grlib/amba/ambapp_find_by_idx.c

0001 /* SPDX-License-Identifier: BSD-2-Clause */
0002
0003 /*
0004  *  AMBA Plug & Play routines
0005  *
0006  *  COPYRIGHT (c) 2011
0007  *  Aeroflex Gaisler
0008  *
0009  * Redistribution and use in source and binary forms, with or without
0010  * modification, are permitted provided that the following conditions
0011  * are met:
0012  * 1. Redistributions of source code must retain the above copyright
0013  *    notice, this list of conditions and the following disclaimer.
0014  * 2. Redistributions in binary form must reproduce the above copyright
0015  *    notice, this list of conditions and the following disclaimer in the
0016  *    documentation and/or other materials provided with the distribution.
0017  *
0018  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
0019  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
0020  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
0021  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
0022  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
0023  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
0024  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
0025  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
0026  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
0027  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
0028  * POSSIBILITY OF SUCH DAMAGE.
0029  */
0030
0031 #include <grlib/ambapp.h>
0032
0033 /* AMBAPP helper routine to find a device by index. The function is given to
0034  * ambapp_for_each, the argument may be NULL (find first device) or a pointer
0035  * to a index which is downcounted until 0 is reached. If the int-pointer
0036  * points to a value of:
0037  *   0  - first device is returned
0038  *   1  - second device is returned
0039  *   ...
0040  *
0041  * The matching device is returned, which will stop the ambapp_for_each search.
0042  * If zero is returned from ambapp_for_each no device matching the index was
0043  * found
0044  */
0045 int ambapp_find_by_idx(struct ambapp_dev *dev, int index, void *pcount)
0046 {
0047   int *pi = pcount;
0048
0049   if (pi) {
0050     if ((*pi)-- == 0)
0051       return (int)dev;
0052     else
0053       return 0;
0054   } else {
0055     /* Satisfied with first matching device, stop search */
0056     return (int)dev;
0057   }
0058 }