€•±®      Œsphinx.addnodes”Œdocument”“”)”}”(Œ	rawsource”Œ ”Œchildren”]”(Œtranslations”ŒLanguagesNode”“”)”}”(hhh]”(h Œpending_xref”“”)”}”(hhh]”Œdocutils.nodes”ŒText”“”ŒChinese (Simplified)”…””}”Œparent”hsbaŒ
attributes”}”(Œids”]”Œclasses”]”Œnames”]”Œdupnames”]”Œbackrefs”]”Œ	refdomain”Œstd”Œreftype”Œdoc”Œ	reftarget”Œ"/translations/zh_CN/sound/soc/dpcm”Œmodname”NŒ	classname”NŒrefexplicit”ˆuŒtagname”hhhubh)”}”(hhh]”hŒChinese (Traditional)”…””}”hh2sbah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ"/translations/zh_TW/sound/soc/dpcm”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒItalian”…””}”hhFsbah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ"/translations/it_IT/sound/soc/dpcm”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒJapanese”…””}”hhZsbah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ"/translations/ja_JP/sound/soc/dpcm”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒKorean”…””}”hhnsbah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ"/translations/ko_KR/sound/soc/dpcm”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒPortuguese (Brazilian)”…””}”hh‚sbah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ"/translations/pt_BR/sound/soc/dpcm”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒSpanish”…””}”hh–sbah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ"/translations/sp_SP/sound/soc/dpcm”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubeh}”(h]”h ]”h"]”h$]”h&]”Œcurrent_language”ŒEnglish”uh1h
hhŒ	_document”hŒsource”NŒline”NubhŒsection”“”)”}”(hhh]”(hŒtitle”“”)”}”(hŒDynamic PCM”h]”hŒDynamic PCM”…””}”(hh¼h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hºhh·h²hh³Œ</var/lib/git/docbuild/linux/Documentation/sound/soc/dpcm.rst”h´Kubh¶)”}”(hhh]”(h»)”}”(hŒDescription”h]”hŒDescription”…””}”(hhÎh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hºhhËh²hh³hÊh´KubhŒ	paragraph”“”)”}”(hX+  Dynamic PCM allows an ALSA PCM device to digitally route its PCM audio to
various digital endpoints during the PCM stream runtime. e.g. PCM0 can route
digital audio to I2S DAI0, I2S DAI1 or PDM DAI2. This is useful for on SoC DSP
drivers that expose several ALSA PCMs and can route to multiple DAIs.”h]”hX+  Dynamic PCM allows an ALSA PCM device to digitally route its PCM audio to
various digital endpoints during the PCM stream runtime. e.g. PCM0 can route
digital audio to I2S DAI0, I2S DAI1 or PDM DAI2. This is useful for on SoC DSP
drivers that expose several ALSA PCMs and can route to multiple DAIs.”…””}”(hhÞh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÜh³hÊh´KhhËh²hubhÝ)”}”(hX  The DPCM runtime routing is determined by the ALSA mixer settings in the same
way as the analog signal is routed in an ASoC codec driver. DPCM uses a DAPM
graph representing the DSP internal audio paths and uses the mixer settings to
determine the path used by each ALSA PCM.”h]”hX  The DPCM runtime routing is determined by the ALSA mixer settings in the same
way as the analog signal is routed in an ASoC codec driver. DPCM uses a DAPM
graph representing the DSP internal audio paths and uses the mixer settings to
determine the path used by each ALSA PCM.”…””}”(hhìh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÜh³hÊh´KhhËh²hubhÝ)”}”(hŒbDPCM re-uses all the existing component codec, platform and DAI drivers without
any modifications.”h]”hŒbDPCM re-uses all the existing component codec, platform and DAI drivers without
any modifications.”…””}”(hhúh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÜh³hÊh´KhhËh²hubh¶)”}”(hhh]”(h»)”}”(hŒ%Phone Audio System with SoC based DSP”h]”hŒ%Phone Audio System with SoC based DSP”…””}”(hj  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hºhj  h²hh³hÊh´KubhÝ)”}”(hŒgConsider the following phone audio subsystem. This will be used in this
document for all examples :-
::”h]”hŒdConsider the following phone audio subsystem. This will be used in this
document for all examples :-”…””}”(hj  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÜh³hÊh´Khj  h²hubhŒliteral_block”“”)”}”(hXŠ  | Front End PCMs    |  SoC DSP  | Back End DAIs | Audio devices |

                    *************
PCM0 <------------> *           * <----DAI0-----> Codec Headset
                    *           *
PCM1 <------------> *           * <----DAI1-----> Codec Speakers
                    *   DSP     *
PCM2 <------------> *           * <----DAI2-----> MODEM
                    *           *
PCM3 <------------> *           * <----DAI3-----> BT
                    *           *
                    *           * <----DAI4-----> DMIC
                    *           *
                    *           * <----DAI5-----> FM
                    *************”h]”hXŠ  | Front End PCMs    |  SoC DSP  | Back End DAIs | Audio devices |

