linux-kernel - [PATCH v3 2/9] Input: goodix - make gpiod_get honor GPIOD

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Message-Id: <20221103-upstream-goodix-reset-v3-2-0975809eb183@theobroma-systems.com>
Date:   Mon,  5 Dec 2022 14:40:31 +0100
From:   Quentin Schulz <foss+kernel@...il.net>
To:     Samuel Holland <samuel@...lland.org>,
        Bastien Nocera <hadess@...ess.net>,
        Guido Günther <agx@...xcpu.org>,
        Sascha Hauer <s.hauer@...gutronix.de>,
        Pengutronix Kernel Team <kernel@...gutronix.de>,
        Angus Ainslie <angus@...ea.ca>,
        Ondrej Jirman <megous@...ous.com>,
        Icenowy Zheng <icenowy@...c.io>,
        Andy Gross <agross@...nel.org>,
        Aleksei Mamlin <mamlinav@...il.com>,
        Fabio Estevam <festevam@...il.com>,
        David Jander <david@...tonic.nl>,
        Frieder Schrempf <frieder.schrempf@...tron.de>,
        Bjorn Andersson <andersson@...nel.org>,
        Konrad Dybcio <konrad.dybcio@...ainline.org>,
        Peter Geis <pgwipeout@...il.com>,
        Heiko Stuebner <heiko@...ech.de>,
        Shawn Guo <shawnguo@...nel.org>,
        Jernej Skrabec <jernej.skrabec@...il.com>,
        Lukasz Majewski <lukma@...x.de>,
        AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@...ainline.org>,
        Chen-Yu Tsai <wens@...e.org>,
        Michael Riesch <michael.riesch@...fvision.net>,
        Rob Herring <robh+dt@...nel.org>,
        NXP Linux Team <linux-imx@....com>,
        Dmitry Torokhov <dmitry.torokhov@...il.com>,
        Hans de Goede <hdegoede@...hat.com>,
        Jagan Teki <jagan@...rulasolutions.com>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>
Cc:     Quentin Schulz <quentin.schulz@...obroma-systems.com>,
        linux-input@...r.kernel.org, linux-arm-msm@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        linux-sunxi@...ts.linux.dev, devicetree@...r.kernel.org,
        linux-rockchip@...ts.infradead.org
Subject: [PATCH v3 2/9] Input: goodix - make gpiod_get honor GPIOD_ASIS

From: Quentin Schulz <quentin.schulz@...obroma-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@...hat.com>
Signed-off-by: Quentin Schulz <quentin.schulz@...obroma-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