[PATCH v4 12/14] coresight: allow tmc to be built as a module

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

Allow to build coresight-tmc 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-tmc by the Makefile
- add an tmc_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          |  6 ++---
 .../{coresight-tmc.c => coresight-tmc-core.c} | 22 ++++++++++++++++++-
 3 files changed, 28 insertions(+), 5 deletions(-)
 rename drivers/hwtracing/coresight/{coresight-tmc.c => coresight-tmc-core.c} (95%)

diff --git a/drivers/hwtracing/coresight/Kconfig b/drivers/hwtracing/coresight/Kconfig
index 2f44adb82361..ae05b4b89ff9 100644
--- a/drivers/hwtracing/coresight/Kconfig
+++ b/drivers/hwtracing/coresight/Kconfig
@@ -22,7 +22,7 @@ config CORESIGHT_LINKS_AND_SINKS
 	  entity at run time to form a complete trace path.
 
 config CORESIGHT_LINK_AND_SINK_TMC
-	bool "Coresight generic TMC driver"
+	tristate "Coresight generic TMC driver"
 	depends on CORESIGHT_LINKS_AND_SINKS
 	help
 	  This enables support for the Trace Memory Controller driver.
@@ -31,6 +31,9 @@ config CORESIGHT_LINK_AND_SINK_TMC
 	  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-tmc.
+
 config CORESIGHT_SINK_TPIU
 	tristate "Coresight generic TPIU driver"
 	depends on CORESIGHT_LINKS_AND_SINKS
diff --git a/drivers/hwtracing/coresight/Makefile b/drivers/hwtracing/coresight/Makefile
index 1623ed266b04..45d7a0f34170 100644
--- a/drivers/hwtracing/coresight/Makefile
+++ b/drivers/hwtracing/coresight/Makefile
@@ -4,9 +4,9 @@
 #
 obj-$(CONFIG_CORESIGHT) += coresight.o coresight-etm-perf.o
 obj-$(CONFIG_OF) += of_coresight.o
-obj-$(CONFIG_CORESIGHT_LINK_AND_SINK_TMC) += coresight-tmc.o \
-					     coresight-tmc-etf.o \
-					     coresight-tmc-etr.o
+obj-$(CONFIG_CORESIGHT_LINK_AND_SINK_TMC) += coresight-tmc.o
+coresight-tmc-objs := coresight-tmc-core.o coresight-tmc-etf.o \
+		      coresight-tmc-etr.o
 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 \
diff --git a/drivers/hwtracing/coresight/coresight-tmc.c b/drivers/hwtracing/coresight/coresight-tmc-core.c
similarity index 95%
rename from drivers/hwtracing/coresight/coresight-tmc.c
rename to drivers/hwtracing/coresight/coresight-tmc-core.c
index 1b817ec1192c..ec4867b81be8 100644
--- a/drivers/hwtracing/coresight/coresight-tmc.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-core.c
@@ -474,6 +474,19 @@ static int tmc_probe(struct amba_device *adev, const struct amba_id *id)
 	return ret;
 }
 
+static int __exit tmc_remove(struct amba_device *adev)
+{
+	struct tmc_drvdata *drvdata = dev_get_drvdata(&adev->dev);
+
+	/* free ETB/ETF or ETR memory */
+	tmc_read_unprepare(drvdata);
+
+	misc_deregister(&drvdata->miscdev);
+	coresight_unregister(drvdata->csdev);
+
+	return 0;
+}
+
 static const struct amba_id tmc_ids[] = {
 	{
 		.id     = 0x000bb961,
@@ -498,6 +511,8 @@ static const struct amba_id tmc_ids[] = {
 	{ 0, 0},
 };
 
+MODULE_DEVICE_TABLE(amba, tmc_ids);
+
 static struct amba_driver tmc_driver = {
 	.drv = {
 		.name   = "coresight-tmc",
@@ -505,6 +520,11 @@ static struct amba_driver tmc_driver = {
 		.suppress_bind_attrs = true,
 	},
 	.probe		= tmc_probe,
+	.remove		= tmc_remove,
 	.id_table	= tmc_ids,
 };
-builtin_amba_driver(tmc_driver);
+module_amba_driver(tmc_driver);
+
+MODULE_AUTHOR("Pratik Patel <pratikp@codeaurora.org>");
+MODULE_DESCRIPTION("Arm CoreSight Trace Memory Controller driver");
+MODULE_LICENSE("GPL v2");
-- 
2.17.0