Hi All, I am pondering the best approach to adding PPS over CTS lines of serial ports. We are considering using a platform where the UARTs do not have DCD lines and so we cannot use the usual PPS serial line discipline which has a DCD change handler. The serial ports do, however, have CTS lines with interrupt capability. I'm wondering if setting up the serial port to no flow control and routing the PPS over CTS line might work. We could configure the serial port for no flow control and extend the serial line discipline framework to allow CTS change handlers. This could be accomplished by adding another function pointer to struct tty_ldisc and handing off to it at the bottom of uart_handle_cts_change like uart_handle_dcd_change does to the dcd_change pointer of the current struct tty_ldisc. Future patches would probably involve adding #ifdef CONFIG_HARD_PPS to the uart_handle_cts_change function but I think a PPS line-discipline only would be fine for the time-being. Best Regards, Ben Gardiner --- Nanometrics Inc. http://www.nanometrics.ca -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
