Kernel Functions for Drivers                 pcireportpmcap(9F)



NAME
     pcireportpmcap - Report Power Management capability  of  a
     PCI device

SYNOPSIS
     #include 
     #include 



     int pcireportpmcap(devinfot *dip,  int cap, void *arg);


INTERFACE LEVEL
     Solaris DI specific (Solaris DI)

PARAMETERS
     dip    Pointer to the device's devinfo structure


     cap    Power management capability


     arg    Argument for the capability


DESCRIPTION
     Some PCI devices provide power  management  capabilities  in
     addition  to  those  provided  by  the  PCI Power Management
     Specification. The pcireportpmcap() function reports those
     Power  Management  capabilities  of  the  PCI  device to the
     framework. Framework supports dynamic changing of the  capa-
     bility  by allowing pcireportpmcap() to be called multiple
     times. Following are the supported capabilities as indicated
     by the cap:


     PCIPMIDLESPED - The PCIPMIDLESPED value indicates  the
     lowest PCI clock speed that a device can tolerate when idle,
     and is  applicable only to 33 MHz PCI  bus.  arg  represents
     the  lowest  possible  idle speed in KHz (1 KHz is 1000 Hz).
     The integer value representing the speed should be  cast  to
     (void *)before passing as arg to pcireportpmcap().


     The special values of arg are:

     PCIPMIDLESPEDANY     The device can  tolerate  any  idle
                              clock speed.






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Kernel Functions for Drivers                 pcireportpmcap(9F)



     PCIPMIDLESPEDNONE    The device cannot tolerate  slowing
                              down of PCI clock even when idle.



     If the driver doesn't make this call,  PCIPMIDLESPEDNONE
     is  assumed. In this case, one offending device can keep the
     entire bus from being power managed.

RETURN VALUES
     The pcireportpmcap() function returns:

     DISUCES    Successful reporting of the capability


     DIFAILURE    Failure  to  report  capability  because   of
                    invalid argument(s)


CONTEXT
     The pcireportpmcap() function can  be  called  from  user,
     kernel and interrupt context.

EXAMPLES
     1. A device driver knows that the device it  controls  works
     with any clock between DC and 33 MHz as specified in Section
     4.2.3.1: Clock Specification  of the PCI  Bus  Specification
     Revision  2.1.  The  device  driver makes the following call
     from its attach(9E):

       if (pcireportpmcap(dip, PCIPMIDLESPED, PCIPMIDLESPEDANY) !=
                   DISUCES)
                       cmnerr(CEWARN, "%s%d: pcireportpmcap failed\n",
                           ddidrivername(dip), ddigetinstance(dip));



     2. A device driver controls  a  10/100  Mb  Ethernet  device
     which runs the device state machine on the chip from the PCI
     clock. For the device state machine to  receive  packets  at
     100  Mb,  the  PCI clock cannot drop below 4 MHz. The driver
     makes the following call whenever it  negotiates  a  100  Mb
     Ethernet connection:

       if (pcireportpmcap(dip,  PCIPMIDLESPED, (void *)4000) !=
                      DISUCES)
                       cmnerr(CEWARN, "%s%d: pcireportpmcap failed\n",
                           ddidrivername(dip), ddigetinstance(dip));


ATRIBUTES




SunOS 5.11         Last change: 13 August 1999                  2






Kernel Functions for Drivers                 pcireportpmcap(9F)



     See attributes(5) for descriptions of the  following  attri-
     butes:



     
           ATRIBUTE TYPE               ATRIBUTE VALUE       
    
     Interface Stability          Committed                   
    


SEE ALSO
     Writing Device Drivers


     PCI Bus Power Management Interface Specification Version 1.1


     PCI Bus Specification Revision 2.1



































SunOS 5.11         Last change: 13 August 1999                  3