timer Q : request callback 2 ms after interrupt to drop RTS on RS485

timer Q : request callback 2 ms after interrupt to drop RTS on RS485

[Philippe De Muyter]

Hello linux timer experts

I need to arm a timer to expire about 1.5 ms after an interrupt.

How can I do that ?

Thanks in advance

Philippe

More context for the interested ones : I need to deactivate the RTS signal
on a serial line, but I get only TxREADY interrupts, not TxEMPTY ones.
Knowing the hardware and baud rate involved I know how much time is needed
to flush the last bytes and bits and I need to drop RTS as soon as the
last bit is sent.
Of course, in the timer callback I'll do a small amount of busy waiting
to be sure TxEMPTY state is reached.

-- 
Philippe De Muyter  phdm at macqel dot be  Tel +32 27029044
Macq Electronique SA  rue de l'Aeronef 2  B-1140 Bruxelles  Fax +32 27029077