Input: atmel_mxt_ts - fix up inverted RESET handler

This driver uses GPIO descriptors to drive the touchscreen RESET line. In
the existing device trees this has in conflict with intution been flagged
as GPIO_ACTIVE_HIGH and the driver then applies the reverse action by
driving the line low (setting to 0) to enter reset state and driving the
line high (setting to 1) to get out of reset state.

The correct way to handle active low GPIO lines is to provide the
GPIO_ACTIVE_LOW in the device tree (thus properly describing the hardware)
and letting the GPIO framework invert the assertion (driving high) to a
low level and vice versa.

This is considered a bug since the device trees are incorrectly
mis-specifying the line as active high.

Fix the driver and all device trees specifying a reset line.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Philippe Schenker <philippe.schenker@toradex.com>
Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
Link: https://lore.kernel.org/r/20201104153032.1387747-1-linus.walleij@linaro.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

11 files changed, 14 insertions, 12 deletions

diff --git a/arch/arm/boot/dts/imx53-ppd.dts b/arch/arm/boot/dts/imx53-ppd.dts
index f7dcdf96e5c0..8f4a63ea912e 100644
--- a/arch/arm/boot/dts/imx53-ppd.dts
+++ b/arch/arm/boot/dts/imx53-ppd.dts
@@ -589,7 +589,7 @@
 
 	touchscreen@4b {
 		compatible = "atmel,maxtouch";
-		reset-gpio = <&gpio5 19 GPIO_ACTIVE_HIGH>;
+		reset-gpio = <&gpio5 19 GPIO_ACTIVE_LOW>;
 		reg = <0x4b>;
 		interrupt-parent = <&gpio5>;
 		interrupts = <4 IRQ_TYPE_LEVEL_LOW>;
diff --git a/arch/arm/boot/dts/imx6dl-colibri-eval-v3.dts b/arch/arm/boot/dts/imx6dl-colibri-eval-v3.dts
index 65359aece950..7da74e6f46d9 100644
--- a/arch/arm/boot/dts/imx6dl-colibri-eval-v3.dts
+++ b/arch/arm/boot/dts/imx6dl-colibri-eval-v3.dts
@@ -143,7 +143,7 @@
 		reg = <0x4a>;
 		interrupt-parent = <&gpio1>;
 		interrupts = <9 IRQ_TYPE_EDGE_FALLING>;		/* SODIMM 28 */
-		reset-gpios = <&gpio2 10 GPIO_ACTIVE_HIGH>;	/* SODIMM 30 */
+		reset-gpios = <&gpio2 10 GPIO_ACTIVE_LOW>;	/* SODIMM 30 */
 		status = "disabled";
 	};
 
diff --git a/arch/arm/boot/dts/imx6q-apalis-eval.dts b/arch/arm/boot/dts/imx6q-apalis-eval.dts
index fab83abb6466..a0683b4aeca1 100644
--- a/arch/arm/boot/dts/imx6q-apalis-eval.dts
+++ b/arch/arm/boot/dts/imx6q-apalis-eval.dts
@@ -140,7 +140,7 @@
 		reg = <0x4a>;
 		interrupt-parent = <&gpio6>;
 		interrupts = <10 IRQ_TYPE_EDGE_FALLING>;
-		reset-gpios = <&gpio6 9 GPIO_ACTIVE_HIGH>; /* SODIMM 13 */
+		reset-gpios = <&gpio6 9 GPIO_ACTIVE_LOW>; /* SODIMM 13 */
 		status = "disabled";
 	};
 
diff --git a/arch/arm/boot/dts/imx6q-apalis-ixora-v1.1.dts b/arch/arm/boot/dts/imx6q-apalis-ixora-v1.1.dts
index 1614b1ae501d..86e84781cf5d 100644
--- a/arch/arm/boot/dts/imx6q-apalis-ixora-v1.1.dts
+++ b/arch/arm/boot/dts/imx6q-apalis-ixora-v1.1.dts
@@ -145,7 +145,7 @@
 		reg = <0x4a>;
 		interrupt-parent = <&gpio6>;
 		interrupts = <10 IRQ_TYPE_EDGE_FALLING>;
-		reset-gpios = <&gpio6 9 GPIO_ACTIVE_HIGH>; /* SODIMM 13 */
+		reset-gpios = <&gpio6 9 GPIO_ACTIVE_LOW>; /* SODIMM 13 */
 		status = "disabled";
 	};
 
diff --git a/arch/arm/boot/dts/imx6q-apalis-ixora.dts b/arch/arm/boot/dts/imx6q-apalis-ixora.dts
index fa9f98dd15ac..62e72773e53b 100644
--- a/arch/arm/boot/dts/imx6q-apalis-ixora.dts
+++ b/arch/arm/boot/dts/imx6q-apalis-ixora.dts
@@ -144,7 +144,7 @@
 		reg = <0x4a>;
 		interrupt-parent = <&gpio6>;
 		interrupts = <10 IRQ_TYPE_EDGE_FALLING>;
-		reset-gpios = <&gpio6 9 GPIO_ACTIVE_HIGH>; /* SODIMM 13 */
+		reset-gpios = <&gpio6 9 GPIO_ACTIVE_LOW>; /* SODIMM 13 */
 		status = "disabled";
 	};
 
diff --git a/arch/arm/boot/dts/imx7-colibri-aster.dtsi b/arch/arm/boot/dts/imx7-colibri-aster.dtsi
index 9fa701bec2ec..139188eb9f40 100644
--- a/arch/arm/boot/dts/imx7-colibri-aster.dtsi
+++ b/arch/arm/boot/dts/imx7-colibri-aster.dtsi
@@ -99,7 +99,7 @@
 		reg = <0x4a>;
 		interrupt-parent = <&gpio2>;
 		interrupts = <15 IRQ_TYPE_EDGE_FALLING>;	/* SODIMM 107 */
-		reset-gpios = <&gpio2 28 GPIO_ACTIVE_HIGH>;	/* SODIMM 106 */
+		reset-gpios = <&gpio2 28 GPIO_ACTIVE_LOW>;	/* SODIMM 106 */
 	};
 
