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 f7dcdf96e5c00918fea0ec54149f28977d83c9c1..8f4a63ea912e8865c2641494a438b51688993d5e 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 65359aece950dbe3f25ee82f2b0ac596780b344a..7da74e6f46d9b57eca6a20c8445a88efdf80976f 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 fab83abb64660eef35b0a56dfaf1f9111c56f3a6..a0683b4aeca159d8d6b790b667ab21a914fe20bc 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 1614b1ae501d90a979fc9420c694aa7fc28d1229..86e84781cf5d85f5853565b6ac20e619ca0b755a 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 fa9f98dd15ac65a483af32363501c8d8880b3120..62e72773e53b39721bbcc37c67b78813c5a2b933 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 9fa701bec2eca11a27545af3f427346cbc16a1af..139188eb9f409c76306c7b8e690b21668ea1de05 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 97601375f26407293c6f496943ce9ee8fba0647b..3caf450735d7ecd02b081bdebf28990ae502eb03 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 1990239cc6af6cf281ef7e64c174a1094783eab7..70fc71cbb9457aa525ce898586a8fc6655776af4 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 822207f63ee0a994f1cf168baa9820381f0e2291..96e8c2287d6197089d8409a1b30c67e8416df815 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 2d683c9a1a5d65a7d3a1ee2a1f89d0d6a2fc26b2..a150e3419c8f55dfa62275876d95817a4493a378 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 98f17fa3a8926e2e02d7e9c0bba3090291905cec..ef7915400c9f57e735b7c369671e5ba20fe6fce1 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);
        }