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Topology Interface

Data Structures

struct  snd_tplg_tlv_template
 Template type for all TLV objects. More...
struct  snd_tplg_tlv_dbscale_template
 Template type for TLV Scale objects. More...
struct  snd_tplg_channel_elem
struct  snd_tplg_channel_map_template
 Template type for channel mapping. More...
struct  snd_tplg_pdata_template
 Template type for private data objects. More...
struct  snd_tplg_io_ops_template
 Template type for object operations mapping. More...
struct  snd_tplg_ctl_template
 Template type for control objects. More...
struct  snd_tplg_mixer_template
 Template type for mixer control objects. More...
struct  snd_tplg_enum_template
 Template type for enumerated control objects. More...
struct  snd_tplg_bytes_template
 Template type for TLV Scale objects. More...
struct  snd_tplg_graph_elem
 Template type for single DAPM graph element. More...
struct  snd_tplg_graph_template
 Template type for array of DAPM graph elements. More...
struct  snd_tplg_widget_template
 Template type for DAPM widget objects. More...
struct  snd_tplg_stream_template
 Stream configurations. More...
struct  snd_tplg_stream_caps_template
 Stream Capabilities. More...
struct  snd_tplg_pcm_template
 Template type for PCM (FE DAI & DAI links). More...
struct  snd_tplg_link_template
 Template type for BE and CC DAI Links. More...
struct  snd_tplg_obj_template_t
struct  snd_tplg_channel_template
 Template type for single channel mapping. More...
struct  snd_tplg_obj_template
 Generic Template Object. More...

Defines

#define SND_TPLG_MAX_CHAN   8

Typedefs

typedef struct snd_tplg snd_tplg_t

Enumerations

enum  snd_tplg_type {
  SND_TPLG_TYPE_TLV = 0, SND_TPLG_TYPE_MIXER, SND_TPLG_TYPE_ENUM, SND_TPLG_TYPE_TEXT,
  SND_TPLG_TYPE_DATA, SND_TPLG_TYPE_BYTES, SND_TPLG_TYPE_STREAM_CONFIG, SND_TPLG_TYPE_STREAM_CAPS,
  SND_TPLG_TYPE_PCM, SND_TPLG_TYPE_DAPM_WIDGET, SND_TPLG_TYPE_DAPM_GRAPH, SND_TPLG_TYPE_BE,
  SND_TPLG_TYPE_CC, SND_TPLG_TYPE_MANIFEST
}

Functions

snd_tplg_tsnd_tplg_new (void)
 Create a new topology parser instance.
void snd_tplg_free (snd_tplg_t *tplg)
 Free a topology parser instance.
int snd_tplg_build_file (snd_tplg_t *tplg, const char *infile, const char *outfile)
 Parse and build topology text file into binary file.
void snd_tplg_verbose (snd_tplg_t *tplg, int verbose)
 Enable verbose reporting of binary file output.
int snd_tplg_add_object (snd_tplg_t *tplg, snd_tplg_obj_template_t *t)
 Register topology template object.
int snd_tplg_build (snd_tplg_t *tplg, const char *outfile)
 Build all registered topology data into binary file.
int snd_tplg_set_manifest_data (snd_tplg_t *tplg, const void *data, int len)
 Attach private data to topology manifest.
int snd_tplg_set_version (snd_tplg_t *tplg, unsigned int version)
 Set an optional vendor specific version number.

ALSA Topology Interface

The topology interface allows developers to define DSP topologies in a text file format and to convert the text topology to a binary topology representation that can be understood by the kernel. The topology core currently recognises the following object types :-

* Controls (mixer, enumerated and byte) including TLV data. * PCMs (FE and BE configurations and capabilities) * DAPM widgets * DAPM graph elements. * Private data for each object type. * Manifest (containing count of each object type)

Topology File Format

The topology text format uses the standard ALSA configuration file format to describe each topology object type. This allows topology objects to include other topology objects as part of their definition. i.e. a TLV data object can be shared amongst many control objects that use the same TLV data.

