Documentation/sound/alsa/HD-Audio-Controls.txt

   1 This file explains the codec-specific mixer controls.
   2
   3 Realtek codecs
   4 --------------
   5
   6 * Channel Mode
   7   This is an enum control to change the surround-channel setup,
   8   appears only when the surround channels are available.
   9   It gives the number of channels to be used, "2ch", "4ch", "6ch",
  10   and "8ch".  According to the configuration, this also controls the
  11   jack-retasking of multi-I/O jacks.
  12
  13 * Auto-Mute Mode
  14   This is an enum control to change the auto-mute behavior of the
  15   headphone and line-out jacks.  If built-in speakers and headphone
  16   and/or line-out jacks are available on a machine, this controls
  17   appears.
  18   When there are only either headphones or line-out jacks, it gives
  19   "Disabled" and "Enabled" state.  When enabled, the speaker is muted
  20   automatically when a jack is plugged.
  21
  22   When both headphone and line-out jacks are present, it gives
  23   "Disabled", "Speaker Only" and "Line-Out+Speaker".  When
  24   speaker-only is chosen, plugging into a headphone or a line-out jack
  25   mutes the speakers, but not line-outs.  When line-out+speaker is
  26   selected, plugging to a headphone jack mutes both speakers and
  27   line-outs.
  28
  29
  30 IDT/Sigmatel codecs
  31 -------------------
  32
  33 * Analog Loopback
  34   This control enables/disables the analog-loopback circuit.  This
  35   appears only when "loopback" is set to true in a codec hint
  36   (see HD-Audio.txt).  Note that on some codecs the analog-loopback
  37   and the normal PCM playback are exclusive, i.e. when this is on, you
  38   won't hear any PCM stream.
  39
  40 * Swap Center/LFE
  41   Swaps the center and LFE channel order.  Normally, the left
  42   corresponds to the center and the right to the LFE.  When this is
  43   ON, the left to the LFE and the right to the center.
  44
  45 * Headphone as Line Out
  46   When this control is ON, treat the headphone jacks as line-out
  47   jacks.  That is, the headphone won't auto-mute the other line-outs,
  48   and no HP-amp is set to the pins.
  49
  50 * Mic Jack Mode, Line Jack Mode, etc
  51   These enum controls the direction and the bias of the input jack
  52   pins.  Depending on the jack type, it can set as "Mic In" and "Line
  53   In", for determining the input bias, or it can be set to "Line Out"
  54   when the pin is a multi-I/O jack for surround channels.
  55
  56
  57 VIA codecs
  58 ----------
  59
  60 * Smart 5.1
  61   An enum control to re-task the multi-I/O jacks for surround outputs.
  62   When it's ON, the corresponding input jacks (usually a line-in and a
  63   mic-in) are switched as the surround and the CLFE output jacks.
  64
  65 * Independent HP
  66   When this enum control is enabled, the headphone output is routed
  67   from an individual stream (the third PCM such as hw:0,2) instead of
  68   the primary stream.  In the case the headphone DAC is shared with a
  69   side or a CLFE-channel DAC, the DAC is switched to the headphone
  70   automatically.
  71
  72 * Loopback Mixing
  73   An enum control to determine whether the analog-loopback route is
  74   enabled or not.  When it's enabled, the analog-loopback is mixed to
  75   the front-channel.  Also, the same route is used for the headphone
  76   and speaker outputs.  As a side-effect, when this mode is set, the
  77   individual volume controls will be no longer available for
  78   headphones and speakers because there is only one DAC connected to a
  79   mixer widget.
  80
  81 * Dynamic Power-Control
  82   This control determines whether the dynamic power-control per jack
  83   detection is enabled or not.  When enabled, the widgets power state
  84   (D0/D3) are changed dynamically depending on the jack plugging
  85   state for saving power consumptions.  However, if your system
  86   doesn't provide a proper jack-detection, this won't work; in such a
  87   case, turn this control OFF.
  88
  89 * Jack Detect
  90   This control is provided only for VT1708 codec which gives no proper
  91   unsolicited event per jack plug.  When this is on, the driver polls
  92   the jack detection so that the headphone auto-mute can work, while
  93   turning this off would reduce the power consumption.
  94
  95
  96 Conexant codecs
  97 ---------------
  98
  99 * Auto-Mute Mode
 100   See Reatek codecs.
 101
 102
 103 Analog codecs
 104 --------------
 105
 106 * Channel Mode
 107   This is an enum control to change the surround-channel setup,
 108   appears only when the surround channels are available.
 109   It gives the number of channels to be used, "2ch", "4ch" and "6ch".
 110   According to the configuration, this also controls the
 111   jack-retasking of multi-I/O jacks.
 112
 113 * Independent HP
 114   When this enum control is enabled, the headphone output is routed
 115   from an individual stream (the third PCM such as hw:0,2) instead of
 116   the primary stream.