i2s_chan_config_t struct

I2S port id.

I2S role, I2S_ROLE_MASTER or I2S_ROLE_SLAVE.

I2S DMA buffer number, it is also the number of DMA descriptor.

I2S frame number in one DMA buffer. One frame means one-time sample data in all slots, it should be the multiple of `3` when the data bit width is 24.

Set to auto clear DMA TX buffer before `on_sent` callback, I2S will always send zero automatically if no data to send So that user can access data in the callback that just finished to send.

Set to allow power down. When this flag set, the driver will backup/restore the I2S registers before/after entering/exist sleep mode. By this approach, the system can power off I2S's power domain. This can save power, but at the expense of more RAM being consumed.

I2S interrupt priority, range [0, 7], if set to 0, the driver will try to allocate an interrupt with a relative low priority (1,2,3).