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Input: atmel_mxt_ts - fix up inverted RESET handler
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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 <[email protected]>
Reviewed-by: Philippe Schenker <[email protected]>
Acked-by: Krzysztof Kozlowski <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Dmitry Torokhov <[email protected]>
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@linusw @dtor
linusw authored and dtor committed Nov 18, 2020
1 parent 05909cd commit feedaac
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Showing 11 changed files with 14 additions and 12 deletions.
2 changes: 1 addition & 1 deletion arch/arm/boot/dts/imx53-ppd.dts
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Expand Up @@ -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>;
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2 changes: 1 addition & 1 deletion arch/arm/boot/dts/imx6dl-colibri-eval-v3.dts
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Expand Up @@ -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";
};

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2 changes: 1 addition & 1 deletion arch/arm/boot/dts/imx6q-apalis-eval.dts
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Expand Up @@ -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";
};

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2 changes: 1 addition & 1 deletion arch/arm/boot/dts/imx6q-apalis-ixora-v1.1.dts
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Expand Up @@ -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";
};

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2 changes: 1 addition & 1 deletion arch/arm/boot/dts/imx6q-apalis-ixora.dts
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Expand Up @@ -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";
};

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2 changes: 1 addition & 1 deletion arch/arm/boot/dts/imx7-colibri-aster.dtsi
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Expand Up @@ -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 */
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2 changes: 1 addition & 1 deletion arch/arm/boot/dts/imx7-colibri-eval-v3.dtsi
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Expand Up @@ -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";
};

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2 changes: 1 addition & 1 deletion arch/arm/boot/dts/motorola-mapphone-common.dtsi
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Expand Up @@ -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>,
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2 changes: 1 addition & 1 deletion arch/arm/boot/dts/s5pv210-aries.dtsi
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Expand Up @@ -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>;
};
};

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2 changes: 1 addition & 1 deletion arch/arm/boot/dts/tegra20-acer-a500-picasso.dts
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Expand Up @@ -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>;
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6 changes: 4 additions & 2 deletions drivers/input/touchscreen/atmel_mxt_ts.c
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Expand Up @@ -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);
Expand All @@ -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);
}

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