remoteproc: sysmon: Add notifications for events

Add notification for other stages of remoteproc boot and shutdown. This
includes adding callback functions for the prepare and unprepare events,
and fleshing out the callback function for start.

Acked-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Siddharth Gupta <sidgup@codeaurora.org>
Link: https://lore.kernel.org/r/1586389003-26675-3-git-send-email-sidgup@codeaurora.org
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

drivers/remoteproc/qcom_sysmon.c

@@ -439,8 +439,31 @@ static const struct qmi_ops ssctl_ops = {
 	.del_server = ssctl_del_server,
 };
 
+static int sysmon_prepare(struct rproc_subdev *subdev)
+{
+	struct qcom_sysmon *sysmon = container_of(subdev, struct qcom_sysmon,
+						  subdev);
+	struct sysmon_event event = {
+		.subsys_name = sysmon->name,
+		.ssr_event = SSCTL_SSR_EVENT_BEFORE_POWERUP
+	};
+
+	blocking_notifier_call_chain(&sysmon_notifiers, 0, (void *)&event);
+
+	return 0;
+}
+
 static int sysmon_start(struct rproc_subdev *subdev)
 {
+	struct qcom_sysmon *sysmon = container_of(subdev, struct qcom_sysmon,
+						  subdev);
+	struct sysmon_event event = {
+		.subsys_name = sysmon->name,
+		.ssr_event = SSCTL_SSR_EVENT_AFTER_POWERUP
+	};
+
+	blocking_notifier_call_chain(&sysmon_notifiers, 0, (void *)&event);
+
 	return 0;
 }
 
@@ -464,6 +487,18 @@ static void sysmon_stop(struct rproc_subdev *subdev, bool crashed)
 		sysmon_request_shutdown(sysmon);
 }
 
+static void sysmon_unprepare(struct rproc_subdev *subdev)
+{
+	struct qcom_sysmon *sysmon = container_of(subdev, struct qcom_sysmon,
+						  subdev);
+	struct sysmon_event event = {
+		.subsys_name = sysmon->name,
+		.ssr_event = SSCTL_SSR_EVENT_AFTER_SHUTDOWN
+	};
+
+	blocking_notifier_call_chain(&sysmon_notifiers, 0, (void *)&event);
+}
+
 /**
  * sysmon_notify() - notify sysmon target of another's SSR
  * @nb:		notifier_block associated with sysmon instance
@@ -563,8 +598,10 @@ struct qcom_sysmon *qcom_add_sysmon_subdev(struct rproc *rproc,
 
 	qmi_add_lookup(&sysmon->qmi, 43, 0, 0);
 
+	sysmon->subdev.prepare = sysmon_prepare;
 	sysmon->subdev.start = sysmon_start;
 	sysmon->subdev.stop = sysmon_stop;
+	sysmon->subdev.unprepare = sysmon_unprepare;
 
 	rproc_add_subdev(rproc, &sysmon->subdev);