On 27/04/2023 10:00, Tao Zhang wrote:
TPDM device need a node to reset the configurations and status of
it. This change provides a node to reset the configurations and
disable the TPDM if it has been enabled.
Signed-off-by: Tao Zhang <quic_taozha@xxxxxxxxxxx>
---
.../ABI/testing/sysfs-bus-coresight-devices-tpdm | 10 ++++++++
drivers/hwtracing/coresight/coresight-tpdm.c | 27 ++++++++++++++++++++++
2 files changed, 37 insertions(+)
diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm
index 4a58e64..686bdde 100644
--- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm
+++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm
@@ -11,3 +11,13 @@ Description:
Accepts only one of the 2 values - 1 or 2.
1 : Generate 64 bits data
2 : Generate 32 bits data
+
+What: /sys/bus/coresight/devices/<tpdm-name>/reset
+Date: March 2023
+KernelVersion 6.3
+Contact: Jinlong Mao (QUIC) <quic_jinlmao@xxxxxxxxxxx>, Tao Zhang (QUIC) <quic_taozha@xxxxxxxxxxx>
+Description:
+ (Write) Reset the dataset of the tpdm, and disable the tpdm.
+
+ Accepts only one value - 1.
+ 1 : Reset the dataset of the tpdm
diff --git a/drivers/hwtracing/coresight/coresight-tpdm.c b/drivers/hwtracing/coresight/coresight-tpdm.c
index 6f8a8ab..2e64cfd 100644
--- a/drivers/hwtracing/coresight/coresight-tpdm.c
+++ b/drivers/hwtracing/coresight/coresight-tpdm.c
@@ -164,6 +164,32 @@ static int tpdm_datasets_setup(struct tpdm_drvdata *drvdata)
return 0;
}
+static ssize_t reset_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf,
+ size_t size)
+{
+ int ret = 0;
+ unsigned long val;
+ struct tpdm_drvdata *drvdata = dev_get_drvdata(dev->parent);
+
+ ret = kstrtoul(buf, 10, &val);
+ if (ret || val != 1)
+ return -EINVAL;
+
+ spin_lock(&drvdata->spinlock);
+ tpdm_reset_datasets(drvdata);
+
+ spin_unlock(&drvdata->spinlock);
+
+ /* Disable tpdm if enabled */
+ if (drvdata->enable)
+ coresight_disable_source(drvdata->csdev, NULL);
I am not really keen on doing this behind the back. What about the path
of components ? We could simply reject the request when the TPDA is
enabled and let the user alway follow :
1) Disable the TPDM manually via sysfs
2) Reset the TPDM.
So, please remove the disable step here.
Suzuki
+
+ return size;
+}
+static DEVICE_ATTR_WO(reset);
+
/*
* value 1: 64 bits test data
* value 2: 32 bits test data
@@ -204,6 +230,7 @@ static ssize_t integration_test_store(struct device *dev,
static DEVICE_ATTR_WO(integration_test);
static struct attribute *tpdm_attrs[] = {
+ &dev_attr_reset.attr,
&dev_attr_integration_test.attr,
NULL,
};
