NetBSD-5.0.2/share/man/man9/sysmon_envsys.9

.\"	$NetBSD: sysmon_envsys.9,v 1.19 2008/04/30 13:10:58 martin Exp $
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.\" This code is derived from software contributed to The NetBSD Foundation
.\" by Juan Romero Pardines.
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.Dd February 28, 2008
.Dt SYSMON_ENVSYS 9
.Os
.Sh NAME
.Nm sysmon_envsys
.Nd kernel part of the envsys 2 framework
.Sh SYNOPSIS
.In dev/sysmon/sysmonvar.h
.Ft struct sysmon_envsys *
.Fn sysmon_envsys_create "void"
.Ft void
.Fn sysmon_envsys_destroy "struct sysmon_envsys *"
.Ft int
.Fn sysmon_envsys_register "struct sysmon_envsys *"
.Ft void
.Fn sysmon_envsys_unregister "struct sysmon_envsys *"
.Ft int
.Fn sysmon_envsys_sensor_attach "struct sysmon_envsys *, envsys_data_t *"
.Ft int
.Fn sysmon_envsys_sensor_detach "struct sysmon_envsys *, envsys_data_t *"
.Sh DESCRIPTION
.Pp
.Nm
is the kernel part of the
.Xr envsys 4
framework.
With this framework you are able to register and unregister a
.Nm
device, attach or detach sensors into a device and enable or disable
automatic monitoring for some sensors without any user interactivity,
among other things.
.Pp
.Ss HOW TO USE THE FRAMEWORK
.Pp
To register a new driver to the
.Nm
framework, a
.Sy sysmon_envsys
object must be allocated and initialized; the
.Fn sysmon_envsys_create
function is used for this. This returns a zero'ed pointer to a sysmon_envsys
structure and takes care of initialization of some private features.
.Pp
Once we have the object we could start initializing sensors (see the
.Em SENSOR DETAILS
section for more information) and attaching
them to the device, this is acomplished by the
.Fn sysmon_envsys_sensor_attach
function. This function attachs the envsys_data_t (sensor) specified
as second argument into the sysmon_envsys object specified in the
first argument.
.Pp
Finally when the sensors are already attached, the device needs to set
some required (and optional) members of the sysmon_envsys struct before
calling the
.Fn sysmon_envsys_register
function to register the device.
.Pp
If there's some error before registering the device, the
.Fn sysmon_envsys_destroy
function must be used to detach the sensors previously attached
and free the sysmon_envsys object allocated by the
.Fn sysmon_envsys_create
function.
.Pp
The
.Em sysmon_envsys
structure is defined as follow
(only the public members are shown):
.Bd -literal
struct sysmon_envsys {
	const char 	*sme_name;
	int		sme_flags;
	int		sme_class;
	uint64_t	sme_events_timeout;
	void 		*sme_cookie;
	void (*sme_refresh)(struct sysmon_envsys *, envsys_data_t *);
};
.Ed
.Pp
The members have the following meaning:
.Pp
.Bl -tag -width "sme_sensor_data_xxxxxxxxx"
.It Fa sme_class
This specifies the class of the sysmon envsys device. See the
.Sy DEVICE CLASSES
section for more information (OPTIONAL).
.It Fa sme_name
The name that will be used in the driver (REQUIRED).
.It Fa sme_flags
Additional flags for the
.Nm
device. Currently supporting
.Ar SME_DISABLE_REFRESH .
If enabled, the
.Ar sme_refresh
function callback won't be used
to refresh sensors data and the driver will use its own method.
Hence
.Ar sme_cookie
won't be necessary either (OPTIONAL).
.It Fa sme_events_timeout
This is used to specify the default timeout value that will be used to
check for critical events if any monitoring flag was set. The value
is used as seconds (OPTIONAL).
.El
.Pp
.Pp
If the driver wants to refresh sensors data via the
.Nm
framework, the following members must be specified:
.Pp
.Bl -tag -width "sme_sensor_data_xxxxxxxxx"
.It Fa sme_cookie
Pointer to the device struct (also called
.Dq softc
). This may be used in the
.Sy sme_refresh
function callback.
.It Fa sme_refresh
Pointer to a function that will be used to refresh sensor data in
the device. This can be used to set the state and other properties of the
sensor depending of the returned data by the driver.
.Em NOTE :
.Em You don't have to refresh all sensors, only the sensor specified by the
.Sy edata->sensor
.Em index.
.El
.Pp
Note that it's not necessary to refresh the sensors data before the
driver is registered, only do it if you need the data in your driver
to check for a specific condition.
