[PATCH v4 09/14] coresight: allow etm4x to be built as a module

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

Allow to build coresight-etm4x 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-etm4x by the Makefile
- add an etm4_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          |  4 +--
 ...resight-etm4x.c => coresight-etm4x-core.c} | 25 ++++++++++++++++++-
 3 files changed, 30 insertions(+), 4 deletions(-)
 rename drivers/hwtracing/coresight/{coresight-etm4x.c => coresight-etm4x-core.c} (97%)

diff --git a/drivers/hwtracing/coresight/Kconfig b/drivers/hwtracing/coresight/Kconfig
index 56675e4f5a15..c32673f9177a 100644
--- a/drivers/hwtracing/coresight/Kconfig
+++ b/drivers/hwtracing/coresight/Kconfig
@@ -64,7 +64,7 @@ config CORESIGHT_SOURCE_ETM3X
 	  module will be called coresight-etm3x.
 
 config CORESIGHT_SOURCE_ETM4X
-	bool "CoreSight Embedded Trace Macrocell 4.x driver"
+	tristate "CoreSight Embedded Trace Macrocell 4.x driver"
 	depends on ARM64
 	select CORESIGHT_LINKS_AND_SINKS
 	help
@@ -73,6 +73,9 @@ config CORESIGHT_SOURCE_ETM4X
 	  for instruction level tracing. Depending on the implemented version
 	  data tracing may also be available.
 
+	  To compile this driver as a module, choose M here: the
+	  module will be called coresight-etm4x.
+
 config CORESIGHT_DYNAMIC_REPLICATOR
 	tristate "CoreSight Programmable Replicator driver"
 	depends on CORESIGHT_LINKS_AND_SINKS
diff --git a/drivers/hwtracing/coresight/Makefile b/drivers/hwtracing/coresight/Makefile
index c3281e37e542..1623ed266b04 100644
--- a/drivers/hwtracing/coresight/Makefile
+++ b/drivers/hwtracing/coresight/Makefile
@@ -14,8 +14,8 @@ obj-$(CONFIG_CORESIGHT_LINKS_AND_SINKS) += coresight-funnel.o \
 obj-$(CONFIG_CORESIGHT_SOURCE_ETM3X) += coresight-etm3x.o
 coresight-etm3x-objs := coresight-etm3x-core.o coresight-etm-cp14.o \
 					coresight-etm3x-sysfs.o
-obj-$(CONFIG_CORESIGHT_SOURCE_ETM4X) += coresight-etm4x.o \
-					coresight-etm4x-sysfs.o
+obj-$(CONFIG_CORESIGHT_SOURCE_ETM4X) += coresight-etm4x.o
+coresight-etm4x-objs := coresight-etm4x-core.o coresight-etm4x-sysfs.o
 obj-$(CONFIG_CORESIGHT_DYNAMIC_REPLICATOR) += coresight-dynamic-replicator.o
 obj-$(CONFIG_CORESIGHT_STM) += coresight-stm.o
 obj-$(CONFIG_CORESIGHT_CPU_DEBUG) += coresight-cpu-debug.o
diff --git a/drivers/hwtracing/coresight/coresight-etm4x.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
similarity index 97%
rename from drivers/hwtracing/coresight/coresight-etm4x.c
rename to drivers/hwtracing/coresight/coresight-etm4x-core.c
index 1d94ebec027b..0f4828c2268c 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
@@ -1046,6 +1046,20 @@ static int etm4_probe(struct amba_device *adev, const struct amba_id *id)
 	return ret;
 }
 
+static int __exit etm4_remove(struct amba_device *adev)
+{
+	struct etmv4_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;
+}
+
 #define ETM4x_AMBA_ID(pid)			\
 	{					\
 		.id	= pid,			\
@@ -1061,12 +1075,21 @@ static const struct amba_id etm4_ids[] = {
 	{},
 };
 
+MODULE_DEVICE_TABLE(amba, etm4_ids);
+
 static struct amba_driver etm4x_driver = {
 	.drv = {
 		.name   = "coresight-etm4x",
+		.owner  = THIS_MODULE,
 		.suppress_bind_attrs = true,
 	},
 	.probe		= etm4_probe,
+	.remove         = etm4_remove,
 	.id_table	= etm4_ids,
 };
-builtin_amba_driver(etm4x_driver);
+module_amba_driver(etm4x_driver);
+
+MODULE_AUTHOR("Pratik Patel <pratikp@codeaurora.org>");
+MODULE_AUTHOR("Mathieu Poirier <mathieu.poirier@linaro.org>");
+MODULE_DESCRIPTION("Arm CoreSight Program Flow Trace v4 driver");
+MODULE_LICENSE("GPL v2");
-- 
2.17.0