Retrieving the helper device of the specific coresight device based on
its helper_subtype because a single coresight device may has multiple types
of the helper devices.
Reviewed-by: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Jie Gan <jie.gan@oss.qualcomm.com>
---
drivers/hwtracing/coresight/coresight-core.c | 35 ++++++++++++++++++++++++++++
drivers/hwtracing/coresight/coresight-priv.h | 2 ++
2 files changed, 37 insertions(+)
diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c
index 0e8448784c62..667883ccb4b7 100644
--- a/drivers/hwtracing/coresight/coresight-core.c
+++ b/drivers/hwtracing/coresight/coresight-core.c
@@ -585,6 +585,41 @@ struct coresight_device *coresight_get_sink(struct coresight_path *path)
}
EXPORT_SYMBOL_GPL(coresight_get_sink);
+/**
+ * coresight_get_helper: find the helper device of the assigned csdev.
+ *
+ * @csdev: The csdev the helper device is conntected to.
+ * @type: helper_subtype of the expected helper device.
+ *
+ * Retrieve the helper device for the specific csdev based on its
+ * helper_subtype.
+ *
+ * Return: the helper's csdev upon success or NULL for fail.
+ */
+struct coresight_device *coresight_get_helper(struct coresight_device *csdev,
+ enum coresight_dev_subtype_helper subtype)
+{
+ int i;
+ struct coresight_device *helper;
+
+ /* protect the connections */
+ mutex_lock(&coresight_mutex);
+ for (i = 0; i < csdev->pdata->nr_outconns; ++i) {
+ helper = csdev->pdata->out_conns[i]->dest_dev;
+ if (!helper || !coresight_is_helper(helper))
+ continue;
+
+ if (helper->subtype.helper_subtype == subtype) {
+ mutex_unlock(&coresight_mutex);
+ return helper;
+ }
+ }
+ mutex_unlock(&coresight_mutex);
+
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(coresight_get_helper);
+
/**
* coresight_get_in_port: Find the input port number at @csdev where a @remote
* device is connected to.
diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h
index cbf80b83e5ce..8e39a4dc7256 100644
--- a/drivers/hwtracing/coresight/coresight-priv.h
+++ b/drivers/hwtracing/coresight/coresight-priv.h
@@ -157,6 +157,8 @@ void coresight_path_assign_trace_id(struct coresight_path *path,
enum cs_mode mode);
int coresight_get_in_port(struct coresight_device *csdev,
struct coresight_device *remote);
+struct coresight_device *coresight_get_helper(struct coresight_device *csdev,
+ enum coresight_dev_subtype_helper subtype);
#if IS_ENABLED(CONFIG_CORESIGHT_SOURCE_ETM3X)
int etm_readl_cp14(u32 off, unsigned int *val);
--
2.34.1