Dock resistors (Dock, Car, Headset) topic

I was searching for the correct resistor value to enable the advanced function on my generic compatible dock.
Looked at the kernel and found on drivers/misc/cable_detect_8xxx.c the function cable_detect_get_type
...
if (adc > 150 && adc < 220)
type = DOCK_STATE_CAR;
else if (adc > 370 && adc < 440)
type = DOCK_STATE_USB_HEADSET;
else if (adc > 440 && adc < 550)
type = DOCK_STATE_DMB;
else if (adc > 550 && adc < 900)
type = DOCK_STATE_DESK;
else
type = DOCK_STATE_UNDEFINED;
...
Need help to find how to convert these values to resistor values.
Thank you