On Wed, Oct 18, 2023 at 9:29 PM Dmitry Rokosov <ddrokosov@xxxxxxxxxxxxxxxxx> wrote: > > HWEN is hardware control, which is used for enable/disable aw200xx chip. > It's high active, internally pulled down to GND. > > After HWEN pin set high the chip begins to load the OTP information, > which takes 200us to complete. About 200us wait time is needed for > internal oscillator startup and display SRAM initialization. After > display SRAM initialization, the registers in page 1 to page 5 can be > configured via i2c interface. Is there any Documentation update for this new binding? ... > + chip->hwen = devm_gpiod_get_optional(&client->dev, "hwen", GPIOD_OUT_HIGH); With _optional APIs we distinguish 3 cases: found, not found, error. And error can be (among others) the deferred probe, meaning that GPIO _is coming_. Hence the rule of thumb for the _optional() APIs is to check for error and bail out on that condition (note, it's applicable to any _optional() APIs, not limited by GPIO library). ... > aw200xx_chip_reset(chip); > + aw200xx_disable(chip); It seems it can be modeled as a (GPIO) regulator. At least many drivers do so, but I leave this to the maintainers to decide. -- With Best Regards, Andy Shevchenko
