TM4C123GH6PM: CAN SAMPLING POINT

you can use the CANBitTimingSet: (see TIVAWare Peripheral Driver Library)
void CANBitTimingSet(unsigned long ulBase, tCANBitClkParms *pClkParms)
For instance, in my case, running at 500kbps, for a distance of 100m,
CIA DS301 standard specifies the location of sample point at 14Tq.
So, I used:

// bit timing parameters
tCANBitClkParms canbusClkParms =
{
13, // SyncPropPhase1Seg, ( Propagation + PhaseBuffer 1) segments,
// (13 Tq per Prop + Phase_1)
2, // Phase Buffer 2 segment, 2 Tq; 13 + 2 + 1Tq(sync) = 16 Tq
2, // SJW = min(4, Phase_2)
10 // uint32_t ui32QuantumPrescaler;
};

......
......

CANBitTimingSet(CAN0_BASE, &canbusClkParms);

Regards,
Claudio