[PATCH input-next 0/4] Add polling mode to the MPR121 touchkey

[PATCH input-next 0/4] Add polling mode to the MPR121 touchkey

[Michal Vokáč]

This series is another attempt to use the MPR121 touch sensor
controller in polling mode. This version uses the brand new
input-poller API that is currently queued in input/next.

Michal Vokáč (4):
  dt-bindings: input: Convert mpr121 binding to json-schema
  dt-bindings: input: mpr121: Add poll-interval property
  Input: mpr121: Add polling mode
  ARM: dts: imx6dl-yapp4: Enable the MPR121 touchkey controller on Hydra

 .../bindings/input/fsl,mpr121-touchkey.yaml        | 82 ++++++++++++++++++++++
 .../devicetree/bindings/input/mpr121-touchkey.txt  | 30 --------
 arch/arm/boot/dts/imx6dl-yapp4-common.dtsi         | 13 ++++
 arch/arm/boot/dts/imx6dl-yapp4-hydra.dts           |  4 ++
 drivers/input/keyboard/mpr121_touchkey.c           | 68 +++++++++++++-----
 5 files changed, 149 insertions(+), 48 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/input/fsl,mpr121-touchkey.yaml
 delete mode 100644 Documentation/devicetree/bindings/input/mpr121-touchkey.txt

-- 
2.1.4

[PATCH input-next 1/4] dt-bindings: input: Convert mpr121 binding to json-schema

[Michal Vokáč]

Convert the mpr121 binding to DT schema format using json-schema.

Signed-off-by: Michal Vokáč <michal.vokac@ysoft.com>
---
Hi Rob,

I will appreciate your help converting this binding. Currently
the scheme is not valid and the error output of dt_binding_check
is not really helpful.

Also, who shoud be the maintainer of this binding?
I put Dmitry in there as he is the input subsystem maintainer but
I am not sure it is correct.

Thank you,
Michal

 .../bindings/input/fsl,mpr121-touchkey.yaml        | 64 ++++++++++++++++++++++
 .../devicetree/bindings/input/mpr121-touchkey.txt  | 30 ----------
 2 files changed, 64 insertions(+), 30 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/input/fsl,mpr121-touchkey.yaml
 delete mode 100644 Documentation/devicetree/bindings/input/mpr121-touchkey.txt

diff --git a/Documentation/devicetree/bindings/input/fsl,mpr121-touchkey.yaml b/Documentation/devicetree/bindings/input/fsl,mpr121-touchkey.yaml
new file mode 100644
index 000000000000..c463c1c81755
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/fsl,mpr121-touchkey.yaml
@@ -0,0 +1,64 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/input/fsl,mpr121-touchkey.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Freescale MPR121 capacitive touch sensor controller
+
+maintainers:
+  - Dmitry Torokhov <dmitry.torokhov@gmail.com>
+
+description: |
+  The MPR121 supports up to 12 completely independent electrodes/capacitance
+  sensing inputs in which 8 are multifunctional for LED driving and GPIO.
+  https://www.nxp.com/docs/en/data-sheet/MPR121.pdf
+
+properties:
+  compatible:
+    const: fsl,mpr121-touchkey
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  vdd-supply:
+    maxItems: 1
+
+  linux,keycodes:
+    description:
+      Specifies an array of numeric keycode values to be used for reporting
+      button presses. The array can contain up to 12 entries.
+    minItems: 1
+    maxItems: 12
+
+  wakeup-source: Use any event on keypad as wakeup event.
+    type: boolean
+
+  autorepeat:
+    description: Enable autorepeat when key is pressed and held down.
+    type: boolean
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - vdd-supply
+  - linux,keycodes
+
+examples:
+  - |
+    #include "dt-bindings/input/input.h"
+    touchkey: mpr121@5a {
+        compatible = "fsl,mpr121-touchkey";
+        reg = <0x5a>;
+        interrupt-parent = <&gpio1>;
+        interrupts = <28 2>;
+        autorepeat;
+        vdd-supply = <&ldo4_reg>;
+        linux,keycodes = <KEY_0>, <KEY_1>, <KEY_2>, <KEY_3>,
+                         <KEY_4> <KEY_5>, <KEY_6>, <KEY_7>,
+                         <KEY_8>, <KEY_9>, <KEY_A>, <KEY_B>;
+    };
diff --git a/Documentation/devicetree/bindings/input/mpr121-touchkey.txt b/Documentation/devicetree/bindings/input/mpr121-touchkey.txt
deleted file mode 100644
index b7c61ee5841b..000000000000
--- a/Documentation/devicetree/bindings/input/mpr121-touchkey.txt
+++ /dev/null
@@ -1,30 +0,0 @@
-* Freescale MPR121 Controllor
-
-Required Properties:
-- compatible:		Should be "fsl,mpr121-touchkey"
-- reg:			The I2C slave address of the device.
-- interrupts:		The interrupt number to the cpu.
-- vdd-supply:		Phandle to the Vdd power supply.
-- linux,keycodes:	Specifies an array of numeric keycode values to
-			be used for reporting button presses. The array can
-			contain up to 12 entries.
-
-Optional Properties:
-- wakeup-source:	Use any event on keypad as wakeup event.
-- autorepeat:		Enable autorepeat feature.
-
-Example:
-
-#include "dt-bindings/input/input.h"
-
-	touchkey: mpr121@5a {
-		compatible = "fsl,mpr121-touchkey";
-		reg = <0x5a>;
-		interrupt-parent = <&gpio1>;
-		interrupts = <28 2>;
-		autorepeat;
-		vdd-supply = <&ldo4_reg>;
-		linux,keycodes = <KEY_0>, <KEY_1>, <KEY_2>, <KEY_3>,
-				<KEY_4> <KEY_5>, <KEY_6>, <KEY_7>,
-				<KEY_8>, <KEY_9>, <KEY_A>, <KEY_B>;
-	};
-- 
2.1.4

