Add tmc_etr_get_ctcu_device function to find the ptr of the
coresight_device of the CTCU device if the CTCU device is connected to
the TMC ETR device.

Signed-off-by: Jie Gan <jie.gan@oss.qualcomm.com>
---
 drivers/hwtracing/coresight/coresight-tmc-etr.c | 24 ++++++++++++++++++++++++
 drivers/hwtracing/coresight/coresight-tmc.h     |  1 +
 2 files changed, 25 insertions(+)

diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c
index cbbb15648fb7..2ece3985e2bc 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-etr.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c
@@ -867,6 +867,30 @@ tmc_etr_get_catu_device(struct tmc_drvdata *drvdata)
 }
 EXPORT_SYMBOL_GPL(tmc_etr_get_catu_device);
 
+/*
+ * TMC ETR could be connected to a CTCU device, which can provide ATID filter
+ * and byte-cntr service. This is represented by the output port of the TMC
+ * (ETR) connected to the input port of the CTCU.
+ *
+ * Retruns	: coresight_device ptr for the CTCU device if a CTCU is found.
+ *		: NULL otherwise.
+ */
+struct coresight_device *
+tmc_etr_get_ctcu_device(struct tmc_drvdata *drvdata)
+{
+	struct coresight_device *etr = drvdata->csdev;
+	union coresight_dev_subtype ctcu_subtype = {
+		.helper_subtype = CORESIGHT_DEV_SUBTYPE_HELPER_CTCU
+	};
+
+	if (!IS_ENABLED(CONFIG_CORESIGHT_CTCU))
+		return NULL;
+
+	return coresight_find_output_type(etr->pdata, CORESIGHT_DEV_TYPE_HELPER,
+					  ctcu_subtype);
+}
+EXPORT_SYMBOL_GPL(tmc_etr_get_ctcu_device);
+
 static const struct etr_buf_operations *etr_buf_ops[] = {
 	[ETR_MODE_FLAT] = &etr_flat_buf_ops,
 	[ETR_MODE_ETR_SG] = &etr_sg_buf_ops,
diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h
index c780f6d5dede..8ea2de08ffd0 100644
--- a/drivers/hwtracing/coresight/coresight-tmc.h
+++ b/drivers/hwtracing/coresight/coresight-tmc.h
@@ -470,6 +470,7 @@ static inline uint32_t find_crash_tracedata_crc(struct tmc_drvdata *drvdata,
 }
 
 struct coresight_device *tmc_etr_get_catu_device(struct tmc_drvdata *drvdata);
+struct coresight_device *tmc_etr_get_ctcu_device(struct tmc_drvdata *drvdata);
 
 void tmc_etr_set_catu_ops(const struct etr_buf_operations *catu);
 void tmc_etr_remove_catu_ops(void);

-- 
2.34.1