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.\" by Juan Romero Pardines.
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.Dd May 4, 2021
.Dt ENVSYS 4
.Os
.Sh NAME
.Nm envsys
.Nd Environmental Systems framework (version 2)
.Sh SYNOPSIS
.In sys/envsys.h
.Sh DESCRIPTION
The
.Nm
framework provides support to handle hardware monitor devices.
Hardware monitoring chips are able to report values from different types of
sensors.
.Pp
The
.Nm
framework consists of two parts:
.Pp
.Bl -enum -offset indent -compact
.It
the userland part, to receive the current sensor data and
to set some properties on sensors:
.Xr envstat 8 .
.It
The kernel part that is able to talk to the devices providing sensor
data:
.Xr sysmon_envsys 9 .
.El
.Pp
The
.Nm
framework uses
.Xr proplib 3
for communication between kernel and user space.
The following
.Xr ioctl 2
types are available:
.Bl -tag -width XX
.It Dv ENVSYS_GETDICTIONARY Pq prop_dictionary_t
.Pp
This
.Xr ioctl 2
is used to receive the global dictionary that is being used in
the kernel by the
.Xr sysmon_envsys 9
framework.
It will contain an array of dictionaries per device
and one dictionary per sensor plus another special dictionary that
contains the properties for a device.
Each sensor dictionary will have its own characteristics and values.
.Pp
The following XML property list represents a virtual device
.Dq device0
with one entry for sensor
.Dq sensor0
and all available properties set on it, plus another entry for the
.Dq device-properties
dictionary (which contains specific properties for a device):
.Bd -literal
\&<key\&>device0\&<\&/key\&>
\&<array\&>
	\&<dict\&>
		\&<key\&>allow-rfact\&<\&/key\&>
		\&<true\&/\&>
		\&<key\&>avg-value\&<\&/key\&>
		\&<integer\&>36400\&<\&/integer\&>
		\&<key\&>battery-capacity\&<\&/key\&>
		\&<string\&>NORMAL\&<\&/string\&>
		\&<key\&>critical-capacity\&<\&/key\&>
		\&<integer\&>21417\&<\&/integer\&>
		\&<key\&>critical-max\&<\&/key\&>
		\&<integer\&>343150000\&<\&/integer\&>
		\&<key\&>critical-min\&<\&/key\&>
		\&<integer\&>288150000\&<\&/integer\&>
		\&<key\&>cur-value\&<\&/key\&>
		\&<integer\&>406000\&<\&/integer\&>
		\&<key\&>description\&<\&/key\&>
		\&<string\&>CPU Temp\&<\&/string\&>
		\&<key\&>high-capacity\&<\&/key\&>
		\&<integer\&>21417\&<\&/integer\&>
		\&<key\&>index\&<\&/key\&>
		\&<string\&>sensor0\&<\&/string\&>
		\&<key\&>max-value\&<\&/key\&>
		\&<integer\&>3894000\&<\&/integer\&>
		\&<key\&>maximum-capacity\&<\&/key\&>
		\&<integer\&>21417\&<\&/integer\&>
		\&<key\&>min-value\&<\&/key\&>
		\&<integer\&>2894000\&<\&/integer\&>
		\&<key\&>monitoring-state-critical\&<\&/key\&>
		\&<true\&/\&>
		\&<key\&>monitoring-state-critover\&<\&/key\&>
		\&<true\&/\&>
		\&<key\&>monitoring-state-critunder\&<\&/key\&>
		\&<true\&/\&>
		\&<key\&>monitoring-state-state-changed\&<\&/key\&>
		\&<true\&/\&>
		\&<key\&>monitoring-state-warnover\&<\&/key\&>
		\&<true\&/\&>
		\&<key\&>monitoring-state-warnunder\&<\&/key\&>
		\&<true\&/\&>
		\&<key\&>monitoring-supported\&<\&/key\&>
		\&<true\&/\&>
		\&<key\&>state\&<\&/key\&>
		\&<string\&>valid\&<\&/string\&>
		\&<key\&>type\&<\&/key\&>
		\&<string\&>Ampere hour\&<\&/string\&>
		\&<key\&>want-percentage\&<\&/key\&>
		\&<true\&/\&>
		\&<key\&>warning-capacity\&<\&/key\&>
		\&<integer\&>19234\&<\&/integer\&>
		\&<key\&>warning-max\&<\&/key\&>
		\&<integer\&>323150000\&<\&/integer\&>
		\&<key\&>warning-min\&<\&/key\&>
		\&<integer\&>298150000\&<\&/integer\&>
	\&<\&/dict\&>
	\&<dict\&>
		\&<key\&>device-properties\&<\&/key\&>
		\&<dict\&>
			\&<key\&>refresh-timeout\&<\&/key\&>
			\&<integer\&>0xa\&<\&/integer\&>
		\&<\&/dict\&>
	\&<\&/dict\&>
\&<\&/array\&>
.Ed
.Pp
Let's explain some more about those objects:
.Bl -tag -width "monitoring-state-critical-overxx"
.It Fa allow-rfact
Set to
.Em true
means that the sensor is able to change the resistor factor,
only used in Voltage sensors.
.It Fa avg-value
Current average value in the sensor.
.It Fa battery-capacity
Current capacity state for a battery capacity sensor.
.It Fa critical-capacity
Critical capacity set previously by the
.Dv ENVSYS_SETDICTIONARY
.Xr ioctl 2 .
Only available on sensors with the
.Em want-percentage
object enabled.
.It Fa critical-max
Critical max limit set previously by the
.Dv ENVSYS_SETDICTIONARY
.Xr ioctl 2 .
.It Fa critical-min
Critical min limit set previously by the
.Dv ENVSYS_SETDICTIONARY
.Xr ioctl 2 .
.It Fa cur-value
Current value in the sensor.
.It Fa description
Description of the sensor.
.It Fa high-capacity
High capacity set previously by the
.Dv ENVSYS_SETDICTIONARY
.Xr ioctl 2 .
Only available on sensors with the
.Em want-percentage
object enabled.
Used to monitor possible over-charging of batteries.
.It Fa index
Index position of the sensor.
.It Fa max-value
Current max value in the sensor.
.It Fa maximum-capacity
Maximum capacity set previously by the
.Dv ENVSYS_SETDICTIONARY
.Xr ioctl 2 .
Only available on sensors with the
.Em want-percentage
object enabled.
Used to monitor possible over-charging of batteries.
.It Fa min-value
Current min value in the sensor.
.It Fa monitoring-state-critical
