firmware: arm_scmi: Add SCMI v3.0 sensors descriptors extensions

Add support for new SCMI v3.0 Sensors extensions related to new sensors'
features, like multiple axis and update intervals, while keeping
compatibility with SCMI v2.0 features.

While at that, refactor and simplify all the internal helpers macros and
move struct scmi_sensor_info to use only non-fixed-size typing.

Link: https://lore.kernel.org/r/20201119174906.43862-3-cristian.marussi@arm.comSigned-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

include/linux/scmi_protocol.h

@@ -8,6 +8,7 @@
 #ifndef _LINUX_SCMI_PROTOCOL_H
 #define _LINUX_SCMI_PROTOCOL_H
 
+#include <linux/bitfield.h>
 #include <linux/device.h>
 #include <linux/notifier.h>
 #include <linux/types.h>
@@ -148,13 +149,135 @@ struct scmi_power_ops {
 			 u32 *state);
 };
 
+/**
+ * scmi_range_attrs  - specifies a sensor or axis values' range
+ * @min_range: The minimum value which can be represented by the sensor/axis.
+ * @max_range: The maximum value which can be represented by the sensor/axis.
+ */
+struct scmi_range_attrs {
+	long long min_range;
+	long long max_range;
+};
+
+/**
+ * scmi_sensor_axis_info  - describes one sensor axes
+ * @id: The axes ID.
+ * @type: Axes type. Chosen amongst one of @enum scmi_sensor_class.
+ * @scale: Power-of-10 multiplier applied to the axis unit.
+ * @name: NULL-terminated string representing axes name as advertised by
+ *	  SCMI platform.
+ * @extended_attrs: Flag to indicate the presence of additional extended
+ *		    attributes for this axes.
+ * @resolution: Extended attribute representing the resolution of the axes.
+ *		Set to 0 if not reported by this axes.
+ * @exponent: Extended attribute representing the power-of-10 multiplier that
+ *	      is applied to the resolution field. Set to 0 if not reported by
+ *	      this axes.
+ * @attrs: Extended attributes representing minimum and maximum values
+ *	   measurable by this axes. Set to 0 if not reported by this sensor.
+ */
+struct scmi_sensor_axis_info {
+	unsigned int id;
+	unsigned int type;
+	int scale;
+	char name[SCMI_MAX_STR_SIZE];
+	bool extended_attrs;
+	unsigned int resolution;
+	int exponent;
+	struct scmi_range_attrs attrs;
+};
+
+/**
+ * scmi_sensor_intervals_info  - describes number and type of available update
+ * intervals
+ * @segmented: Flag for segmented intervals' representation. When True there
+ *	       will be exactly 3 intervals in @desc, with each entry
+ *	       representing a member of a segment in this order:
+ *	       {lowest update interval, highest update interval, step size}
+ * @count: Number of intervals described in @desc.
+ * @desc: Array of @count interval descriptor bitmask represented as detailed in
+ *	  the SCMI specification: it can be accessed using the accompanying
+ *	  macros.
+ * @prealloc_pool: A minimal preallocated pool of desc entries used to avoid
+ *		   lesser-than-64-bytes dynamic allocation for small @count
+ *		   values.
+ */
+struct scmi_sensor_intervals_info {
+	bool segmented;
+	unsigned int count;
+#define SCMI_SENS_INTVL_SEGMENT_LOW	0
+#define SCMI_SENS_INTVL_SEGMENT_HIGH	1
+#define SCMI_SENS_INTVL_SEGMENT_STEP	2
+	unsigned int *desc;
+#define SCMI_SENS_INTVL_GET_SECS(x)		FIELD_GET(GENMASK(20, 5), (x))
+#define SCMI_SENS_INTVL_GET_EXP(x)					\
+	({								\
+		int __signed_exp = FIELD_GET(GENMASK(4, 0), (x));	\
+									\
+		if (__signed_exp & BIT(4))				\
+			__signed_exp |= GENMASK(31, 5);			\
+		__signed_exp;						\
+	})
+#define SCMI_MAX_PREALLOC_POOL			16
+	unsigned int prealloc_pool[SCMI_MAX_PREALLOC_POOL];
+};
+
+/**
+ * struct scmi_sensor_info - represents information related to one of the
+ * available sensors.
+ * @id: Sensor ID.
+ * @type: Sensor type. Chosen amongst one of @enum scmi_sensor_class.
+ * @scale: Power-of-10 multiplier applied to the sensor unit.
+ * @num_trip_points: Number of maximum configurable trip points.
+ * @async: Flag for asynchronous read support.
+ * @update: Flag for continuouos update notification support.
+ * @timestamped: Flag for timestamped read support.
+ * @tstamp_scale: Power-of-10 multiplier applied to the sensor timestamps to
+ *		  represent it in seconds.
+ * @num_axis: Number of supported axis if any. Reported as 0 for scalar sensors.
+ * @axis: Pointer to an array of @num_axis descriptors.
+ * @intervals: Descriptor of available update intervals.
+ * @sensor_config: A bitmask reporting the current sensor configuration as
+ *		   detailed in the SCMI specification: it can accessed and
+ *		   modified through the accompanying macros.
+ * @name: NULL-terminated string representing sensor name as advertised by
+ *	  SCMI platform.
+ * @extended_scalar_attrs: Flag to indicate the presence of additional extended
+ *			   attributes for this sensor.
+ * @sensor_power: Extended attribute representing the average power
+ *		  consumed by the sensor in microwatts (uW) when it is active.
+ *		  Reported here only for scalar sensors.
+ *		  Set to 0 if not reported by this sensor.
+ * @resolution: Extended attribute representing the resolution of the sensor.
+ *		Reported here only for scalar sensors.
+ *		Set to 0 if not reported by this sensor.
+ * @exponent: Extended attribute representing the power-of-10 multiplier that is
+ *	      applied to the resolution field.
+ *	      Reported here only for scalar sensors.
+ *	      Set to 0 if not reported by this sensor.
+ * @scalar_attrs: Extended attributes representing minimum and maximum
+ *		  measurable values by this sensor.
+ *		  Reported here only for scalar sensors.
+ *		  Set to 0 if not reported by this sensor.
+ */
 struct scmi_sensor_info {
-	u32 id;
-	u8 type;
-	s8 scale;
-	u8 num_trip_points;
+	unsigned int id;
+	unsigned int type;
+	int scale;
+	unsigned int num_trip_points;
 	bool async;
+	bool update;
+	bool timestamped;
+	int tstamp_scale;
+	unsigned int num_axis;
+	struct scmi_sensor_axis_info *axis;
+	struct scmi_sensor_intervals_info intervals;
 	char name[SCMI_MAX_STR_SIZE];
+	bool extended_scalar_attrs;
+	unsigned int sensor_power;
+	unsigned int resolution;
+	int exponent;
+	struct scmi_range_attrs scalar_attrs;
 };
 
 /*
@@ -249,6 +372,14 @@ enum scmi_sensor_class {
 	SQ_FEET = 0x54,
 	SQ_CM = 0x55,
 	SQ_METERS = 0x56,
+	RADIANS_SEC = 0x57,
+	BPM = 0x58,
+	METERS_SEC_SQUARED = 0x59,
+	METERS_SEC = 0x5A,
+	CUBIC_METERS_SEC = 0x5B,
+	MM_MERCURY = 0x5C,
+	RADIANS_SEC_SQUARED = 0x5D,
+	OEM_UNIT = 0xFF
 };
 
 /**