Less nesting pin search

gistfile1.txt

//SCK is not optional. MOSI and MISO are
for (uint i=0; i<sck_len;i++) {
    if (mcu_spi_sck_list[i].pin == sck) {
        uint j = 0;
        if (miso != mp_const_none) {
            for (j=0; j<miso_len;j++) {
                RETRY:
                if ((mcu_spi_miso_list[j].pin == miso) //only SCK and MISO need the same index
                    && (mcu_spi_sck_list[i].spi_index == mcu_spi_miso_list[j].spi_index)) {
                    //store pins if not
                    if (mosi == mp_const_none) {
                        self->sck = &mcu_spi_sck_list[i];
                        self->mosi = NULL;
                        self->miso = &mcu_spi_miso_list[j];
                    }
                    break;
                }
            }  
        if (mosi != mp_const_none) {
            for (uint k=0; k<mosi_len;k++) {
                if ((mcu_spi_mosi_list[k].pin == mosi) //only SCK and MOSI need the same index
                    && (mcu_spi_sck_list[i].spi_index == mcu_spi_mosi_list[k].spi_index)) {
                    if (miso == mp_const_none) {
                        //keep looking if the SPI is taken, edge case
                        if (reserved_spi[mcu_spi_sck_list[i].spi_index-1]) {
                            spi_taken = true;
                            continue;
                        }
                        //store pins if not
                        self->sck = &mcu_spi_sck_list[i];
                        self->mosi = &mcu_spi_mosi_list[j];
                        self->miso = NULL;
                    } else if (mcu_spi_sck_list[i].spi_index == mcu_spi_miso_list[j].spi_index) {
                        //keep looking if the SPI is taken, edge case
                        if (reserved_spi[mcu_spi_sck_list[i].spi_index-1]) {
                            spi_taken = true;
                            continue;
                        }
                        //store pins if not
                        self->sck = &mcu_spi_sck_list[i];
                        self->mosi = &mcu_spi_mosi_list[j];
                        self->miso = &mcu_spi_mosi_list[k];
                    }
                    break;
                }
            }  
        }
        if (self->mosi == NULL && mosi != mp_const_none && j<miso_len) {
            goto: RETRY;
        }
    }
}