On Mon, Nov 11, 2024 at 10:45:13AM +0100, Geert Uytterhoeven wrote: > On Mon, Nov 4, 2024 at 10:37 AM Andy Shevchenko > <andriy.shevchenko@xxxxxxxxxxxxxxx> wrote: ... > > - if (template->active_low) > > - flags |= GPIOF_ACTIVE_LOW; > > - > > - ret = devm_gpio_request_one(dev, template->gpio, flags, > > + ret = devm_gpio_request_one(dev, template->gpio, GPIOF_OUT_INIT_LOW, > > template->name); > > Just wondering, as I am not 100% sure: can this change change the > initial state of the GPIO? You probably wonder how ACTIVE_LOW affects the OUT_INIT_LOW given above. I have an answer to you, however I might be mistaken as well, but I spent some time to investigate. The above mentioned call ends up in the gpiod_direction_output_raw_commit() which uses the value (low in this case) as an absolute value. It does not include the ACTIVE_LOW in the value calculations. Hence, setting ACTIVE_LOW before or afterwards has no effect on the existing flow. If you notice a mistake, please elaborate this, so I can fix the approach! > > if (ret < 0) > > return ERR_PTR(ret); ... > > + if (template->active_low ^ gpiod_is_active_low(gpiod)) > > + gpiod_toggle_active_low(gpiod); > > + -- With Best Regards, Andy Shevchenko
