Add a function to get a pin number from mraa_gpio_context

[yoneken]

I add a function named mraa_gpio_get_pin .
This function is useful to restore a physical pin number in callback function.

For example,

void interrupt_in(void *arg)
{
  mraa_gpio_context dev = (mraa_gpio_context)arg;
  printf("Pushed %d", mraa_gpio_get_pin(dev));
}

int main(int argc, char *argv[])
{
  mraa_gpio_context in0 = mraa_gpio_init(14);
  mraa_gpio_dir(in0, MRAA_GPIO_IN);
  mraa_gpio_mode(in0, MRAA_GPIO_PULLUP);
  mraa_gpio_isr(in, MRAA_GPIO_EDGE_FALLING, interrupt_in, (void *)in0);

  mraa_gpio_context in1 = mraa_gpio_init(15);
  mraa_gpio_dir(in1, MRAA_GPIO_IN);
  mraa_gpio_mode(in1, MRAA_GPIO_PULLUP);
  mraa_gpio_isr(in, MRAA_GPIO_EDGE_FALLING, interrupt_in, (void *)in1);

  sleep(30);

  return 0;
}

Signed-off-by: Kenta Yonekura yoneken@ieee.org

[arfoll]

Thanks a lot or this just one change before I can merge, the return type should be int not mraa_result_t. Thanks

[tingleby]

Also having a sign-off in the the commit would be nice.

[arfoll]

@tingleby oh didn't realise the sign off came with the PR msg! Yes, please run git commit --amend --signoff

[yoneken]

@arfoll @tingleby Thanks a lot for your gentle suggestion. I changed the return type and made a sign-off.

[arfoll]

Thank you very much for contributing! Merged with 74d172c.