If true, the device has enabled the flag to monitor a critical state.
.It Fa monitoring-state-hw-range-limits
If true, the device has enabled the flag to monitor warning or critical
limits.
.It Fa monitoring-state-state-changed
If true, the device has enabled the flag to monitor for state changes in
a drive or Battery state sensor.
.It Fa monitoring-supported
If true, critical/warning capacity/max/min limits may be set by the
.Dv ENVSYS_SETDICTIONARY
.Xr ioctl 2 .
.It Fa state
Current state in the sensor.
.It Fa type
Type of unit in the sensor.
.It Fa want-percentage
If true,
.Em max-value
and
.Em cur-value
are valid and a percentage may be computed from them.
.It Fa warning-capacity
Warning capacity set previously by the
.Dv ENVSYS_SETDICTIONARY
.Xr ioctl 2 .
Only available on sensors with the
.Em want-percentage
object enabled.
.It Fa warning-max
Warning max limit set previously by the
.Dv ENVSYS_SETDICTIONARY
.Xr ioctl 2 .
.It Fa warning-min
Warning min limit set previously by the
.Dv ENVSYS_SETDICTIONARY
.Xr ioctl 2 .
.El
.It Dv ENVSYS_REMOVEPROPS Pq prop_dictionary_t
.Pp
This
.Xr ioctl 2
is used to remove all properties that are currently set via the
.Dv ENVSYS_SETDICTIONARY
ioctl.
The values will be set to defaults, the ones that the device uses.
.Pp
Only one object is allowed on this dictionary:
.Bd -literal -offset ident
<key>envsys-remove-props</key>
<true/>
.Ed
.Pp
It is a boolean object and must be set to
.Em true
to be effective.
.It Dv ENVSYS_SETDICTIONARY Pq prop_dictionary_t
This
.Xr ioctl 2
is used to send a dictionary with new properties that should be
processed by the
.Nm
framework.
Only a set of predefined keywords are recognized by the kernel part.
The following is the property list representation
of a dictionary with all recognized and required keywords that
a sensor understands:
.Bd -literal
\&<dict\&>
	\&<key\&>description\&<\&/key\&>
	\&<string\&>cpu temp\&<\&/string\&>
	\&<key\&>rfact\&<\&/key\&>
	\&<integer\&>56000\&<\&/integer\&>
	\&<key\&>critical-capacity\&<\&/key\&>
	\&<integer\&>10\&<\&/integer\&>
	\&<key\&>critical-max\&<\&/key\&>
	\&<integer\&>3400\&<\&/integer\&>
	\&<key\&>critical-min\&<\&/key\&>
	\&<integer\&>2800\&<\&/integer\&>
	\&<key\&>high-capacity\&<\&/key\&>
	\&<integer\&>95\&<\&/integer\&>
	\&<key\&>maximum-capacity\&<\&/key\&>
	\&<integer\&>100\&<\&/integer\&>
	\&<key\&>warning-capacity\&<\&/key\&>
	\&<integer\&>15\&<\&/integer\&>
	\&<key\&>warning-max\&<\&/key\&>
	\&<integer\&>3200\&<\&/integer\&>
	\&<key\&>warning-min\&<\&/key\&>
	\&<integer\&>2900\&<\&/integer\&>
\&<\&/dict\&>
.Ed
.Pp
Also if some properties in a device need to be changed, the
.Dq device-properties
dictionary must be used.
At this moment only the
.Dq refresh-timeout
property is understood.
This has the following structure:
.Bd -literal
\&<dict\&>
	\&<key\&>device-properties\&<\&/key\&>
	\&<dict\&>
		\&<key\&>refresh-timeout\&<\&/key\&>
		\&<integer\&>0xa\&<\&/integer\&>
	\&<\&/dict\&>
\&<\&/dict\&>
.Ed
.Pp
A dictionary sent to the kernel with this
.Xr ioctl 2
should have the following structure:
.Bd -literal
\&<dict\&>
	\&<key\&>device_name\&<\&/key\&>
	\&<array\&>
		\&<dict\&>
			\&<key\&>index\&<\&/key\&>
			\&<string\&>sensor0\&<\&/string\&>
			\&<key\&>description\&<\&/key\&>
			\&<string\&>cpu temp\&<\&/string\&>
			...
			Another property for this sensor
			...
		\&<\&/dict\&>
		...
		Another dictionary for device-properties or sensor
		...
	\&<\&/array\&>
	...
	Another device as above
	...
\&<\&/dict\&>
.Ed
.Pp
The named device will be an array and will contain dictionaries,
any dictionary needs to have the
.Em index
object specifying the sensor that is required for the new properties.
.Pp
If an unknown object was sent with the dictionary,
.Er EINVAL
will be returned, or if the sensor does not support changing
rfact (voltage sensors) or critical/warning/capacity limits,
.Er ENOTSUP
will be returned.
.El
.Pp
Additionally, the following
.Xr ioctl 2
commands are provided for compatibility purposes
for applications written against the original experimental
.Nm
API available between
.Nx 1.5
and
.Nx 4.0 ;
they have been deprecated since
.Nx 5.0 ,
and may be removed at any time:
.Bl -tag -width Ds
.It Dv ENVSYS_GTREDATA Pq envsys_tre_data_t
.It Dv ENVSYS_GTREINFO Pq envsys_basic_info_t
.El
.Sh NOTES
When setting a critical/warning max or min limit with the
.Dv ENVSYS_SETDICTIONARY
.Xr ioctl 2 ,
the user must be aware that
.Xr sysmon_envsys 9
expects to have a proper unit, so the value must be converted.
Please see
.Xr sysmon_envsys 9
for more information.
.Pp
Also when setting a critical or warning capacity limit, the formula to send a
proper value to
.Xr sysmon_envsys 9
is the following:
.Em value = (value / 100) * max value .
The max value is available in the sensor's dictionary.
.Sh EXAMPLES
The following example shows how to change the description
of
.Ql sensor0
in the
.Ql aibs0
device with the
.Dv ENVSYS_SETDICTIONARY
.Xr ioctl 2 :
.Bd -literal
int
main(void)
{
	prop_dictionary_t global_dict, sensor_dict;
	prop_array_t array;
	prop_object_t obj;
	int fd, error;

