Re: [PATCH V6 01/15] ARM: dts: imx6q-dhcom: Add the parallel system bus

Marek Vasut
2021-07-18T16:24:39Z

On 7/18/21 5:31 PM, Fabio Estevam wrote:
> Hi Christoph,
>
> On 14/07/2021 18:06, Christoph Niedermaier wrote:
>
>> +    /* OE pin of the latch is low active */
>> +    reg_latch_oe_on: regulator-latch-oe-on {
>> +        compatible = "regulator-fixed";
>> +        gpio = <&gpio3 22 0>;
>
> I understand that the GPIO polarity is ignored, but it would be better to
> just describe the real polarity in the devicetree:
>
> gpio = <&gpio3 22 GPIO_ACTIVE_LOW>;

The 0 is correct as the field is ignored, please keep it.

Any other variants (like GPIO_ACTIVE_LOW = 1) interact badly with
drivers/gpio/gpiolib-of.c of_gpio_flags_quirks()
which is already a total compatibility attempt mess and lead to odd
misbehavior of the regulator where the polarity of the GPIO is randomly
interpreted as low or high dependent on the kernel version.