Determine direction of GPIO pin

[kolban]

I can set a GPIO pin to be input or output using gpio_output_set(). My question is ... is there a way to determine the current input and output direction of a given pin?

For example, if I want to know whether GPIO0 is an input or an output pin ... is that possible?

[tve]

I believe GPIO_PIN_CONFIG_GET in eagle_soc.h is your ticket. The config register can be read as well as written.

[kolban]

Howdy Tve,
Thanks for the response. I looked at GPIO_PIN_CONFIG_GET(x) and it appears to be an expression evaluation. Do you know of any docs on how to use these functions? I have a feeling that the methods I have been using (such as gpio_output_set and gpio_input_get) are high level wrappers and the functions in eagle_soc.h are lower level. If I can learn how these work, I'll write them up for the community.

Neil

[dkinzer]

[...]is there a way to determine the current input and output direction of a given pin?

The "direction" register is at offset 0x0c, given by GPIO_ENABLE_ADDRESS. The value resulting from GPIO_REG_READ(GPIO_ENABLE_ADDRESS) will have 1s in bit positions corresponding to pins that are outputs. This assumes, of course, that the IO MUX is set for the bit to be a GPIO.