greybus: tracing: add module traces

Define a new gb_module trace point event class, used to trace events
associated with the module abstraction.  Define four basic trace
points for this--creation time, drop of last reference, before
registring interfaces and after de-registering them.

Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

2 files changed, 62 insertions, 0 deletions

diff --git a/drivers/staging/greybus/greybus_trace.h b/drivers/staging/greybus/greybus_trace.h
index cbbc959..ecf2253 100644
--- a/drivers/staging/greybus/greybus_trace.h
+++ b/drivers/staging/greybus/greybus_trace.h
@@ -156,6 +156,59 @@ DEFINE_OPERATION_EVENT(gb_operation_put_active);
 
 #undef DEFINE_OPERATION_EVENT
 
+DECLARE_EVENT_CLASS(gb_module,
+
+	TP_PROTO(struct gb_module *module),
+
+	TP_ARGS(module),
+
+	TP_STRUCT__entry(
+		__field(int, hd_bus_id)
+		__field(u8, module_id)
+		__field(u8, num_interfaces)
+		__field(bool, disconnected)
+	),
+
+	TP_fast_assign(
+		__entry->hd_bus_id = module->hd->bus_id;
+		__entry->module_id = module->module_id;
+		__entry->disconnected = module->disconnected;
+	),
+
+	TP_printk("greybus: hd_bus_id=%d module_id=%hhu disconnected=%u",
+		__entry->hd_bus_id, __entry->module_id, __entry->disconnected)
+);
+
+#define DEFINE_MODULE_EVENT(name)					\
+		DEFINE_EVENT(gb_module, name,				\
+				TP_PROTO(struct gb_module *module),	\
+				TP_ARGS(module))
+
+/*
+ * Occurs after a new module is successfully created, before
+ * creating any of its interfaces.
+ */
+DEFINE_MODULE_EVENT(gb_module_create);
+
+/*
+ * Occurs after the last reference to a module has been dropped.
+ */
+DEFINE_MODULE_EVENT(gb_module_release);
+
+/*
+ * Occurs after a module is successfully created, before registering
+ * any of its interfaces.
+ */
+DEFINE_MODULE_EVENT(gb_module_add);
+
+/*
+ * Occurs when a module is deleted, before deregistering its
+ * interfaces.
+ */
+DEFINE_MODULE_EVENT(gb_module_del);
+
+#undef DEFINE_MODULE_EVENT
+
 DECLARE_EVENT_CLASS(gb_host_device,
 
 	TP_PROTO(struct gb_host_device *hd),
diff --git a/drivers/staging/greybus/module.c b/drivers/staging/greybus/module.c
index ea58954..c56b988 100644
--- a/drivers/staging/greybus/module.c
+++ b/drivers/staging/greybus/module.c
@@ -9,6 +9,7 @@
 
 #include "greybus.h"
 
+#include "greybus_trace.h"
 
 static ssize_t eject_store(struct device *dev,
 				struct device_attribute *attr,
@@ -77,6 +78,8 @@ static void gb_module_release(struct device *dev)
 {
 	struct gb_module *module = to_gb_module(dev);
 
+	trace_gb_module_release(module);
+
 	kfree(module);
 }
 
@@ -109,6 +112,8 @@ struct gb_module *gb_module_create(struct gb_host_device *hd, u8 module_id,
 	device_initialize(&module->dev);
 	dev_set_name(&module->dev, "%d-%u", hd->bus_id, module_id);
 
+	trace_gb_module_create(module);
+
 	for (i = 0; i < num_interfaces; ++i) {
 		intf = gb_interface_create(module, module_id + i);
 		if (!intf) {
@@ -215,6 +220,8 @@ int gb_module_add(struct gb_module *module)
 		return ret;
 	}
 
+	trace_gb_module_add(module);
+
 	for (i = 0; i < module->num_interfaces; ++i)
 		gb_module_register_interface(module->interfaces[i]);
 
@@ -229,6 +236,8 @@ void gb_module_del(struct gb_module *module)
 	for (i = 0; i < module->num_interfaces; ++i)
 		gb_module_deregister_interface(module->interfaces[i]);
 
+	trace_gb_module_del(module);
+
 	device_del(&module->dev);
 }