Add ES7210 audio ADC driver for NuttX implementing the audio
lower-half interface. Supports 4-channel recording via I2S with
configurable sample rate, bit depth, and mic gain.
- drivers/audio/es7210.c: Codec driver using LPWORK for async buffer
management, I2C register access, and NuttX audio buffer management
- drivers/audio/es7210.h: Internal register definitions and macros
- include/nuttx/audio/es7210.h: Public header with platform config
structure and es7210_initialize() API
- drivers/audio/Kconfig, Make.defs, CMakeLists.txt: Build system
integration for CONFIG_AUDIO_ES7210
Key implementation details:
- ES7210_SDP_NORMAL (normal I2S) instead of TDM, matching NuttX
I2S standard Philips mode
- ES7210_ADC_PGA_POWER_ON bit in gain registers REG43-46, required
for analog front-end amplifier power-on
- 50ms startup delay in es7210_start for codec clock stabilization
- I2S_IOCTL(AUDIOIOC_STOP) in es7210_stop to notify I2S layer,
preventing DMA from running without buffers after stop
Signed-off-by: wangjianyu3 <wangjianyu3@xiaomi.com>