                    *************
PCM0 <------------> *           * <----DAI0-----> Codec Headset
                    *           *
PCM1 <------------> *           * <----DAI1-----> Codec Speakers
                    *   DSP     *
PCM2 <------------> *           * <----DAI2-----> MODEM
                    *           *
PCM3 <------------> *           * <----DAI3-----> BT
                    *           *
                    *           * <----DAI4-----> DMIC
                    *           *
                    *           * <----DAI5-----> FM
                    *************”…””}”hj)  sbah}”(h]”h ]”h"]”h$]”h&]”Œ	xml:space”Œpreserve”uh1j'  h³hÊh´Khj  h²hubhÝ)”}”(hXƒ  This diagram shows a simple smart phone audio subsystem. It supports Bluetooth,
FM digital radio, Speakers, Headset Jack, digital microphones and cellular
modem. This sound card exposes 4 DSP front end (FE) ALSA PCM devices and
supports 6 back end (BE) DAIs. Each FE PCM can digitally route audio data to any
of the BE DAIs. The FE PCM devices can also route audio to more than 1 BE DAI.”h]”hXƒ  This diagram shows a simple smart phone audio subsystem. It supports Bluetooth,
FM digital radio, Speakers, Headset Jack, digital microphones and cellular
modem. This sound card exposes 4 DSP front end (FE) ALSA PCM devices and
supports 6 back end (BE) DAIs. Each FE PCM can digitally route audio data to any
of the BE DAIs. The FE PCM devices can also route audio to more than 1 BE DAI.”…””}”(hj9  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÜh³hÊh´K-hj  h²hubeh}”(h]”Œ%phone-audio-system-with-soc-based-dsp”ah ]”h"]”Œ%phone audio system with soc based dsp”ah$]”h&]”uh1hµhhËh²hh³hÊh´Kubh¶)”}”(hhh]”(h»)”}”(hŒ3Example - DPCM Switching playback from DAI0 to DAI1”h]”hŒ3Example - DPCM Switching playback from DAI0 to DAI1”…””}”(hjR  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hºhjO  h²hh³hÊh´K6ubhÝ)”}”(hŒ}Audio is being played to the Headset. After a while the user removes the headset
and audio continues playing on the speakers.”h]”hŒ}Audio is being played to the Headset. After a while the user removes the headset
and audio continues playing on the speakers.”…””}”(hj`  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÜh³hÊh´K8hjO  h²hubhÝ)”}”(hŒ1Playback on PCM0 to Headset would look like :-
::”h]”hŒ.Playback on PCM0 to Headset would look like :-”…””}”(hjn  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÜh³hÊh´K;hjO  h²hubj(  )”}”(hXG                      *************
PCM0 <============> *           * <====DAI0=====> Codec Headset
                    *           *
PCM1 <------------> *           * <----DAI1-----> Codec Speakers
                    *   DSP     *
PCM2 <------------> *           * <----DAI2-----> MODEM
                    *           *
PCM3 <------------> *           * <----DAI3-----> BT
                    *           *
                    *           * <----DAI4-----> DMIC
                    *           *
                    *           * <----DAI5-----> FM
                    *************”h]”hXG                      *************
PCM0 <============> *           * <====DAI0=====> Codec Headset
                    *           *
PCM1 <------------> *           * <----DAI1-----> Codec Speakers
                    *   DSP     *
PCM2 <------------> *           * <----DAI2-----> MODEM
                    *           *
PCM3 <------------> *           * <----DAI3-----> BT
                    *           *
                    *           * <----DAI4-----> DMIC
                    *           *
                    *           * <----DAI5-----> FM
                    *************”…””}”hj|  sbah}”(h]”h ]”h"]”h$]”h&]”j7  j8  uh1j'  h³hÊh´K>hjO  h²hubhÝ)”}”(hŒSThe headset is removed from the jack by user so the speakers must now be used :-
::”h]”hŒPThe headset is removed from the jack by user so the speakers must now be used :-”…””}”(hjŠ  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÜh³hÊh´KLhjO  h²hubj(  )”}”(hXG                      *************
PCM0 <============> *           * <----DAI0-----> Codec Headset
                    *           *
PCM1 <------------> *           * <====DAI1=====> Codec Speakers
                    *   DSP     *
PCM2 <------------> *           * <----DAI2-----> MODEM
                    *           *
PCM3 <------------> *           * <----DAI3-----> BT
                    *           *
                    *           * <----DAI4-----> DMIC
                    *           *
                    *           * <----DAI5-----> FM
                    *************”h]”hXG                      *************
PCM0 <============> *           * <----DAI0-----> Codec Headset
                    *           *
PCM1 <------------> *           * <====DAI1=====> Codec Speakers
                    *   DSP     *
PCM2 <------------> *           * <----DAI2-----> MODEM
                    *           *
PCM3 <------------> *           * <----DAI3-----> BT
                    *           *
                    *           * <----DAI4-----> DMIC
                    *           *
                    *           * <----DAI5-----> FM
                    *************”…””}”hj˜  sbah}”(h]”h ]”h"]”h$]”h&]”j7  j8  uh1j'  h³hÊh´KOhjO  h²hubhÝ)”}”(hŒ-The audio driver processes this as follows :-”h]”hŒ-The audio driver processes this as follows :-”…””}”(hj¦  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÜh³hÊh´K]hjO  h²hubhŒenumerated_list”“”)”}”(hhh]”(hŒ	list_item”“”)”}”(hŒ,Machine driver receives Jack removal event.
”h]”hÝ)”}”(hŒ+Machine driver receives Jack removal event.”h]”hŒ+Machine driver receives Jack removal event.”…””}”(hj¿  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÜh³hÊh´K_hj»  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j¹  hj¶  h²hh³hÊh´Nubjº  )”}”(hŒ7Machine driver OR audio HAL disables the Headset path.
”h]”hÝ)”}”(hŒ6Machine driver OR audio HAL disables the Headset path.”h]”hŒ6Machine driver OR audio HAL disables the Headset path.”…””}”(hj×  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÜh³hÊh´KahjÓ  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j¹  hj¶  h²hh³hÊh´Nubjº  )”}”(hŒvDPCM runs the PCM trigger(stop), hw_free(), shutdown() operations on DAI0
for headset since the path is now disabled.
”h]”hÝ)”}”(hŒuDPCM runs the PCM trigger(stop), hw_free(), shutdown() operations on DAI0
for headset since the path is now disabled.”h]”hŒuDPCM runs the PCM trigger(stop), hw_free(), shutdown() operations on DAI0
for headset since the path is now disabled.”…””}”(hjï  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÜh³hÊh´Kchjë  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j¹  hj¶  h²hh³hÊh´Nubjº  )”}”(hŒ6Machine driver or audio HAL enables the speaker path.
”h]”hÝ)”}”(hŒ5Machine driver or audio HAL enables the speaker path.”h]”hŒ5Machine driver or audio HAL enables the speaker path.”…””}”(hj  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÜh³hÊh´Kfhj  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j¹  hj¶  h²hh³hÊh´Nubjº  )”}”(hŒ|DPCM runs the PCM ops for startup(), hw_params(), prepare() and
trigger(start) for DAI1 Speakers since the path is enabled.
”h]”hÝ)”}”(hŒ{DPCM runs the PCM ops for startup(), hw_params(), prepare() and
trigger(start) for DAI1 Speakers since the path is enabled.”h]”hŒ{DPCM runs the PCM ops for startup(), hw_params(), prepare() and
trigger(start) for DAI1 Speakers since the path is enabled.”…””}”(hj  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÜh³hÊh´Khhj  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j¹  hj¶  h²hh³hÊh´Nubeh}”(h]”h ]”h"]”h$]”h&]”Œenumtype”Œarabic”Œprefix”hŒsuffix”Œ.”uh1j´  hjO  h²hh³hÊh´K_ubhÝ)”}”(hŒêIn this example, the machine driver or userspace audio HAL can alter the routing
and then DPCM will take care of managing the DAI PCM operations to either bring
the link up or down. Audio playback does not stop during this transition.”h]”hŒêIn this example, the machine driver or userspace audio HAL can alter the routing
and then DPCM will take care of managing the DAI PCM operations to either bring
the link up or down. Audio playback does not stop during this transition.”…””}”(hj>  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÜh³hÊh´KkhjO  h²hubeh}”(h]”Œ1example-dpcm-switching-playback-from-dai0-to-dai1”ah ]”h"]”Œ3example - dpcm switching playback from dai0 to dai1”ah$]”h&]”uh1hµhhËh²hh³hÊh´K6ubeh}”(h]”Œdescription”ah ]”h"]”Œdescription”ah$]”h&]”uh1hµhh·h²hh³hÊh´Kubh¶)”}”(hhh]”(h»)”}”(hŒDPCM machine driver”h]”hŒDPCM machine driver”…””}”(hj_  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hºhj\  h²hh³hÊh´KrubhÝ)”}”(hŒhThe DPCM enabled ASoC machine driver is similar to normal machine drivers
except that we also have to :-”h]”hŒhThe DPCM enabled ASoC machine driver is similar to normal machine drivers
except that we also have to :-”…””}”(hjm  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÜh³hÊh´Kthj\  h²hubjµ  )”}”(hhh]”(jº  )”}”(hŒ Define the FE and BE DAI links.
”h]”hÝ)”}”(hŒDefine the FE and BE DAI links.”h]”hŒDefine the FE and BE DAI links.”…””}”(hj‚  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÜh³hÊh´Kwhj~  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j¹  hj{  h²hh³hÊh´Nubjº  )”}”(hŒ!Define any FE/BE PCM operations.
”h]”hÝ)”}”(hŒ Define any FE/BE PCM operations.”h]”hŒ Define any FE/BE PCM operations.”…””}”(hjš  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÜh³hÊh´Kyhj–  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j¹  hj{  h²hh³hÊh´Nubjº  )”}”(hŒ"Define widget graph connections.

