coresight: etb: Allow etb to be built as a module

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>
Tested-by: Mike Leach <mike.leach@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Kim Phillips <kim.phillips@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/20200928163513.70169-12-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/hwtracing/coresight/Kconfig b/drivers/hwtracing/coresight/Kconfig
index d6e107b..996d84a 100644 (file)
--- 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 04ee9cd..248cc82 100644 (file)
--- a/drivers/hwtracing/coresight/coresight-etb10.c
+++ b/drivers/hwtracing/coresight/coresight-etb10.c
@@ -801,6 +801,21 @@ err_misc_register:
        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 +861,13 @@ 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");