GPIO in the kernel: an introduction

Posted Jul 20, 2016 7:52 UTC (Wed) by codename_y (guest, #109837)
Parent article: GPIO in the kernel: an introduction

Hi, I have tried to make a driver that utilize linux/gpio.h, but when I try to insmod it, I keep getting this error:

[ 3030.112044] gpiotest: Unknown symbol gpio_direction_output (err 0)
[ 3030.118537] gpiotest: Unknown symbol gpio_request (err 0)

Could you give me some insight about why this happened? I have tried to find by myself but no luck so far.

Thanks for your help

Posted Jul 20, 2016 8:05 UTC (Wed) by mjg59 (subscriber, #23239) [Link]

They're EXPORT_SYMBOL_GPL - make sure that your MODULE_LICENSE tag is GPL compatible.