Controls

Topology audio controls can belong to three different types :- * Mixer control * Enumerated control * Byte control

Each control type can contain TLV data, private data, operations and also belong to widget objects.

Control Operations

Driver Kcontrol callback info(), get() and put() operations are mapped with the CTL ops section in topology configuration files. The ctl ops section can assign operations using the standard names (listed below) for the standard kcontrol types or use ID numbers (>256) to map to bespoke driver controls.

	ops."ctl" {
		info "volsw"
		get "257"
		put "257"
	}
 

This mapping shows info() using the standard "volsw" info callback whilst the get() and put() are mapped to bespoke driver callbacks.

The Standard operations names for control get(), put() and info calls are :- * volsw * volsw_sx * volsw_xr_sx * enum * bytes * enum_value * range * strobe

Control TLV Data

Controls can also use TLV data to represent dB information. This can be done by defining a TLV section and using the TLV section within the control. The TLV data for DBScale types are defined as follows :-

	scale {
		min "-9000"
		step "300"
		mute "1"
	}
 

Where the meanings and values for min, step and mute are exactly the same as defined in driver code.

Control Channel Mapping

Controls can also specify which channels they are mapped with. This is useful for userspace as it allows applications to determine the correct control channel for Left and Right etc. Channel maps are defined as follows :-

	channel."name" {
		reg "0"
		shift "0"
	}
 

The channel map reg is the register offset for the control, shift is the bit shift within the register for the channel and the section name is the channel name and can be one of the following :-

  * mono		# mono stream
  * fl 		# front left
  * fr		# front right
  * rl		# rear left
  * rr		# rear right
  * fc		# front center
  * lfe		# LFE
  * sl		# side left
  * sr		# side right
  * rc		# rear center
  * flc		# front left center
  * frc		# front right center
  * rlc		# rear left center
  * rrc		# rear right center
  * flw		# front left wide
  * frw		# front right wide
  * flh		# front left high
  * fch		# front center high
  * frh		# front right high
  * tc		# top center
  * tfl		# top front left
  * tfr		# top front right
  * tfc		# top front center
  * trl		# top rear left
  * trr		# top rear right
  * trc		# top rear center
  * tflc		# top front left center
  * tfrc		# top front right center
  * tsl		# top side left
  * tsr		# top side right
  * llfe		# left LFE
  * rlfe		# right LFE
  * bc		# bottom center
  * blc		# bottom left center
  * brc		# bottom right center
 
Control Private Data

Controls can also have private data. This can be done by defining a private data section and including the section within the control. The private data section is defined as follows :-

 SectionData."pdata for EQU1" {
	file "/path/to/file"
	bytes "0x12,0x34,0x56,0x78"
	shorts "0x1122,0x3344,0x5566,0x7788"
	words "0xaabbccdd,0x11223344,0x66aa77bb,0xefef1234"
 };
 

The file, bytes, shorts and words keywords are all mutually exclusive as the private data should only be taken from one source. The private data can either be read from a separate file or defined in the topology file using the bytes, shorts or words keywords.

Mixer Controls

A mixer control is defined as a new section that can include channel mapping, TLV data, callback operations and private data. The mixer section also includes a few other config options that are shown here :-

 SectionControlMixer."mixer name" {
	comment "optional comments"
	index "1"			# Index number
	channel."name" {		# Channel maps
	   ....
	}
	ops."ctl" {			# Ops callback functions
	   ....
	}
	max "32"			# Max control value
	invert "0"			# Whether control values are inverted
	tlv "tld_data"			# optional TLV data
	data "pdata for mixer1"		# optional private data
 }
 

The section name is used to define the mixer name. The index number can be used to identify topology objects groups. This allows driver operations on objects with index number N and can be used to add/remove pipelines of objects whilst other objects are unaffected.