Re: [PATCH input-next 1/4] dt-bindings: input: Convert mpr121 binding to json-schema

[Rob Herring]

On Mon, Sep 02, 2019 at 01:40:14PM +0200, Michal Vokáč wrote:
> Convert the mpr121 binding to DT schema format using json-schema.
> 
> Signed-off-by: Michal Vokáč <michal.vokac@ysoft.com>
> ---
> Hi Rob,
> 
> I will appreciate your help converting this binding. Currently
> the scheme is not valid and the error output of dt_binding_check
> is not really helpful.

What's the error? I don't see anything obvious.

> 
> Also, who shoud be the maintainer of this binding?
> I put Dmitry in there as he is the input subsystem maintainer but
> I am not sure it is correct.

My preference is the author or driver maintainer.

>  .../bindings/input/fsl,mpr121-touchkey.yaml        | 64 ++++++++++++++++++++++
>  .../devicetree/bindings/input/mpr121-touchkey.txt  | 30 ----------
>  2 files changed, 64 insertions(+), 30 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/input/fsl,mpr121-touchkey.yaml
>  delete mode 100644 Documentation/devicetree/bindings/input/mpr121-touchkey.txt

[PATCH input-next 2/4] dt-bindings: input: mpr121: Add poll-interval property

[Michal Vokáč]

Add an option to periodicaly poll the device to get the buttons states
as the interrupt line may not be used on some platforms.

Signed-off-by: Michal Vokáč <michal.vokac@ysoft.com>
---
I am not sure how to propperly handle this.
Either interrupt or linux,poll-interval is required, but not both.

 .../bindings/input/fsl,mpr121-touchkey.yaml          | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/input/fsl,mpr121-touchkey.yaml b/Documentation/devicetree/bindings/input/fsl,mpr121-touchkey.yaml
index c463c1c81755..2b3073a3c9f4 100644
--- a/Documentation/devicetree/bindings/input/fsl,mpr121-touchkey.yaml
+++ b/Documentation/devicetree/bindings/input/fsl,mpr121-touchkey.yaml
@@ -34,6 +34,10 @@ properties:
     minItems: 1
     maxItems: 12
 
+  linux,poll-interval:
+    description: Poll interval time in milliseconds.
+    maxItems: 1
+
   wakeup-source: Use any event on keypad as wakeup event.
     type: boolean
 
@@ -44,12 +48,12 @@ properties:
 required:
   - compatible
   - reg
-  - interrupts
   - vdd-supply
   - linux,keycodes
 
 examples:
   - |
+    // Example with interrupts
     #include "dt-bindings/input/input.h"
     touchkey: mpr121@5a {
         compatible = "fsl,mpr121-touchkey";
@@ -62,3 +66,17 @@ examples:
                          <KEY_4> <KEY_5>, <KEY_6>, <KEY_7>,
                          <KEY_8>, <KEY_9>, <KEY_A>, <KEY_B>;
     };
+
+  - |
+    // Example with polling
+    #include "dt-bindings/input/input.h"
+    touchkey: mpr121@5a {
+        compatible = "fsl,mpr121-touchkey";
+        reg = <0x5a>;
+        linux,poll-interval = <20>;
+        autorepeat;
+        vdd-supply = <&ldo4_reg>;
+        linux,keycodes = <KEY_0>, <KEY_1>, <KEY_2>, <KEY_3>,
+                         <KEY_4> <KEY_5>, <KEY_6>, <KEY_7>,
+                         <KEY_8>, <KEY_9>, <KEY_A>, <KEY_B>;
+    );
-- 
2.1.4

Re: [PATCH input-next 2/4] dt-bindings: input: mpr121: Add poll-interval property

[Rob Herring]

On Mon, Sep 02, 2019 at 01:40:15PM +0200, Michal Vokáč wrote:
> Add an option to periodicaly poll the device to get the buttons states
> as the interrupt line may not be used on some platforms.
> 
> Signed-off-by: Michal Vokáč <michal.vokac@ysoft.com>
> ---
> I am not sure how to propperly handle this.
> Either interrupt or linux,poll-interval is required, but not both.

