Chapter 5. Sound Devices
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Chapter 5. Sound Devices
Table of Contents
snd_printk
— printk wrapper
snd_printd
— debug printk
snd_BUG
— give a BUG warning message and stack trace
snd_printd_ratelimit
—
snd_BUG_ON
— debugging check macro
snd_printdd
— debug printk
register_sound_special_device
— register a special sound node
register_sound_mixer
— register a mixer device
register_sound_midi
— register a midi device
register_sound_dsp
— register a DSP device
unregister_sound_special
— unregister a special sound device
unregister_sound_mixer
— unregister a mixer
unregister_sound_midi
— unregister a midi device
unregister_sound_dsp
— unregister a DSP device
snd_pcm_stream_linked
— Check whether the substream is linked with others
snd_pcm_stream_lock_irqsave
— Lock the PCM stream
snd_pcm_group_for_each_entry
— iterate over the linked substreams
snd_pcm_running
— Check whether the substream is in a running state
bytes_to_samples
— Unit conversion of the size from bytes to samples
bytes_to_frames
— Unit conversion of the size from bytes to frames
samples_to_bytes
— Unit conversion of the size from samples to bytes
frames_to_bytes
— Unit conversion of the size from frames to bytes
frame_aligned
— Check whether the byte size is aligned to frames
snd_pcm_lib_buffer_bytes
— Get the buffer size of the current PCM in bytes
snd_pcm_lib_period_bytes
— Get the period size of the current PCM in bytes
snd_pcm_playback_avail
— Get the available (writable) space for playback
snd_pcm_capture_avail
— Get the available (readable) space for capture
snd_pcm_playback_hw_avail
— Get the queued space for playback
snd_pcm_capture_hw_avail
— Get the free space for capture
snd_pcm_playback_ready
— check whether the playback buffer is available
snd_pcm_capture_ready
— check whether the capture buffer is available
snd_pcm_playback_data
— check whether any data exists on the playback buffer
snd_pcm_playback_empty
— check whether the playback buffer is empty
snd_pcm_capture_empty
— check whether the capture buffer is empty
snd_pcm_trigger_done
— Mark the master substream
params_channels
— Get the number of channels from the hw params
params_rate
— Get the sample rate from the hw params
params_period_size
— Get the period size (in frames) from the hw params
params_periods
— Get the number of periods from the hw params
params_buffer_size
— Get the buffer size (in frames) from the hw params
params_buffer_bytes
— Get the buffer size (in bytes) from the hw params
snd_pcm_hw_constraint_single
— Constrain parameter to a single value
snd_pcm_format_cpu_endian
— Check the PCM format is CPU-endian
snd_pcm_set_runtime_buffer
— Set the PCM runtime buffer
snd_pcm_gettime
— Fill the timespec depending on the timestamp mode
snd_pcm_lib_alloc_vmalloc_buffer
— allocate virtual DMA buffer
snd_pcm_lib_alloc_vmalloc_32_buffer
— allocate 32-bit-addressable buffer
snd_pcm_sgbuf_get_addr
— Get the DMA address at the corresponding offset
snd_pcm_sgbuf_get_ptr
— Get the virtual address at the corresponding offset
snd_pcm_sgbuf_get_chunk_size
— Compute the max size that fits within the contig. page from the given size
snd_pcm_mmap_data_open
— increase the mmap counter
snd_pcm_mmap_data_close
— decrease the mmap counter
snd_pcm_limit_isa_dma_size
— Get the max size fitting with ISA DMA transfer
snd_pcm_stream_str
— Get a string naming the direction of a stream
snd_pcm_chmap_substream
— get the PCM substream assigned to the given chmap info
pcm_format_to_bits
— Strong-typed conversion of pcm_format to bitwise
snd_pcm_format_name
— Return a name string for the given PCM format
snd_pcm_new_stream
— create a new PCM stream
snd_pcm_new
— create a new PCM instance
snd_pcm_new_internal
— create a new internal PCM instance
snd_pcm_notify
— Add/remove the notify list
snd_device_new
— create an ALSA device component
snd_device_disconnect
— disconnect the device
snd_device_free
— release the device from the card
snd_device_register
— register the device
snd_info_get_line
— read one line from the procfs buffer
snd_info_get_str
— parse a string token
snd_info_create_module_entry
— create an info entry for the given module
snd_info_create_card_entry
— create an info entry for the given card
snd_info_free_entry
— release the info entry
snd_info_register
— register the info entry
snd_rawmidi_receive
— receive the input data from the device
snd_rawmidi_transmit_empty
— check whether the output buffer is empty
__snd_rawmidi_transmit_peek
— copy data from the internal buffer
snd_rawmidi_transmit_peek
— copy data from the internal buffer
__snd_rawmidi_transmit_ack
— acknowledge the transmission
snd_rawmidi_transmit_ack
— acknowledge the transmission
snd_rawmidi_transmit
— copy from the buffer to the device
snd_rawmidi_new
— create a rawmidi instance
snd_rawmidi_set_ops
— set the rawmidi operators
snd_request_card
— try to load the card module
snd_lookup_minor_data
— get user data of a registered device
snd_register_device
— Register the ALSA device file for the card
snd_unregister_device
— unregister the device on the given card
copy_to_user_fromio
— copy data from mmio-space to user-space
copy_from_user_toio
— copy data from user-space to mmio-space
snd_pcm_lib_preallocate_free_for_all
— release all pre-allocated buffers on the pcm
snd_pcm_lib_preallocate_pages
— pre-allocation for the given DMA type
snd_pcm_lib_preallocate_pages_for_all
— pre-allocation for continuous memory type (all substreams)
snd_pcm_sgbuf_ops_page
— get the page struct at the given offset
snd_pcm_lib_malloc_pages
— allocate the DMA buffer
snd_pcm_lib_free_pages
— release the allocated DMA buffer.
