diff options
Diffstat (limited to 'Documentation/sound')
| -rw-r--r-- | Documentation/sound/alsa/DocBook/writing-an-alsa-driver.tmpl | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/Documentation/sound/alsa/DocBook/writing-an-alsa-driver.tmpl b/Documentation/sound/alsa/DocBook/writing-an-alsa-driver.tmpl index db0b7d2dc477..0475478c2484 100644 --- a/Documentation/sound/alsa/DocBook/writing-an-alsa-driver.tmpl +++ b/Documentation/sound/alsa/DocBook/writing-an-alsa-driver.tmpl @@ -3422,10 +3422,17 @@ struct _snd_pcm_runtime { <para> The <structfield>iface</structfield> field specifies the type of - the control, - <constant>SNDRV_CTL_ELEM_IFACE_XXX</constant>. There are - <constant>MIXER</constant>, <constant>PCM</constant>, - <constant>CARD</constant>, etc. + the control, <constant>SNDRV_CTL_ELEM_IFACE_XXX</constant>, which + is usually <constant>MIXER</constant>. + Use <constant>CARD</constant> for global controls that are not + logically part of the mixer. + If the control is closely associated with some specific device on + the sound card, use <constant>HWDEP</constant>, + <constant>PCM</constant>, <constant>RAWMIDI</constant>, + <constant>TIMER</constant>, or <constant>SEQUENCER</constant>, and + specify the device number with the + <structfield>device</structfield> and + <structfield>subdevice</structfield> fields. </para> <para> |
