PMF(9) | Kernel Developer's Manual | PMF(9)

# NAME

`PMF`, `pmf_device_register`, `pmf_device_register1`, `pmf_device_deregister`, `pmf_device_suspend`, `pmf_device_resume`, `pmf_device_recursive_suspend`, `pmf_device_recursive_resume`, `pmf_device_resume_subtree`, `pmf_class_network_register`, `pmf_class_input_register`, `pmf_class_display_register`, `pmf_system_suspend`, `pmf_system_resume`, `pmf_system_shutdown`, `pmf_event_register`, `pmf_event_deregister`, `pmf_event_inject`, `pmf_set_platform`, `pmf_get_platform` — power management and inter-driver messaging framework

# SYNOPSIS

`#include <sys/device.h>`

bool
`pmf_device_register`(device_t dev, bool (*suspend)(device_t dev, const pmf_qual_t *qual), bool (*resume)(device_t dev, const pmf_qual_t *qual));

bool
`pmf_device_register1`(device_t dev, bool (*suspend)(device_t dev, const pmf_qual_t *qual), bool (*resume)(device_t dev, const pmf_qual_t *qual), bool (*shutdown)(device_t dev, int how));

void
`pmf_device_deregister`(device_t dev);

bool
`pmf_device_suspend`(device_t dev, const pmf_qual_t *qual);

bool
`pmf_device_resume`(device_t dev, const pmf_qual_t *qual);

bool
`pmf_device_recursive_suspend`(device_t dev, const pmf_qual_t *qual);

bool
`pmf_device_recursive_resume`(device_t dev, const pmf_qual_t *qual);

bool
`pmf_device_subtree_resume`(device_t dev, const pmf_qual_t *qual);

void
`pmf_class_network_register`(device_t dev, struct ifnet *ifp);

bool
`pmf_class_input_register`(device_t dev);

bool
`pmf_class_display_register`(device_t dev);

bool
`pmf_system_suspend`(const pmf_qual_t *qual);

bool
`pmf_system_resume`(const pmf_qual_t *qual);

void
`pmf_system_shutdown`(int);

bool
`pmf_event_register`(device_t dev, pmf_generic_event_t ev, void (*handler)(device_t dev), bool global);

void
`pmf_event_deregister`(device_t dev, pmf_generic_event_t ev, void (*handler)(device_t dev), bool global);

bool
`pmf_event_inject`(device_t dev, pmf_generic_event_t ev);

bool
`pmf_set_platform`(const char *key, const char *value);

const char *
`pmf_get_platform`(const char *key);

# DESCRIPTION

The machine-independent `PMF` framework provides power management and inter-driver messaging support for device drivers.

# DATA TYPES

Drivers for devices implementing `PMF` may make use of the following data type:

pmf_qual_t
  An opaque aggregate of qualifications on a `PMF` suspend or resume call.
pmf_generic_event_t
  A device driver can register as a listener for specific events, or inject events into the message queue. The following message types are defined:
  - `PMFE_DISPLAY_ON`
  - `PMFE_DISPLAY_REDUCED`
  - `PMFE_DISPLAY_STANDBY`
  - `PMFE_DISPLAY_SUSPEND`
  - `PMFE_DISPLAY_OFF`
  - `PMFE_DISPLAY_BRIGHTNESS_UP`
  - `PMFE_DISPLAY_BRIGHTNESS_DOWN`
  - `PMFE_AUDIO_VOLUME_UP`
  - `PMFE_AUDIO_VOLUME_DOWN`
  - `PMFE_AUDIO_VOLUME_TOGGLE`
  - `PMFE_CHASSIS_LID_CLOSE`
  - `PMFE_CHASSIS_LID_OPEN`

# FUNCTIONS

`pmf_device_register`(dev, suspend, resume)
  Register a device with the power management framework. The suspend and resume functions are passed dev and a pmf_qual_t, and will be called when the system state changes; they should return `true` on success and `false` on failure. If either suspend or resume is `NULL` then it is assumed that device state does not need to be captured and resumed on a power transition. Bus and class-level power management will still be performed.