Byte Controls

A byte control is defined as a new section that can include channel mapping, TLV data, callback operations and private data. The bytes section also includes a few other config options that are shown here :-

 SectionControlBytes."name" {
	comment "optional comments"
	index "1"			# Index number
	channel."name" {		# Channel maps
	   ....
	}
	ops."ctl" {			# Ops callback functions
	   ....
	}
	base "0"			# Register base
	num_regs "16"			# Number of registers
	mask "0xff"			# Mask
	max "255"			# Maximum value
	tlv "tld_data"			# optional TLV data
	data "pdata for mixer1"		# optional private data
 }
 
Enumerated Controls

A enumerated control is defined as a new section (like mixer and byte) that can include channel mapping, callback operations, private data and text strings to represent the enumerated control options.

The text strings for the enumerated controls are defined in a separate section as follows :-

 SectionText."name" {
		Values [
			"value1"
			"value2"
			"value3"
		]
 }
 

All the enumerated text values are listed in the values list.
The enumerated control is similar to the other controls and defined as follows :-

 SectionControlMixer."name" {
	comment "optional comments"
	index "1"			# Index number
	texts "EQU1"			# Enumerated text items
	channel."name" {		# Channel maps
	   ....
	}
	ops."ctl" {			# Ops callback functions
	   ....
	}
	data "pdata for mixer1"		# optional private data
 }
 

DAPM Graph

DAPM graphs can easily be defined using the topology file. The format is very similar to the DAPM graph kernel format. :-

 SectionGraph."dsp" {
	index "1"			# Index number
	lines [
		"sink1, control, source1"
		"sink2, , source2"
	]
 }
 

The lines in the graph are defined as a variable size list of sinks, controls and sources. The control name is optional as some graph lines have no associated controls. The section name can be used to differentiate the graph with other graphs, it's not used by the kernel atm.

DAPM Widgets

DAPM widgets are similar to controls in that they can include many other objects. Widgets can contain private data, mixer controls and enum controls.

The following widget types are supported and match the driver types :-

* input * output * mux * mixer * pga * out_drv * adc * dac * switch * pre * post * aif_in * aif_out * dai_in * dai_out * dai_link

Widgets are defined as follows :-

 SectionWidget."name" {
	index "1"			# Index number
	type "aif_in"			# Widget type - detailed above
	no_pm "true"			# No PM control bit.
	reg "20"			# PM bit register offset
	shift "0"			# PM bit register shift
	invert "1			# PM bit is inverted
	subseq "8"			# subsequence number
	event_type "1"			# DAPM widget event type
	event_flags "1"			# DAPM widget event flags
	mixer "name"			# Optional Mixer Control
	enum "name"			# Optional Enum Control
	data "name"			# optional private data
 }
 

The section name is the widget name. The mixer and enum fields are mutually exclusive and used to include controls into the widget. The index and data fields are the same for widgets as they are for controls whilst the other fields map on very closely to the driver widget fields.

PCM Capabilities

Topology can also define the capabilities of FE and BE PCMs. Capabilities can be defined with the following section :-

 SectionPCMCapabilities."name" {
	formats "S24_LE,S16_LE"		# Supported formats
	rate_min "48000"		# Max supported sample rate
	rate_max "48000"		# Min supported sample rate
	channels_min "2"		# Min number of channels
	channels_max "2"		# max number of channels
 }
 

The supported formats use the same naming convention as the driver macros. The PCM capabilities name can be referred to and included by BE, PCM and Codec <-> codec topology sections.

PCM Configurations

PCM runtime configurations can be defined for playback and capture stream directions with the following section :-

 SectionPCMConfig."name" {
	config."playback" {		# playback config
		format "S16_LE"		# playback format
		rate "48000"		# playback sample rate
		channels "2"		# playback channels
		tdm_slot "0xf"		# playback TDM slot
	}
	config."capture" {		# capture config
		format "S16_LE"		# capture format
		rate "48000"		# capture sample rate
		channels "2"		# capture channels
		tdm_slot "0xf"		# capture TDM slot
	}
 }
 

The supported formats use the same naming convention as the driver macros. The PCM configuration name can be referred to and included by BE, PCM and Codec <-> codec topology sections.

