1 /*
   2  * Copyright (c) 2003, 2015, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 //#define USE_ERROR
  27 //#define USE_TRACE
  28 
  29 #include "PLATFORM_API_LinuxOS_ALSA_CommonUtils.h"
  30 
  31 static void alsaDebugOutput(const char *file, int line, const char *function, int err, const char *fmt, ...) {
  32 #ifdef USE_ERROR
  33     va_list args;
  34     va_start(args, fmt);
  35     printf("%s:%d function %s: error %d: %s\n", file, line, function, err, snd_strerror(err));
  36     if (strlen(fmt) > 0) {
  37         vprintf(fmt, args);
  38     }
  39     va_end(args);
  40 #endif
  41 }
  42 
  43 static int alsa_inited = 0;
  44 static int alsa_enumerate_pcm_subdevices = FALSE; // default: no
  45 static int alsa_enumerate_midi_subdevices = FALSE; // default: no
  46 
  47 /*
  48  * Declare library specific JNI_Onload entry if static build
  49  */
  50 DEF_STATIC_JNI_OnLoad
  51 
  52 void initAlsaSupport() {
  53     char* enumerate;
  54     if (!alsa_inited) {
  55         alsa_inited = TRUE;
  56         snd_lib_error_set_handler(&alsaDebugOutput);
  57 
  58         enumerate = getenv(ENV_ENUMERATE_PCM_SUBDEVICES);
  59         if (enumerate != NULL && strlen(enumerate) > 0
  60             && (enumerate[0] != 'f')   // false
  61             && (enumerate[0] != 'F')   // False
  62             && (enumerate[0] != 'n')   // no
  63             && (enumerate[0] != 'N')) { // NO
  64             alsa_enumerate_pcm_subdevices = TRUE;
  65         }
  66 #ifdef ALSA_MIDI_ENUMERATE_SUBDEVICES
  67         alsa_enumerate_midi_subdevices = TRUE;
  68 #endif
  69     }
  70 }
  71 
  72 
  73 /* if true (non-zero), ALSA sub devices should be listed as separate devices
  74  */
  75 int needEnumerateSubdevices(int isMidi) {
  76     initAlsaSupport();
  77     return isMidi ? alsa_enumerate_midi_subdevices
  78                   : alsa_enumerate_pcm_subdevices;
  79 }
  80 
  81 
  82 /*
  83  * deviceID contains packed card, device and subdevice numbers
  84  * each number takes 10 bits
  85  * "default" device has id == ALSA_DEFAULT_DEVICE_ID
  86  */
  87 UINT32 encodeDeviceID(int card, int device, int subdevice) {
  88     return (((card & 0x3FF) << 20) | ((device & 0x3FF) << 10)
  89            | (subdevice & 0x3FF)) + 1;
  90 }
  91 
  92 
  93 void decodeDeviceID(UINT32 deviceID, int* card, int* device, int* subdevice,
  94                     int isMidi) {
  95     deviceID--;
  96     *card = (deviceID >> 20) & 0x3FF;
  97     *device = (deviceID >> 10) & 0x3FF;
  98     if (needEnumerateSubdevices(isMidi)) {
  99         *subdevice = deviceID  & 0x3FF;
 100     } else {
 101         *subdevice = -1; // ALSA will choose any subdevices
 102     }
 103 }
 104 
 105 
 106 void getDeviceString(char* buffer, int card, int device, int subdevice,
 107                      int usePlugHw, int isMidi) {
 108     if (needEnumerateSubdevices(isMidi)) {
 109         sprintf(buffer, "%s:%d,%d,%d",
 110                         usePlugHw ? ALSA_PLUGHARDWARE : ALSA_HARDWARE,
 111                         card, device, subdevice);
 112     } else {
 113         sprintf(buffer, "%s:%d,%d",
 114                         usePlugHw ? ALSA_PLUGHARDWARE : ALSA_HARDWARE,
 115                         card, device);
 116     }
 117 }
 118 
 119 
 120 void getDeviceStringFromDeviceID(char* buffer, UINT32 deviceID,
 121                                  int usePlugHw, int isMidi) {
 122     int card, device, subdevice;
 123 
 124     if (deviceID == ALSA_DEFAULT_DEVICE_ID) {
 125         strcpy(buffer, ALSA_DEFAULT_DEVICE_NAME);
 126     } else {
 127         decodeDeviceID(deviceID, &card, &device, &subdevice, isMidi);
 128         getDeviceString(buffer, card, device, subdevice, usePlugHw, isMidi);
 129     }
 130 }
 131 
 132 
 133 static int hasGottenALSAVersion = FALSE;
 134 #define ALSAVersionString_LENGTH 200
 135 static char ALSAVersionString[ALSAVersionString_LENGTH];
 136 
 137 void getALSAVersion(char* buffer, int len) {
 138     if (!hasGottenALSAVersion) {
 139         // get alsa version from proc interface
 140         FILE* file;
 141         int curr, len, totalLen, inVersionString;
 142         file = fopen(ALSA_VERSION_PROC_FILE, "r");
 143         ALSAVersionString[0] = 0;
 144         if (file) {
 145             if (NULL != fgets(ALSAVersionString, ALSAVersionString_LENGTH, file)) {
 146                 // parse for version number
 147                 totalLen = strlen(ALSAVersionString);
 148                 inVersionString = FALSE;
 149                 len = 0;
 150                 curr = 0;
 151                 while (curr < totalLen) {
 152                     if (!inVersionString) {
 153                         // is this char the beginning of a version string ?
 154                         if (ALSAVersionString[curr] >= '0'
 155                             && ALSAVersionString[curr] <= '9') {
 156                             inVersionString = TRUE;
 157                         }
 158                     }
 159                     if (inVersionString) {
 160                         // the version string ends with white space
 161                         if (ALSAVersionString[curr] <= 32) {
 162                             break;
 163                         }
 164                         if (curr != len) {
 165                             // copy this char to the beginning of the string
 166                             ALSAVersionString[len] = ALSAVersionString[curr];
 167                         }
 168                         len++;
 169                     }
 170                     curr++;
 171                 }
 172                 // remove trailing dots
 173                 while ((len > 0) && (ALSAVersionString[len - 1] == '.')) {
 174                     len--;
 175                 }
 176                 // null terminate
 177                 ALSAVersionString[len] = 0;
 178             }
 179             fclose(file);
 180             hasGottenALSAVersion = TRUE;
 181         }
 182     }
 183     strncpy(buffer, ALSAVersionString, len);
 184 }
 185 
 186 
 187 /* end */