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NAME

     snd_hda — Intel High Definition Audio bridge device driver

SYNOPSIS

     To compile this driver into the kernel, place the following lines in your kernel
     configuration file:

           device sound
           device snd_hda

     Alternatively, to load the driver as a module at boot time, place the following line in
     loader.conf(5):

           snd_hda_load="YES"

DESCRIPTION

     The High Definition (HD) Audio specification was developed by Intel as the logical successor
     of the old AC'97 specification and has several advantages, such as higher bandwidth which
     allows more channels and more detailed formats, support for several logical audio devices,
     and general purpose DMA channels.

     The snd_hda driver is a HDA bus controller driver and HDA codecs audio functions bridge
     driver that allows the generic audio driver, sound(4), to be used with this hardware.  Only
     audio functions are supported by snd_hda.  Modem and other possible functions are not
     implemented.

     The snd_hda driver supports hardware that conforms with revision 1.0 of the Intel High
     Definition Audio specification and tries to behave much like the Microsoft Universal Audio
     Architecture (UAA) draft (revision 0.7b) for handling audio devices.

     According to HDA and UAA specifications, depending on the number of HDA buses and codecs
     present in system, their audio capabilities and BIOS provided configuration, the snd_hda
     driver often provides several PCM audio devices.  For example, one device for main rear 7.1
     output and inputs, one device for independent headset connectors at front and one device for
     SPDIF or HDMI audio input/output.  The assignment of audio inputs and outputs may be tuned
     with device.hints(5).  The driver's verbose boot messages provide a lot of information about
     the operation of the driver and present audio setup.

     The default audio device may be tuned by setting the hw.snd.default_unit sysctl, as
     described in sound(4), or explicitly specified in application settings.

   Boot-time Configuration
     The following variables are available at boot-time through the device.hints(5) file:

           hint.hdac.%d.config  Configures a range of possible options.  Possible values are:
                                “dmapos”, “eapdinv”, “gpio0”, “gpio1”, “gpio2”, “gpio3”, “gpio4”,
                                “gpio5”, “gpio6”, “gpio7”, “gpioflush”, “ivref”, “ivref50”,
                                “ivref80”, “ivref100”, “fixedrate”, “forcestereo”, “ovref”,
                                “ovref50”, “ovref80”, “ovref100”, “senseinv”, “softpcmvol”, and
                                “vref”.  An option prefixed with “no”, such as “nofixedrate”,
                                will do the opposite and takes precedence.  Options can be
                                separated by whitespace and commas.

                                “GPIOs” are a codec's General Purpose I/O pins which system
                                integrators sometimes use to control external muters, amplifiers
                                and so on.  If you have no sound, or sound volume is not
                                adequate, you may have to experiment a bit with the GPIO setup to
                                find the optimal setup for your system.

                                The “ivrefX” and “ovrefX” options control the voltage used to
                                power external microphones.

           hint.hdac.%d.msi     Controls MSI (Message Signaled Interrupts) support.

           hint.hdac.%d.cad%d.nid%d.config
                                Overrides codec pin configuration set by BIOS.  May be specified
                                as a 32-bit hexadecimal value with a leading “0x”, or as a set of
                                space-separated “option=value” pairs.

     Pin configuration is the UAA driver's main source of information about codec usage.  This
     information is usually provided by the codec manufacturer and tuned by system integrators
     for specific system requirements.  The snd_hda driver allows users to override it to fix
     integrator mistakes or to use the available codec in alternative ways (for example to get
     stereo output and 2 inputs instead of a single 5.1 output).

     The following options are supported:

           as       Association number.  Associations are used to group individual pins to form a
                    complex multi-pin device.  For example, to group 4 connectors for 7.1 output,
                    or to treat several input connectors as sources for the same input device.
                    Association numbers can be specified as numeric values from 0 to 15.  A value
                    of 0 means disabled pin.  A value of 15 is a set of independent unassociated
                    pins.  Each association includes only pins of the same direction (in/out) and
                    is detected atomically (all pins or none).  A separate PCM audio device is
                    created for every pair of input and output associations.

           seq      Sequence number.  A unique, per-association number used to order pins inside
                    the particular association.  Sequence numbers can be specified as numeric
                    values from 0 to 15.

                    For output assotiations sequence numbers encode speaker pairs positions: 0 -
                    Front, 1 - Center/LFE, 2 - Back, 3 - Front Wide Center, 4 - Side.  Standard
                    combinations are: (0) - Stereo; (0, 2), (0, 4) - Quadro; (0, 1, 2), (0, 1, 4)
                    - 5.1; (0, 1, 2, 4) - 7.1.

