[PATCH v4 2/2] remoteproc: qcom: Add notification types to SSR

[Rishabh Bhatnagar <rishabhb@xxxxxxxxxxxxxx>]

From: Siddharth Gupta <sidgup@xxxxxxxxxxxxxx>

The SSR subdevice only adds callback for the unprepare event. Add callbacks
for unprepare, start and prepare events. The client driver for a particular
remoteproc might be interested in knowing the status of the remoteproc
while undergoing SSR, not just when the remoteproc has finished shutting
down.

Signed-off-by: Siddharth Gupta <sidgup@xxxxxxxxxxxxxx>
Signed-off-by: Rishabh Bhatnagar <rishabhb@xxxxxxxxxxxxxx>
---
 drivers/remoteproc/qcom_common.c      | 46 +++++++++++++++++++++++++++++++++--
 include/linux/remoteproc/qcom_rproc.h | 14 +++++++++++
 2 files changed, 58 insertions(+), 2 deletions(-)

diff --git a/drivers/remoteproc/qcom_common.c b/drivers/remoteproc/qcom_common.c
index 61ff2dd..5c5a1eb 100644
--- a/drivers/remoteproc/qcom_common.c
+++ b/drivers/remoteproc/qcom_common.c
@@ -228,7 +228,7 @@ struct qcom_ssr_subsystem *qcom_ssr_get_subsys(const char *name)
  *
  * This registers the @nb notifier block as part the notifier chain for a
  * remoteproc associated with @name. The notifier block's callback
- * will be invoked when the particular remote processor is stopped.
+ * will be invoked when the particular remote processor is started/stopped.
  */
 void *qcom_register_ssr_notifier(const char *name, struct notifier_block *nb)
 {
@@ -258,6 +258,44 @@ int qcom_unregister_ssr_notifier(void *notify, struct notifier_block *nb)
 }
 EXPORT_SYMBOL_GPL(qcom_unregister_ssr_notifier);
 
+static int ssr_notify_prepare(struct rproc_subdev *subdev)
+{
+	struct qcom_rproc_ssr *ssr = to_ssr_subdev(subdev);
+	struct qcom_ssr_notif_data data = {
+		.name = ssr->info->name,
+		.crashed = false,
+	};
+
+	srcu_notifier_call_chain(&ssr->info->notifier_list,
+				 QCOM_SSR_BEFORE_POWERUP, &data);
+	return 0;
+}
+
+static int ssr_notify_start(struct rproc_subdev *subdev)
+{
+	struct qcom_rproc_ssr *ssr = to_ssr_subdev(subdev);
+	struct qcom_ssr_notif_data data = {
+		.name = ssr->info->name,
+		.crashed = false,
+	};
+
+	srcu_notifier_call_chain(&ssr->info->notifier_list,
+				 QCOM_SSR_AFTER_POWERUP, &data);
+	return 0;
+}
+
+static void ssr_notify_stop(struct rproc_subdev *subdev, bool crashed)
+{
+	struct qcom_rproc_ssr *ssr = to_ssr_subdev(subdev);
+	struct qcom_ssr_notif_data data = {
+		.name = ssr->info->name,
+		.crashed = crashed,
+	};
+
+	srcu_notifier_call_chain(&ssr->info->notifier_list,
+				 QCOM_SSR_BEFORE_SHUTDOWN, &data);
+}
+
 static void ssr_notify_unprepare(struct rproc_subdev *subdev)
 {
 	struct qcom_rproc_ssr *ssr = to_ssr_subdev(subdev);
@@ -266,7 +304,8 @@ static void ssr_notify_unprepare(struct rproc_subdev *subdev)
 		.crashed = false,
 	};
 
-	srcu_notifier_call_chain(&ssr->info->notifier_list, 0, &data);
+	srcu_notifier_call_chain(&ssr->info->notifier_list,
+				 QCOM_SSR_AFTER_SHUTDOWN, &data);
 }
 
 
@@ -294,6 +333,9 @@ void qcom_add_ssr_subdev(struct rproc *rproc, struct qcom_rproc_ssr *ssr,
 
 	mutex_unlock(&qcom_ssr_subsys_lock);
 	ssr->info = info;
+	ssr->subdev.prepare = ssr_notify_prepare;
+	ssr->subdev.start = ssr_notify_start;
+	ssr->subdev.stop = ssr_notify_stop;
 	ssr->subdev.unprepare = ssr_notify_unprepare;
 
 	rproc_add_subdev(rproc, &ssr->subdev);
diff --git a/include/linux/remoteproc/qcom_rproc.h b/include/linux/remoteproc/qcom_rproc.h
index 58422b1..a558183 100644
--- a/include/linux/remoteproc/qcom_rproc.h
+++ b/include/linux/remoteproc/qcom_rproc.h
@@ -5,6 +5,20 @@
 
 #if IS_ENABLED(CONFIG_QCOM_RPROC_COMMON)
 
+/**
+ * enum qcom_ssr_notif_type - Different stages of remoteproc notifications
+ * @QCOM_SSR_BEFORE_SHUTDOWN:	unprepare stage of  remoteproc
+ * @QCOM_SSR_AFTER_SHUTDOWN:	stop stage of  remoteproc
+ * @QCOM_SSR_BEFORE_POWERUP:	prepare stage of  remoteproc
+ * @QCOM_SSR_AFTER_POWERUP:	start stage of  remoteproc
+ */
+enum qcom_ssr_notif_type {
+	QCOM_SSR_BEFORE_SHUTDOWN,
+	QCOM_SSR_AFTER_SHUTDOWN,
+	QCOM_SSR_BEFORE_POWERUP,
+	QCOM_SSR_AFTER_POWERUP,
+};
+
 struct qcom_ssr_notif_data {
 	const char *name;
 	bool crashed;
-- 
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