.Pp
.Pp
The timeout value for the monitoring events on a device may be changed via the
.Em ENVSYS_SETDICTIONARY
.Xr ioctl 2
or the
.Xr envstat 8
command.
.Pp
To unregister a driver previously registered with the
.Nm
framework, the
.Fn sysmon_envsys_unregister
function must be used. If there were monitoring events registered for the
driver, they all will be destroyed before the device is unregistered and
its sensors will be detached; finally the
.Em sysmon_envsys
object will be freed, so there's no need to call
.Fn sysmon_envsys_destroy
if we are going to unregister a device.
.Pp
.Ss DEVICE CLASSES
The
.Fa sme_class
member of the
.Fa sysmon_envsys
structure is an optional flag that specifies the class of the
sysmon envsys device. Currently there are two classes:
.Pp
.Bl -tag -width ident
.It SME_CLASS_ACADAPTER
.Pp
This class is for devices that want to act as an
.Em AC adapter .
The device writer must ensure that at least there is a
sensor with
.Em units
of
.Sy ENVSYS_INDICATOR .
This will be used to report its current state (on/off).
.It SME_CLASS_BATTERY
.Pp
This class is for devices that want to act as an
.Em Battery .
The device writer must ensure that at least there are two sensors with
units of
.Sy ENVSYS_BATTERY_CAPACITY
and
.Sy ENVSYS_BATTERY_CHARGE .
.Pp
These two sensors are used to ensure that the battery device won't
never send a
.Em low-power
event to the
.Xr powerd 8 
daemon (if running) when all battery devices are in a critical state.
The critical state means that a battery is not currently charging
and its charge state is low or critical.
When the
.Em low-power
condition is met, an event is sent to the
.Xr powerd 8
daemon (if running) and will shutdown the system gracefully via the
.Fa /etc/powerd/scripts/sensor_battery
script.
.Pp
If
.Xr powerd 8
is not running, the system will be powered off via the
.Xr cpu_reboot 9
call with the
.Em RB_POWERDOWN
flag.
.Pp
.El
.Em NOTE:
If a
.Em SME_CLASS_ACADAPTER
or
.Em SME_CLASS_BATTERY
class don't have the sensors required, the
.Em low-power
event will never be sent, and the graceful shutdown won't be possible.
.Ss SENSOR DETAILS
.Pp
Each sensor uses a
.Sy envsys_data_t
structure, it's defined as follow (only the public members are shown);
.Bd -literal
typedef struct envsys_data {
	uint32_t	units;
	uint32_t	state;
	uint32_t	flags;
	uint32_t	rpms;
	int32_t		rfact;
	int32_t		value_cur;
	int32_t		value_max;
	int32_t		value_min;
	int32_t		value_avg;
	bool		monitor;
	char		desc[ENVSYS_DESCLEN];
} envsys_data_t;
.Ed
.Pp
The members for the
.Sy envsys_data_t
structure have the following meaning:
.Pp
.Bl -tag -width cdoscdosrunru
.It Fa units
Used to set the units type.
.It Fa state
Used to set the current state.
.It Fa flags
Used to set additional flags.
.It Fa rpms
Used to set the nominal RPM value for
.Sy fan 
sensors.
.It Fa rfact
Used to set the rfact value for
.Sy voltage
sensors.
.It Fa value_cur
Used to set the current value.
.It Fa value_max
Used to set the maximum value.
.It Fa value_min
Used to set the minimum value.
.It Fa value_avg
Used to set the average value.
.It Fa monitor
Used to enable automatic sensor monitoring (by default
it's disabled). The automatic sensor monitoring will check if
a condition is met periodically and will send an event to the
.Xr powerd 8
daemon (if running). The monitoring event will be registered when this flag
is
.Em true
and one or more of the
.Em ENVSYS_FMONFOO
flags were set in the
.Ar flags
member.
.It Fa desc
Used to set the description string.
.Em NOTE
.Em that the description string must be unique in a device, and sensors with
.Em duplicate or empty description will simply be ignored.
.El
.Pp
Users of this framework must take care about the following points:
.Bl -bullet
.It
The
.Ar desc
member needs to have a valid description, unique in a device and non empty
to be valid.
.It
The
.Ar units
type must be valid. The following units are defined:
.Pp
.Bl -tag -width "ENVSYS_BATTERY_CAPACITY" -compact
.It ENVSYS_STEMP
For temperature sensors.
.It ENVSYS_SFANRPM
For fan sensors.
.It ENVSYS_SVOLTS_AC
For AC Voltage.
.It ENVSYS_SVOLTS_DC
For DC Voltage.
.It ENVSYS_SOHMS
For Ohms.
.It ENVSYS_SWATTS
For Watts.
