[RFC PATCH 02/20] coresight: etm3x: implementing 'is_enabled()' API

From: Mathieu Poirier
Date: Fri Sep 18 2015 - 12:34:03 EST


Adding an interface to lookup the status of a tracer along with
a source operation allowing external customers to access it.

Signed-off-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
---
drivers/hwtracing/coresight/coresight-etm3x.c | 13 +++++++++++++
include/linux/coresight.h | 2 ++
2 files changed, 15 insertions(+)

diff --git a/drivers/hwtracing/coresight/coresight-etm3x.c b/drivers/hwtracing/coresight/coresight-etm3x.c
index 999c62a59c70..a44bc3532585 100644
--- a/drivers/hwtracing/coresight/coresight-etm3x.c
+++ b/drivers/hwtracing/coresight/coresight-etm3x.c
@@ -374,6 +374,18 @@ static int etm_configure(struct coresight_device *csdev)
etm_configure_cpu, csdev, 1);
}

+static bool etm_is_enabled(struct coresight_device *csdev)
+{
+ bool enabled;
+ struct etm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+
+ spin_lock(&drvdata->spinlock);
+ enabled = drvdata->enable;
+ spin_unlock(&drvdata->spinlock);
+
+ return enabled;
+}
+
/**
* etm_trace_enable - enable ETM tracer
* @csdev - the etm that needs to be enabled/disabled.
@@ -525,6 +537,7 @@ static void etm_disable(struct coresight_device *csdev)

static const struct coresight_ops_source etm_source_ops = {
.trace_id = etm_trace_id,
+ .is_enabled = etm_is_enabled,
.configure = etm_configure,
.trace_enable = etm_trace_enable,
.enable = etm_enable,
diff --git a/include/linux/coresight.h b/include/linux/coresight.h
index 70f3dafa5194..d16e874079b7 100644
--- a/include/linux/coresight.h
+++ b/include/linux/coresight.h
@@ -207,6 +207,7 @@ struct coresight_ops_link {
* Operations available for sources.
* @trace_id: returns the value of the component's trace ID as known
* to the HW.
+ * @is_enabled: returns whether a source has been enabled or not.
* @configure: performs configuration for a source but doesn't enable it.
* @trace_enable: enable/disable tracing on a source.
* @enable: enables tracing for a source.
@@ -216,6 +217,7 @@ struct coresight_ops_link {
*/
struct coresight_ops_source {
int (*trace_id)(struct coresight_device *csdev);
+ bool (*is_enabled)(struct coresight_device *csdev);
int (*configure)(struct coresight_device *csdev);
int (*trace_enable)(struct coresight_device *csdev, bool enable);
int (*enable)(struct coresight_device *csdev);
--
1.9.1

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