Merge tag 'scmi-updates-5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux into arm/drivers

ARM SCMI/SCPI updates for v5.9

The main addition for this time is the support for platform notifications.
SCMI protocol specification allows the platform to signal events to the
interested agents via notification messages. We are adding support for
the dispatch and delivery of such notifications to the interested users
inside the kernel.

Other than that, there are minor changes like checking and using the
fast_switch capability quering the firmware instead of doing it
unconditionally(using polling mode transfer), cosmetic trace update,
use of HAVE_ARM_SMCCC_DISCOVERY instead of ARM_PSCI_FW and a fix in
scmi clock registration logic for all the clocks with discrete rates.

* tag 'scmi-updates-5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux:
  firmware: arm_scmi: Remove fixed size fields from reports/scmi_event_header
  firmware: arm_scmi: Remove unneeded __packed attribute
  firmware: arm_scmi: Remove zero-length array in SCMI notifications
  firmware: arm_scmi: Provide a missing function param description
  clk: scmi: Fix min and max rate when registering clocks with discrete rates
  firmware: arm_scmi: Keep the discrete clock rates sorted
  firmware: arm_scmi: Add base notifications support
  firmware: arm_scmi: Add reset notifications support
  firmware: arm_scmi: Add sensor notifications support
  firmware: arm_scmi: Add perf notifications support
  firmware: arm_scmi: Add power notifications support
  firmware: arm_scmi: Enable notification core
  firmware: arm_scmi: Add notification dispatch and delivery
  firmware: arm_scmi: Add notification callbacks-registration
  firmware: arm_scmi: Add notification protocol-registration
  firmware: arm_scmi: Fix SCMI genpd domain probing
  firmware: arm_scmi: Use HAVE_ARM_SMCCC_DISCOVERY instead of ARM_PSCI_FW
  cpufreq: arm_scmi: Set fast_switch_possible conditionally
  firmware: arm_scmi: Add fast_switch_possible() interface
  firmware: arm_scmi: Use signed integer to report transfer status

Link: https://lore.kernel.org/r/20200713161410.12324-1-sudeep.holla@arm.com
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

2 files changed, 108 insertions, 8 deletions

diff --git a/include/linux/scmi_protocol.h b/include/linux/scmi_protocol.h
index ce2f5c28b2df..7e5dd7d1e221 100644
--- a/include/linux/scmi_protocol.h
+++ b/include/linux/scmi_protocol.h
@@ -9,6 +9,7 @@
 #define _LINUX_SCMI_PROTOCOL_H
 
 #include <linux/device.h>
+#include <linux/notifier.h>
 #include <linux/types.h>
 
 #define SCMI_MAX_STR_SIZE	16
@@ -118,6 +119,8 @@ struct scmi_perf_ops {
 			unsigned long *rate, bool poll);
 	int (*est_power_get)(const struct scmi_handle *handle, u32 domain,
 			     unsigned long *rate, unsigned long *power);
+	bool (*fast_switch_possible)(const struct scmi_handle *handle,
+				     struct device *dev);
 };
 
 /**
@@ -173,18 +176,13 @@ enum scmi_sensor_class {
  *
  * @count_get: get the count of sensors provided by SCMI
  * @info_get: get the information of the specified sensor
- * @trip_point_notify: control notifications on cross-over events for
- *	the trip-points
  * @trip_point_config: selects and configures a trip-point of interest
  * @reading_get: gets the current value of the sensor
  */
 struct scmi_sensor_ops {
 	int (*count_get)(const struct scmi_handle *handle);
-
 	const struct scmi_sensor_info *(*info_get)
 		(const struct scmi_handle *handle, u32 sensor_id);
-	int (*trip_point_notify)(const struct scmi_handle *handle,
-				 u32 sensor_id, bool enable);
 	int (*trip_point_config)(const struct scmi_handle *handle,
 				 u32 sensor_id, u8 trip_id, u64 trip_value);
 	int (*reading_get)(const struct scmi_handle *handle, u32 sensor_id,
@@ -212,6 +210,49 @@ struct scmi_reset_ops {
 };
 
