iio: add power and energy measurement modifiers

Add new IIO modifiers to support power and energy measurement devices:

Power modifiers:
- IIO_MOD_ACTIVE: Real power consumed by the load
- IIO_MOD_REACTIVE: Power that oscillates between source and load
- IIO_MOD_APPARENT: Magnitude of complex power

Signal quality modifiers:
- IIO_MOD_RMS: Root Mean Square value

Additionally adds:
- IIO_CHAN_INFO_POWERFACTOR: Power factor channel info type for
representing the ratio of active power to apparent power

These modifiers enable proper representation of power measurement
devices like energy meters and power analyzers.

Signed-off-by: Antoniu Miclaus <[e-mail]>
Signed-off-by: Jonathan Cameron <[e-mail]>

Documentation/ABI/testing/sysfs-bus-iio

···
 		is required is a consistent labeling.  Units after application
 		of scale and offset are millivolts.
 
+What:		/sys/bus/iio/devices/iio:deviceX/in_altvoltageY_rms_raw
+KernelVersion:	6.18
+Contact:	[e-mail]
+Description:
+		Raw (unscaled) Root Mean Square (RMS) voltage measurement from
+		channel Y. Units after application of scale and offset are
+		millivolts.
+
 What:		/sys/bus/iio/devices/iio:deviceX/in_powerY_raw
+What:		/sys/bus/iio/devices/iio:deviceX/in_powerY_active_raw
+What:		/sys/bus/iio/devices/iio:deviceX/in_powerY_reactive_raw
+What:		/sys/bus/iio/devices/iio:deviceX/in_powerY_apparent_raw
 KernelVersion:	4.5
 Contact:	[e-mail]
 Description:
···
 		channel Y. The number must always be specified and
 		unique to allow association with event codes. Units after
 		application of scale and offset are milliwatts.
+
+What:		/sys/bus/iio/devices/iio:deviceX/in_powerY_powerfactor
+KernelVersion:	6.18
+Contact:	[e-mail]
+Description:
+		Power factor measurement from channel Y. Power factor is the
+		ratio of active power to apparent power. The value is unitless.
 
 What:		/sys/bus/iio/devices/iio:deviceX/in_capacitanceY_raw
 KernelVersion:	3.2
···
 
 What:		/sys/.../iio:deviceX/in_energy_input
 What:		/sys/.../iio:deviceX/in_energy_raw
+What:		/sys/.../iio:deviceX/in_energyY_active_raw
+What:		/sys/.../iio:deviceX/in_energyY_reactive_raw
+What:		/sys/.../iio:deviceX/in_energyY_apparent_raw
 KernelVersion:	4.0
 Contact:	[e-mail]
 Description:
···
 		channels refer to the same signal. The 'i' channel contains the in-phase
 		component of the signal while the 'q' channel contains the quadrature
 		component.
+
+What:		/sys/bus/iio/devices/iio:deviceX/in_altcurrentY_rms_raw
+KernelVersion:	6.18
+Contact:	[e-mail]
+Description:
+		Raw (unscaled no bias removal etc.) Root Mean Square (RMS) current
+		measurement from channel Y. Units after application of scale and
+		offset are milliamps.
 
 What:		/sys/.../iio:deviceX/in_energy_en
 What:		/sys/.../iio:deviceX/in_distance_en

drivers/iio/industrialio-core.c

···
 	[IIO_MOD_PITCH] = "pitch",
 	[IIO_MOD_YAW] = "yaw",
 	[IIO_MOD_ROLL] = "roll",
+	[IIO_MOD_RMS] = "rms",
+	[IIO_MOD_ACTIVE] = "active",
+	[IIO_MOD_REACTIVE] = "reactive",
+	[IIO_MOD_APPARENT] = "apparent",
 };
 
 /* relies on pairs of these shared then separate */
···
 	[IIO_CHAN_INFO_ZEROPOINT] = "zeropoint",
 	[IIO_CHAN_INFO_TROUGH] = "trough_raw",
 	[IIO_CHAN_INFO_CONVDELAY] = "convdelay",
+	[IIO_CHAN_INFO_POWERFACTOR] = "powerfactor",
 };
 /**
  * iio_device_id() - query the unique ID for the device

include/linux/iio/types.h

···
 	IIO_CHAN_INFO_ZEROPOINT,
 	IIO_CHAN_INFO_TROUGH,
 	IIO_CHAN_INFO_CONVDELAY,
+	IIO_CHAN_INFO_POWERFACTOR,
 };
 
 #endif /* _IIO_TYPES_H_ */

include/uapi/linux/iio/types.h

···
 	IIO_MOD_ROLL,
 	IIO_MOD_LIGHT_UVA,
 	IIO_MOD_LIGHT_UVB,
+	IIO_MOD_RMS,
+	IIO_MOD_ACTIVE,
+	IIO_MOD_REACTIVE,
+	IIO_MOD_APPARENT,
 };
 
 enum iio_event_type {

tools/iio/iio_event_monitor.c

···
 	[IIO_MOD_PITCH] = "pitch",
 	[IIO_MOD_YAW] = "yaw",
 	[IIO_MOD_ROLL] = "roll",
+	[IIO_MOD_RMS] = "rms",
+	[IIO_MOD_ACTIVE] = "active",
+	[IIO_MOD_REACTIVE] = "reactive",
+	[IIO_MOD_APPARENT] = "apparent",
 };
 
 static bool event_is_known(struct iio_event_data *event)
···
 	case IIO_MOD_PM4:
 	case IIO_MOD_PM10:
 	case IIO_MOD_O2:
+	case IIO_MOD_RMS:
+	case IIO_MOD_ACTIVE:
+	case IIO_MOD_REACTIVE:
+	case IIO_MOD_APPARENT:
 		break;
 	default:
 		return false;