Messages in this thread | | | Date | Wed, 10 Nov 2021 18:36:54 +0100 | From | Andreas Kemnade <> | Subject | Re: [PATCH v2 2/4] Documentation: DT: bindings: input: Add documentation for cyttsp5 |
| |
On Wed, 10 Nov 2021 22:59:50 +1000 Alistair Francis <alistair23@gmail.com> wrote:
[...] > > > > > + reset-gpios = <&pio 7 1 GPIO_ACTIVE_HIGH>; > > > > hmm, if the reset gpio at the chip is active low (I guess it is) that > > would indicate an inverter between SoC and gpio. So a nonstandard setup > > as an example, probably not a good idea. > > It seems to be common for the cypress,tt2100, as the original > documentation and the rM2 both do this. Does the Kobo not do this? >
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.
Regards, Andreas
| |