 /**
+ * struct scmi_notify_ops  - represents notifications' operations provided by
+ * SCMI core
+ * @register_event_notifier: Register a notifier_block for the requested event
+ * @unregister_event_notifier: Unregister a notifier_block for the requested
+ *			       event
+ *
+ * A user can register/unregister its own notifier_block against the wanted
+ * platform instance regarding the desired event identified by the
+ * tuple: (proto_id, evt_id, src_id) using the provided register/unregister
+ * interface where:
+ *
+ * @handle: The handle identifying the platform instance to use
+ * @proto_id: The protocol ID as in SCMI Specification
+ * @evt_id: The message ID of the desired event as in SCMI Specification
+ * @src_id: A pointer to the desired source ID if different sources are
+ *	    possible for the protocol (like domain_id, sensor_id...etc)
+ *
+ * @src_id can be provided as NULL if it simply does NOT make sense for
+ * the protocol at hand, OR if the user is explicitly interested in
+ * receiving notifications from ANY existent source associated to the
+ * specified proto_id / evt_id.
+ *
+ * Received notifications are finally delivered to the registered users,
+ * invoking the callback provided with the notifier_block *nb as follows:
+ *
+ *	int user_cb(nb, evt_id, report)
+ *
+ * with:
+ *
+ * @nb: The notifier block provided by the user
+ * @evt_id: The message ID of the delivered event
+ * @report: A custom struct describing the specific event delivered
+ */
+struct scmi_notify_ops {
+	int (*register_event_notifier)(const struct scmi_handle *handle,
+				       u8 proto_id, u8 evt_id, u32 *src_id,
+				       struct notifier_block *nb);
+	int (*unregister_event_notifier)(const struct scmi_handle *handle,
+					 u8 proto_id, u8 evt_id, u32 *src_id,
+					 struct notifier_block *nb);
+};
+
+/**
  * struct scmi_handle - Handle returned to ARM SCMI clients for usage.
  *
  * @dev: pointer to the SCMI device
@@ -221,6 +262,7 @@ struct scmi_reset_ops {
  * @clk_ops: pointer to set of clock protocol operations
  * @sensor_ops: pointer to set of sensor protocol operations
  * @reset_ops: pointer to set of reset protocol operations
+ * @notify_ops: pointer to set of notifications related operations
  * @perf_priv: pointer to private data structure specific to performance
  *	protocol(for internal use only)
  * @clk_priv: pointer to private data structure specific to clock
@@ -231,6 +273,8 @@ struct scmi_reset_ops {
  *	protocol(for internal use only)
  * @reset_priv: pointer to private data structure specific to reset
  *	protocol(for internal use only)
+ * @notify_priv: pointer to private data structure specific to notifications
+ *	(for internal use only)
  */
 struct scmi_handle {
 	struct device *dev;
@@ -240,12 +284,14 @@ struct scmi_handle {
 	struct scmi_power_ops *power_ops;
 	struct scmi_sensor_ops *sensor_ops;
 	struct scmi_reset_ops *reset_ops;
+	struct scmi_notify_ops *notify_ops;
 	/* for protocol internal use */
 	void *perf_priv;
 	void *clk_priv;
 	void *power_priv;
 	void *sensor_priv;
 	void *reset_priv;
+	void *notify_priv;
 };
 
 enum scmi_std_protocol {
@@ -324,4 +370,58 @@ typedef int (*scmi_prot_init_fn_t)(struct scmi_handle *);
 int scmi_protocol_register(int protocol_id, scmi_prot_init_fn_t fn);
 void scmi_protocol_unregister(int protocol_id);
 
+/* SCMI Notification API - Custom Event Reports */
+enum scmi_notification_events {
+	SCMI_EVENT_POWER_STATE_CHANGED = 0x0,
+	SCMI_EVENT_PERFORMANCE_LIMITS_CHANGED = 0x0,
+	SCMI_EVENT_PERFORMANCE_LEVEL_CHANGED = 0x1,
+	SCMI_EVENT_SENSOR_TRIP_POINT_EVENT = 0x0,
+	SCMI_EVENT_RESET_ISSUED = 0x0,
+	SCMI_EVENT_BASE_ERROR_EVENT = 0x0,
+};
+
+struct scmi_power_state_changed_report {
+	ktime_t		timestamp;
+	unsigned int	agent_id;
+	unsigned int	domain_id;
+	unsigned int	power_state;
+};
+
+struct scmi_perf_limits_report {
+	ktime_t		timestamp;
+	unsigned int	agent_id;
+	unsigned int	domain_id;
+	unsigned int	range_max;
+	unsigned int	range_min;
+};
+
+struct scmi_perf_level_report {
+	ktime_t		timestamp;
+	unsigned int	agent_id;
+	unsigned int	domain_id;
+	unsigned int	performance_level;
+};
+
+struct scmi_sensor_trip_point_report {
+	ktime_t		timestamp;
+	unsigned int	agent_id;
+	unsigned int	sensor_id;
+	unsigned int	trip_point_desc;
+};
+
+struct scmi_reset_issued_report {
+	ktime_t		timestamp;
+	unsigned int	agent_id;
+	unsigned int	domain_id;
+	unsigned int	reset_state;
+};
+
+struct scmi_base_error_report {
+	ktime_t			timestamp;
+	unsigned int		agent_id;
+	bool			fatal;
+	unsigned int		cmd_count;
+	unsigned long long	reports[];
+};
+
 #endif /* _LINUX_SCMI_PROTOCOL_H */
diff --git a/include/trace/events/scmi.h b/include/trace/events/scmi.h
index f076c430d243..f3a4b4d60714 100644
--- a/include/trace/events/scmi.h
+++ b/include/trace/events/scmi.h
@@ -35,7 +35,7 @@ TRACE_EVENT(scmi_xfer_begin,
 
 TRACE_EVENT(scmi_xfer_end,
 	TP_PROTO(int transfer_id, u8 msg_id, u8 protocol_id, u16 seq,
-		 u32 status),
+		 int status),
 	TP_ARGS(transfer_id, msg_id, protocol_id, seq, status),
 
 	TP_STRUCT__entry(
@@ -43,7 +43,7 @@ TRACE_EVENT(scmi_xfer_end,
 		__field(u8, msg_id)
 		__field(u8, protocol_id)
 		__field(u16, seq)
-		__field(u32, status)
+		__field(int, status)
 	),
 
 	TP_fast_assign(
@@ -54,7 +54,7 @@ TRACE_EVENT(scmi_xfer_end,
 		__entry->status = status;
 	),
 
-	TP_printk("transfer_id=%d msg_id=%u protocol_id=%u seq=%u status=%u",
+	TP_printk("transfer_id=%d msg_id=%u protocol_id=%u seq=%u status=%d",
 		__entry->transfer_id, __entry->msg_id, __entry->protocol_id,
 		__entry->seq, __entry->status)
 );