[RFC PATCH v2 12/13] firmware: arm_scmi: Add Reset notifications support

[Cristian Marussi <cristian.marussi@arm.com>]

Make SCMI Reset protocol register with the notification core.

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
---
V1 --> V2
- simplified .set_notify_enabled() implementation moving the ALL_SRCIDs
  logic out of protocol. ALL_SRCIDs logic is now in charge of the
  notification core, together with proper reference counting of enables
- switched to devres protocol-registration
---
 drivers/firmware/arm_scmi/reset.c | 100 +++++++++++++++++++++++++++++-
 include/linux/scmi_protocol.h     |   6 ++
 2 files changed, 105 insertions(+), 1 deletion(-)

diff --git a/drivers/firmware/arm_scmi/reset.c b/drivers/firmware/arm_scmi/reset.c
index de73054554f3..4316d772a0cf 100644
--- a/drivers/firmware/arm_scmi/reset.c
+++ b/drivers/firmware/arm_scmi/reset.c
@@ -6,6 +6,7 @@
  */
 
 #include "common.h"
+#include "notify.h"
 
 enum scmi_reset_protocol_cmd {
 	RESET_DOMAIN_ATTRIBUTES = 0x3,
@@ -40,6 +41,17 @@ struct scmi_msg_reset_domain_reset {
 #define ARCH_COLD_RESET		(ARCH_RESET_TYPE | COLD_RESET_STATE)
 };
 
+struct scmi_msg_reset_notify {
+	__le32 id;
+	__le32 event_control;
+#define RESET_TP_NOTIFY_ALL	BIT(0)
+};
+
+struct scmi_reset_issued_notify_payld {
+	__le32 domain_id;
+	__le32 reset_state;
+};
+
 struct reset_dom_info {
 	bool async_reset;
 	bool reset_notify;
@@ -51,8 +63,11 @@ struct scmi_reset_info {
 	u32 version;
 	int num_domains;
 	struct reset_dom_info *dom_info;
+	const struct scmi_handle *handle;
 };
 
+static struct scmi_reset_info *pinfo;
+
 static int scmi_reset_attributes_get(const struct scmi_handle *handle,
 				     struct scmi_reset_info *pi)
 {
@@ -190,11 +205,87 @@ static struct scmi_reset_ops reset_ops = {
 	.deassert = scmi_reset_domain_deassert,
 };
 
+static int scmi_reset_notify(const struct scmi_handle *handle, u32 domain_id,
+			     bool enable)
+{
+	int ret;
+	u32 evt_cntl = enable ? RESET_TP_NOTIFY_ALL : 0;
+	struct scmi_xfer *t;
+	struct scmi_msg_reset_notify *cfg;
+
+	ret = scmi_xfer_get_init(handle, RESET_NOTIFY,
+				 SCMI_PROTOCOL_RESET, sizeof(*cfg), 0, &t);
+	if (ret)
+		return ret;
+
+	cfg = t->tx.buf;
+	cfg->id = cpu_to_le32(domain_id);
+	cfg->event_control = cpu_to_le32(evt_cntl);
+
+	ret = scmi_do_xfer(handle, t);
+
+	scmi_xfer_put(handle, t);
+	return ret;
+}
+
+static bool scmi_reset_set_notify_enabled(u8 evt_id, u32 src_id, bool enable)
+{
+	int ret;
+
+	ret = scmi_reset_notify(pinfo->handle, src_id, enable);
+	if (ret)
+		pr_warn("SCMI Notifications - Proto:%X - FAIL_ENABLED - evt[%X] dom[%d] - ret:%d\n",
+			SCMI_PROTOCOL_RESET, evt_id, src_id, ret);
+
+	return !ret ? true : false;
+}
+
+static void *scmi_reset_fill_custom_report(u8 evt_id, u64 timestamp,
+					   const void *payld, size_t payld_sz,
+					   void *report, u32 *src_id)
+{
+	void *rep = NULL;
+
+	switch (evt_id) {
+	case RESET_ISSUED:
+	{
+		const struct scmi_reset_issued_notify_payld *p = payld;
+		struct scmi_reset_issued_report *r = report;
+
+		if (sizeof(*p) != payld_sz)
+			break;
+
+		r->timestamp = timestamp;
+		r->domain_id = le32_to_cpu(p->domain_id);
+		r->reset_state = le32_to_cpu(p->reset_state);
+		*src_id = r->domain_id;
+		rep = r;
+		break;
+	}
+	default:
+		break;
+	}
+
+	return rep;
+}
+
+static const struct scmi_event reset_events[] = {
+	{
+		.evt_id = RESET_NOTIFY,
+		.max_payld_sz = 8,
+		.max_report_sz = sizeof(struct scmi_reset_issued_report),
+	},
+};
+
+static const struct scmi_protocol_event_ops reset_event_ops = {
+	.set_notify_enabled = scmi_reset_set_notify_enabled,
+	.fill_custom_report = scmi_reset_fill_custom_report,
+};
+
 static int scmi_reset_protocol_init(struct scmi_handle *handle)
 {
 	int domain;
 	u32 version;
-	struct scmi_reset_info *pinfo;
 
 	scmi_version_get(handle, SCMI_PROTOCOL_RESET, &version);
 
@@ -218,7 +309,14 @@ static int scmi_reset_protocol_init(struct scmi_handle *handle)
 		scmi_reset_domain_attributes_get(handle, domain, dom);
 	}
 
+	scmi_register_protocol_events(handle->dev,
+				      SCMI_PROTOCOL_RESET, PAGE_SIZE,
+				      &reset_event_ops, reset_events,
+				      ARRAY_SIZE(reset_events),
+				      pinfo->num_domains);
+
 	pinfo->version = version;
+	pinfo->handle = handle;
 	handle->reset_ops = &reset_ops;
 	handle->reset_priv = pinfo;
 
diff --git a/include/linux/scmi_protocol.h b/include/linux/scmi_protocol.h
index 77cf107a7391..e6d4fc01d560 100644
--- a/include/linux/scmi_protocol.h
+++ b/include/linux/scmi_protocol.h
@@ -418,4 +418,10 @@ struct scmi_sensor_trip_point_report {
 	u32	trip_point_desc;
 };
 
+struct scmi_reset_issued_report {
+	ktime_t	timestamp;
+	u32	domain_id;
+	u32	reset_state;
+};
+
 #endif /* _LINUX_SCMI_PROTOCOL_H */
-- 
2.17.1