I got I2C working. Now, onto GPIO.

I'll need 4-5 GPIOs. Lokking at the pinout, the best candidates are those UART1 pins (25-32). What I've gathered from this forum is that only GPIO5 has been successfully working, and you have to use mmio to get it into GPIO mode.

My questions are:

1. Has anyone been able to get any other GPIO to work?
2. Is there a list of addresses (for use with mmio) for all of the available GPIOs?

And I can confirm GPIO works just fine: I've been using some from the kernel as an one-wire interface and a GPIO-based SPI port, plus some from software, both as outputs and inputs. Never had problems with it.

Which GPIO pins were you using?

I think I mostly used the ones that are shared with serial port 0.

Actually, it depends. From the kernel code and datasheet, GPIO 7-14 are shared between PCM, I2S, and UART0.
They are reserved when you your kernel is compiled with PCM, I2S, etc. If you look at the file /sys/kernel/debug/gpio, you can see if they're claimed or not. Straight from the default kernel, setting gpioctl on some of these will result in error.

Any way, I've found a way to patch the kernel to claim them for my system. It's better for us this way.

Hi All

Not sure if this has been done but, i am looking for a gpio to include a "Rotary Encoder".
Did the "Google" thing and found a few but i do not see them as been available in the "Software" section.

I am new to Linux and have never compiled a package...but.
If someone has a "Virtual Box" file and give me some pointers, i am willing to try.

Z69

This is an old topic, but just in case someone else needs GPIO, I've written a little library that tries to resemble the arduino API for pin handling. It uses the GPIO registers on the RT3052 so it's pretty fast.

It's available here:

Cheers!