M_FIFO_RX_THLD_SHIFT
val &= ~(M_FIFO_RX_THLD_MASK << M_FIFO_RX_THLD_SHIFT);
val |= (bytes_left << M_FIFO_RX_THLD_SHIFT);
tmp &= ~(M_FIFO_RX_THLD_MASK << M_FIFO_RX_THLD_SHIFT);
tmp |= iproc_i2c->thld_bytes << M_FIFO_RX_THLD_SHIFT;