”h]”hÝ)”}”(hŒ Define widget graph connections.”h]”hŒ Define widget graph connections.”…””}”(hj²  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÜh³hÊh´K{hj®  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j¹  hj{  h²hh³hÊh´Nubeh}”(h]”h ]”h"]”h$]”h&]”j9  j:  j;  hj<  j=  uh1j´  hj\  h²hh³hÊh´Kwubh¶)”}”(hhh]”(h»)”}”(hŒFE and BE DAI links”h]”hŒFE and BE DAI links”…””}”(hjÏ  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hºhjÌ  h²hh³hÊh´Kubj(  )”}”(hXŠ  | Front End PCMs    |  SoC DSP  | Back End DAIs | Audio devices |

                    *************
PCM0 <------------> *           * <----DAI0-----> Codec Headset
                    *           *
PCM1 <------------> *           * <----DAI1-----> Codec Speakers
                    *   DSP     *
PCM2 <------------> *           * <----DAI2-----> MODEM
                    *           *
PCM3 <------------> *           * <----DAI3-----> BT
                    *           *
                    *           * <----DAI4-----> DMIC
                    *           *
                    *           * <----DAI5-----> FM
                    *************”h]”hXŠ  | Front End PCMs    |  SoC DSP  | Back End DAIs | Audio devices |

                    *************
PCM0 <------------> *           * <----DAI0-----> Codec Headset
                    *           *
PCM1 <------------> *           * <----DAI1-----> Codec Speakers
                    *   DSP     *
PCM2 <------------> *           * <----DAI2-----> MODEM
                    *           *
PCM3 <------------> *           * <----DAI3-----> BT
                    *           *
                    *           * <----DAI4-----> DMIC
                    *           *
                    *           * <----DAI5-----> FM
                    *************”…””}”hjÝ  sbah}”(h]”h ]”h"]”h$]”h&]”j7  j8  uh1j'  h³hÊh´K‚hjÌ  h²hubhÝ)”}”(hŒxFor the example above we have to define 4 FE DAI links and 6 BE DAI links. The
FE DAI links are defined as follows :-
::”h]”hŒuFor the example above we have to define 4 FE DAI links and 6 BE DAI links. The
FE DAI links are defined as follows :-”…””}”(hjë  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÜh³hÊh´K’hjÌ  h²hubj(  )”}”(hX  SND_SOC_DAILINK_DEFS(pcm0,
       DAILINK_COMP_ARRAY(COMP_CPU("System Pin")),
       DAILINK_COMP_ARRAY(COMP_DUMMY()),
       DAILINK_COMP_ARRAY(COMP_PLATFORM("dsp-audio")));

 static struct snd_soc_dai_link machine_dais[] = {
       {
               .name = "PCM0 System",
               .stream_name = "System Playback",
               SND_SOC_DAILINK_REG(pcm0),
               .dynamic = 1,
               .trigger = {SND_SOC_DPCM_TRIGGER_POST, SND_SOC_DPCM_TRIGGER_POST},
       },
       .....< other FE and BE DAI links here >
 };”h]”hX  SND_SOC_DAILINK_DEFS(pcm0,
       DAILINK_COMP_ARRAY(COMP_CPU("System Pin")),
       DAILINK_COMP_ARRAY(COMP_DUMMY()),
       DAILINK_COMP_ARRAY(COMP_PLATFORM("dsp-audio")));

