[PATCH v3 2/9] Input: goodix - make gpiod_get honor GPIOD_ASIS

Quentin Schulz
2022-12-05T13:41:49Z

From: Quentin Schulz <quentin.schulz@theobroma-systems.com>

For some reason the ACPI GPIO lookup code (acpi_find_gpio followed by
acpi_gpio_update_gpiod_flags) will override the gpiod_flags
passed to gpiod_get() if it can determine a set of flags from the ACPI
GpioIo entry.

For output pins like the reset pin, this requires a pull bias to be set,
which often is not the case, so then the GPIOD_ASIS which we pass in is
used.

But if a pull bias is specified in the ACPI GpioIo entry for the reset
pin then that gets translated to GPIOD_OUT_LOW or GPIOD_OUT_HIGH meaning
we cannot guarantee the same behavior on all boards.

So this may cause unintended side-effects, c.f. commit a2fd46cd3dbb
("Input: goodix - try not to touch the reset-pin on x86/ACPI devices")
for some background.

This is something which we can fix though, we can force the ACPI GPIO
code to honor the GPIOD_ASIS we pass in by passing
ACPI_GPIO_QUIRK_NO_IO_RESTRICTION to the ACPI gpio mapping.

Suggested-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Quentin Schulz <quentin.schulz@theobroma-systems.com>
---
drivers/input/touchscreen/goodix.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/input/touchscreen/goodix.c b/drivers/input/touchscreen/goodix.c
index d73d4272a8ea5..1639f2f8a31e3 100644
--- a/drivers/input/touchscreen/goodix.c
+++ b/drivers/input/touchscreen/goodix.c
@@ -803,6 +803,7 @@ static int goodix_reset(struct goodix_ts_data *ts)
.name = _name, \
.data = _params, \
.size = _size, \
+ .quirks = ACPI_GPIO_QUIRK_NO_IO_RESTRICTION, \
}

static const struct acpi_gpio_params first_gpio = { 0, 0, false };

--
b4 0.10.1