firmware: arm_scmi: add initial support for sensor protocol

The sensor protocol provides functions to manage platform sensors, and
provides the commands to describe the protocol version and the various
attribute flags. It also provides commands to discover various sensors
implemented and managed by the platform, read any sensor synchronously
or asynchronously as allowed by the platform, program sensor attributes
and/or configurations, if applicable.

This patch adds support for most of the above features.

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

1 files changed, 46 insertions, 0 deletions

diff --git a/include/linux/scmi_protocol.h b/include/linux/scmi_protocol.h
index 8cd0348787bc..5d63da9435ba 100644
--- a/include/linux/scmi_protocol.h
+++ b/include/linux/scmi_protocol.h
@@ -137,6 +137,49 @@ struct scmi_power_ops {
 			 u32 *state);
 };
 
+struct scmi_sensor_info {
+	u32 id;
+	u8 type;
+	char name[SCMI_MAX_STR_SIZE];
+};
+
+/*
+ * Partial list from Distributed Management Task Force (DMTF) specification:
+ * DSP0249 (Platform Level Data Model specification)
+ */
+enum scmi_sensor_class {
+	NONE = 0x0,
+	TEMPERATURE_C = 0x2,
+	VOLTAGE = 0x5,
+	CURRENT = 0x6,
+	POWER = 0x7,
+	ENERGY = 0x8,
+};
+
+/**
+ * struct scmi_sensor_ops - represents the various operations provided
+ *	by SCMI Sensor Protocol
+ *
+ * @count_get: get the count of sensors provided by SCMI
+ * @info_get: get the information of the specified sensor
+ * @configuration_set: control notifications on cross-over events for
+ *	the trip-points
+ * @trip_point_set: 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 (*configuration_set)(const struct scmi_handle *handle,
+				 u32 sensor_id);
+	int (*trip_point_set)(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,
+			   bool async, u64 *value);
+};
+
 /**
  * struct scmi_handle - Handle returned to ARM SCMI clients for usage.
  *
@@ -145,6 +188,7 @@ struct scmi_power_ops {
  * @power_ops: pointer to set of power protocol operations
  * @perf_ops: pointer to set of performance protocol operations
  * @clk_ops: pointer to set of clock protocol operations
+ * @sensor_ops: pointer to set of sensor protocol operations
  */
 struct scmi_handle {
 	struct device *dev;
@@ -152,10 +196,12 @@ struct scmi_handle {
 	struct scmi_perf_ops *perf_ops;
 	struct scmi_clk_ops *clk_ops;
 	struct scmi_power_ops *power_ops;
+	struct scmi_sensor_ops *sensor_ops;
 	/* for protocol internal use */
 	void *perf_priv;
 	void *clk_priv;
 	void *power_priv;
+	void *sensor_priv;
 };
 
 enum scmi_std_protocol {