdev = data;
+ i_csdev = to_coresight_device(dev);
+
+ /*
+ * No need to care about oneself and components that are not
+ * sources or not enabled
+ */
+ if (i_csdev == csdev || !i_csdev->enable ||
+ i_csdev->type != CORESIGHT_DEV_TYPE_SOURCE)
+ return 0;
+
+ /* Get the source ID for both compoment */
+ trace_id = source_ops(csdev)->trace_id(csdev);
+ i_trace_id = source_ops(i_csdev)->trace_id(i_csdev);
+
+ /* All you need is one */
+ if (trace_id == i_trace_id)
+ return 1;
+
+ return 0;
+}
+
+static int coresight_source_is_unique(struct coresight_device *csdev)
+{
+ int trace_id = source_ops(csdev)->trace_id(csdev);
+
+ /* this shouldn't happen */
+ if (trace_id < 0)
+ return 0;
+
+ return !bus_for_each_dev(&coresight_bustype, NULL,
+ csdev, coresight_id_match);
+}
+
+static int coresight_find_link_inport(struct coresight_device *csdev)
+{
+ int i;
+ struct coresight_device *parent;
+ struct coresight_connection *conn;
+
+ parent = container_of(csdev->path_link.next,
+ struct coresight_device, path_link);
+
+ for (i = 0; i < parent->nr_outport; i++) {
+ conn = &parent->conns[i];
+ if (conn->child_dev == csdev)
+ return conn->child_port;
+ }
+
+ dev_err(&csdev->dev, "couldn't find inport, parent: %s, child: %s\n",
+ dev_name(&parent->dev), dev_name(&csdev->dev));
+
+ return 0;
+}
+
+static int coresight_find_link_outport(struct coresight_device *csdev)
+{
+ int i;
+ struct coresight_device *child;
+ struct coresight_connection *conn;
+
+ child = container_of(csdev->path_link.prev,
+ struct coresight_device, path_link);
+
+ for (i = 0; i < csdev->nr_outport; i++) {
+ conn = &csdev->conns[i];
+ if (conn->child_dev == child)
+ return conn->outport;
+ }
+
+ dev_err(&csdev->dev, "couldn't find outport, parent: %s, child: %s\n",
+ dev_name(&csdev->dev), dev_name(&child->dev));
+
+ return 0;
+}
+
+static int coresight_enable_sink(struct coresight_device *csdev)
+{
+ int ret;
+
+ if (!csdev->enable) {
+ if (sink_ops(csdev)->enable) {
+ ret = sink_ops(csdev)->enable(csdev);
+ if (ret)
+ return ret;
+ }
+ csdev->enable = true;
+ }
+
+ atomic_inc(csdev->refcnt);
+
+ return 0;
+}
+
+static void coresight_disable_sink(struct coresight_device *csdev)
+{
+ if (atomic_dec_return(csdev->refcnt) == 0) {
+ if (sink_ops(csdev)->disable) {
+ sink_ops(csdev)->disable(csdev);
+ csdev->enable = false;
+ }
+ }
+}
+
+static int coresight_enable_link(struct coresight_device *csdev)
+{
+ int ret;
+ int link_subtype;
+ int refport, inport, outport;
+
+ inport = coresight_find_link_inport(csdev);
+ outport = coresight_find_link_outport(csdev);
+ link_subtype = csdev->subtype.link_subtype;
+
+ if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_MERG)
+ refport = inport;
+ else if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_SPLIT)
+ refport = outport;
+ else
+ refport = 0;
+
+ if (atomic_inc_return(&csdev->refcnt[refport]) == 1) {
+ if (link_ops(csdev)->enable) {
