diff options
Diffstat (limited to 'drivers/hwtracing/coresight/coresight.c')
| -rw-r--r-- | drivers/hwtracing/coresight/coresight.c | 720 |
1 files changed, 720 insertions, 0 deletions
diff --git a/drivers/hwtracing/coresight/coresight.c b/drivers/hwtracing/coresight/coresight.c new file mode 100644 index 000000000000..894531d315b8 --- /dev/null +++ b/drivers/hwtracing/coresight/coresight.c @@ -0,0 +1,720 @@ +/* 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->type == CORESIGHT_DEV_TYPE_LINKSINK) && + 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 { + /* 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"); |