Olimex Support Forum

OLinuXino Android / Linux boards and System On Modules => A20 => Topic started by: tomio64 on October 26, 2015, 11:51:44 AM

Title: oluxino lime2 Gpio irq
Post by: tomio64 on October 26, 2015, 11:51:44 AM
Hello,
1 / I would like the limitation of number of gpio than can "polled" with select or epoll , by irq interrupt,
with edge in both, rising and falling ?

2 / So have you the precise list of gpio than can use interrupt ?
i work in c.

thank you
best regards

Title: Re: oluxino lime2 Gpio irq
Post by: soenke on October 26, 2015, 02:57:47 PM
With direct access to /dev/mem and kernel 3.4 you can reach about 2MHz get/set/reset frequency on one gpio. I have not measured the exact speed drop if you set/reset 2,5,10 gpios at once. My guess is a linear behaviour.
Title: Re: oluxino lime2 Gpio irq
Post by: tomio64 on October 27, 2015, 10:37:53 AM
Hello,
in fact is not my question,
just i would like the list of gpio with interruption.
All gpio don't have interruption.
So wher i can found the list of gpio with interrupt for oluxino lime 2 ?
thank you
Title: Re: oluxino lime2 Gpio irq
Post by: soenke on October 27, 2015, 11:08:50 AM
https://github.com/OLIMEX/OLINUXINO/tree/master/HARDWARE/A20-PDFs

User Manual --> GIC (p.147)
Title: Re: oluxino lime2 Gpio irq
Post by: tomio64 on October 28, 2015, 11:02:38 AM
hello,
thank you,
i read that, but is not clear in list GIC what is gpio port number ?
Title: Re: oluxino lime2 Gpio irq
Post by: soenke on October 28, 2015, 11:05:52 AM
Look into the chapter "port controller", there you see the pin names like PB10. These are the names used by uboot (fex-file) where the mapping pin->gpio is configured.