pci_save_config_regs(9F)				   Kernel Functions for Drivers 				  pci_save_config_regs(9F)

NAME

       pci_save_config_regs, pci_restore_config_regs - save and restore the PCI configuration registers

SYNOPSIS

       #include <sys/ddi.h>
       #include <sys/sunddi.h>

       int pci_save_config_regs(dev_info_t *dip);

       int pci_restore_config_regs(dev_info_t *dip);

INTERFACE LEVEL

       Solaris DDI-specific (Solaris DDI).

ARGUMENTS

       dip    Pointer to the device's dev_info structure.

DESCRIPTION

       pci_save_config_regs() saves the current configuration registers on persistent system memory. pci_restore_config_regs() restores configura-
       tion registers previously saved by pci_save_config_regs().

       pci_save_config_regs() should be called by the driver's power() entry point before powering a device  off  (to  PCI  state  D3).  Likewise,
       pci_restore_config_regs() should be called after powering a device on (from PCI state D3), but before accessing the device. See power(9E).

RETURN VALUES

       pci_save_config_regs() and pci_restore_config_regs() return:

       DDI_SUCCESS    Operation completed successfully.

       DDI_FAILURE    Operation failed to complete successfully.

CONTEXT

       Both these functions can be called from user or kernel context.

EXAMPLES

       Example 1 Invoking the save and restore functions

	 static int
	 xx_power(dev_info_t *dip, int component, int level) {
	    struct xx *xx;
	    int rval = DDI_SUCCESS;

	    xx = ddi_get_soft_state(xx_softstate, ddi_get_instance(dip));
	    if (xx == NULL) {
		return (DDI_FAILURE);
	    }

	    mutex_enter(&xx->x_mutex);

	    switch (level) {
	    case PM_LEVEL_D0:
		XX_POWER_ON(xx);
		if (pci_restore_config_regs(dip) == DDI_FAILURE) {
		    /*
		     * appropriate error path handling here
		     */
		    ...
		    rval = DDI_FAILURE;
		    }
		break;

	    case PM_LEVEL_D3:
		if (pci_save_config_regs(dip) == DDI_FAILURE) {
		     /*
		      * appropriate error path handling here
		      */
		     ...
		     rval = DDI_FAILURE;
		     }
		 else {
		     XX_POWER_OFF(xx);
		 }
		 break;

	     default:
		   rval = DDI_FAILURE;
		   break;
	     }

	     mutex_exit(&xx->x_mutex);
	     return (rval);
	 }

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Committed 		   |
       +-----------------------------+-----------------------------+

SEE ALSO

       attributes(5), power(9E)

       Writing Device Drivers

       PCI Bus Power Management Interface Specification Version 1.1

       PCI Bus Specification Revision 2.1

SunOS 5.11							   02 June 2000 					  pci_save_config_regs(9F)