 static struct snd_soc_dai_link machine_dais[] = {
       {
               .name = "PCM0 System",
               .stream_name = "System Playback",
               SND_SOC_DAILINK_REG(pcm0),
               .dynamic = 1,
               .trigger = {SND_SOC_DPCM_TRIGGER_POST, SND_SOC_DPCM_TRIGGER_POST},
       },
       .....< other FE and BE DAI links here >
 };”…””}”hjù  sbah}”(h]”h ]”h"]”h$]”h&]”j7  j8  uh1j'  h³hÊh´K–hjÌ  h²hubhÝ)”}”(hX‚  This FE DAI link is pretty similar to a regular DAI link except that we also
set the DAI link to a DPCM FE with the ``dynamic = 1``.
There is also an option to specify the ordering of the trigger call for
each FE. This allows the ASoC core to trigger the DSP before or after the other
components (as some DSPs have strong requirements for the ordering DAI/DSP
start and stop sequences).”h]”(hŒtThis FE DAI link is pretty similar to a regular DAI link except that we also
set the DAI link to a DPCM FE with the ”…””}”(hj  h²hh³Nh´NubhŒliteral”“”)”}”(hŒ``dynamic = 1``”h]”hŒdynamic = 1”…””}”(hj  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j  hj  ubhŒÿ.
There is also an option to specify the ordering of the trigger call for
each FE. This allows the ASoC core to trigger the DSP before or after the other
components (as some DSPs have strong requirements for the ordering DAI/DSP
start and stop sequences).”…””}”(hj  h²hh³Nh´Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÜh³hÊh´K¦hjÌ  h²hubhÝ)”}”(hŒƒThe FE DAI above sets the codec and code DAIs to dummy devices since the BE is
dynamic and will change depending on runtime config.”h]”hŒƒThe FE DAI above sets the codec and code DAIs to dummy devices since the BE is
dynamic and will change depending on runtime config.”…””}”(hj)  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÜh³hÊh´K­hjÌ  h²hubhÝ)”}”(hŒ+The BE DAIs are configured as follows :-
::”h]”hŒ(The BE DAIs are configured as follows :-”…””}”(hj7  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÜh³hÊh´K°hjÌ  h²hubj(  )”}”(hXE  SND_SOC_DAILINK_DEFS(headset,
       DAILINK_COMP_ARRAY(COMP_CPU("ssp-dai.0")),
       DAILINK_COMP_ARRAY(COMP_CODEC("rt5640.0-001c", "rt5640-aif1")));

 static struct snd_soc_dai_link machine_dais[] = {
       .....< FE DAI links here >
       {
               .name = "Codec Headset",
               SND_SOC_DAILINK_REG(headset),
               .no_pcm = 1,
               .ignore_suspend = 1,
               .ignore_pmdown_time = 1,
               .be_hw_params_fixup = hswult_ssp0_fixup,
               .ops = &haswell_ops,
       },
       .....< other BE DAI links here >
 };”h]”hXE  SND_SOC_DAILINK_DEFS(headset,
       DAILINK_COMP_ARRAY(COMP_CPU("ssp-dai.0")),
       DAILINK_COMP_ARRAY(COMP_CODEC("rt5640.0-001c", "rt5640-aif1")));

 static struct snd_soc_dai_link machine_dais[] = {
       .....< FE DAI links here >
       {
               .name = "Codec Headset",
               SND_SOC_DAILINK_REG(headset),
               .no_pcm = 1,
               .ignore_suspend = 1,
               .ignore_pmdown_time = 1,
               .be_hw_params_fixup = hswult_ssp0_fixup,
               .ops = &haswell_ops,
       },
       .....< other BE DAI links here >
 };”…””}”hjE  sbah}”(h]”h ]”h"]”h$]”h&]”j7  j8  uh1j'  h³hÊh´K³hjÌ  h²hubhÝ)”}”(hŒxThis BE DAI link connects DAI0 to the codec (in this case RT5460 AIF1). It sets
the ``no_pcm`` flag to mark it has a BE.”h]”(hŒTThis BE DAI link connects DAI0 to the codec (in this case RT5460 AIF1). It sets
the ”…””}”(hjS  h²hh³Nh´Nubj  )”}”(hŒ
``no_pcm``”h]”hŒno_pcm”…””}”(hj[  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j  hjS  ubhŒ flag to mark it has a BE.”…””}”(hjS  h²hh³Nh´Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÜh³hÊh´KÅhjÌ  h²hubhÝ)”}”(hŒµThe BE has also flags set for ignoring suspend and PM down time. This allows
the BE to work in a hostless mode where the host CPU is not transferring data
like a BT phone call :-
::”h]”hŒ²The BE has also flags set for ignoring suspend and PM down time. This allows
the BE to work in a hostless mode where the host CPU is not transferring data
like a BT phone call :-”…””}”(hjs  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÜh³hÊh´KÈhjÌ  h²hubj(  )”}”(hXG                      *************
PCM0 <------------> *           * <----DAI0-----> Codec Headset
                    *           *
PCM1 <------------> *           * <----DAI1-----> Codec Speakers
                    *   DSP     *
PCM2 <------------> *           * <====DAI2=====> MODEM
                    *           *
PCM3 <------------> *           * <====DAI3=====> BT
                    *           *
                    *           * <----DAI4-----> DMIC
                    *           *
                    *           * <----DAI5-----> FM
                    *************”h]”hXG                      *************
PCM0 <------------> *           * <----DAI0-----> Codec Headset
                    *           *
PCM1 <------------> *           * <----DAI1-----> Codec Speakers
                    *   DSP     *
PCM2 <------------> *           * <====DAI2=====> MODEM
                    *           *
PCM3 <------------> *           * <====DAI3=====> BT
                    *           *
                    *           * <----DAI4-----> DMIC
                    *           *
                    *           * <----DAI5-----> FM
                    *************”…””}”hj  sbah}”(h]”h ]”h"]”h$]”h&]”j7  j8  uh1j'  h³hÊh´KÍhjÌ  h²hubhÝ)”}”(hŒaThis allows the host CPU to sleep while the DSP, MODEM DAI and the BT DAI are
still in operation.”h]”hŒaThis allows the host CPU to sleep while the DSP, MODEM DAI and the BT DAI are
still in operation.”…””}”(hj  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÜh³hÊh´KÛhjÌ  h²hubhÝ)”}”(hŒkA BE DAI link can also set the codec to a dummy device if the codec is a device
that is managed externally.”h]”hŒkA BE DAI link can also set the codec to a dummy device if the codec is a device
that is managed externally.”…””}”(hj  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÜh³hÊh´KÞhjÌ  h²hubhÝ)”}”(hŒ]Likewise a BE DAI can also set a dummy cpu DAI if the CPU DAI is managed by the
DSP firmware.”h]”hŒ]Likewise a BE DAI can also set a dummy cpu DAI if the CPU DAI is managed by the
DSP firmware.”…””}”(hj«  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÜh³hÊh´KáhjÌ  h²hubeh}”(h]”Œfe-and-be-dai-links”ah ]”h"]”Œfe and be dai links”ah$]”h&]”uh1hµhj\  h²hh³hÊh´Kubh¶)”}”(hhh]”(h»)”}”(hŒFE/BE PCM operations”h]”hŒFE/BE PCM operations”…””}”(hjÄ  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hºhjÁ  h²hh³hÊh´KæubhÝ)”}”(hŒæThe BE above also exports some PCM operations and a ``fixup`` callback. The fixup
callback is used by the machine driver to (re)configure the DAI based upon the
FE hw params. i.e. the DSP may perform SRC or ASRC from the FE to BE.”h]”(hŒ4The BE above also exports some PCM operations and a ”…””}”(hjÒ  h²hh³Nh´Nubj  )”}”(hŒ	``fixup``”h]”hŒfixup”…””}”(hjÚ  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j  hjÒ  ubhŒ© callback. The fixup
callback is used by the machine driver to (re)configure the DAI based upon the
FE hw params. i.e. the DSP may perform SRC or ASRC from the FE to BE.”…””}”(hjÒ  h²hh³Nh´Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÜh³hÊh´KèhjÁ  h²hubhÝ)”}”(hŒþe.g. DSP converts all FE hw params to run at fixed rate of 48k, 16bit, stereo for
DAI0. This means all FE hw_params have to be fixed in the machine driver for
DAI0 so that the DAI is running at desired configuration regardless of the FE
configuration.
::”h]”hŒûe.g. DSP converts all FE hw params to run at fixed rate of 48k, 16bit, stereo for
DAI0. This means all FE hw_params have to be fixed in the machine driver for
DAI0 so that the DAI is running at desired configuration regardless of the FE
configuration.”…””}”(hjò  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÜh³hÊh´KìhjÁ  h²hubj(  )”}”(hX_  static int dai0_fixup(struct snd_soc_pcm_runtime *rtd,
                      struct snd_pcm_hw_params *params)
{
      struct snd_interval *rate = hw_param_interval(params,
                      SNDRV_PCM_HW_PARAM_RATE);
      struct snd_interval *channels = hw_param_interval(params,
                                              SNDRV_PCM_HW_PARAM_CHANNELS);

