On 08/09/2017 21:53, Tim Harvey wrote:
PPS signals with very short pulse-widths can be missed if their state
changes by the time the interrupt handler reads the GPIO pin state.
To avoid this in the case where we are only looking for one edge we can
use the edge configuration for the pin state but fall back to reading the
pin if both edges are being watched.
I disagree. The "rising_edge" status should be get from the hardware and not
derived by an empirical computation. Or, at least, it should be specifically
activated by setting something like this:
pps {
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_pps>;
gpios = <&gpio1 26 GPIO_ACTIVE_HIGH>;
Yes-I-want-get-signal-status-in-an-epirical-way;
compatible = "pps-gpio";
status = "okay";
};
This setting should also print a warning in order to be clear for the user that
he/she should know what he/she is doing.
Then the code should check also the compatibility with property
"assert-falling-edge"...
Ciao,
Rodolfo
--
HCE Engineering e-mail: giome...@hce-engineering.it
GNU/Linux Solutions giome...@enneenne.com
Linux Device Driver giome...@linux.it
Embedded Systems phone: +39 349 2432127
UNIX programming skype: rodolfo.giometti
Cosino Project - the quick prototyping embedded system - www.cosino.it
Freelance ICT Italia - Consulente ICT Italia - www.consulenti-ict.it
