1 /*- 2 * Copyright (c) 2015-2022 Hans Petter Selasky 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23 * SUCH DAMAGE. 24 */ 25 26 #include <sys/queue.h> 27 #include <sys/filio.h> 28 #include <sys/soundcard.h> 29 30 #include <stdint.h> 31 #include <stdlib.h> 32 #include <string.h> 33 #include <fcntl.h> 34 #include <unistd.h> 35 #include <err.h> 36 #include <time.h> 37 38 #include "backend.h" 39 #include "int.h" 40 41 static void 42 null_close(struct voss_backend *pbe __unused) 43 { 44 } 45 46 static int 47 null_open(struct voss_backend *pbe __unused, const char *devname __unused, 48 int samplerate __unused, int bufsize __unused, int *pchannels __unused, 49 int *pformat) 50 { 51 int value[3]; 52 int i; 53 54 value[0] = *pformat & VPREFERRED_SNE_AFMT; 55 value[1] = *pformat & VPREFERRED_SLE_AFMT; 56 value[2] = *pformat & VPREFERRED_SBE_AFMT; 57 58 for (i = 0; i != 3; i++) { 59 if (value[i] == 0) 60 continue; 61 *pformat = value[i]; 62 return (0); 63 } 64 return (-1); 65 } 66 67 static int 68 null_rec_transfer(struct voss_backend *pbe __unused, void *ptr, int len) 69 { 70 71 if (voss_has_synchronization == 0) 72 virtual_oss_wait(); 73 memset(ptr, 0, len); 74 return (len); 75 } 76 77 static int 78 null_play_transfer(struct voss_backend *pbe __unused, void *ptr __unused, 79 int len) 80 { 81 return (len); 82 } 83 84 static void 85 null_delay(struct voss_backend *pbe __unused, int *pdelay) 86 { 87 *pdelay = -1; 88 } 89 90 struct voss_backend voss_backend_null_rec = { 91 .open = null_open, 92 .close = null_close, 93 .transfer = null_rec_transfer, 94 .delay = null_delay, 95 }; 96 97 struct voss_backend voss_backend_null_play = { 98 .open = null_open, 99 .close = null_close, 100 .transfer = null_play_transfer, 101 .delay = null_delay, 102 }; 103