Audio DMIC¶
Overview¶
The audio DMIC interface provides access to digital microphones.
API Reference¶
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group
audio_dmic_interface Abstraction for digital microphones.
Enums
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enum
dmic_state¶ DMIC driver states
Values:
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enumerator
DMIC_STATE_UNINIT¶
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enumerator
DMIC_STATE_INITIALIZED¶
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enumerator
DMIC_STATE_CONFIGURED¶
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enumerator
DMIC_STATE_ACTIVE¶
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enumerator
DMIC_STATE_PAUSED¶
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enumerator
Functions
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static inline uint32_t
dmic_build_channel_map(uint8_t channel, uint8_t pdm, enum pdm_lr lr)¶ Build the channel map to populate struct pdm_chan_cfg
Returns the map of PDM controller and LEFT/RIGHT channel shifted to the bit position corresponding to the input logical channel value
- Parameters
channel – The logical channel number
pdm – The PDM hardware controller number
lr – LEFT/RIGHT channel within the chosen PDM hardware controller
- Returns
Bit-map containing the PDM and L/R channel information
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static inline void
dmic_parse_channel_map(uint32_t channel_map_lo, uint32_t channel_map_hi, uint8_t channel, uint8_t *pdm, enum pdm_lr *lr)¶ Helper function to parse the channel map in pdm_chan_cfg
Returns the PDM controller and LEFT/RIGHT channel corresponding to the channel map and the logical channel provided as input
- Parameters
channel_map_lo – Lower order/significant bits of the channel map
channel_map_hi – Higher order/significant bits of the channel map
channel – The logical channel number
pdm – Pointer to the PDM hardware controller number
lr – Pointer to the LEFT/RIGHT channel within the PDM controller
- Returns
none
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static inline uint32_t
dmic_build_clk_skew_map(uint8_t pdm, uint8_t skew)¶ Build a bit map of clock skew values for each PDM channel
Returns the bit-map of clock skew value shifted to the bit position corresponding to the input PDM controller value
- Parameters
pdm – The PDM hardware controller number
skew – The skew to apply for the clock output from the PDM controller
- Returns
Bit-map containing the clock skew information
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static inline int
dmic_configure(const struct device *dev, struct dmic_cfg *cfg)¶ Configure the DMIC driver and controller(s)
Configures the DMIC driver device according to the number of channels, channel mapping, PDM I/O configuration, PCM stream configuration, etc.
- Parameters
dev – Pointer to the device structure for DMIC driver instance
cfg – Pointer to the structure containing the DMIC configuration
- Returns
0 on success, a negative error code on failure
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static inline int
dmic_trigger(const struct device *dev, enum dmic_trigger cmd) Send a command to the DMIC driver
Sends a command to the driver to perform a specific action
- Parameters
dev – Pointer to the device structure for DMIC driver instance
cmd – The command to be sent to the driver instance
- Returns
0 on success, a negative error code on failure
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static inline int
dmic_read(const struct device *dev, uint8_t stream, void **buffer, size_t *size, int32_t timeout)¶ Read received decimated PCM data stream
Optionally waits for audio to be received and provides the received audio buffer from the requested stream
- Parameters
dev – Pointer to the device structure for DMIC driver instance
stream – Stream identifier
buffer – Pointer to the received buffer address
size – Pointer to the received buffer size
timeout – Timeout in milliseconds to wait in case audio is not yet received, or SYS_FOREVER_MS
- Returns
0 on success, a negative error code on failure
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struct
pdm_io_cfg¶ - #include <dmic.h>
PDM Input/Output signal configuration
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struct
pcm_stream_cfg¶ - #include <dmic.h>
Configuration of the PCM streams to be output by the PDM hardware
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struct
pdm_chan_cfg¶ - #include <dmic.h>
Mapping/ordering of the PDM channels to logical PCM output channel
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struct
dmic_cfg¶ - #include <dmic.h>
Input configuration structure for the DMIC configuration API
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enum