      /* The DSP will convert the FE rate to 48k, stereo */
      rate->min = rate->max = 48000;
      channels->min = channels->max = 2;

      /* set DAI0 to 16 bit */
      params_set_format(params, SNDRV_PCM_FORMAT_S16_LE);
      return 0;
}”h]”hX_  static int dai0_fixup(struct snd_soc_pcm_runtime *rtd,
                      struct snd_pcm_hw_params *params)
{
      struct snd_interval *rate = hw_param_interval(params,
                      SNDRV_PCM_HW_PARAM_RATE);
      struct snd_interval *channels = hw_param_interval(params,
                                              SNDRV_PCM_HW_PARAM_CHANNELS);

      /* The DSP will convert the FE rate to 48k, stereo */
      rate->min = rate->max = 48000;
      channels->min = channels->max = 2;

      /* set DAI0 to 16 bit */
      params_set_format(params, SNDRV_PCM_FORMAT_S16_LE);
      return 0;
}”…””}”hj   sbah}”(h]”h ]”h"]”h$]”h&]”j7  j8  uh1j'  h³hÊh´KòhjÁ  h²hubhÝ)”}”(hŒPThe other PCM operation are the same as for regular DAI links. Use as necessary.”h]”hŒPThe other PCM operation are the same as for regular DAI links. Use as necessary.”…””}”(hj  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÜh³hÊh´MhjÁ  h²hubeh}”(h]”Œfe-be-pcm-operations”ah ]”h"]”Œfe/be pcm operations”ah$]”h&]”uh1hµhj\  h²hh³hÊh´Kæubh¶)”}”(hhh]”(h»)”}”(hŒWidget graph connections”h]”hŒWidget graph connections”…””}”(hj'  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hºhj$  h²hh³hÊh´MubhÝ)”}”(hŒËThe BE DAI links will normally be connected to the graph at initialisation time
by the ASoC DAPM core. However, if the BE codec or BE DAI is a dummy then this
has to be set explicitly in the driver :-
::”h]”hŒÈThe BE DAI links will normally be connected to the graph at initialisation time
by the ASoC DAPM core. However, if the BE codec or BE DAI is a dummy then this
has to be set explicitly in the driver :-”…””}”(hj5  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÜh³hÊh´M	hj$  h²hubj(  )”}”(hŒ•/* BE for codec Headset -  DAI0 is dummy and managed by DSP FW */
{"DAI0 CODEC IN", NULL, "AIF1 Capture"},
{"AIF1 Playback", NULL, "DAI0 CODEC OUT"},”h]”hŒ•/* BE for codec Headset -  DAI0 is dummy and managed by DSP FW */
{"DAI0 CODEC IN", NULL, "AIF1 Capture"},
{"AIF1 Playback", NULL, "DAI0 CODEC OUT"},”…””}”hjC  sbah}”(h]”h ]”h"]”h$]”h&]”j7  j8  uh1j'  h³hÊh´Mhj$  h²hubeh}”(h]”Œwidget-graph-connections”ah ]”h"]”Œwidget graph connections”ah$]”h&]”uh1hµhj\  h²hh³hÊh´Mubeh}”(h]”Œdpcm-machine-driver”ah ]”h"]”Œdpcm machine driver”ah$]”h&]”uh1hµhh·h²hh³hÊh´Krubh¶)”}”(hhh]”(h»)”}”(hŒWriting a DPCM DSP driver”h]”hŒWriting a DPCM DSP driver”…””}”(hjd  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hºhja  h²hh³hÊh´MubhÝ)”}”(hŒ£The DPCM DSP driver looks much like a standard platform class ASoC driver
combined with elements from a codec class driver. A DSP platform driver must
implement :-”h]”hŒ£The DPCM DSP driver looks much like a standard platform class ASoC driver
combined with elements from a codec class driver. A DSP platform driver must
implement :-”…””}”(hjr  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÜh³hÊh´Mhja  h²hubjµ  )”}”(hhh]”(jº  )”}”(hŒ5Front End PCM DAIs - i.e. struct snd_soc_dai_driver.
”h]”hÝ)”}”(hŒ4Front End PCM DAIs - i.e. struct snd_soc_dai_driver.”h]”hŒ4Front End PCM DAIs - i.e. struct snd_soc_dai_driver.”…””}”(hj‡  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÜh³hÊh´Mhjƒ  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j¹  hj€  h²hh³hÊh´Nubjº  )”}”(hŒ:DAPM graph showing DSP audio routing from FE DAIs to BEs.
”h]”hÝ)”}”(hŒ9DAPM graph showing DSP audio routing from FE DAIs to BEs.”h]”hŒ9DAPM graph showing DSP audio routing from FE DAIs to BEs.”…””}”(hjŸ  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÜh³hÊh´Mhj›  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j¹  hj€  h²hh³hÊh´Nubjº  )”}”(hŒDAPM widgets from DSP graph.
”h]”hÝ)”}”(hŒDAPM widgets from DSP graph.”h]”hŒDAPM widgets from DSP graph.”…””}”(hj·  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÜh³hÊh´Mhj³  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j¹  hj€  h²hh³hÊh´Nubjº  )”}”(hŒ Mixers for gains, routing, etc.
”h]”hÝ)”}”(hŒMixers for gains, routing, etc.”h]”hŒMixers for gains, routing, etc.”…””}”(hjÏ  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÜh³hÊh´M hjË  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j¹  hj€  h²hh³hÊh´Nubjº  )”}”(hŒDMA configuration.