+ ret = link_ops(csdev)->enable(csdev, inport, outport);
+ if (ret)
+ return ret;
+ }
+ }
+
+ csdev->enable = true;
+
+ return 0;
+}
+
+static void coresight_disable_link(struct coresight_device *csdev)
+{
+ int i, nr_conns;
+ int link_subtype;
+ int refport, inport, outport;
+
+ inport = coresight_find_link_inport(csdev);
+ outport = coresight_find_link_outport(csdev);
+ link_subtype = csdev->subtype.link_subtype;
+
+ if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_MERG) {
+ refport = inport;
+ nr_conns = csdev->nr_inport;
+ } else if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_SPLIT) {
+ refport = outport;
+ nr_conns = csdev->nr_outport;
+ } else {
+ refport = 0;
+ nr_conns = 1;
+ }
+
+ if (atomic_dec_return(&csdev->refcnt[refport]) == 0) {
+ if (link_ops(csdev)->disable)
+ link_ops(csdev)->disable(csdev, inport, outport);
+ }
+
+ for (i = 0; i < nr_conns; i++)
+ if (atomic_read(&csdev->refcnt[i]) != 0)
+ return;
+
+ csdev->enable = false;
+}
+
+static int coresight_enable_source(struct coresight_device *csdev)
+{
+ int ret;
+
+ if (!coresight_source_is_unique(csdev)) {
+ dev_warn(&csdev->dev, "traceID %d not unique\n",
+ source_ops(csdev)->trace_id(csdev));
+ return -EINVAL;
+ }
+
+ if (!csdev->enable) {
+ if (source_ops(csdev)->enable) {
+ ret = source_ops(csdev)->enable(csdev);
+ if (ret)
+ return ret;
+ }
+ csdev->enable = true;
+ }
+
+ atomic_inc(csdev->refcnt);
+
+ return 0;
+}
+
+static void coresight_disable_source(struct coresight_device *csdev)
+{
+ if (atomic_dec_return(csdev->refcnt) == 0) {
+ if (source_ops(csdev)->disable) {
+ source_ops(csdev)->disable(csdev);
+ csdev->enable = false;
+ }
+ }
+}
+
+static int coresight_enable_path(struct list_head *path)
+{
+ int ret = 0;
+ struct coresight_device *cd;
+
+ list_for_each_entry(cd, path, path_link) {
+ if (cd == list_first_entry(path, struct coresight_device,
+ path_link)) {
+ ret = coresight_enable_sink(cd);
+ } else if (list_is_last(&cd->path_link, path)) {
+ /*
+ * Don't enable the source just yet - this needs to
+ * happen at the very end when all links and sink
+ * along the path have been configured properly.
+ */
+ ;
+ } else {
+ ret = coresight_enable_link(cd);
+ }
+ if (ret)
+ goto err;
+ }
+
+ return 0;
+err:
+ list_for_each_entry_continue_reverse(cd, path, path_link) {
+ if (cd == list_first_entry(path, struct coresight_device,
+ path_link)) {
+ coresight_disable_sink(cd);
+ } else if (list_is_last(&cd->path_link, path)) {
+ ;
+ } else {
+ coresight_disable_link(cd);
+ }
+ }
+
+ return ret;
+}
+
+static int coresight_disable_path(struct list_head *path)
+{
+ struct coresight_device *cd;
+
+ list_for_each_entry_reverse(cd, path, path_link) {
+ if (cd == list_first_entry(path, struct coresight_device,
+ path_link)) {
+ coresight_disable_sink(cd);
+ } else if (list_is_last(&cd->path_link, path)) {
+ /*
+ * The source has already been stopped, no need
+ * to do it again here.