 	/* M41T0M6 real time clock on carrier board */
diff --git a/arch/arm/boot/dts/imx7-colibri-eval-v3.dtsi b/arch/arm/boot/dts/imx7-colibri-eval-v3.dtsi
index 97601375f264..3caf450735d7 100644
--- a/arch/arm/boot/dts/imx7-colibri-eval-v3.dtsi
+++ b/arch/arm/boot/dts/imx7-colibri-eval-v3.dtsi
@@ -124,7 +124,7 @@
 		reg = <0x4a>;
 		interrupt-parent = <&gpio1>;
 		interrupts = <9 IRQ_TYPE_EDGE_FALLING>;		/* SODIMM 28 */
-		reset-gpios = <&gpio1 10 GPIO_ACTIVE_HIGH>;	/* SODIMM 30 */
+		reset-gpios = <&gpio1 10 GPIO_ACTIVE_LOW>;	/* SODIMM 30 */
 		status = "disabled";
 	};
 
diff --git a/arch/arm/boot/dts/motorola-mapphone-common.dtsi b/arch/arm/boot/dts/motorola-mapphone-common.dtsi
index 1990239cc6af..70fc71cbb945 100644
--- a/arch/arm/boot/dts/motorola-mapphone-common.dtsi
+++ b/arch/arm/boot/dts/motorola-mapphone-common.dtsi
@@ -428,7 +428,7 @@
 		pinctrl-names = "default";
 		pinctrl-0 = <&touchscreen_pins>;
 
-		reset-gpios = <&gpio6 13 GPIO_ACTIVE_HIGH>; /* gpio173 */
+		reset-gpios = <&gpio6 13 GPIO_ACTIVE_LOW>; /* gpio173 */
 
 		/* gpio_183 with sys_nirq2 pad as wakeup */
 		interrupts-extended = <&gpio6 23 IRQ_TYPE_LEVEL_LOW>,
diff --git a/arch/arm/boot/dts/s5pv210-aries.dtsi b/arch/arm/boot/dts/s5pv210-aries.dtsi
index 822207f63ee0..96e8c2287d61 100644
--- a/arch/arm/boot/dts/s5pv210-aries.dtsi
+++ b/arch/arm/boot/dts/s5pv210-aries.dtsi
@@ -620,7 +620,7 @@
 		interrupts = <5 IRQ_TYPE_EDGE_FALLING>;
 		pinctrl-names = "default";
 		pinctrl-0 = <&ts_irq>;
-		reset-gpios = <&gpj1 3 GPIO_ACTIVE_HIGH>;
+		reset-gpios = <&gpj1 3 GPIO_ACTIVE_LOW>;
 	};
 };
 
diff --git a/arch/arm/boot/dts/tegra20-acer-a500-picasso.dts b/arch/arm/boot/dts/tegra20-acer-a500-picasso.dts
index 2d683c9a1a5d..a150e3419c8f 100644
--- a/arch/arm/boot/dts/tegra20-acer-a500-picasso.dts
+++ b/arch/arm/boot/dts/tegra20-acer-a500-picasso.dts
@@ -436,7 +436,7 @@
 			interrupt-parent = <&gpio>;
 			interrupts = <TEGRA_GPIO(V, 6) IRQ_TYPE_LEVEL_LOW>;
 
-			reset-gpios = <&gpio TEGRA_GPIO(Q, 7) GPIO_ACTIVE_HIGH>;
+			reset-gpios = <&gpio TEGRA_GPIO(Q, 7) GPIO_ACTIVE_LOW>;
 
 			avdd-supply = <&vdd_3v3_sys>;
 			vdd-supply  = <&vdd_3v3_sys>;
diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
index 98f17fa3a892..ef7915400c9f 100644
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c
@@ -3134,8 +3134,9 @@ static int mxt_probe(struct i2c_client *client, const struct i2c_device_id *id)
 	if (error)
 		return error;
 
+	/* Request the RESET line as asserted so we go into reset */
 	data->reset_gpio = devm_gpiod_get_optional(&client->dev,
-						   "reset", GPIOD_OUT_LOW);
+						   "reset", GPIOD_OUT_HIGH);
 	if (IS_ERR(data->reset_gpio)) {
 		error = PTR_ERR(data->reset_gpio);
 		dev_err(&client->dev, "Failed to get reset gpio: %d\n", error);
@@ -3153,8 +3154,9 @@ static int mxt_probe(struct i2c_client *client, const struct i2c_device_id *id)
 	disable_irq(client->irq);
 
 	if (data->reset_gpio) {
+		/* Wait a while and then de-assert the RESET GPIO line */
 		msleep(MXT_RESET_GPIO_TIME);
-		gpiod_set_value(data->reset_gpio, 1);
+		gpiod_set_value(data->reset_gpio, 0);
 		msleep(MXT_RESET_INVALID_CHG);
 	}