Re: [PATCH v2 2/4] Documentation: DT: bindings: input: Add documentation for cyttsp5

On Wed, Nov 10, 2021 at 6:37 PM Andreas Kemnade [off-list ref] wrote:

Alistair Francis [off-list ref] wrote:

You have a kind of double inversion here, so things are automagically fixed.
IMHO to describe it correctly would be to set GPIO_ACTIVE_LOW here
and in the driver

        /* Reset the gpio to be in a reset state */
        ts->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
        if (IS_ERR(ts->reset_gpio)) {
                rc = PTR_ERR(ts->reset_gpio);
                dev_err(dev, "Failed to request reset gpio, error %d\n", rc);
                return rc;
        }
        gpiod_set_value(ts->reset_gpio, 0);

That is the way how other active-low reset lines are handled.

Correct.

This is a source of confusion, I contemplated just changing the name
of GPIOD_OUT_HIGH to GPIOD_OUT_ASSERTED etc to indicate
what is going on.

gpiod_set_value(ts->reset_gpio, 0) should similarly be interpreted
as "de-assert this line" no matter the polarity.

Yours,
Linus Walleij

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