GPIO and sysfs Post: 303030779

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Top Forums UNIX for Advanced & Expert Users GPIO and sysfs Post 303030779 by Circuits on Friday 15th of February 2019 11:08:29 AM

02-15-2019

Registered User

@Corona688 Thanks I will be sure to change my code! So I did managed to figure out the gpio lib. Apparently there is a formula that the Linux kernel uses for identifying pins based on their GPIO number:

linux gpio number = (gpio_bank - 1) * 32 + gpio_bit

So if you're pin is: GPIO2_18, then in the Linux kernel that would be: (2-1)32+18 = 50

That is the number you would have to reference in order to toggle the pin from within the user space using gpiolib.

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LEARN ABOUT NETBSD

gpiolock

GPIOLOCK(4)						   BSD Kernel Interfaces Manual 					       GPIOLOCK(4)

NAME

     gpiolock -- support for multi-position keylocks attached to GPIO pins

SYNOPSIS

     gpiolock* at gpio? offset ? mask ?
     gpiolock* at gpio?

DESCRIPTION

     The gpiolock driver allows connecting of multi-position keylocks over GPIO pins.  The keylock driver registers with an in-kernel keylock sup-
     porting system and provides kauth(9) support through an experimental security model.  The keylock state can be queried using the hw.keylock
     sysctl variables.	Only locks with 2-4 positions are currently supported.	The pin number is specified in the kernel configuration with the
     offset locator.  The mask locator denotes the pins used for the lock (minimum 2, maximum 4 pins are used).  The offset and mask can also be
     specified when gpiolock is attached at runtime using the GPIOATTACH ioctl(2) on the gpio(4) device.

SEE ALSO

     gpio(4), intro(4)

HISTORY

     The gpiolock driver first appeared in NetBSD 6.0.

AUTHORS

     The gpiolock driver was written by Marc Balmer <marc@msys.ch>.

BSD
								  August 21, 2009							       BSD