pdiag_pcicfg_read
Purpose
Reads a PCI Configuration register.
Syntax
#include <sys/pdiagex_dds.h>
#include <sys/pdiag_def.h>
int32 pdiag_pcicfg_read( device_instance, reg_offset, datasize, data )
pdiag_addr_t device_instance;
ulong reg_offset;
int datasize;
uchar *data;
Description
The pdiag_pcicfg_read() function reads 8, 16, or 32 bits of a PCI Configuration register for this particular resource. The reg_offset parameter contains the register offset into the device's PCI configuration table. The calling application must provide a valid register offset before calling pdiag_pcicfg_read. The returned data is the 8, 16, or 32 bit value read from the PCI register configuration table. All the byte swapping required is performed internally by this function; the calling application must not alter the byte positioning of the data.
Execution Environment
The pdiag_pcicfg_read() function can be called from the process environment only.
Parameters
| Parameter | Description |
|---|---|
| device_instance | Pointer to the string name of the specific device to read. |
| reg_offset | Contains the offset within the PCI configuration table register to be read. |
| datasize | The data size will be specified as follows:
|
| data | Pointer to the data to be read within the PCI Configuration
Table. Note: The value read is the specified size on the datasize
parameter.
|
Return Value
The pdiag_pcicfg_read function returns one of the following values:
| Return Value | Description |
|---|---|
| 0 | Successful return |
| -1 | Software error |