snd_ac97_update(9) [suse man page]

SND_AC97_UPDATE(9)						 Control/Mixer API						SND_AC97_UPDATE(9)

NAME

       snd_ac97_update - update the value on the given register

SYNOPSIS

       int snd_ac97_update(struct snd_ac97 * ac97, unsigned short reg, unsigned short value);

ARGUMENTS

       ac97
	   the ac97 instance

       reg
	   the register to change

       value
	   the value to set

DESCRIPTION

       Compares the value with the register cache and updates the value only when the value is changed.

       Returns 1 if the value is changed, 0 if no change, or a negative code on failure.

COPYRIGHT

Kernel Hackers Manual 2.6.					     July 2010							SND_AC97_UPDATE(9)

PCI(3)							   BSD Library Functions Manual 						    PCI(3)

NAME

     pci -- library interface for PCI bus access

LIBRARY

     PCI Bus Access Library (libpci, -lpci)

SYNOPSIS

     #include <pci.h>

     int
     pcibus_conf_read(int pcifd, u_int bus, u_int dev, u_int func, u_int reg, pcireg_t *valp);

     int
     pcibus_conf_write(int pcifd, u_int bus, u_int dev, u_int func, u_int reg, pcireg_t val);

     int
     pcidev_conf_read(int devfd, u_int reg, pcireg_t *valp);

     int
     pcidev_conf_write(int devfd, u_int reg, pcireg_t val);

     char *
     pci_findvendor(pcireg_t id_reg);

     void
     pci_devinfo(pcireg_t id_reg, pcireg_t class_reg, char *devinfo, size_t len);

     void
     pci_conf_print(int pcifd, u_int bus, u_int dev, u_int func);

DESCRIPTION

     The pci library provides support for accessing the PCI bus by user programs.

     These functions are available in the libpci library.  Programs should be linked with -lpci.

CONFIGURATION SPACE FUNCTIONS

     The following functions are used to access PCI configuration space:

     pcibus_conf_read()
	   Access the PCI configuration register reg on the device located at bus, dev, func, and place the result in *valp.  pcifd must be an
	   open file descriptor to a PCI bus within the target PCI domain.

     pcibus_conf_write()
	   Write the value specified by val into the PCI configuration register reg on the device located at bus, dev, func.  pcifd must be an
	   open file descriptor to a PCI bus within the target PCI domain.

     pcidev_conf_read()
	   Access the PCI configuration register reg on the device associated with the open file descriptor devfd and place the result in *valp.

     pcidev_conf_write()
	   Write the value specified by val into the PCI configuration register reg on the device associated with the open file descriptor devfd.

MISCELLANEOUS FUNCTIONS

     The following miscellaneous functions are available:

     pci_findvendor()
	   Return an ASCII description of the PCI vendor in the PCI ID register id_reg.

     pci_devinfo()
	   Return an ASCII description of the PCI vendor, PCI product, and PCI class specified by the PCI ID register id_reg and PCI class ID reg-
	   ister class_reg.  The description is placed into the buffer pointed to by devinfo; the size of that buffer is specified in len.

     pci_conf_print()
	   Print the PCI configuration information for the device located at bus, dev, func.  pcifd must be an open file descriptor to a PCI bus
	   within the target PCI domain.

RETURN VALUES

     The pcibus_conf_read(), pcibus_conf_write(), pcidev_conf_read(), and pcidev_conf_write() functions return 0 on success and -1 on failure.

     The pci_findvendor() function returns NULL if the PCI vendor description cannot be found.

SEE ALSO

     pci(4)

HISTORY

     The pcibus_conf_read(), pcibus_conf_write(), pcidev_conf_read(), pcidev_conf_write(), pci_findvendor(), pci_devinfo(), and pci_conf_print()
     functions first appeared in NetBSD 1.6.

BSD
								  April 24, 2004							       BSD