.It ENVSYS_SAMPS
For Ampere.
.It ENVSYS_SWATTHOUR
For Watts hour.
.It ENVSYS_SAMPHOUR
For Ampere hour.
.It ENVSYS_INDICATOR
For sensors that only want a boolean type.
.It ENVSYS_INTEGER
For sensors that only want an integer type.
.It ENVSYS_DRIVE
For drive sensors.
.It ENVSYS_BATTERY_CAPACITY
For Battery device classes. This sensor unit uses the ENVSYS_BATTERY_CAPACITY_*
values in
.Ar value_cur
to report its current capacity to userland. Mandatory if
.Em sme_class
is set to
.Em SME_CLASS_BATTERY .
.It ENVSYS_BATTERY_CHARGE
For Battery device classes. This sensor is equivalent to the Indicator type,
it's a boolean. Use it to specify in what state is the Battery state:
.Sy true
if the battery is currently charging or
.Sy false
otherwise. Mandatory if
.Em sme_class
is set to
.Em SME_CLASS_BATTERY .
.El
.It
When initializing or refreshing the sensor, the
.Ar state
member should be set to a known state (otherwise it will be in
unknown state). Possible values:
.Pp
.Bl -tag -width "ENVSYS_SCRITUNDERXX" -compact
.It ENVSYS_SVALID
Sets the sensor to a valid state.
.It ENVSYS_SINVALID
Sets the sensor to an invalid state.
.It ENVSYS_SCRITICAL
Sets the sensor to a critical state.
.It ENVSYS_SCRITUNDER
Sets the sensor to a critical under state.
.It ENVSYS_SCRITOVER
Sets the sensor to a critical over state.
.It ENVSYS_SWARNUNDER
Sets the sensor to a warning under state.
.It ENVSYS_SWARNOVER
Sets the sensor to a warning over state.
.El
.Pp
.It
The
.Ar flags
member accepts one or more of the following flags:
.Pp
.Bl -tag -width "ENVSYS_FCHANGERFACTXX"
.It ENVSYS_FCHANGERFACT
Marks the sensor with ability to change the
.Ar rfact
value on the fly (in voltage sensors). The
.Ar rfact
member must be used in the correct place of the code
that retrieves and converts the value of the sensor.
.It ENVSYS_FPERCENT
This uses the
.Ar value_cur
and
.Ar value_max
members to make a percentage. Both values must be enabled
and have data.
.It ENVSYS_FVALID_MAX
Marks the
.Ar value_max
value as valid.
.It ENVSYS_FVALID_MIN
Marks the
.Ar value_min
value as valid.
.It ENVSYS_FVALID_AVG
Marks the
.Ar value_avg
value as valid.
.It ENVSYS_FMONCRITICAL
Enables and registers a new event to monitor a critical state.
.It ENVSYS_FMONCRITUNDER
Enables and registers a new event to monitor a critical under state.
.It ENVSYS_FMONCRITOVER
Enables and registers a new event to monitor a critical over state.
.It ENVSYS_FMONWARNUNDER
Enables and registers a new event to monitor a warning under state.
.It ENVSYS_FMONWARNOVER
Enables and registers a new event to monitor a warning over state.
.It ENVSYS_FMONSTCHANGED
Enables and registers a new event to monitor Battery capacity or drive state
sensors. It won't be effective if the
.Ar units
member is not set to
.Ar ENVSYS_DRIVE
or
.Ar ENVSYS_BATTERY_CAPACITY .
.It ENVSYS_FMONNOTSUPP
Disallows to set a critical limit via the
.Em ENVSYS_SETDICTIONARY
.Xr ioctl(2) .
This flag has not any effect for monitoring flags set in the driver and it's
only meant to disable setting critical limits from userland.
.El
.Pp
.Em If the driver has to use any of the
.Ar value_max ,
.Ar value_min
.Em or
.Ar value_avg
.Em members, they should be marked as valid with the appropiate flag.
.Pp
.It
If
.Ar units
is set to
.Ar ENVSYS_DRIVE ,
there are some predefined states that must be set (only one)
to the
.Ar value_cur
member:
.Pp
.Bl -tag -width "ENVSYS_DRIVE_POWERDOWNXX" -compact
.It ENVSYS_DRIVE_EMPTY
Drive state is unknown.
.It ENVSYS_DRIVE_READY
Drive is ready.
.It ENVSYS_DRIVE_POWERUP
Drive is powering up.
.It ENVSYS_DRIVE_ONLINE
Drive is online.
.It ENVSYS_DRIVE_OFFLINE
Drive is offline.
.It ENVSYS_DRIVE_IDLE
Drive is idle.
