source: rtems/cpukit/libpci/pci_find.c @ a31845f7

/*  PCI Help function, Find a PCI device by VENDOR/DEVICE ID
 *
 *  COPYRIGHT (c) 2010.
 *  Cobham Gaisler AB.
 *
 *  The license and distribution terms for this file may be
 *  found in the file LICENSE in this distribution or at
 *  http://www.rtems.com/license/LICENSE.
 */

#include <pci.h>
#include <pci/access.h>

struct compare_info {
        int index;
        uint16_t vendor;
        uint16_t device;
};

static int compare_dev_id(pci_dev_t pcidev, void *arg)
{
        struct compare_info *info = arg;
        uint16_t vid, did;

        pci_cfg_r16(pcidev, PCI_VENDOR_ID, &vid);
        pci_cfg_r16(pcidev, PCI_DEVICE_ID, &did);
        if ((vid != info->vendor) || (did != info->device))
                return 0;
        if (info->index-- == 0)
                return pcidev;
        else
                return 0;
}

/* Find a Device in PCI configuration space */
int pci_find(uint16_t ven, uint16_t dev, int index, pci_dev_t *pdev)
{
        struct compare_info info;
        int result;

        info.index = index;
        info.vendor = ven;
        info.device = dev;

        result = pci_for_each(compare_dev_id, &info);
        if (pdev)
                *pdev = (pci_dev_t)result;
        if (result == 0)
                return -1;
        else
                return 0;
}