PCM Configurations

PCM, BE and Codec to Codec link sections define the supported capabilities and configurations for supported playback and capture streams. The definitions and content for PCMs, BE and Codec links are the same with the exception of the section type :-

 SectionPCM."name" {
	....
 }
 SectionBE."name" {
	....
 }
 SectionCC."name" {
	....
 }
 

The section types above should be used for PCMs, Back Ends and Codec to Codec links respectively.

The data for each section is defined as follows :-

 SectionPCM."name" {
	index "1"			# Index number
	id "0"				# used for binding to the PCM
	pcm."playback" {
		capabilities "capabilities1"	# capabilities for playback
		configs [		# supported configs for playback
			"config1"
			"config2"
		]
	}
	pcm."capture" {
		capabilities "capabilities2"	# capabilities for capture
		configs [		# supported configs for capture
			"config1"
			"config2"
			"config3"
		]
	}
 }
 

Define Documentation

#define SND_TPLG_MAX_CHAN   8

Maximum number of channels supported in one control


Typedef Documentation

typedef struct snd_tplg snd_tplg_t

Topology context


Enumeration Type Documentation

Topology object types

Enumerator:
SND_TPLG_TYPE_TLV 

TLV Data

SND_TPLG_TYPE_MIXER 

Mixer control

SND_TPLG_TYPE_ENUM 

Enumerated control

SND_TPLG_TYPE_TEXT 

Text data

SND_TPLG_TYPE_DATA 

Private data

SND_TPLG_TYPE_BYTES 

Byte control

SND_TPLG_TYPE_STREAM_CONFIG 

PCM Stream configuration

SND_TPLG_TYPE_STREAM_CAPS 

PCM Stream capabilities

SND_TPLG_TYPE_PCM 

PCM stream device

SND_TPLG_TYPE_DAPM_WIDGET 

DAPM widget

SND_TPLG_TYPE_DAPM_GRAPH 

DAPM graph elements

SND_TPLG_TYPE_BE 

BE DAI link

SND_TPLG_TYPE_CC 

Hostless codec <-> codec link

SND_TPLG_TYPE_MANIFEST 

Topology manifest


Function Documentation

Register topology template object.

Parameters:
tplgTopology instance.
tTemplate object.
Returns:
Zero on success, otherwise a negative error code
int snd_tplg_build ( snd_tplg_t tplg,
const char *  outfile 
)

Build all registered topology data into binary file.

Parameters:
tplgTopology instance.
outfileBinary topology output file.
Returns:
Zero on success, otherwise a negative error code
int snd_tplg_build_file ( snd_tplg_t tplg,
const char *  infile,
const char *  outfile 
)

Parse and build topology text file into binary file.

Parameters:
tplgTopology instance.
infileTopology text input file to be parsed
outfileBinary topology output file.
Returns:
Zero on success, otherwise a negative error code
void snd_tplg_free ( snd_tplg_t tplg)

Free a topology parser instance.

Parameters:
tplgTopology parser instance
snd_tplg_t* snd_tplg_new ( void  )

Create a new topology parser instance.

Returns:
New topology parser instance
int snd_tplg_set_manifest_data ( snd_tplg_t tplg,
const void *  data,
int  len 
)

Attach private data to topology manifest.

Parameters:
tplgTopology instance.
dataPrivate data.
lenLength of data in bytes.
Returns:
Zero on success, otherwise a negative error code
int snd_tplg_set_version ( snd_tplg_t tplg,
unsigned int  version 
)

Set an optional vendor specific version number.

Parameters:
tplgTopology instance.
versionVendor specific version number.
Returns:
Zero on success, otherwise a negative error code
void snd_tplg_verbose ( snd_tplg_t tplg,
int  verbose 
)

Enable verbose reporting of binary file output.

Parameters:
tplgTopology Instance
verboseEnable verbose output level if non zero
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