On Mon, Mar 8, 2021 at 12:57 AM Dmitry Torokhov
[off-list ref] wrote:

On Mon, Mar 08, 2021 at 12:05:48AM +0200, Andy Shevchenko wrote:

...

quoted

-     return !gpio_get_value(ts->gpio);
+     return !gpiod_get_value(ts->gpiod);

This is not correct. gpio_get_value() is raw polarity vs
gpiod_get_value() using logical active/inactive, and tsc2007 GPIO lines
are active low. The negation must be dropped after switching to GPIOD
API.

Ah, indeed, I missed that, thanks!

...

quoted

-     ts->gpio = of_get_gpio(np, 0);
-     if (gpio_is_valid(ts->gpio))
-             ts->get_pendown_state = tsc2007_get_pendown_state_gpio;
-     else
-             dev_warn(&client->dev,
-                      "GPIO not specified in DT (of_get_gpio returned %d)\n",
-                      ts->gpio);
+     ts->gpiod = devm_gpiod_get_optional(dev, NULL, GPIOD_IN);

GPIO is definitely not optional in DT case, at least in the way the
driver written right now.

Can you elaborate this, please? I don't see from the dev_warn() w/o
any error code returned that it's mandatory.
In the bindings one may read:

  Optional properties:
  - gpios: the interrupt gpio the chip is connected to (trough the penirq pin).
    The penirq pin goes to low when the panel is touched.
    (see GPIO binding[1] for more details).

Nothing suggested it's mandatory. What have I missed?

quoted

+     if (IS_ERR(ts->gpiod))
+             return PTR_ERR(ts->gpiod);

-- 
With Best Regards,
Andy Shevchenko