”h]”hÝ)”}”(hŒDMA configuration.”h]”hŒDMA configuration.”…””}”(hjç  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÜh³hÊh´M"hjã  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j¹  hj€  h²hh³hÊh´Nubjº  )”}”(hŒBE AIF widgets.
”h]”hÝ)”}”(hŒBE AIF widgets.”h]”hŒBE AIF widgets.”…””}”(hjÿ  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÜh³hÊh´M$hjû  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j¹  hj€  h²hh³hÊh´Nubeh}”(h]”h ]”h"]”h$]”h&]”j9  j:  j;  hj<  j=  uh1j´  hja  h²hh³hÊh´MubhÝ)”}”(hŒ¦Items 6 is important for routing the audio outside of the DSP. AIF need to be
defined for each BE and each stream direction. e.g for BE DAI0 above we would
have :-
::”h]”hŒ£Items 6 is important for routing the audio outside of the DSP. AIF need to be
defined for each BE and each stream direction. e.g for BE DAI0 above we would
have :-”…””}”(hj  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÜh³hÊh´M&hja  h²hubj(  )”}”(hŒzSND_SOC_DAPM_AIF_IN("DAI0 RX", NULL, 0, SND_SOC_NOPM, 0, 0),
SND_SOC_DAPM_AIF_OUT("DAI0 TX", NULL, 0, SND_SOC_NOPM, 0, 0),”h]”hŒzSND_SOC_DAPM_AIF_IN("DAI0 RX", NULL, 0, SND_SOC_NOPM, 0, 0),
SND_SOC_DAPM_AIF_OUT("DAI0 TX", NULL, 0, SND_SOC_NOPM, 0, 0),”…””}”hj'  sbah}”(h]”h ]”h"]”h$]”h&]”j7  j8  uh1j'  h³hÊh´M+hja  h²hubhÝ)”}”(hŒnThe BE AIF are used to connect the DSP graph to the graphs for the other
component drivers (e.g. codec graph).”h]”hŒnThe BE AIF are used to connect the DSP graph to the graphs for the other
component drivers (e.g. codec graph).”…””}”(hj5  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÜh³hÊh´M.hja  h²hubeh}”(h]”Œwriting-a-dpcm-dsp-driver”ah ]”h"]”Œwriting a dpcm dsp driver”ah$]”h&]”uh1hµhh·h²hh³hÊh´Mubh¶)”}”(hhh]”(h»)”}”(hŒHostless PCM streams”h]”hŒHostless PCM streams”…””}”(hjN  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hºhjK  h²hh³hÊh´M3ubhÝ)”}”(hŒA hostless PCM stream is a stream that is not routed through the host CPU. An
example of this would be a phone call from handset to modem.
::”h]”hŒŠA hostless PCM stream is a stream that is not routed through the host CPU. An
example of this would be a phone call from handset to modem.”…””}”(hj\  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÜh³hÊh´M5hjK  h²hubj(  )”}”(hXK                      *************
PCM0 <------------> *           * <----DAI0-----> Codec Headset
                    *           *
PCM1 <------------> *           * <====DAI1=====> Codec Speakers/Mic
                    *   DSP     *
PCM2 <------------> *           * <====DAI2=====> MODEM
                    *           *
PCM3 <------------> *           * <----DAI3-----> BT
                    *           *
                    *           * <----DAI4-----> DMIC
                    *           *
                    *           * <----DAI5-----> FM
                    *************”h]”hXK                      *************
PCM0 <------------> *           * <----DAI0-----> Codec Headset
                    *           *
PCM1 <------------> *           * <====DAI1=====> Codec Speakers/Mic
                    *   DSP     *
PCM2 <------------> *           * <====DAI2=====> MODEM
                    *           *
PCM3 <------------> *           * <----DAI3-----> BT
                    *           *
                    *           * <----DAI4-----> DMIC
                    *           *
                    *           * <----DAI5-----> FM
                    *************”…””}”hjj  sbah}”(h]”h ]”h"]”h$]”h&]”j7  j8  uh1j'  h³hÊh´M9hjK  h²hubhÝ)”}”(hŒ—In this case the PCM data is routed via the DSP. The host CPU in this use case
is only used for control and can sleep during the runtime of the stream.”h]”hŒ—In this case the PCM data is routed via the DSP. The host CPU in this use case
is only used for control and can sleep during the runtime of the stream.”…””}”(hjx  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÜh³hÊh´MGhjK  h²hubhÝ)”}”(hŒ3The host can control the hostless link either by :-”h]”hŒ3The host can control the hostless link either by :-”…””}”(hj†  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÜh³hÊh´MJhjK  h²hubhŒblock_quote”“”)”}”(hX}  1. Configuring the link as a CODEC <-> CODEC style link. In this case the link
   is enabled or disabled by the state of the DAPM graph. This usually means
   there is a mixer control that can be used to connect or disconnect the path
   between both DAIs.

