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>

diff --git a/arch/arm/boot/dts/imx53-ppd.dts b/arch/arm/boot/dts/imx53-ppd.dts
index f7dcdf9..8f4a63e 100644 (file)
--- 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 65359ae..7da74e6 100644 (file)
--- 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 fab83ab..a0683b4 100644 (file)
--- 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 1614b1a..86e8478 100644 (file)
--- 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 fa9f98d..62e7277 100644 (file)
--- 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 9fa701b..139188e 100644 (file)
--- 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 9760137..3caf450 100644 (file)
--- 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 1990239..70fc71c 100644 (file)
--- 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 822207f..96e8c22 100644 (file)
--- 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 2d683c9..a150e34 100644 (file)
--- 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 98f17fa..ef79154 100644 (file)
--- 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);
        }