Re: [PATCH v4 04/11] coresight-tpdm: Add reset node to TPDM node

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



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,
  };




[Index of Archives]     [Device Tree Compilter]     [Device Tree Spec]     [Linux Driver Backports]     [Video for Linux]     [Linux USB Devel]     [Linux PCI Devel]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [XFree86]     [Yosemite Backpacking]


  Powered by Linux