Coresight: Set correct cs_mode for TPDM to fix disable issue

The coresight_disable_source_sysfs function should verify the
mode of the coresight device before disabling the source.

However, the mode for the TPDM device is always set to
CS_MODE_DISABLED, resulting in the check consistently failing.
As a result, TPDM cannot be properly disabled.

Configure CS_MODE_SYSFS/CS_MODE_PERF during the enablement.
Configure CS_MODE_DISABLED during the disablement.

Fixes: b3c71626 ("Coresight: Add coresight TPDM source driver")
Signed-off-by: Jie Gan <quic_jiegan@quicinc.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20240812043043.2890694-1-quic_jiegan@quicinc.com

drivers/hwtracing/coresight/coresight-tpdm.c

@@ -449,6 +449,11 @@ static int tpdm_enable(struct coresight_device *csdev, struct perf_event *event,
 		return -EBUSY;
 	}
 
+	if (!coresight_take_mode(csdev, mode)) {
+		spin_unlock(&drvdata->spinlock);
+		return -EBUSY;
+	}
+
 	__tpdm_enable(drvdata);
 	drvdata->enable = true;
 	spin_unlock(&drvdata->spinlock);
@@ -506,6 +511,7 @@ static void tpdm_disable(struct coresight_device *csdev,
 	}
 
 	__tpdm_disable(drvdata);
+	coresight_set_mode(csdev, CS_MODE_DISABLED);
 	drvdata->enable = false;
 	spin_unlock(&drvdata->spinlock);