[PATCH v8 11/24] coresight: etb: allow etb to be built as a module

Tingwei Zhang
2020-08-07T11:16:12Z

From: Kim Phillips <kim.phillips@arm.com>

Allow to build coresight-etb10 as a module, for ease of development.

- Kconfig becomes a tristate, to allow =m
- add an etb_remove function, for module unload
- add a MODULE_DEVICE_TABLE for autoloading on boot

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Suzuki K Poulose <Suzuki.Poulose@arm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Russell King <linux@armlinux.org.uk>
Signed-off-by: Kim Phillips <kim.phillips@arm.com>
Signed-off-by: Tingwei Zhang <tingwei@codeaurora.org>
Tested-by: Mike Leach <mike.leach@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
drivers/hwtracing/coresight/Kconfig | 5 +++-
drivers/hwtracing/coresight/coresight-etb10.c | 25 ++++++++++++++++++-
2 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/drivers/hwtracing/coresight/Kconfig b/drivers/hwtracing/coresight/Kconfig
index d6e107bbd30b..996d84a1edb8 100644
--- a/drivers/hwtracing/coresight/Kconfig
+++ b/drivers/hwtracing/coresight/Kconfig
@@ -57,13 +57,16 @@ config CORESIGHT_SINK_TPIU
the on-board coresight memory can handle.

config CORESIGHT_SINK_ETBV10
- bool "Coresight ETBv1.0 driver"
+ tristate "Coresight ETBv1.0 driver"
depends on CORESIGHT_LINKS_AND_SINKS
help
This enables support for the Embedded Trace Buffer version 1.0 driver
that complies with the generic implementation of the component without
special enhancement or added features.

+ To compile this driver as a module, choose M here: the
+ module will be called coresight-etb10.
+
config CORESIGHT_SOURCE_ETM3X
tristate "CoreSight Embedded Trace Macrocell 3.x driver"
depends on !ARM64
diff --git a/drivers/hwtracing/coresight/coresight-etb10.c b/drivers/hwtracing/coresight/coresight-etb10.c
index 04ee9cda988d..29ef6c7f7be5 100644
--- a/drivers/hwtracing/coresight/coresight-etb10.c
+++ b/drivers/hwtracing/coresight/coresight-etb10.c
@@ -801,6 +801,21 @@ static int etb_probe(struct amba_device *adev, const struct amba_id *id)
return ret;
}

+static int __exit etb_remove(struct amba_device *adev)
+{
+ struct etb_drvdata *drvdata = dev_get_drvdata(&adev->dev);
+
+ /*
+ * Since misc_open() holds a refcount on the f_ops, which is
+ * etb fops in this case, device is there until last file
+ * handler to this device is closed.
+ */
+ misc_deregister(&drvdata->miscdev);
+ coresight_unregister(drvdata->csdev);
+
+ return 0;
+}
+
#ifdef CONFIG_PM
static int etb_runtime_suspend(struct device *dev)
{
@@ -835,6 +850,8 @@ static const struct amba_id etb_ids[] = {
{ 0, 0},
};

+MODULE_DEVICE_TABLE(amba, etb_ids);
+
static struct amba_driver etb_driver = {
.drv = {
.name = "coresight-etb10",
@@ -844,6 +861,12 @@ static struct amba_driver etb_driver = {

},
.probe = etb_probe,
+ .remove = etb_remove,
.id_table = etb_ids,
};
-builtin_amba_driver(etb_driver);
+module_amba_driver(etb_driver);
+
+MODULE_AUTHOR("Pratik Patel <pratikp@codeaurora.org>");
+MODULE_AUTHOR("Mathieu Poirier <mathieu.poirier@linaro.org>");
+MODULE_DESCRIPTION("Arm CoreSight Embedded Trace Buffer driver");
+MODULE_LICENSE("GPL v2");
--
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