	global_dict = prop_dictionary_create();
	sensor_dict = prop_dictionary_create();
	array = prop_array_create();

	if (!prop_dictionary_set(global_dict, "aibs0", array))
		err(EINVAL, "prop_dictionary_set global");

	obj = prop_string_create_nocopy("sensor0");
	if (obj == NULL ||
	    !prop_dictionary_set(sensor_dict, "index", obj))
		err(EINVAL, "sensor index");

	prop_object_release(obj);

	/* new description */
	obj = prop_string_create_cstring_nocopy("CPU core voltage");
	if (obj == NULL ||
	    !prop_dictionary_set(sensor_dict, "description", obj))
		err(EINVAL, "new description");

	prop_object_release(obj);

	if (!prop_array_add(array, sensor_dict))
		err(EINVAL, "prop_array_add");

	if ((fd = open(_PATH_SYSMON, O_RDWR)) == \-1)
		err(EXIT_FAILURE, "open");

	/* we are done, send the dictionary */
	error = prop_dictionary_send_ioctl(global_dict,
					   fd,
					   ENVSYS_SETDICTIONARY);
	prop_object_release(array);
	prop_object_release(sensor_dict);
	prop_object_release(global_dict);
	(void)close(fd);
	return error;
}
.Ed
.Sh SEE ALSO
.Xr envsys.conf 5 ,
.Xr envstat 8 ,
.Xr powerd 8 ,
.Xr sysmon_envsys 9
.Sh HISTORY
The first
.Em envsys
framework first appeared in
.Nx 1.5 .
The
.Em envsys 2
framework first appeared in
.Nx 5.0 .
.Sh AUTHORS
The (current)
.Em envsys 2
framework was implemented by
.An Juan Romero Pardines .
Additional input on the design was provided by many
.Nx
developers around the world.
.Pp
The first
.Em envsys
framework was implemented by Jason R. Thorpe, Tim Rightnour,
and Bill Squier.