Hi Suzuki,
On 3/24/2023 6:44 PM, Suzuki K Poulose wrote:
On 24/03/2023 06:16, Hao Zhang wrote:
Some Coresight devices that HLOS don't have permission to access
or configure. Such as Coresight sink EUD, some TPDMs etc. So there
need driver to register dummy devices as Coresight devices. Provide
Coresight API for dummy device operations, such as enabling and
disabling dummy devices. Build the Coresight path for dummy sink or
dummy source for debugging.
Signed-off-by: Hao Zhang <quic_hazha@xxxxxxxxxxx>
---
drivers/hwtracing/coresight/Kconfig | 11 ++
drivers/hwtracing/coresight/Makefile | 1 +
drivers/hwtracing/coresight/coresight-dummy.c | 176 ++++++++++++++++++
3 files changed, 188 insertions(+)
create mode 100644 drivers/hwtracing/coresight/coresight-dummy.c
diff --git a/drivers/hwtracing/coresight/Kconfig
b/drivers/hwtracing/coresight/Kconfig
index 2b5bbfffbc4f..06f0a7594169 100644
--- a/drivers/hwtracing/coresight/Kconfig
+++ b/drivers/hwtracing/coresight/Kconfig
@@ -236,4 +236,15 @@ config CORESIGHT_TPDA
To compile this driver as a module, choose M here: the module
will be
called coresight-tpda.
+
+config CORESIGHT_DUMMY
+ tristate "Dummy driver support"
+ help
+ Enables support for dummy driver. Dummy driver can be used for
+ CoreSight sources/sinks that are owned and configured by some
+ other subsystem and use Linux drivers to configure rest of trace
+ path.
+
+ To compile this driver as a module, choose M here: the module
will be
+ called coresight-dummy.
endif
diff --git a/drivers/hwtracing/coresight/Makefile
b/drivers/hwtracing/coresight/Makefile
index 33bcc3f7b8ae..995d3b2c76df 100644
--- a/drivers/hwtracing/coresight/Makefile
+++ b/drivers/hwtracing/coresight/Makefile
@@ -30,3 +30,4 @@ obj-$(CONFIG_CORESIGHT_TPDA) += coresight-tpda.o
coresight-cti-y := coresight-cti-core.o coresight-cti-platform.o \
coresight-cti-sysfs.o
obj-$(CONFIG_ULTRASOC_SMB) += ultrasoc-smb.o
+obj-$(CONFIG_CORESIGHT_DUMMY) += coresight-dummy.o
diff --git a/drivers/hwtracing/coresight/coresight-dummy.c
b/drivers/hwtracing/coresight/coresight-dummy.c
new file mode 100644
index 000000000000..2d4eb3e546eb
--- /dev/null
+++ b/drivers/hwtracing/coresight/coresight-dummy.c
@@ -0,0 +1,176 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2023 Qualcomm Innovation Center, Inc. All rights
reserved.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/coresight.h>
+#include <linux/of.h>
+#include <linux/pm_runtime.h>
+
+#include "coresight-priv.h"
+#include "coresight-trace-id.h"
+
+struct dummy_drvdata {
+ struct device *dev;
+ struct coresight_device *csdev;
+ int traceid;
+};
+
+DEFINE_CORESIGHT_DEVLIST(dummy_devs, "dummy");
+
+static int dummy_source_enable(struct coresight_device *csdev,
+ struct perf_event *event, u32 mode)
+{
+ struct dummy_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+
+ dev_info(drvdata->dev, "Dummy source enabled\n");
Please use dev_dbg everywher.
Sure, I will change to dev_dbg in the next patch series.
