SCO OpenServer

pci_read(D3oddi)

pci_read: pci_readbyte, pci_readword, pci_readdword -- read data from PCI configuration space

Synopsis

   #include <sys/pci.h>
      
   int pci_readbyte(struct pci_devinfo infptr, unsigned short reg,
                   unsigned char dataptr);
      
   int pci_readword(struct pci_devinfo infptr, unsigned short reg,
                   unsigned short dataptr);
      
   int pci_readdword(struct pci_devinfo infptr, unsigned short reg,
                    unsigned long dataptr);

Description

The three functions pci_readbyte( ), pci_readword( ), and pci_readdword( ) functions read a byte, word, or 32-bit word (double word), respectively, from a configuration space register.

Arguments

infptr: Pointer to a pci_businfo(D4oddi) structure.
reg: Register to be read.
dataptr: Pointer to a pci_devinfo(D4oddi) structure into which the data will be returned.

Return values

A return value of 1 indicates success; the contents of reg is written to the dataptr structure.

A return value of 0 indicates failure. A failure can occur if the device is not found or if the register offset is invalid or misaligned.

Usage

The register offset must be aligned to correspond with the size of the data field being returned. In other words, the register offset for pci_readword( ) must be 2-byte aligned, and the register offset for pci_readdword( ) must be 4-byte aligned.

Incorrect alignment will result in a failure.

Context and synchronization

Initialization context

Hardware applicability

PCI bus

Version applicability

oddi: 3, 3mp, 4, 4mp, 5, 5mp, 6, 6mp

SVR5 DDI compatibility

DDI drivers access PCI configuration information through the resource manager database. Use the cm_getval(D3) function to access information supported by the parameters documented on the cm_params(D5) manual page and function such as cm_read_devconfig(D3) and cm_write_devconfig(D3) to access other configuration information. Note that DDI drivers cannot access all the PCI configuration information that SCO OpenServer 5 drivers can access.

References

pci(D4oddi), pci(HW)

pci_buspresent(D3oddi), pci_search(D3oddi), pci_specialcycle(D3oddi), pci_write(D3oddi)

``PCI'' in HDK Technical Reference