cpukit/libpci/pci_find.c

0001 /* SPDX-License-Identifier: BSD-2-Clause */
0002
0003 /*  PCI Help function, Find a PCI device by VENDOR/DEVICE ID
0004  *
0005  *  COPYRIGHT (c) 2010 Cobham Gaisler AB.
0006  *
0007  * Redistribution and use in source and binary forms, with or without
0008  * modification, are permitted provided that the following conditions
0009  * are met:
0010  * 1. Redistributions of source code must retain the above copyright
0011  *    notice, this list of conditions and the following disclaimer.
0012  * 2. Redistributions in binary form must reproduce the above copyright
0013  *    notice, this list of conditions and the following disclaimer in the
0014  *    documentation and/or other materials provided with the distribution.
0015  *
0016  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
0017  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
0018  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
0019  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
0020  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
0021  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
0022  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
0023  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
0024  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
0025  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
0026  * POSSIBILITY OF SUCH DAMAGE.
0027  */
0028
0029 #include <pci.h>
0030 #include <pci/access.h>
0031
0032 struct compare_info {
0033     int index;
0034     uint16_t vendor;
0035     uint16_t device;
0036 };
0037
0038 static int compare_dev_id(pci_dev_t pcidev, void *arg)
0039 {
0040     struct compare_info *info = arg;
0041     uint16_t vid, did;
0042
0043     pci_cfg_r16(pcidev, PCIR_VENDOR, &vid);
0044     pci_cfg_r16(pcidev, PCIR_DEVICE, &did);
0045     if ((vid != info->vendor) || (did != info->device))
0046         return 0;
0047     if (info->index-- == 0)
0048         return pcidev;
0049     else
0050         return 0;
0051 }
0052
0053 /* Find a Device in PCI configuration space */
0054 int pci_find(uint16_t ven, uint16_t dev, int index, pci_dev_t *pdev)
0055 {
0056     struct compare_info info;
0057     int result;
0058
0059     info.index = index;
0060     info.vendor = ven;
0061     info.device = dev;
0062
0063     result = pci_for_each(compare_dev_id, &info);
0064     if (pdev)
0065         *pdev = (pci_dev_t)result;
0066     if (result == 0)
0067         return -1;
0068     else
0069         return 0;
0070 }