DRV8860: Freewheeling Diode and Resistor needed?

Hi.

in designing a driver for 8 solenoid valves that uses DRV8860 I am asking if I have to consider to add at every utput a freewheeling diode in parallel with a resistor to act as a freewheeling diode to dissipate the energy stored in the magnetic filed of the solenoid once the valve opens us, even if in PWM mode.

If Yes cold you please suggest some formula to be used for calculating the resistor value and the diode characteristic for a valve that is driven by 24VDC and has 150mA max current?

Best regards and thanks.

Stefano