.It ENVSYS_DRIVE_ACTIVE
Drive is active.
.It ENVSYS_DRIVE_BUILD
Drive is building.
.It ENVSYS_DRIVE_REBUILD
Drive is rebuilding.
.It ENVSYS_DRIVE_POWERDOWN
Drive is powering down.
.It ENVSYS_DRIVE_FAIL
Drive has failed.
.It ENVSYS_DRIVE_PFAIL
Drive has been degraded.
.It ENVSYS_DRIVE_MIGRATING
Drive is migrating.
.It ENVSYS_DRIVE_CHECK
Drive is checking its state.
.El
.Pp
.It
If
.Ar units
is set to
.Ar ENVSYS_BATTERY_CAPACITY ,
there are some predefined capacity states that must be set (only one)
to the
.Ar value_cur
member:
.Pp
.Bl -tag -width "ENVSYS_BATTERY_CAPACITY_CRITICAL" -compact
.It ENVSYS_BATTERY_CAPACITY_NORMAL
Battery charge is in normal capacity.
.It ENVSYS_BATTERY_CAPACITY_CRITICAL
Battery charge is in critical capacity.
.It ENVSYS_BATTERY_CAPACITY_LOW
Battery charge is in low capacity.
.It ENVSYS_BATTERY_CAPACITY_WARNING
Battery charge is in warning capacity.
.El
.It
The
.Xr envsys 4
framework expects to have the values converted to
a unit that can be converted to another one easily. That means the user
should convert the value returned by the driver to the appropiate unit.
For example voltage sensors to
.Sy mV ,
temperature sensors to
.Sy uK ,
Watts to
.Sy mW ,
Ampere to
.Sy mA ,
etc.
.Pp
The following types shouldn't need any conversion:
.Ar ENVSYS_BATTERY_CAPACITY ,
.Ar ENVSYS_BATTERY_CHARGE ,
.Ar ENVSYS_INDICATOR ,
.Ar ENVSYS_INTEGER
and
.Ar ENVSYS_DRIVE .
.Pp
.Em PLEASE NOTE THAT YOU MUST AVOID USING FLOATING POINT OPERATIONS
.Em IN KERNEL WHEN CONVERTING THE DATA RETURNED BY THE DRIVER TO THE
.Em APPROPIATE UNIT, IT'S NOT ALLOWED.
.Pp
.El
.Ss HOW TO ENABLE AUTOMATIC MONITORING IN SENSORS
The following example illustrates how to enable automatic monitoring
in a virtual driver for a 
.Em critical
state in the first sensor
.Em (sc_sensor[0]):
.Pp
.Bd -literal
int
mydriver_initialize_sensors(struct mysoftc *sc)
{
	...
	/* sensor is initialized with a valid state */
	sc->sc_sensor[0].state = ENVSYS_SVALID;

	/* 
	 * the monitor member must be true to enable
	 * automatic monitoring.
	 */
	sc->sc_sensor[0].monitor = true;

	/* and now we specify the type of the monitoring event */
	sc->sc_sensor[0].flags |= ENVSYS_FMONCRITICAL;
	...
}

int
mydriver_refresh(struct sysmon_envsys *sme, envsys_data_t *edata)
{
	struct mysoftc *sc = sme->sme_cookie;

	/* we get current data from the driver */
	edata->value_cur = sc->sc_getdata();

	/* 
	 * if value is too high, mark the sensor in
	 * critical state.
	 */
	if (edata->value_cur > MYDRIVER_SENSOR0_HIWAT) {
		edata->state = ENVSYS_SCRITICAL;
		/* a critical event will be sent now automatically */
	} else {
		/* 
		 * if value is within the limits, and we came from
		 * a critical state make sure to change sensor's state
		 * to valid.
		 */
		edata->state = ENVSYS_SVALID;
	}
	...
}
.Ed
.Pp
.Sh CODE REFERENCES
This section describes places within the NetBSD source tree where actual
code implementing the
.Sy envsys 2
framework can be found. All pathnames are relative to
.Pa /usr/src .
.Pp
The
.Sy envsys 2
framework is implemented within the files:
.Pp
.Pa sys/dev/sysmon/sysmon_envsys.c
.Pp
.Pa sys/dev/sysmon/sysmon_envsys_events.c
.Pp
.Pa sys/dev/sysmon/sysmon_envsys_tables.c
.Pp
.Pa sys/dev/sysmon/sysmon_envsys_util.c
.Pp
There's an example LKM driver that shows how the framework works in:
.Pa sys/lkm/misc/envsys2/lkminit_envsys2.c .
.Sh SEE ALSO
.Xr envsys 4 ,
.Xr envstat 8
.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.