Re: [PATCH v2 2/2] serial: sc16is7xx: hard reset the chip if reset-gpios is defined in dt

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On 05/06/2024 13:19, Maarten Brock wrote:
>>> To make this a proper reset pulse for the device you must first assert the reset,
>>> then wait >3us, and finally deassert the reset.
>>>
>>> Maarten Brock
>> Hi Maarten,
>>
>> My understanding is when calling devm_gpiod_get_optional(dev, "reset",
>> GPIOD_OUT_LOW) and returning a valid (gpio_desc *), the flag
>> GPIOD_OUT_LOW guarantees the GPIO is set to output and low (assert the
>> reset pin).
> 
> Ah, right. Sorry, I missed that.
> So GPIOD_OUT_LOW disregards the inversion from GPIO_ACTIVE_LOW.

It doesn't.

> And gpiod_set_value_cansleep(reset_gpiod, 0) uses the inversion to make the pin high.
> Looks fine to me now.

They both respect pin polarity.

Best regards,
Krzysztof





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