                    The sequence number 15 has a special meaning for output associations.  Output
                    pins with this number and device type “Headphones” will duplicate (with
                    automatic mute if jack detection is supported) the first pin in that
                    association.

           device   Device type.  Can be specified as a number from 0 to 15 or as a name:
                    “Line-out”, “Speaker”, “Headphones,” “CD”, “SPDIF-out”, “Digital-out”,
                    “Modem-line”, “Modem-handset”, “Line-in”, “AUX”, “Mic”, “Telephony”,
                    “SPDIF-in”, “Digital-in”, “Res.E”, or “Other”.  The device type also
                    describes the pin direction (in/out).  For example, “CD” always means an
                    input pin, while “Headphones” always means an output.

           conn     Connection type.  Can be specified as a number from 0 to 3.  The connection
                    type can also be specified as one of the special names “Jack”, “None”,
                    “Fixed”, or “Both”.  Pins with a connection type of “None” are disabled.

           ctype    Connector physical type.  Can be specified as a number from 0 to 15.  This is
                    a reference only value.  It is ignored by the snd_hda driver.

           color    Connector color.  Can be specified as a number from 0 to 15 or as one of the
                    names “Unknown”, “Black”, “Grey”, “Blue”, “Green”, “Red”, “Orange”, “Yellow”,
                    “Purple”, “Pink”, “Res.A”, “Res.B”, “Res.C”, “Res.D”, “White”, or “Other”.
                    This is a reference only value.  It is ignored by the snd_hda driver.

           loc      Connector physical location.  Can be specified as a number from 0 to 63.
                    This is a reference only value.  It is ignored by the snd_hda driver.

           misc     Misc bits.  Can be specified as a number from 0 to 15.  Bit 0 has a special
                    meaning.  When set it means that jack detection is not implemented in
                    hardware.

   Runtime Configuration
     The following sysctl(8) variables are available in addition to those available to all
     sound(4) devices:

           dev.hdac.%d.polling  Enables polling mode.  In this mode the driver operates by
                                querying the device state on timer ticks using callout(9) instead
                                of interrupts.  Polling is disabled by default.  Do not enable it
                                unless you are facing weird interrupt problems or if the device
                                cannot generate interrupts at all.

           dev.hdac.%d.polling_interval
                                Controller/Jack Sense polling interval (1-1000 ms)

           dev.hdac.%d.pindump  Setting this to a non-zero value dumps the current pin
                                configuration, main capabilities and jack sense status to console
                                and syslog.

EXAMPLES

     Taking HP Compaq DX2300 with Realtek ALC888 HDA codec for example.  This system has two
     audio connectors on a front side, three audio connectors on a rear side and one internal
     speaker.  According to verbose driver output and the codec datasheet, this codec has five
     stereo DACs and two stereo ADCs, all of them are routable to any codec pin (external
     connector).  All codec pins are reversible (could be configured either as input or output).

     So high codec uniformity and flexibility allow driver to configure it in many different
     ways, depending on requested pins usage decribed by pins configuration.  The driver reports
     such default pin configuration when verbose messages enabled:

     hdac0: nid 20 0x01014020 as  2 seq  0   Line-out  Jack jack 1 loc  1 color   Green misc 0
     hdac0: nid 21 0x99130110 as  1 seq  0    Speaker Fixed jack 3 loc 25 color Unknown misc 1
     hdac0: nid 22 0x411111f0 as 15 seq  0    Speaker  None jack 1 loc  1 color   Black misc 1
     hdac0: nid 23 0x411111f0 as 15 seq  0    Speaker  None jack 1 loc  1 color   Black misc 1
     hdac0: nid 24 0x01a19830 as  3 seq  0        Mic  Jack jack 1 loc  1 color    Pink misc 8
     hdac0: nid 25 0x02a1983f as  3 seq 15        Mic  Jack jack 1 loc  2 color    Pink misc 8
     hdac0: nid 26 0x01813031 as  3 seq  1    Line-in  Jack jack 1 loc  1 color    Blue misc 0
     hdac0: nid 27 0x0221401f as  1 seq 15 Headphones  Jack jack 1 loc  2 color   Green misc 0
     hdac0: nid 28 0x411111f0 as 15 seq  0    Speaker  None jack 1 loc  1 color   Black misc 1
     hdac0: nid 30 0x411111f0 as 15 seq  0    Speaker  None jack 1 loc  1 color   Black misc 1
     hdac0: nid 31 0x411111f0 as 15 seq  0    Speaker  None jack 1 loc  1 color   Black misc 1

     Here we can see, that the nodes with ID (nid) 25 and 27 are front panel connectors (Jack,
     loc 2), nids 20, 24 and 26 are rear panel connectors (Jack, loc 1) and nid 21 is a built-in
     speaker (Fixed, loc 25).  Pins with nids 22, 23, 28, 30 and 31 will be disabled by driver
     due to "None" connectivity. So the pin count and description matches to connectors that we
     have.