snd_pcm_lib_free_vmalloc_buffer
— free vmalloc buffer
snd_pcm_lib_get_vmalloc_page
— map vmalloc buffer offset to page struct
snd_device_initialize
— Initialize struct device for sound devices
snd_card_new
— create and initialize a soundcard structure
snd_card_disconnect
— disconnect all APIs from the file-operations (user space)
snd_card_free_when_closed
— Disconnect the card, free it later eventually
snd_card_free
— frees given soundcard structure
snd_card_set_id
— set card identification name
snd_card_add_dev_attr
— Append a new sysfs attribute group to card
snd_card_register
— register the soundcard
snd_component_add
— add a component string
snd_card_file_add
— add the file to the file list of the card
snd_card_file_remove
— remove the file from the file list
snd_power_wait
— wait until the power-state is changed.
snd_dma_program
— program an ISA DMA transfer
snd_dma_disable
— stop the ISA DMA transfer
snd_dma_pointer
— return the current pointer to DMA transfer buffer in bytes
snd_ctl_notify
— Send notification to user-space for a control change
snd_ctl_new1
— create a control instance from the template
snd_ctl_free_one
— release the control instance
snd_ctl_add
— add the control instance to the card
snd_ctl_replace
— replace the control instance of the card
snd_ctl_remove
— remove the control from the card and release it
snd_ctl_remove_id
— remove the control of the given id and release it
snd_ctl_activate_id
— activate/inactivate the control of the given id
snd_ctl_rename_id
— replace the id of a control on the card
snd_ctl_find_numid
— find the control instance with the given number-id
snd_ctl_find_id
— find the control instance with the given id
snd_ctl_register_ioctl
— register the device-specific control-ioctls
snd_ctl_register_ioctl_compat
— register the device-specific 32bit compat control-ioctls
snd_ctl_unregister_ioctl
— de-register the device-specific control-ioctls
snd_ctl_unregister_ioctl_compat
— de-register the device-specific compat 32bit control-ioctls
snd_ctl_boolean_mono_info
— Helper function for a standard boolean info callback with a mono channel
snd_ctl_boolean_stereo_info
— Helper function for a standard boolean info callback with stereo two channels
snd_ctl_enum_info
— fills the info structure for an enumerated control
snd_pcm_set_ops
— set the PCM operators
snd_pcm_set_sync
— set the PCM sync id
snd_interval_refine
— refine the interval value of configurator
snd_interval_ratnum
— refine the interval value
snd_interval_list
— refine the interval value from the list
snd_interval_ranges
— refine the interval value from the list of ranges
snd_pcm_hw_rule_add
— add the hw-constraint rule
snd_pcm_hw_constraint_mask64
— apply the given bitmap mask constraint
snd_pcm_hw_constraint_integer
— apply an integer constraint to an interval
snd_pcm_hw_constraint_minmax
— apply a min/max range constraint to an interval
snd_pcm_hw_constraint_list
— apply a list of constraints to a parameter
snd_pcm_hw_constraint_ranges
— apply list of range constraints to a parameter
snd_pcm_hw_constraint_ratnums
— apply ratnums constraint to a parameter
snd_pcm_hw_constraint_ratdens
— apply ratdens constraint to a parameter
snd_pcm_hw_constraint_msbits
— add a hw constraint msbits rule
snd_pcm_hw_constraint_step
— add a hw constraint step rule
snd_pcm_hw_constraint_pow2
— add a hw constraint power-of-2 rule
snd_pcm_hw_rule_noresample
— add a rule to allow disabling hw resampling
snd_pcm_hw_param_value
— return
params
field
var
value
snd_pcm_hw_param_first
— refine config space and return minimum value
snd_pcm_hw_param_last
— refine config space and return maximum value
snd_pcm_lib_ioctl
— a generic PCM ioctl callback
snd_pcm_period_elapsed
— update the pcm status for the next period
snd_pcm_add_chmap_ctls
— create channel-mapping control elements
snd_hwdep_new
— create a new hwdep instance
snd_pcm_stream_lock
— Lock the PCM stream
snd_pcm_stream_unlock
— Unlock the PCM stream
snd_pcm_stream_lock_irq
— Lock the PCM stream
snd_pcm_stream_unlock_irq
— Unlock the PCM stream
snd_pcm_stream_unlock_irqrestore
— Unlock the PCM stream
snd_pcm_stop
— try to stop all running streams in the substream group
snd_pcm_stop_xrun
— stop the running streams as XRUN
snd_pcm_suspend
— trigger SUSPEND to all linked streams
snd_pcm_suspend_all
— trigger SUSPEND to all substreams in the given pcm
snd_pcm_lib_default_mmap
— Default PCM data mmap function
snd_pcm_lib_mmap_iomem
— Default PCM data mmap function for I/O mem
snd_malloc_pages
— allocate pages with the given size
snd_free_pages
— release the pages
snd_dma_alloc_pages
— allocate the buffer area according to the given type
snd_dma_alloc_pages_fallback
— allocate the buffer area according to the given type with fallback
snd_dma_free_pages
— release the allocated buffer