apm(4/amd64)	power management interface
apm(4/arm64)	power management interface
apm(4/i386)	advanced power management device interface
apm(4/loongson)	advanced power management device interface
apm(4/macppc)	advanced power management device interface

NAME

apm — power management interface

SYNOPSIS

acpi0 at mainbus?

The apm driver provides a user interface to the acpi(4) driver.

The apm driver implements the following ioctl(2) calls. They are defined in <machine/apmvar.h>.

(no parameters) Request “standby” mode.

(no parameters) Request “suspend” mode.

(no parameters) Request “hibernate” mode.

(struct apm_power_info) Request the current power state. The argument structure is as follows:

struct apm_power_info {
	u_char battery_state;
	u_char ac_state;
	u_char battery_life;
	u_char spare1;
	u_int minutes_left;
	u_int spare2[6];
};

The following values are defined for battery_state:

APM_BATT_HIGH: Battery has a high state of charge.
APM_BATT_LOW: Battery has a low state of charge.
APM_BATT_CRITICAL: Battery has a critical state of charge.
APM_BATT_CHARGING: Battery is not high, low, or critical and is currently charging.
APM_BATT_UNKNOWN: Cannot read the current battery state.
APM_BATTERY_ABSENT: No battery installed.

The following values are defined for ac_state:

The battery_life value contains the estimated percentage of battery life available. 100% indicates a full charge.

The minutes_left value contains the estimated number of minutes of battery life remaining.

(struct apm_ctl) Allows an application to directly set the APM operating mode. The argument structure is as follows:

struct apm_ctl {
	u_int dev;
	u_int mode;
};

dev indicates the device, typically APM_DEV_ALLDEVS.

mode indicates the desired operating mode. Possible values are

(int) This ioctl(2) controls message output by the APM driver when a power change event is detected. The integer parameter is one of:

APM_PRINT_ON: All power change events result in a message. This is the normal operating mode for the driver.
APM_PRINT_OFF: Power change event messages are suppressed.
APM_PRINT_PCT: Power change event messages are suppressed unless the estimated battery life percentage changes.

/dev/apm: Power management data device. May only be opened read-only. May be opened by multiple concurrent users.
/dev/apmctl: Power management control device. May be opened read-write or write-only. May only be opened by one user at a time. An attempt to open the file when in use will fail, returning EBUSY.