     Using association (as) and sequence (seq) fields values pins are grouped into 3
     associations:

     hdac0: Association 0 (1) out:
     hdac0:   Pin nid=21 seq=0
     hdac0:   Pin nid=27 seq=15
     hdac0: Association 1 (2) out:
     hdac0:   Pin nid=20 seq=0
     hdac0: Association 2 (3) in:
     hdac0:   Pin nid=24 seq=0
     hdac0:   Pin nid=26 seq=1
     hdac0:   Pin nid=25 seq=15

     Each pcm(4) device uses two associations: one for playback and one for recording.
     Associations processed and assigned to pcm(4) devices in increasing numerical order.  In
     this case association #0 (1) will become pcm0 device playback, using the internal speakers
     and Headphones jack with speaker automute on the headphones jack connection.  Association #1
     (2) will become pcm1 playback, using the Line-out jack.  Association #2 (3) will become pcm0
     recording, using the external microphones and the Line-in jack.

     The snd_hda driver provides extensive verbose messages to diagnose its operation logic and
     describe its current codec configuration.

     Using device.hints(5) it is possible to modify the configuration of the existing pins,
     allowing a broad range of different audio setups.  Here are a few examples of some setups
     possible for this particular hardware:

   Example 1
     Setting the device.hints(5) options

     hint.hdac.0.cad0.nid20.config="as=1"
     hint.hdac.0.cad0.nid21.config="as=2"

     will swap line-out and speaker functions.  So the pcm0 device will play to the line-out and
     headphones jacks. Line-out will be muted on the headphones jack connection.  Recording on
     pcm0 will go from two external microphones and line-in jacks.  pcm1 playback will go to the
     internal speaker.

   Example 2
     Setting the device.hints(5) options

     hint.hdac.0.cad0.nid20.config="as=1 seq=15 device=Headphones"
     hint.hdac.0.cad0.nid27.config="as=2 seq=0"
     hint.hdac.0.cad0.nid25.config="as=4 seq=0"

     will split the headphones and one of the microphones to a separate device.  The pcm0 device
     will play to the internal speaker and to the line-out jack, with speaker automute on the
     line-out jack connection.  Recording on pcm0 will use input from one external microphone and
     the line-in jacks.  The pcm1 device will be completely dedicated to a headset (headphones
     and mic) connected to the front connectors.

   Example 3
     Setting the device.hints(5) options

     hint.hdac.0.cad0.nid20.config="as=1 seq=0"
     hint.hdac.0.cad0.nid26.config="as=2 seq=0"
     hint.hdac.0.cad0.nid27.config="as=3 seq=0"
     hint.hdac.0.cad0.nid25.config="as=4 seq=0"
     hint.hdac.0.cad0.nid24.config="as=5 seq=0 device=Line-out"
     hint.hdac.0.cad0.nid21.config="as=6 seq=0"

     will give 4 independent devices: pcm0 (line-out and line-in), pcm1 (headphones and mic),
     pcm2 (additional line-out via retasked rear mic jack), and pcm3 (internal speaker).

   Example 4
     Setting the device.hints(5) options

     hint.hdac.0.cad0.nid20.config="as=1 seq=0"
     hint.hdac.0.cad0.nid24.config="as=1 seq=1 device=Line-out"
     hint.hdac.0.cad0.nid26.config="as=1 seq=2 device=Line-out"
     hint.hdac.0.cad0.nid21.config="as=2 seq=0"

     will give 2 devices: pcm0 for 5.1 playback via 3 rear connectors (line-out and retasked mic
     and line-in) and headset (headphones and mic) at front connectors.  pcm1 for internal
     speaker playback.  On headphones connection rear connectors will be muted.