+ */
+ ;
+ } else {
+ coresight_disable_link(cd);
+ }
+ }
+
+ return 0;
+}
+
+static int coresight_build_paths(struct coresight_device *csdev,
+ struct list_head *path,
+ bool enable)
+{
+ int i, ret = -EINVAL;
+ struct coresight_connection *conn;
+
+ list_add(&csdev->path_link, path);
+
+ if (csdev->type == CORESIGHT_DEV_TYPE_SINK && csdev->activated) {
+ if (enable)
+ ret = coresight_enable_path(path);
+ else
+ ret = coresight_disable_path(path);
+ } else {
+ for (i = 0; i < csdev->nr_outport; i++) {
+ conn = &csdev->conns[i];
+ if (coresight_build_paths(conn->child_dev,
+ path, enable) == 0)
+ ret = 0;
+ }
+ }
+
+ if (list_first_entry(path, struct coresight_device, path_link) != csdev)
+ dev_err(&csdev->dev, "wrong device in %s\n", __func__);
+
+ list_del(&csdev->path_link);
+
+ return ret;
+}
+
+int coresight_enable(struct coresight_device *csdev)
+{
+ int ret = 0;
+ LIST_HEAD(path);
+
+ mutex_lock(&coresight_mutex);
+ if (csdev->type != CORESIGHT_DEV_TYPE_SOURCE) {
+ ret = -EINVAL;
+ dev_err(&csdev->dev, "wrong device type in %s\n", __func__);
+ goto out;
+ }
+ if (csdev->enable)
+ goto out;
+
+ if (coresight_build_paths(csdev, &path, true)) {
+ dev_err(&csdev->dev, "building path(s) failed\n");
+ goto out;
+ }
+
+ if (coresight_enable_source(csdev))
+ dev_err(&csdev->dev, "source enable failed\n");
+out:
+ mutex_unlock(&coresight_mutex);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(coresight_enable);
+
+void coresight_disable(struct coresight_device *csdev)
+{
+ LIST_HEAD(path);
+
+ mutex_lock(&coresight_mutex);
+ if (csdev->type != CORESIGHT_DEV_TYPE_SOURCE) {
+ dev_err(&csdev->dev, "wrong device type in %s\n", __func__);
+ goto out;
+ }
+ if (!csdev->enable)
+ goto out;
+
+ coresight_disable_source(csdev);
+ if (coresight_build_paths(csdev, &path, false))
+ dev_err(&csdev->dev, "releasing path(s) failed\n");
+
+out:
+ mutex_unlock(&coresight_mutex);
+}
+EXPORT_SYMBOL_GPL(coresight_disable);
+
+static ssize_t enable_sink_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct coresight_device *csdev = to_coresight_device(dev);
+
+ return scnprintf(buf, PAGE_SIZE, "%u\n", (unsigned)csdev->activated);
+}
+
+static ssize_t enable_sink_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t size)
+{
+ int ret;
+ unsigned long val;
+ struct coresight_device *csdev = to_coresight_device(dev);
+
+ ret = kstrtoul(buf, 10, &val);
+ if (ret)
+ return ret;
+
+ if (val)
+ csdev->activated = true;
+ else
+ csdev->activated = false;
+
+ return size;
+
+}
+static DEVICE_ATTR_RW(enable_sink);
+
+static ssize_t enable_source_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct coresight_device *csdev = to_coresight_device(dev);
+
+ return scnprintf(buf, PAGE_SIZE, "%u\n", (unsigned)csdev->enable);
+}
+
+static ssize_t enable_source_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t size)
+{
+ int ret = 0;
+ unsigned long val;
+ struct coresight_device *csdev = to_coresight_device(dev);
+
+ ret = kstrtoul(buf, 10, &val);
+ if (ret)
+ return ret;
+
+ if (val) {
+ ret = coresight_enable(csdev);
+ if (ret)
+ return ret;
+ } else {
+ coresight_disable(csdev);
+ }
+
+ return size;
+}
+static DEVICE_ATTR_RW(enable_source);
+
+static struct attribute *coresight_sink_attrs[] = {
+ &dev_attr_enable_sink.attr,
+ NULL,
+};
+ATTRIBUTE_GROUPS(coresight_sink);
+
+static struct attribute *coresight_source_attrs[] = {
+ &dev_attr_enable_source.attr,
+ NULL,
+};
+ATTRIBUTE_GROUPS(coresight_source);
+
+static struct device_type coresight_dev_type[] = {
+ {
+ .name = "none",
+ },
+ {
+ .name = "sink",
+ .groups = coresight_sink_groups,
+ },
+ {
+ .name = "link",
+ },
+ {
+ .name = "linksink",
+ .groups = coresight_sink_groups,
+ },
+ {
+ .name = "source",
+ .groups = coresight_source_groups,
+ },
+};
+
+static void coresight_device_release(struct device *dev)
+{
+ struct coresight_device *csdev = to_coresight_device(dev);
+
+ kfree(csdev);
+}
+
+static int coresight_orphan_match(struct device *dev, void *data)
+{
+ int i;
+ bool still_orphan = false;
+ struct coresight_device *csdev, *i_csdev;
+ struct coresight_connection *conn;
+
+ csdev = data;
+ i_csdev = to_coresight_device(dev);
+
+ /* No need to check oneself */
+ if (csdev == i_csdev)
+ return 0;
+
+ /* Move on to another component if no connection is orphan */
+ if (!i_csdev->orphan)
+ return 0;
+ /*
+ * Circle throuch all the connection of that component. If we find
+ * an orphan connection whose name matches @csdev, link it.
