coresight: catu: Allow catu drivers to be built as modules

Allow to build coresight-catu as modules, for ease of development.
- Kconfig becomes a tristate, to allow =m
- add catu_remove functions, for module unload
- add a MODULE_DEVICE_TABLE for autoloading on boot
Reviewed-by: Mike Leach <mike.leach@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Tingwei Zhang <tingwei@codeaurora.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20200928163513.70169-24-mathieu.poirier@linaro.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/hwtracing/coresight/Kconfig

@@ -42,7 +42,7 @@ config CORESIGHT_LINK_AND_SINK_TMC
 	  module will be called coresight-tmc.
 
 config CORESIGHT_CATU
-	bool "Coresight Address Translation Unit (CATU) driver"
+	tristate "Coresight Address Translation Unit (CATU) driver"
 	depends on CORESIGHT_LINK_AND_SINK_TMC
 	help
 	   Enable support for the Coresight Address Translation Unit (CATU).
@@ -52,6 +52,9 @@ config CORESIGHT_CATU
 	   by looking up the provided table. CATU can also be used in pass-through
 	   mode where the address is not translated.
 
+	   To compile this driver as a module, choose M here: the
+	   module will be called coresight-catu.
+
 config CORESIGHT_SINK_TPIU
 	tristate "Coresight generic TPIU driver"
 	depends on CORESIGHT_LINKS_AND_SINKS

drivers/hwtracing/coresight/coresight-catu.c

@@ -567,11 +567,21 @@ static int catu_probe(struct amba_device *adev, const struct amba_id *id)
 	return ret;
 }
 
+static int __exit catu_remove(struct amba_device *adev)
+{
+	struct catu_drvdata *drvdata = dev_get_drvdata(&adev->dev);
+
+	coresight_unregister(drvdata->csdev);
+	return 0;
+}
+
 static struct amba_id catu_ids[] = {
 	CS_AMBA_ID(0x000bb9ee),
 	{},
 };
 
+MODULE_DEVICE_TABLE(amba, catu_ids);
+
 static struct amba_driver catu_driver = {
 	.drv = {
 		.name			= "coresight-catu",
@@ -579,6 +589,7 @@ static struct amba_driver catu_driver = {
 		.suppress_bind_attrs	= true,
 	},
 	.probe				= catu_probe,
+	.remove				= catu_remove,
 	.id_table			= catu_ids,
 };
 
@@ -601,3 +612,7 @@ static void __exit catu_exit(void)
 
 module_init(catu_init);
 module_exit(catu_exit);
+
+MODULE_AUTHOR("Suzuki K Poulose <suzuki.poulose@arm.com>");
+MODULE_DESCRIPTION("Arm CoreSight Address Translation Unit (CATU) Driver");
+MODULE_LICENSE("GPL v2");