MIXER CONTROLS

     Depending on codec configuration, these controls and signal sources could be reported to
     sound(4):

           vol      overall output level (volume)

           rec      overall recording level

           igain    input-to-output monitoring loopback level

           ogain    external amplifier control

           pcm      PCM playback

           mix      input mix

           mic      first external or second internal microphone input

           monitor  first internal or second external microphone input

           line, line1, line2, line3
                    analog (line) inputs

           dig1, dig2, dig3
                    digital (S/PDIF, HDMI or DisplayPort) inputs

           cd       CD input

           speaker  PC speaker input

           phin, phout, radio. video
                    other random inputs

     Controls have different precision. Some could be just an on/off triggers.  Most of controls
     use logarithmic scale.

HARDWARE

     The snd_hda driver supports many Intel HDA compatible audio chipsets including the
     following:

     ·   ATI SB450
     ·   ATI SB600
     ·   Intel 631x/632xESB
     ·   Intel 82801F (ICH6)
     ·   Intel 82801G (ICH7)
     ·   Intel 82801H (ICH8)
     ·   Intel 82801I (ICH9)
     ·   Intel 82801J (ICH10)
     ·   Intel US15W (SCH)
     ·   nVidia MCP51
     ·   nVidia MCP55
     ·   nVidia MCP61A
     ·   nVidia MCP61B
     ·   nVidia MCP63
     ·   nVidia MCP65A
     ·   nVidia MCP65B
     ·   nVidia MCP67A
     ·   nVidia MCP67B
     ·   nVidia MCP68
     ·   nVidia MCP69
     ·   nVidia MCP73
     ·   nVidia MCP78
     ·   nVidia MCP79
     ·   nVidia MCP89
     ·   SiS 966
     ·   VIA VT8251/8237A

     The following and many other codecs have been verified to work:

     ·   Analog Devices AD1981HD
     ·   Analog Devices AD1983
     ·   Analog Devices AD1984
     ·   Analog Devices AD1986A
     ·   Analog Devices AD1988
     ·   Analog Devices AD1988B
     ·   CMedia CMI9880
     ·   Conexant CX20549 (Venice)
     ·   Conexant CX20551 (Waikiki)
     ·   Conexant CX20561 (Hermosa)
     ·   Realtek ALC260
     ·   Realtek ALC262
     ·   Realtek ALC268
     ·   Realtek ALC660
     ·   Realtek ALC861
     ·   Realtek ALC861VD
     ·   Realtek ALC880
     ·   Realtek ALC882
     ·   Realtek ALC883
     ·   Realtek ALC885
     ·   Realtek ALC888
     ·   Realtek ALC889
     ·   Sigmatel STAC9205
     ·   Sigmatel STAC9220
     ·   Sigmatel STAC9220D / 9223D
     ·   Sigmatel STAC9221
     ·   Sigmatel STAC9221D
     ·   Sigmatel STAC9227D
     ·   Sigmatel STAC9227X
     ·   Sigmatel STAC9228D
     ·   Sigmatel STAC9228X
     ·   Sigmatel STAC9229D
     ·   Sigmatel STAC9229X
     ·   Sigmatel STAC9230D
     ·   Sigmatel STAC9230X
     ·   Sigmatel STAC9271D
     ·   Sigmatel STAC9872AK
     ·   VIA VT1708
     ·   VIA VT1708B
     ·   VIA VT1709

SEE ALSO

     sound(4), snd_ich(4), device.hints(5), loader.conf(5), sysctl(8)

HISTORY

     The snd_hda device driver first appeared in FreeBSD 6.3.

AUTHORS

     The snd_hda driver was written by Stephane E. Potvin <sepotvin@videotron.ca>, Ariff Abdullah
     <ariff@FreeBSD.org> and Alexander Motin <mav@FreeBSD.org>.  This manual page was written by
     Joel Dahl <joel@FreeBSD.org>, Alexander Motin <mav@FreeBSD.org> and Giorgos Keramidas
     <keramida@FreeBSD.org>.

BUGS

     A few Hardware/OEM vendors tend to screw up BIOS settings, thus rendering the snd_hda driver
     useless, which usually results in a state where the snd_hda driver seems to attach and work,
     but without any sound. Some of that cases can be solved by tuning loader.conf variables. But
     before trying to fix problem that way, make sure that problem is really exists and the PCM
     audio device you are using really corresponds to expected audio connector.

     Some vendors use non-standardized General Purpose I/O (GPIO) pins of codec to control
     external amplifiers. In some cases setting proper combination of GPIO bits may be needed to
     make sound work on specific device.

     HDMI and DisplayPort audio may also require support from video driver.