oss_mix.c

   1 /*
   2  * Copyright (C) 1998-2014 Andre Noll <maan@tuebingen.mpg.de>
   3  *
   4  * Licensed under the GPL v2. For licencing details see COPYING.
   5  */
   6
   7 /** \file oss_mix.c The OSS mixer plugin. */
   8
   9 #include <sys/soundcard.h>
  10 #include <sys/ioctl.h>
  11 #include <regex.h>
  12
  13 #include "para.h"
  14 #include "error.h"
  15 #include "mix.h"
  16 #include "fd.h"
  17 #include "string.h"
  18
  19 struct oss_mixer_channel {
  20         const char *name;
  21         int id;
  22 };
  23
  24 static const struct oss_mixer_channel channels[] = {
  25         {.name = "volume", .id = SOUND_MIXER_VOLUME},
  26         {.name = "bass", .id = SOUND_MIXER_BASS},
  27         {.name = "treble", .id = SOUND_MIXER_TREBLE},
  28         {.name = "synth", .id = SOUND_MIXER_SYNTH},
  29         {.name = "pcm", .id = SOUND_MIXER_PCM},
  30         {.name = "speaker", .id = SOUND_MIXER_SPEAKER},
  31         {.name = "line", .id = SOUND_MIXER_LINE},
  32         {.name = "mic", .id = SOUND_MIXER_MIC},
  33         {.name = "cd", .id = SOUND_MIXER_CD},
  34         {.name = "imix", .id = SOUND_MIXER_IMIX},
  35         {.name = "altpcm", .id = SOUND_MIXER_ALTPCM},
  36         {.name = "reclev", .id = SOUND_MIXER_RECLEV},
  37         {.name = "igain", .id = SOUND_MIXER_IGAIN},
  38         {.name = "ogain", .id = SOUND_MIXER_OGAIN},
  39 };
  40
  41 /** Iterate over all defined mixer channels. */
  42 #define FOR_EACH_CHANNEL(i) for ((i) = 0; (i) < ARRAY_SIZE(channels); (i)++)
  43
  44 struct mixer_handle {
  45         int fd;
  46         int id;
  47 };
  48
  49 static int oss_mix_open(const char *dev, struct mixer_handle **handle)
  50 {
  51         int ret;
  52         struct mixer_handle *h;
  53
  54         *handle = NULL;
  55         if (!dev)
  56                 dev = "/dev/mixer";
  57         PARA_INFO_LOG("opening %s\n", dev);
  58         ret = para_open(dev, O_RDWR, 42);
  59         if (ret < 0) {
  60                 PARA_ERROR_LOG("could not open %s\n", dev);
  61                 return ret;
  62         }
  63         h = para_malloc(sizeof(*h));
  64         h->fd = ret;
  65         *handle = h;
  66         return 1;
  67 }
  68
  69 static char *oss_mix_get_channels(__a_unused struct mixer_handle *handle)
  70 {
  71         int i;
  72         char *list = NULL;
  73
  74         FOR_EACH_CHANNEL(i) {
  75                 const char *name = channels[i].name;
  76                 char *tmp = list;
  77                 list = make_message("%s%s%s",
  78                         list? list : "",
  79                         list? ", " : "",
  80                         name);
  81                 free(tmp);
  82         }
  83         return list;
  84 }
  85
  86 static int oss_mix_set_channel(struct mixer_handle *handle,
  87                 const char *mixer_channel)
  88 {
  89         int i;
  90
  91         if (!mixer_channel) {
  92                 handle->id = SOUND_MIXER_VOLUME; /* default */
  93                 return 0;
  94         }
  95         FOR_EACH_CHANNEL(i) {
  96                 if (strcasecmp(channels[i].name, mixer_channel))
  97                         continue;
  98                 handle->id = i;
  99                 return 1;
 100         }
 101         return -E_BAD_CHANNEL;
 102 }
 103
 104 static int oss_mix_get(struct mixer_handle *handle)
 105 {
 106         int val, fd = handle->fd, id = handle->id;
 107
 108         if (ioctl(fd, MIXER_READ(id), &val) < 0)
 109                 return -ERRNO_TO_PARA_ERROR(errno);
 110         /* take the mean value of left and right */
 111         return (val % 256 + (val >> 8)) / 2;
 112 }
 113
 114 static int oss_mix_set(struct mixer_handle *handle, int val)
 115 {
 116         int fd = handle->fd, id = handle->id, tmp = (val << 8) + val;
 117
 118         if (ioctl(fd, MIXER_WRITE(id), &tmp) < 0)
 119                 return -ERRNO_TO_PARA_ERROR(errno);
 120         return 1;
 121 }
 122
 123 static void oss_mix_close(struct mixer_handle **handle)
 124 {
 125         struct mixer_handle *h;
 126
 127         if (!handle)
 128                 return;
 129         h = *handle;
 130         if (h) {
 131                 if (h->fd >= 0)
 132                         close(h->fd);
 133                 free(h);
 134         }
 135         *handle = NULL;
 136 }
 137
 138 /**
 139  * The init function of the OSS mixer.
 140  *
 141  * \param self The structure to initialize.
 142  *
 143  * \sa struct \ref mixer, \ref alsa_mix_init().
 144  */
 145 void oss_mix_init(struct mixer *self)
 146 {
 147         self->open = oss_mix_open;
 148         self->get_channels = oss_mix_get_channels;
 149         self->set_channel = oss_mix_set_channel;
 150         self->get = oss_mix_get;
 151         self->set = oss_mix_set;
 152         self->close = oss_mix_close;
 153 }