2. Hostless FE. This FE has a virtual connection to the BE DAI links on the DAPM
   graph. Control is then carried out by the FE as regular PCM operations.
   This method gives more control over the DAI links, but requires much more
   userspace code to control the link. Its recommended to use CODEC<->CODEC
   unless your HW needs more fine grained sequencing of the PCM ops.

”h]”jµ  )”}”(hhh]”(jº  )”}”(hŒõConfiguring the link as a CODEC <-> CODEC style link. In this case the link
is enabled or disabled by the state of the DAPM graph. This usually means
there is a mixer control that can be used to connect or disconnect the path
between both DAIs.
”h]”hÝ)”}”(hŒôConfiguring the link as a CODEC <-> CODEC style link. In this case the link
is enabled or disabled by the state of the DAPM graph. This usually means
there is a mixer control that can be used to connect or disconnect the path
between both DAIs.”h]”hŒôConfiguring the link as a CODEC <-> CODEC style link. In this case the link
is enabled or disabled by the state of the DAPM graph. This usually means
there is a mixer control that can be used to connect or disconnect the path
between both DAIs.”…””}”(hj¡  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÜh³hÊh´MLhj  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j¹  hjš  ubjº  )”}”(hXl  Hostless FE. This FE has a virtual connection to the BE DAI links on the DAPM
graph. Control is then carried out by the FE as regular PCM operations.
This method gives more control over the DAI links, but requires much more
userspace code to control the link. Its recommended to use CODEC<->CODEC
unless your HW needs more fine grained sequencing of the PCM ops.

”h]”hÝ)”}”(hXj  Hostless FE. This FE has a virtual connection to the BE DAI links on the DAPM
graph. Control is then carried out by the FE as regular PCM operations.
This method gives more control over the DAI links, but requires much more
userspace code to control the link. Its recommended to use CODEC<->CODEC
unless your HW needs more fine grained sequencing of the PCM ops.”h]”hXj  Hostless FE. This FE has a virtual connection to the BE DAI links on the DAPM
graph. Control is then carried out by the FE as regular PCM operations.
This method gives more control over the DAI links, but requires much more
userspace code to control the link. Its recommended to use CODEC<->CODEC
unless your HW needs more fine grained sequencing of the PCM ops.”…””}”(hj¹  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÜh³hÊh´MQhjµ  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j¹  hjš  ubeh}”(h]”h ]”h"]”h$]”h&]”j9  j:  j;  hj<  j=  uh1j´  hj–  ubah}”(h]”h ]”h"]”h$]”h&]”uh1j”  h³hÊh´MLhjK  h²hubh¶)”}”(hhh]”(h»)”}”(hŒCODEC <-> CODEC link”h]”hŒCODEC <-> CODEC link”…””}”(hjÜ  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hºhjÙ  h²hh³hÊh´MYubhÝ)”}”(hŒ™This DAI link is enabled when DAPM detects a valid path within the DAPM graph.
The machine driver sets some additional parameters to the DAI link i.e.
::”h]”hŒ–This DAI link is enabled when DAPM detects a valid path within the DAPM graph.
The machine driver sets some additional parameters to the DAI link i.e.”…””}”(hjê  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÜh³hÊh´M[hjÙ  h²hubj(  )”}”(hXÑ  static const struct snd_soc_pcm_stream dai_params = {
      .formats = SNDRV_PCM_FMTBIT_S32_LE,
      .rate_min = 8000,
      .rate_max = 8000,
      .channels_min = 2,
      .channels_max = 2,
};

static struct snd_soc_dai_link dais[] = {
      < ... more DAI links above ... >
      {
              .name = "MODEM",
              .stream_name = "MODEM",
              .cpu_dai_name = "dai2",
              .codec_dai_name = "modem-aif1",
              .codec_name = "modem",
              .dai_fmt = SND_SOC_DAIFMT_I2S | SND_SOC_DAIFMT_NB_NF
                              | SND_SOC_DAIFMT_CBP_CFP,
              .c2c_params = &dai_params,
              .num_c2c_params = 1,
      }
      < ... more DAI links here ... >”h]”hXÑ  static const struct snd_soc_pcm_stream dai_params = {
      .formats = SNDRV_PCM_FMTBIT_S32_LE,
      .rate_min = 8000,
      .rate_max = 8000,
      .channels_min = 2,
      .channels_max = 2,
};