+ */
+ for (i = 0; i < i_csdev->nr_outport; i++) {
+ conn = &i_csdev->conns[i];
+
+ /* We have found at least one orphan connection */
+ if (conn->child_dev == NULL) {
+ /* Does it match this newly added device? */
+ if (!strcmp(dev_name(&csdev->dev), conn->child_name))
+ conn->child_dev = csdev;
+ } else {
+ /* Too bad, this component still has an orphan */
+ still_orphan = true;
+ }
+ }
+
+ i_csdev->orphan = still_orphan;
+
+ /*
+ * Returning '0' ensures that all known component on the
+ * bus will be checked.
+ */
+ return 0;
+}
+
+static void coresight_fixup_orphan_conns(struct coresight_device *csdev)
+{
+ /*
+ * No need to check for a return value as orphan connection(s)
+ * are hooked-up with each newly added component.
+ */
+ bus_for_each_dev(&coresight_bustype, NULL,
+ csdev, coresight_orphan_match);
+}
+
+
+static int coresight_name_match(struct device *dev, void *data)
+{
+ char *to_match;
+ struct coresight_device *i_csdev;
+
+ to_match = data;
+ i_csdev = to_coresight_device(dev);
+
+ if (!strcmp(to_match, dev_name(&i_csdev->dev)))
+ return 1;
+
+ return 0;
+}
+
+static void coresight_fixup_device_conns(struct coresight_device *csdev)
+{
+ int i;
+ struct device *dev = NULL;
+ struct coresight_connection *conn;
+
+ for (i = 0; i < csdev->nr_outport; i++) {
+ conn = &csdev->conns[i];
+ dev = bus_find_device(&coresight_bustype, NULL,
+ (void *)conn->child_name,
+ coresight_name_match);
+
+ if (dev) {
+ conn->child_dev = to_coresight_device(dev);
+ } else {
+ csdev->orphan = true;
+ conn->child_dev = NULL;
+ }
+ }
+}
+
+/**
+ * coresight_timeout - loop until a bit has changed to a specific state.
+ * @addr: base address of the area of interest.
+ * @offset: address of a register, starting from @addr.
+ * @position: the position of the bit of interest.
+ * @value: the value the bit should have.
+ *
+ * Return: 0 as soon as the bit has taken the desired state or -EAGAIN if
+ * TIMEOUT_US has elapsed, which ever happens first.
+ */
+
+int coresight_timeout(void __iomem *addr, u32 offset, int position, int value)
+{
+ int i;
+ u32 val;
+
+ for (i = TIMEOUT_US; i > 0; i--) {
+ val = __raw_readl(addr + offset);
+ /* waiting on the bit to go from 0 to 1 */
+ if (value) {
+ if (val & BIT(position))
+ return 0;
+ /* waiting on the bit to go from 1 to 0 */
+ } else {
+ if (!(val & BIT(position)))
+ return 0;
+ }
+
+ /*
+ * Delay is arbitrary - the specification doesn't say how long
+ * we are expected to wait. Extra check required to make sure
+ * we don't wait needlessly on the last iteration.
