[PATCH v4 08/14] coresight: allow etm3x to be built as a module

[kim.phillips@arm.com (Kim Phillips)]

Allow to build coresight-etm3x as a module, for ease of development.

- Kconfig becomes a tristate, to allow =m
- append -core to source file name to allow module to
  be called coresight-etm3x by the Makefile
- add an etm_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>
---
 drivers/hwtracing/coresight/Kconfig           |  5 +++-
 drivers/hwtracing/coresight/Makefile          |  3 ++-
 ...resight-etm3x.c => coresight-etm3x-core.c} | 24 ++++++++++++++++++-
 3 files changed, 29 insertions(+), 3 deletions(-)
 rename drivers/hwtracing/coresight/{coresight-etm3x.c => coresight-etm3x-core.c} (97%)

diff --git a/drivers/hwtracing/coresight/Kconfig b/drivers/hwtracing/coresight/Kconfig
index 945b17ca2eed..56675e4f5a15 100644
--- a/drivers/hwtracing/coresight/Kconfig
+++ b/drivers/hwtracing/coresight/Kconfig
@@ -51,7 +51,7 @@ config CORESIGHT_SINK_ETBV10
 	  special enhancement or added features.
 
 config CORESIGHT_SOURCE_ETM3X
-	bool "CoreSight Embedded Trace Macrocell 3.x driver"
+	tristate "CoreSight Embedded Trace Macrocell 3.x driver"
 	depends on !ARM64
 	select CORESIGHT_LINKS_AND_SINKS
 	help
@@ -60,6 +60,9 @@ config CORESIGHT_SOURCE_ETM3X
 	  This is primarily useful for instruction level tracing.  Depending
 	  the ETM version data tracing may also be available.
 
+	  To compile this driver as a module, choose M here: the
+	  module will be called coresight-etm3x.
+
 config CORESIGHT_SOURCE_ETM4X
 	bool "CoreSight Embedded Trace Macrocell 4.x driver"
 	depends on ARM64
diff --git a/drivers/hwtracing/coresight/Makefile b/drivers/hwtracing/coresight/Makefile
index 61db9dd0d571..c3281e37e542 100644
--- a/drivers/hwtracing/coresight/Makefile
+++ b/drivers/hwtracing/coresight/Makefile
@@ -11,7 +11,8 @@ obj-$(CONFIG_CORESIGHT_SINK_TPIU) += coresight-tpiu.o
 obj-$(CONFIG_CORESIGHT_SINK_ETBV10) += coresight-etb10.o
 obj-$(CONFIG_CORESIGHT_LINKS_AND_SINKS) += coresight-funnel.o \
 					   coresight-replicator.o
-obj-$(CONFIG_CORESIGHT_SOURCE_ETM3X) += coresight-etm3x.o coresight-etm-cp14.o \
+obj-$(CONFIG_CORESIGHT_SOURCE_ETM3X) += coresight-etm3x.o
+coresight-etm3x-objs := coresight-etm3x-core.o coresight-etm-cp14.o \
 					coresight-etm3x-sysfs.o
 obj-$(CONFIG_CORESIGHT_SOURCE_ETM4X) += coresight-etm4x.o \
 					coresight-etm4x-sysfs.o
diff --git a/drivers/hwtracing/coresight/coresight-etm3x.c b/drivers/hwtracing/coresight/coresight-etm3x-core.c
similarity index 97%
rename from drivers/hwtracing/coresight/coresight-etm3x.c
rename to drivers/hwtracing/coresight/coresight-etm3x-core.c
index 7c74263c333d..d14c867e9e46 100644
--- a/drivers/hwtracing/coresight/coresight-etm3x.c
+++ b/drivers/hwtracing/coresight/coresight-etm3x-core.c
@@ -864,6 +864,20 @@ static int etm_probe(struct amba_device *adev, const struct amba_id *id)
 	return ret;
 }
 
+static int __exit etm_remove(struct amba_device *adev)
+{
+	struct etm_drvdata *drvdata = dev_get_drvdata(&adev->dev);
+
+	etm_perf_symlink(drvdata->csdev, false);
+
+	cpuhp_remove_state_nocalls(CPUHP_AP_ARM_CORESIGHT_STARTING);
+	cpuhp_remove_state_nocalls(hp_online);
+
+	coresight_unregister(drvdata->csdev);
+
+	return 0;
+}
+
 #ifdef CONFIG_PM
 static int etm_runtime_suspend(struct device *dev)
 {
@@ -924,6 +938,8 @@ static const struct amba_id etm_ids[] = {
 	{ 0, 0},
 };
 
+MODULE_DEVICE_TABLE(amba, etm_ids);
+
 static struct amba_driver etm_driver = {
 	.drv = {
 		.name	= "coresight-etm3x",
@@ -932,6 +948,12 @@ static struct amba_driver etm_driver = {
 		.suppress_bind_attrs = true,
 	},
 	.probe		= etm_probe,
+	.remove         = etm_remove,
 	.id_table	= etm_ids,
 };
-builtin_amba_driver(etm_driver);
+module_amba_driver(etm_driver);
+
+MODULE_AUTHOR("Pratik Patel <pratikp@codeaurora.org>");
+MODULE_AUTHOR("Mathieu Poirier <mathieu.poirier@linaro.org>");
+MODULE_DESCRIPTION("Arm CoreSight Program Flow Trace driver");
+MODULE_LICENSE("GPL v2");
-- 
2.17.0