+
+ return 0;
+}
+
+static void dummy_source_disable(struct coresight_device *csdev,
+ struct perf_event *event)
+{
+ struct dummy_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+
+ dev_info(drvdata->dev, "Dummy source disabled\n");
+}
+
+static int dummy_sink_enable(struct coresight_device *csdev, u32 mode,
+ void *data)
+{
+ struct dummy_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+
+ dev_info(drvdata->dev, "Dummy sink enabled\n");
+
+ return 0;
+}
+
+static int dummy_sink_disable(struct coresight_device *csdev)
+{
+ struct dummy_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+
+ dev_info(drvdata->dev, "Dummy sink disabled\n");
+
+ return 0;
+}
+
+static const struct coresight_ops_source dummy_source_ops = {
+ .enable = dummy_source_enable,
+ .disable = dummy_source_disable,
+};
+
+static const struct coresight_ops_sink dummy_sink_ops = {
+ .enable = dummy_sink_enable,
+ .disable = dummy_sink_disable,
+};
+
+static const struct coresight_ops dummy_cs_ops = {
+ .source_ops = &dummy_source_ops,
+ .sink_ops = &dummy_sink_ops,
+};
+
+static int dummy_probe(struct platform_device *pdev)
+{
+ int ret, trace_id;
+ struct device *dev = &pdev->dev;
+ struct coresight_platform_data *pdata;
+ struct dummy_drvdata *drvdata;
+ struct coresight_desc desc = { 0 };
+
+ desc.name = coresight_alloc_device_name(&dummy_devs, dev);
+ if (!desc.name)
+ return -ENOMEM;
+
+ pdata = coresight_get_platform_data(dev);
+ if (IS_ERR(pdata))
+ return PTR_ERR(pdata);
+ pdev->dev.platform_data = pdata;
+
+ drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
+ if (!drvdata)
+ return -ENOMEM;
+
+ drvdata->dev = &pdev->dev;
+ platform_set_drvdata(pdev, drvdata);
+
+ if (of_property_read_bool(pdev->dev.of_node, "qcom,dummy-source")) {
I don't see any reason why this should be qcom,...
Please could we use : "arm,coresight-", everywhere including the "dt"
compatible ?
It's not only for qcom device, I will update this according to your
advice in the next patch series.
+ desc.type = CORESIGHT_DEV_TYPE_SOURCE;
+ desc.subtype.source_subtype =
+ CORESIGHT_DEV_SUBTYPE_SOURCE_OTHERS;
+ } else if (of_property_read_bool(pdev->dev.of_node,
+ "qcom,dummy-sink")) {
+ desc.type = CORESIGHT_DEV_TYPE_SINK;
+ desc.subtype.sink_subtype = CORESIGHT_DEV_SUBTYPE_SINK_BUFFER;
+ } else {
+ dev_info(dev, "Device type not set\n");
+ return -EINVAL;
+ }
+
+ desc.ops = &dummy_cs_ops;
+ desc.pdata = pdev->dev.platform_data;
+ desc.dev = &pdev->dev;
+ drvdata->csdev = coresight_register(&desc);
+ if (IS_ERR(drvdata->csdev))
+ return PTR_ERR(drvdata->csdev);
+
+ trace_id = coresight_trace_id_get_system_id();
+ if (trace_id < 0) {
+ ret = trace_id;
+ goto cs_unregister;
+ }
+ drvdata->traceid = (u8)trace_id;
+
+ pm_runtime_enable(dev);
+ dev_info(dev, "Dummy device initialized\n");
+
+ return 0;
+
+cs_unregister:
+ coresight_unregister(drvdata->csdev);
+
+ return ret;
+}
+
+static int dummy_remove(struct platform_device *pdev)
+{
+ struct dummy_drvdata *drvdata = platform_get_drvdata(pdev);
+ struct device *dev = &pdev->dev;
+
+ coresight_trace_id_put_system_id(drvdata->traceid);
+ pm_runtime_disable(dev);
+ coresight_unregister(drvdata->csdev);
+ return 0;
+}
+
+static const struct of_device_id dummy_match[] = {
+ {.compatible = "qcom,coresight-dummy"},
As mentioned above, "arm,coresight-dummy-device" ? This has
nothing to do with qcom IP. qcom has a use for this. So, I would
like to keep this "coresight" subsystem specific compatibles.
May be we could even add other types too : i.e,
arm,coresight-dummy-link-split, arm,coresight-dummy-link-merge
Suzuki
I will change this it to "arm,coresight-dummy-device" in the next patch
series.
Thanks,
Hao
+ {},
+};
+
+static struct platform_driver dummy_driver = {
+ .probe = dummy_probe,
+ .remove = dummy_remove,
+ .driver = {
+ .name = "coresight-dummy",
+ .of_match_table = dummy_match,
+ },
+};
+
+static int __init dummy_init(void)
+{
+ return platform_driver_register(&dummy_driver);
+}
+module_init(dummy_init);
+
+static void __exit dummy_exit(void)
+{
+ platform_driver_unregister(&dummy_driver);
+}
+module_exit(dummy_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("CoreSight dummy source driver");
