pci_set_powerstate.9freebsd

Langue: en

Autres versions - même langue

Version: 365343 (ubuntu - 25/10/10)

Section: 9 (Appels noyau Linux)


BSD mandoc

NAME

pci pci_read_config pci_write_config pci_enable_busmaster pci_disable_busmaster pci_enable_io pci_disable_io pci_set_powerstate pci_get_powerstate pci_find_bsf pci_find_dbsf pci_find_device - PCI bus interface

SYNOPSIS

In sys/bus.h In dev/pci/pcivar.h In dev/pci/pcireg.h In machine/pci_cfgreg.h Ft void Fn pci_write_config device_t dev int reg uint32_t val int width Ft int Fn pci_enable_busmaster device_t dev Ft int Fn pci_disable_busmaster device_t dev Ft int Fn pci_enable_io device_t dev int space Ft int Fn pci_disable_io device_t dev int space Ft int Fn pci_set_powerstate device_t dev int state Ft int Fn pci_get_powerstate device_t dev Ft uint32_t Fn pci_read_config device_t dev int reg int width Ft device_t Fn pci_find_bsf uint8_t bus uint8_t slot uint8_t func Ft device_t Fn pci_find_dbsf uint32_t domain uint8_t bus uint8_t slot uint8_t func Ft device_t Fn pci_find_device uint16_t vendor uint16_t device

DESCRIPTION

The set of functions are used for managing PCI devices.

The Fn pci_read_config function is used to read data from the PCI configuration space of the device Fa dev , at offset Fa reg , with Fa width specifying the size of the access.

The Fn pci_write_config function is used to write the value Fa val to the PCI configuration space of the device Fa dev , at offset Fa reg , with Fa width specifying the size of the access.

The Fn pci_enable_busmaster function enables PCI bus mastering for the device Fa dev , by setting the PCIM_CMD_BUSMASTEREN bit in the PCIR_COMMAND register. The Fn pci_disable_busmaster function clears this bit.

The Fn pci_enable_io function enables memory or I/O port address decoding for the device Fa dev , by setting the PCIM_CMD_MEMEN or PCIM_CMD_PORTEN bit in the PCIR_COMMAND register appropriately. The Fn pci_disable_io function clears the appropriate bit. The Fa space argument specifies which resource is affected; this can be either SYS_RES_MEMORY or SYS_RES_IOPORT as appropriate.

NOTE These functions should be used in preference to manually manipulating the configuration space.

The Fn pci_get_powerstate function returns the current ACPI power state of the device Fa dev . If the device does not support power management capabilities, then the default state of PCI_POWERSTATE_D0 is returned. The following power states are defined by ACPI:

PCI_POWERSTATE_D0
State in which device is on and running. It is receiving full power from the system and delivering full functionality to the user.
PCI_POWERSTATE_D1
Class-specific low-power state in which device context may or may not be lost. Busses in this state cannot do anything to the bus, to force devices to lose context.
PCI_POWERSTATE_D2
Class-specific low-power state in which device context may or may not be lost. Attains greater power savings than PCI_POWERSTATE_D1 Busses in this state can cause devices to lose some context. Devices must be prepared for the bus to be in this state or higher.
PCI_POWERSTATE_D3
State in which the device is off and not running. Device context is lost, and power from the device can be removed.
PCI_POWERSTATE_UNKNOWN
State of the device is unknown.

The Fn pci_set_powerstate function is used to transition the device Fa dev to the ACPI power state Fa state . It checks to see if the device is PCI 2.2 compliant. If so, it checks the capabilities pointer to determine which power states the device supports. If the device does not have power management capabilities, the default state of PCI_POWERSTATE_D0 is set.

The Fn pci_find_bsf function looks up the Vt device_t of a PCI device, given its Fa bus , Fa slot , and Fa func . The Fa slot number actually refers to the number of the device on the bus, which does not necessarily indicate its geographic location in terms of a physical slot. Note that in case the system has multiple PCI domains, the Fn pci_find_bsf function only searches the first one. Actually, it is equivalent to:

 pci_find_dbsf(0, bus, slot, func);
 

The Fn pci_find_dbsf function looks up the Vt device_t of a PCI device, given its Fa domain , Fa bus , Fa slot , and Fa func . The Fa slot number actually refers to the number of the device on the bus, which does not necessarily indicate its geographic location in terms of a physical slot.

The Fn pci_find_device function looks up the Vt device_t of a PCI device, given its Fa vendor and Fa device IDs. Note that there can be multiple matches for this search; this function only returns the first matching device.

IMPLEMENTATION NOTES

The Vt pci_addr_t type varies according to the size of the PCI bus address space on the target architecture.

SEE ALSO

pci(4), pciconf(8), bus_alloc_resource9, bus_dma9, bus_release_resource9, bus_setup_intr9, bus_teardown_intr9, devclass(9), device(9), driver(9), rman(9)
FreeBSD Developers' Handbook NewBus http://www.FreeBSD.org/doc/en_US.ISO8859-1/books/developers-handbook/
Shanley Anderson PCI System Architecture 2nd Edition ISBN 0-201-30974-2

AUTHORS

This manual page was written by An Bruce M Simpson Aq bms@FreeBSD.org .

BUGS

The kernel PCI code has a number of references to ``slot numbers'' These do not refer to the geographic location of PCI devices, but to the device number assigned by the combination of the PCI IDSEL mechanism and the platform firmware. This should be taken note of when working with the kernel PCI code.