coresight: Enable and disable helper devices adjacent to the path

Currently CATU is the only helper device, and its enable and disable
calls are hard coded. To allow more helper devices to be added in a
generic way, remove these hard coded calls and just enable and disable
all helper devices.

This has to apply to helpers adjacent to the path, because they will
never be in the path. CATU was already discovered in this way, so
there is no change there.

One change that is needed is for CATU to call back into ETR to allocate
the buffer. Because the enable call was previously hard coded, it was
done at a point where the buffer was already allocated, but this is no
longer the case.

Reviewed-by: Mike Leach <mike.leach@linaro.org>
Signed-off-by: James Clark <james.clark@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230425143542.2305069-13-james.clark@arm.com

1 files changed, 6 insertions, 37 deletions

diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c
index 7993398bdcce..766325de0e29 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-etr.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c
@@ -775,40 +775,19 @@ static const struct etr_buf_operations etr_sg_buf_ops = {
 struct coresight_device *
 tmc_etr_get_catu_device(struct tmc_drvdata *drvdata)
 {
-	int i;
-	struct coresight_device *tmp, *etr = drvdata->csdev;
+	struct coresight_device *etr = drvdata->csdev;
+	union coresight_dev_subtype catu_subtype = {
+		.helper_subtype = CORESIGHT_DEV_SUBTYPE_HELPER_CATU
+	};
 
 	if (!IS_ENABLED(CONFIG_CORESIGHT_CATU))
 		return NULL;
 
-	for (i = 0; i < etr->pdata->nr_outconns; i++) {
-		tmp = etr->pdata->out_conns[i]->dest_dev;
-		if (tmp && coresight_is_catu_device(tmp))
-			return tmp;
-	}
-
-	return NULL;
+	return coresight_find_output_type(etr->pdata, CORESIGHT_DEV_TYPE_HELPER,
+					  catu_subtype);
 }
 EXPORT_SYMBOL_GPL(tmc_etr_get_catu_device);
 
-static inline int tmc_etr_enable_catu(struct tmc_drvdata *drvdata,
-				      struct etr_buf *etr_buf)
-{
-	struct coresight_device *catu = tmc_etr_get_catu_device(drvdata);
-
-	if (catu && helper_ops(catu)->enable)
-		return helper_ops(catu)->enable(catu, etr_buf);
-	return 0;
-}
-
-static inline void tmc_etr_disable_catu(struct tmc_drvdata *drvdata)
-{
-	struct coresight_device *catu = tmc_etr_get_catu_device(drvdata);
-
-	if (catu && helper_ops(catu)->disable)
-		helper_ops(catu)->disable(catu, drvdata->etr_buf);
-}
-
 static const struct etr_buf_operations *etr_buf_ops[] = {
 	[ETR_MODE_FLAT] = &etr_flat_buf_ops,
 	[ETR_MODE_ETR_SG] = &etr_sg_buf_ops,
@@ -1058,13 +1037,6 @@ static int tmc_etr_enable_hw(struct tmc_drvdata *drvdata,
 	if (WARN_ON(drvdata->etr_buf))
 		return -EBUSY;
 
-	/*
-	 * If this ETR is connected to a CATU, enable it before we turn
-	 * this on.
-	 */
-	rc = tmc_etr_enable_catu(drvdata, etr_buf);
-	if (rc)
-		return rc;
 	rc = coresight_claim_device(drvdata->csdev);
 	if (!rc) {
 		drvdata->etr_buf = etr_buf;
@@ -1072,7 +1044,6 @@ static int tmc_etr_enable_hw(struct tmc_drvdata *drvdata,
 		if (rc) {
 			drvdata->etr_buf = NULL;
 			coresight_disclaim_device(drvdata->csdev);
-			tmc_etr_disable_catu(drvdata);
 		}
 	}
 
@@ -1162,8 +1133,6 @@ static void __tmc_etr_disable_hw(struct tmc_drvdata *drvdata)
 void tmc_etr_disable_hw(struct tmc_drvdata *drvdata)
 {
 	__tmc_etr_disable_hw(drvdata);
-	/* Disable CATU device if this ETR is connected to one */
-	tmc_etr_disable_catu(drvdata);
 	coresight_disclaim_device(drvdata->csdev);
 	/* Reset the ETR buf used by hardware */
 	drvdata->etr_buf = NULL;