[PATCH v5 15/19] coresight: Add PM callbacks for sink device

[Leo Yan]

Unlike a system level's sink, the per-CPU sink may lose power during CPU
idle states. Currently, this refers specifically to TRBE as the sink.

This commit registers save and restore callbacks for the sink via the PM
notifier.

Tested-by: James Clark <james.clark at linaro.org>
Signed-off-by: Leo Yan <leo.yan at arm.com>
---
 drivers/hwtracing/coresight/coresight-core.c | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c
index 7a9f2c1b105d097cee846ba7ff54475483a0c8e0..ee97e4adbc395d4a4aa88846df91b0b53ae0bd8d 100644
--- a/drivers/hwtracing/coresight/coresight-core.c
+++ b/drivers/hwtracing/coresight/coresight-core.c
@@ -1647,6 +1647,22 @@ static bool coresight_pm_is_needed(struct coresight_device *csdev)
 	return coresight_ops(csdev)->pm_is_needed(csdev);
 }
 
+static int coresight_pm_sink_save(struct coresight_device *sink)
+{
+	if (!sink || !coresight_ops(sink)->pm_save_disable)
+		return 0;
+
+	return coresight_ops(sink)->pm_save_disable(sink);
+}
+
+static void coresight_pm_sink_restore(struct coresight_device *sink)
+{
+	if (!sink || !coresight_ops(sink)->pm_restore_enable)
+		return;
+
+	coresight_ops(sink)->pm_restore_enable(sink);
+}
+
 static int coresight_pm_save(struct coresight_device *csdev)
 {
 	int ret;
@@ -1665,7 +1681,18 @@ static int coresight_pm_save(struct coresight_device *csdev)
 
 	coresight_disable_helpers(csdev, csdev->path);
 	coresight_disable_path(csdev->path);
+
+	ret = coresight_pm_sink_save(coresight_get_sink(csdev->path));
+	if (ret)
+		goto failed_out;
+
 	return 0;
+
+failed_out:
+	coresight_enable_path(csdev->path, coresight_get_mode(csdev));
+	coresight_ops(csdev)->pm_restore_enable(csdev);
+	csdev->path->in_idle = false;
+	return ret;
 }
 
 static void coresight_pm_restore(struct coresight_device *csdev)
@@ -1673,6 +1700,7 @@ static void coresight_pm_restore(struct coresight_device *csdev)
 	if (WARN_ON(!csdev->path))
 		return;
 
+	coresight_pm_sink_restore(coresight_get_sink(csdev->path));
 	coresight_enable_path(csdev->path, coresight_get_mode(csdev));
 	coresight_ops(csdev)->pm_restore_enable(csdev);
 	csdev->path->in_idle = false;

-- 
2.34.1