DRV110: Rsense, other parts power rating

Part Number:DRV110

So I just need to state I am not an electrical engineer. I have to build a circuit to control a solenoid that requires a 10 kHz PWM signal to drive it open. It is a 12VDC, 3 ohm solenoid coil, requires 2A to drive it open (2A for 0.5-5 seconds) and 1A to hold.

I have calculated Rpeak = 1 MOhm, Rhold = 400k, Rosc = 333k, and Ckeep = 20uF. My Rsense is 30milliohms.

Being that the current is 2A, does Rsense need to be sized to 24W (12volts * 2A)? I've seen other circuits online with a 1A current and use a 1/2W resistor for Rsense. What power rating should I use for Rsense in this case? 

I don't have anything special in the circuit yet like LPF, anything recommendations for good practice that isn't in the datasheet?

Thanks

EDIT:

This circuit is nearly the same except I'm using 12V rather that 24V. http://e2e.ti.com/support/motor-drivers/f/38/p/604730/2227771