  `pmf_device_register`() always returns true. Callers should ignore the return value.

`pmf_device_register1`(dev, suspend, resume, shutdown)
  Like `pmf_device_register`(), but additionally registers a shutdown handler. During system shutdown, `pmf_system_shutdown`() calls shutdown on dev with the reboot(2) “howto” in the second argument. shutdown should return `true` on success and `false` on failure.

  `pmf_device_register1`() always returns true. Callers should ignore the return value.

`pmf_device_deregister`(dev)
  Deregister a device with the power management framework.
`pmf_device_suspend`(dev, qual)
  Suspend a device by first calling the class suspend handler, followed by the driver suspend handler, and finally the bus suspend handler.
`pmf_device_resume`(dev, qual)
  Resume a device by first calling the bus resume handler, followed by the driver resume handler, and finally the class resume handler.
`pmf_device_recursive_suspend`(dev, qual)
  As `pmf_device_suspend`(), but ensures that all child devices of dev are suspended.
`pmf_device_recursive_resume`(dev, qual)
  As `pmf_device_resume`(), but ensures that all parent devices of dev are resumed.
`pmf_device_subtree_resume`(dev, qual)
  As `pmf_device_resume`(), but ensures that all child devices of dev are resumed.
`pmf_class_network_register`(dev, ifp)
  Register a device with the power management framework as a network-class device.
`pmf_class_input_register`(dev)
  Register a device with the power management framework as an input-class device.
`pmf_class_display_register`(dev)
  Register a device with the power management framework as a display-class device.
`pmf_system_suspend`(qual)
  Suspend all attached devices. Devices are suspended by traversing the autoconfiguration tree beginning with the leaf nodes. This function will fail if any attached drivers do not support the power management framework.
`pmf_system_resume`(qual)
  Resume all attached devices. Devices are resumed by traversing the autoconfiguration tree beginning with devices that do not have a parent. This function will fail if any attached drivers do not support the power management framework.
`pmf_system_shutdown`(int)
  Shutdown all attached devices. Devices are shut down by traversing the autoconfiguration tree beginning with the leaf nodes. The integer argument is passed to the driver shutdown functions. It should contain the reboot(2) “howto” argument. This function ignores the presence of attached drivers that do not support the power management framework.
`pmf_event_register`(dev, ev, handler, global)
  Register the callback handler to be called whenever an ev event is triggered. If global is `true`, handler accepts anonymous events from `pmf_event_inject`().
`pmf_event_deregister`(dev, ev, handler, global)
  Deregister the callback previously registered with `pmf_event_register`().
`pmf_event_inject`(dev, ev)
  Inject an inter-driver message into the message queue. If dev is `NULL`, the event is considered to be anonymous and one or more drivers may handle this event, otherwise the event is delivered directly to the callback registered by dev.
`pmf_set_platform`(key, value)
  Insert a name-value pair into the platform information database.
`pmf_get_platform`(key)
  Retrieve the value for key from the platform information database. Returns `NULL` if the key is not present.

# CODE REFERENCES

The power management framework is implemented within the files sys/sys/pmf.h, sys/sys/device.h, sys/kern/kern_pmf.c, and sys/kern/subr_autoconf.c.

# SEE ALSO

autoconf(9), driver(9)

# HISTORY

The `PMF` framework appeared in NetBSD 5.0.

# AUTHORS

Jared D. McNeill <jmcneill@NetBSD.org>
Joerg Sonnenberger <joerg@NetBSD.org>

# BUGS

`pmf_device_register`() and `pmf_device_register1`() never fail and should return void, but until all callers are updated to ignore the return value, they must continue to return bool: PR kern/57575

March 9, 2024 | NetBSD 11.0