| Message ID | 20201104153032.1387747-1-linus.walleij@linaro.org |
|---|---|
| State | Accepted |
| Commit | feedaacdadfc332e1a6e436f3adfbc67e244db47 |
| Headers | show |
| Series | [1/3,v2] Input: atmel_mxt_ts - Fix up inverted RESET handler | expand |
On Wed, Nov 04, 2020 at 04:30:30PM +0100, Linus Walleij wrote: > 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. > > Cc: Krzysztof Kozlowski <krzk@kernel.org> > Cc: linux-arm-kernel@lists.infradead.org > Cc: linux-tegra@vger.kernel.org > Cc: linux-samsung-soc@vger.kernel.org > Cc: NXP Linux Team <linux-imx@nxp.com> > Cc: Pengutronix Kernel Team <kernel@pengutronix.de> > Signed-off-by: Linus Walleij <linus.walleij@linaro.org> > --- > ChangeLog v1->v2: > - New patch fixing this confusion before adding the > new YAML bindings. > - CC some misc maintainers and mailing lists that should > be aware that we do this change. Acked-by: Krzysztof Kozlowski <krzk@kernel.org> Best regards, Krzysztof
On Wed, 04 Nov 2020 16:30:31 +0100, Linus Walleij wrote: > This converts the Armel MXT touchscreen bindings to YAML > format and extends them with the following two properties: > > - vdda-supply: the optional analog supply voltage > - vdd-supply: the optional digital supply voltage > > I also explained about the reset-gpios property that this > better be flagged as active high (0) despite actually > being active low, because all current device trees and > drivers assume that this is the case and will actively > drive the line low to assert RESET. > > Tested the schema with all in-tree users and they verify > fine. > > Cc: Nick Dyer <nick@shmanahar.org> > Cc: Stephan Gerhold <stephan@gerhold.net> > Cc: devicetree@vger.kernel.org > Signed-off-by: Linus Walleij <linus.walleij@linaro.org> > --- > ChangeLog v1->v2: > - State that the GPIO lines shall be flagged as active low. > We will fix all users. > --- > .../bindings/input/atmel,maxtouch.txt | 41 ---------- > .../bindings/input/atmel,maxtouch.yaml | 81 +++++++++++++++++++ > MAINTAINERS | 2 +- > 3 files changed, 82 insertions(+), 42 deletions(-) > delete mode 100644 Documentation/devicetree/bindings/input/atmel,maxtouch.txt > create mode 100644 Documentation/devicetree/bindings/input/atmel,maxtouch.yaml > Reviewed-by: Rob Herring <robh@kernel.org>
On Wed, Nov 04, 2020 at 04:30:30PM +0100, Linus Walleij wrote: > 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. > > Cc: Krzysztof Kozlowski <krzk@kernel.org> > Cc: linux-arm-kernel@lists.infradead.org > Cc: linux-tegra@vger.kernel.org > Cc: linux-samsung-soc@vger.kernel.org > Cc: NXP Linux Team <linux-imx@nxp.com> > Cc: Pengutronix Kernel Team <kernel@pengutronix.de> > Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Applied, thank you. -- Dmitry
On Wed, Nov 04, 2020 at 04:30:31PM +0100, Linus Walleij wrote: > This converts the Armel MXT touchscreen bindings to YAML > format and extends them with the following two properties: > > - vdda-supply: the optional analog supply voltage > - vdd-supply: the optional digital supply voltage > > I also explained about the reset-gpios property that this > better be flagged as active high (0) despite actually > being active low, because all current device trees and > drivers assume that this is the case and will actively > drive the line low to assert RESET. > > Tested the schema with all in-tree users and they verify > fine. > > Cc: Nick Dyer <nick@shmanahar.org> > Cc: Stephan Gerhold <stephan@gerhold.net> > Cc: devicetree@vger.kernel.org > Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Applied, thank you. -- Dmitry
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 @@ &i2c2 { 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 @@ touchscreen@4a { 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 @@ touchscreen@4a { 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 @@ touchscreen@4a { 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 @@ touchscreen@4a { 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 @@ touchscreen@4a { 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 @@ touchscreen@4a { 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 d5ded4f794df..5f8f77cfbe59 100644 --- a/arch/arm/boot/dts/motorola-mapphone-common.dtsi +++ b/arch/arm/boot/dts/motorola-mapphone-common.dtsi @@ -430,7 +430,7 @@ touchscreen@4a { 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 bd4450dbdcb6..4da33d0f2748 100644 --- a/arch/arm/boot/dts/s5pv210-aries.dtsi +++ b/arch/arm/boot/dts/s5pv210-aries.dtsi @@ -632,7 +632,7 @@ touchscreen@4a { 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 a0b829738e8f..10794a870776 100644 --- a/arch/arm/boot/dts/tegra20-acer-a500-picasso.dts +++ b/arch/arm/boot/dts/tegra20-acer-a500-picasso.dts @@ -446,7 +446,7 @@ touchscreen@4c { 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); }
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. Cc: Krzysztof Kozlowski <krzk@kernel.org> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-tegra@vger.kernel.org Cc: linux-samsung-soc@vger.kernel.org Cc: NXP Linux Team <linux-imx@nxp.com> Cc: Pengutronix Kernel Team <kernel@pengutronix.de> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> --- ChangeLog v1->v2: - New patch fixing this confusion before adding the new YAML bindings. - CC some misc maintainers and mailing lists that should be aware that we do this change. --- arch/arm/boot/dts/imx53-ppd.dts | 2 +- arch/arm/boot/dts/imx6dl-colibri-eval-v3.dts | 2 +- arch/arm/boot/dts/imx6q-apalis-eval.dts | 2 +- arch/arm/boot/dts/imx6q-apalis-ixora-v1.1.dts | 2 +- arch/arm/boot/dts/imx6q-apalis-ixora.dts | 2 +- arch/arm/boot/dts/imx7-colibri-aster.dtsi | 2 +- arch/arm/boot/dts/imx7-colibri-eval-v3.dtsi | 2 +- arch/arm/boot/dts/motorola-mapphone-common.dtsi | 2 +- arch/arm/boot/dts/s5pv210-aries.dtsi | 2 +- arch/arm/boot/dts/tegra20-acer-a500-picasso.dts | 2 +- drivers/input/touchscreen/atmel_mxt_ts.c | 6 ++++-- 11 files changed, 14 insertions(+), 12 deletions(-)