+ */
+ if (i - 1)
+ udelay(1);
+ }
+
+ return -EAGAIN;
+}
+
+struct bus_type coresight_bustype = {
+ .name = "coresight",
+};
+
+static int __init coresight_init(void)
+{
+ return bus_register(&coresight_bustype);
+}
+postcore_initcall(coresight_init);
+
+struct coresight_device *coresight_register(struct coresight_desc *desc)
+{
+ int i;
+ int ret;
+ int link_subtype;
+ int nr_refcnts = 1;
+ atomic_t *refcnts = NULL;
+ struct coresight_device *csdev;
+ struct coresight_connection *conns;
+
+ csdev = kzalloc(sizeof(*csdev), GFP_KERNEL);
+ if (!csdev) {
+ ret = -ENOMEM;
+ goto err_kzalloc_csdev;
+ }
+
+ if (desc->type == CORESIGHT_DEV_TYPE_LINK ||
+ desc->type == CORESIGHT_DEV_TYPE_LINKSINK) {
+ link_subtype = desc->subtype.link_subtype;
+
+ if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_MERG)
+ nr_refcnts = desc->pdata->nr_inport;
+ else if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_SPLIT)
+ nr_refcnts = desc->pdata->nr_outport;
+ }
+
+ refcnts = kcalloc(nr_refcnts, sizeof(*refcnts), GFP_KERNEL);
+ if (!refcnts) {
+ ret = -ENOMEM;
+ goto err_kzalloc_refcnts;
+ }
+
+ csdev->refcnt = refcnts;
+
+ csdev->nr_inport = desc->pdata->nr_inport;
+ csdev->nr_outport = desc->pdata->nr_outport;
+ conns = kcalloc(csdev->nr_outport, sizeof(*conns), GFP_KERNEL);
+ if (!conns) {
+ ret = -ENOMEM;
+ goto err_kzalloc_conns;
+ }
+
+ for (i = 0; i < csdev->nr_outport; i++) {
+ conns[i].outport = desc->pdata->outports[i];
+ conns[i].child_name = desc->pdata->child_names[i];
+ conns[i].child_port = desc->pdata->child_ports[i];
+ }
+
+ csdev->conns = conns;
+
+ csdev->type = desc->type;
+ csdev->subtype = desc->subtype;
+ csdev->ops = desc->ops;
+ csdev->orphan = false;
+
+ csdev->dev.type = &coresight_dev_type[desc->type];
+ csdev->dev.groups = desc->groups;
+ csdev->dev.parent = desc->dev;
+ csdev->dev.release = coresight_device_release;
+ csdev->dev.bus = &coresight_bustype;
+ dev_set_name(&csdev->dev, "%s", desc->pdata->name);
+
+ ret = device_register(&csdev->dev);
+ if (ret)
+ goto err_device_register;
+
+ mutex_lock(&coresight_mutex);
+
+ coresight_fixup_device_conns(csdev);
+ coresight_fixup_orphan_conns(csdev);
+
+ mutex_unlock(&coresight_mutex);
+
+ return csdev;
+
+err_device_register:
+ kfree(conns);
+err_kzalloc_conns:
+ kfree(refcnts);
+err_kzalloc_refcnts:
+ kfree(csdev);
+err_kzalloc_csdev:
+ return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(coresight_register);
+
+void coresight_unregister(struct coresight_device *csdev)
+{
+ mutex_lock(&coresight_mutex);
+
+ kfree(csdev->conns);
+ device_unregister(&csdev->dev);
+
+ mutex_unlock(&coresight_mutex);
+}
+EXPORT_SYMBOL_GPL(coresight_unregister);
+
+MODULE_LICENSE("GPL v2");