TIDA-01454: Getting 8 channels from CMB

Hello I want to record 8 channels from TIDA-01454 CMB into a Beaglebone AI. As the CMB is built with two PCM1864 and it is also a Beagle board, I followed this guide with some changes in oder to make it compatible with Beaglebone AI. I have managed to record audio from 4 of the 8 microphones that the CMB has(I just tap the mic to check if that one is working). The working microphones are MIC1, MIC4, MIC5 and MIC8, although I would say there is much noise.

The CMB has 4 data output pins, so I suppose each one transmits 2 channels and therefore this is my dts file:

&mcasp1 { 

    #sound-dai-cells = <0>; 

    pinctrl-names = "default"; 

    pinctrl-0 = <&mcasp1_pins>; 

    status = "okay"; 

    op-mode = <0>; /* MCASP_IIS_MODE */ 

    tdm-slots = <2>; 

    num-serializer = <4>; 

    serial-dir = < /* 1 TX 2 RX 0 unused */ 

        2 2 0 0 0 0 0 0 0 0 2 2

      >; 

    rx-num-evt = <4>; 

    tx-num-evt = <4>; 

};

The serial-dir is that way because I use mcasp1_axr0, mcasp1_axr1, mcasp1_10 and mcasp1_axr11 because those are the one available in Beaglbone AI. This is my configuration for the CMB:

uint8_t U1_PCM1864_CONFIG[][2] = { 

{0x00, 0x00}, // Change to Page 0 

{0x01, 0x40}, // PGA CH1_L to 32dB 

{0x02, 0x40}, // PGA CH1_R to 32dB 

{0x03, 0x40}, // PGA CH2_L to 32dB 

{0x04, 0x40}, // PGA CH2_R to 32dB 

{0x05, 0x86}, // Enable SMOOTH PGA Change; Independent Link PGA; 

{0x06, 0x41}, // Polarity: Normal, Channel: VINL1[SE] 

{0x07, 0x41}, // Polarity: Normal, Channel: VINR1[SE] 

{0x08, 0x44}, // Polarity: Normal, Channel: VINL3[SE] 

{0x09, 0x44}, // Polarity: Normal, Channel: VINR3[SE] 

{0x0A, 0x00}, // Secondary ADC Input: No Selection 

{0x0B, 0x44}, // RX WLEN: 24bit; TX WLEN: 24 bit; FMT: I2S format 

{0x10, 0x03}, // GPIO0_FUNC - SCK Out; GPIO0_POL - Normal 

{0x11, 0x50}, // GPIO3_FUNC - DOUT2; GPIO3_POL - Normal 

{0x12, 0x04}, // GPIO0_DIR - GPIO0 - Output 

{0x13, 0x40}, // GPIO3_DIR � GPIO3 - Output 

{0x20, 0x11}  // MST_MODE: Master; CLKDET_EN: Disable 

}; 

  

uint8_t U2_PCM1864_CONFIG[][2] = { 

{0x00, 0x00}, // Change to Page 0 

{0x01, 0x40}, // PGA CH1_L to 32dB 

{0x02, 0x40}, // PGA CH1_R to 32dB 

{0x03, 0x40}, // PGA CH2_L to 32dB 

{0x04, 0x40}, // PGA CH2_R to 32dB 

{0x05, 0x86}, // Enable SMOOTH PGA Change; Independent Link PGA; 

{0x06, 0x41}, // Polarity: Normal, Channel: VINL1[SE] 

{0x07, 0x41}, // Polarity: Normal, Channel: VINR1[SE] 

{0x08, 0x44}, // Polarity: Normal, Channel: VINL3[SE] 

{0x09, 0x44}, // Polarity: Normal, Channel: VINR3[SE] 

{0x0A, 0x00}, // Secondary ADC Input: No Selection 

{0x0B, 0x44}, // RX WLEN: 24bit; TX WLEN: 24 bit; FMT: I2S format 

{0x10, 0x00}, // GPIO0_FUNC – GPIO0; GPIO0_POL - Normal 

{0x11, 0x50}, // GPIO3_FUNC - DOUT2; GPIO3_POL - Normal 

{0x12, 0x00}, // GPIO0_DIR - GPIO0 - Input 

{0x13, 0x40}, // GPIO3_DIR � GPIO3 - Output 

{0x20, 0x01}  // MST_MODE: Slave; CLKDET_EN: Enable 

};

So what am I missing to get the 8 channels?