[PATCH] ARM: dts: imx: Fix USB host power regulator polarity on M53Menlo

[Marek Vasut]

On 9/5/21 2:00 PM, Fabio Estevam wrote:
> Hi Marek,

Hi,

> On Sat, Sep 4, 2021 at 11:57 PM Marek Vasut <marex at denx.de> wrote:
> 
>> No, the GPIO flags are ignored by gpiolib-of and the signal is active
>> low. That's why there is that zero, no flags, and no enable-active-high
>> property.
> 
> Yes, correct. The GPIO flag is ignored by "regulator-fixed".
> 
> As you removed the 'enable-active-high' property, you turned the
> regulator to active low as needed.
> 
> This is correct.
> 
> gpio = <&gpio1 2 0> is the same as gpio = <&gpio1 2 GPIO_ACTIVE_HIGH>
> 
> I just suggested gpio = <&gpio1 2 GPIO_ACTIVE_LOW> to make it clearer
> what is the real polarity.
> 
> The GPIO flag is ignored, I know. No issues if you want to keep it as
> gpio = <&gpio1 2 0>.

We had the same discussion before around this patch :)
[PATCH V6 01/15] ARM: dts: imx6q-dhcom: Add the parallel system bus
Message-ID: <f33eaeef754377f35b1bfa4fe62def97 at denx.de>

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.