static struct snd_soc_dai_link dais[] = {
      < ... more DAI links above ... >
      {
              .name = "MODEM",
              .stream_name = "MODEM",
              .cpu_dai_name = "dai2",
              .codec_dai_name = "modem-aif1",
              .codec_name = "modem",
              .dai_fmt = SND_SOC_DAIFMT_I2S | SND_SOC_DAIFMT_NB_NF
                              | SND_SOC_DAIFMT_CBP_CFP,
              .c2c_params = &dai_params,
              .num_c2c_params = 1,
      }
      < ... more DAI links here ... >”…””}”hjø  sbah}”(h]”h ]”h"]”h$]”h&]”j7  j8  uh1j'  h³hÊh´M_hjÙ  h²hubhÝ)”}”(hŒöThese parameters are used to configure the DAI hw_params() when DAPM detects a
valid path and then calls the PCM operations to start the link. DAPM will also
call the appropriate PCM operations to disable the DAI when the path is no
longer valid.”h]”hŒöThese parameters are used to configure the DAI hw_params() when DAPM detects a
valid path and then calls the PCM operations to start the link. DAPM will also
call the appropriate PCM operations to disable the DAI when the path is no
longer valid.”…””}”(hj  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÜh³hÊh´MvhjÙ  h²hubeh}”(h]”Œcodec-codec-link”ah ]”h"]”Œcodec <-> codec link”ah$]”h&]”uh1hµhjK  h²hh³hÊh´MYubh¶)”}”(hhh]”(h»)”}”(hŒHostless FE”h]”hŒHostless FE”…””}”(hj  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hºhj  h²hh³hÊh´M}ubhÝ)”}”(hXJ  The DAI link(s) are enabled by a FE that does not read or write any PCM data.
This means creating a new FE that is connected with a virtual path to both
DAI links. The DAI links will be started when the FE PCM is started and stopped
when the FE PCM is stopped. Note that the FE PCM cannot read or write data in
this configuration.”h]”hXJ  The DAI link(s) are enabled by a FE that does not read or write any PCM data.
This means creating a new FE that is connected with a virtual path to both
DAI links. The DAI links will be started when the FE PCM is started and stopped
when the FE PCM is stopped. Note that the FE PCM cannot read or write data in
this configuration.”…””}”(hj-  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÜh³hÊh´Mhj  h²hubeh}”(h]”Œhostless-fe”ah ]”h"]”Œhostless fe”ah$]”h&]”uh1hµhjK  h²hh³hÊh´M}ubeh}”(h]”Œhostless-pcm-streams”ah ]”h"]”Œhostless pcm streams”ah$]”h&]”uh1hµhh·h²hh³hÊh´M3ubeh}”(h]”Œdynamic-pcm”ah ]”h"]”Œdynamic pcm”ah$]”h&]”uh1hµhhh²hh³hÊh´Kubeh}”(h]”h ]”h"]”h$]”h&]”Œsource”hÊuh1hŒcurrent_source”NŒcurrent_line”NŒsettings”Œdocutils.frontend”ŒValues”“”)”}”(hºNŒ	generator”NŒ	datestamp”NŒsource_link”NŒ
source_url”NŒtoc_backlinks”Œentry”Œfootnote_backlinks”KŒsectnum_xform”KŒstrip_comments”NŒstrip_elements_with_classes”NŒstrip_classes”NŒreport_level”KŒ
halt_level”KŒexit_status_level”KŒdebug”NŒwarning_stream”NŒ	traceback”ˆŒinput_encoding”Œ	utf-8-sig”Œinput_encoding_error_handler”Œstrict”Œoutput_encoding”Œutf-8”Œoutput_encoding_error_handler”jv  Œerror_encoding”Œutf-8”Œerror_encoding_error_handler”Œbackslashreplace”Œlanguage_code”Œen”Œrecord_dependencies”NŒconfig”NŒ	id_prefix”hŒauto_id_prefix”Œid”Œdump_settings”NŒdump_internals”NŒdump_transforms”NŒdump_pseudo_xml”NŒexpose_internals”NŒstrict_visitor”NŒ_disable_config”NŒ_source”hÊŒ_destination”NŒ_config_files”]”Œ7/var/lib/git/docbuild/linux/Documentation/docutils.conf”aŒfile_insertion_enabled”ˆŒraw_enabled”KŒline_length_limit”M'Œpep_references”NŒpep_base_url”Œhttps://peps.python.org/”Œpep_file_url_template”Œpep-%04d”Œrfc_references”NŒrfc_base_url”Œ&https://datatracker.ietf.org/doc/html/”Œ	tab_width”KŒtrim_footnote_reference_space”‰Œsyntax_highlight”Œlong”Œsmart_quotes”ˆŒsmartquotes_locales”]”Œcharacter_level_inline_markup”‰Œdoctitle_xform”‰Œdocinfo_xform”KŒsectsubtitle_xform”‰Œimage_loading”Œlink”Œembed_stylesheet”‰Œcloak_email_addresses”ˆŒsection_self_link”‰Œenv”NubŒreporter”NŒindirect_targets”]”Œsubstitution_defs”}”Œsubstitution_names”}”Œrefnames”}”Œrefids”}”Œnameids”}”(jP  jM  jY  jV  jL  jI  jQ  jN  j^  j[  j¾  j»  j!  j  jV  jS  jH  jE  jH  jE  j  j  j@  j=  uŒ	nametypes”}”(jP  ‰jY  ‰jL  ‰jQ  ‰j^  ‰j¾  ‰j!  ‰jV  ‰jH  ‰jH  ‰j  ‰j@  ‰uh}”(jM  h·jV  hËjI  j  jN  jO  j[  j\  j»  jÌ  j  jÁ  jS  j$  jE  ja  jE  jK  j  jÙ  j=  j  uŒfootnote_refs”}”Œcitation_refs”}”Œautofootnotes”]”Œautofootnote_refs”]”Œsymbol_footnotes”]”Œsymbol_footnote_refs”]”Œ	footnotes”]”Œ	citations”]”Œautofootnote_start”KŒsymbol_footnote_start”K Œ
id_counter”Œcollections”ŒCounter”“”}”…”R”Œparse_messages”]”(hŒsystem_message”“”)”}”(hhh]”hÝ)”}”(hŒfPossible title underline, too short for the title.
Treating it as ordinary text because it's so short.”h]”hŒhPossible title underline, too short for the title.
Treating it as ordinary text because itâ€™s so short.”…””}”(hjÝ  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÜhjÚ  ubah}”(h]”h ]”h"]”h$]”h&]”Œlevel”KŒtype”ŒINFO”Œline”K<Œsource”hÊuh1jØ  hjO  h²hh³hÊh´K<ubjÙ  )”}”(hhh]”hÝ)”}”(hŒfPossible title underline, too short for the title.
Treating it as ordinary text because it's so short.”h]”hŒhPossible title underline, too short for the title.
Treating it as ordinary text because itâ€™s so short.”…””}”(hjù  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÜhjö  ubah}”(h]”h ]”h"]”h$]”h&]”Œlevel”KŒtype”jó  Œline”KMŒsource”hÊuh1jØ  hjO  h²hh³hÊh´KMubjÙ  )”}”(hhh]”hÝ)”}”(hŒfPossible title underline, too short for the title.
Treating it as ordinary text because it's so short.”h]”hŒhPossible title underline, too short for the title.
Treating it as ordinary text because itâ€™s so short.”…””}”(hj  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÜhj  ubah}”(h]”h ]”h"]”h$]”h&]”Œlevel”KŒtype”jó  Œline”K±Œsource”hÊuh1jØ  hjÌ  h²hh³hÊh´K±ubeŒtransform_messages”]”Œtransformer”NŒinclude_log”]”Œ
decoration”Nh²hub.