Add this at the top level:

oneOf:
  - required: [ interrupts ]
  - required: [ linux,poll-interval ]

> 
>  .../bindings/input/fsl,mpr121-touchkey.yaml          | 20 +++++++++++++++++++-
>  1 file changed, 19 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/devicetree/bindings/input/fsl,mpr121-touchkey.yaml b/Documentation/devicetree/bindings/input/fsl,mpr121-touchkey.yaml
> index c463c1c81755..2b3073a3c9f4 100644
> --- a/Documentation/devicetree/bindings/input/fsl,mpr121-touchkey.yaml
> +++ b/Documentation/devicetree/bindings/input/fsl,mpr121-touchkey.yaml
> @@ -34,6 +34,10 @@ properties:
>      minItems: 1
>      maxItems: 12
>  
> +  linux,poll-interval:
> +    description: Poll interval time in milliseconds.
> +    maxItems: 1

We already have 'poll-interval' in several bindings. Use that.

This should have a type definition and you don't need maxItems:

$ref: /schemas/types.yaml#/definitions/uint32

Really this should go in a common input schema doc.
> +
>    wakeup-source: Use any event on keypad as wakeup event.
>      type: boolean
>  
> @@ -44,12 +48,12 @@ properties:
>  required:
>    - compatible
>    - reg
> -  - interrupts
>    - vdd-supply
>    - linux,keycodes
>  
>  examples:
>    - |
> +    // Example with interrupts
>      #include "dt-bindings/input/input.h"
>      touchkey: mpr121@5a {
>          compatible = "fsl,mpr121-touchkey";
> @@ -62,3 +66,17 @@ examples:
>                           <KEY_4> <KEY_5>, <KEY_6>, <KEY_7>,
>                           <KEY_8>, <KEY_9>, <KEY_A>, <KEY_B>;
>      };
> +
> +  - |
> +    // Example with polling
> +    #include "dt-bindings/input/input.h"
> +    touchkey: mpr121@5a {
> +        compatible = "fsl,mpr121-touchkey";
> +        reg = <0x5a>;
> +        linux,poll-interval = <20>;
> +        autorepeat;
> +        vdd-supply = <&ldo4_reg>;
> +        linux,keycodes = <KEY_0>, <KEY_1>, <KEY_2>, <KEY_3>,
> +                         <KEY_4> <KEY_5>, <KEY_6>, <KEY_7>,
> +                         <KEY_8>, <KEY_9>, <KEY_A>, <KEY_B>;
> +    );
> -- 
> 2.1.4
> 

[PATCH input-next 3/4] Input: mpr121: Add polling mode

[Michal Vokáč]

In case the interrupt line is not available, polling can be used
to read out the state of the keys. Period of the polling needs to
be configured by the linux,poll-interval DT property.

Signed-off-by: Michal Vokáč <michal.vokac@ysoft.com>
---
 drivers/input/keyboard/mpr121_touchkey.c | 69 +++++++++++++++++++++++---------
 1 file changed, 51 insertions(+), 18 deletions(-)

diff --git a/drivers/input/keyboard/mpr121_touchkey.c b/drivers/input/keyboard/mpr121_touchkey.c
index ee80de44ce3f..2560a7231504 100644
--- a/drivers/input/keyboard/mpr121_touchkey.c
+++ b/drivers/input/keyboard/mpr121_touchkey.c
@@ -54,6 +54,9 @@
 /* MPR121 has 12 keys */
 #define MPR121_MAX_KEY_COUNT		12
 
+#define MPR121_MIN_POLL_INTERVAL	10
+#define MPR121_MAX_POLL_INTERVAL	200
+
 struct mpr121_touchkey {
 	struct i2c_client	*client;
 	struct input_dev	*input_dev;
@@ -115,11 +118,11 @@ static struct regulator *mpr121_vdd_supply_init(struct device *dev)
 	return vdd_supply;
 }
 
-static irqreturn_t mpr_touchkey_interrupt(int irq, void *dev_id)
+static void mpr_touchkey_report(struct input_dev *dev)
 {
-	struct mpr121_touchkey *mpr121 = dev_id;
-	struct i2c_client *client = mpr121->client;
+	struct mpr121_touchkey *mpr121 = input_get_drvdata(dev);
 	struct input_dev *input = mpr121->input_dev;
+	struct i2c_client *client = mpr121->client;
 	unsigned long bit_changed;
 	unsigned int key_num;
 	int reg;
@@ -127,14 +130,14 @@ static irqreturn_t mpr_touchkey_interrupt(int irq, void *dev_id)
 	reg = i2c_smbus_read_byte_data(client, ELE_TOUCH_STATUS_1_ADDR);
 	if (reg < 0) {
 		dev_err(&client->dev, "i2c read error [%d]\n", reg);
-		goto out;
+		return;
 	}
 
 	reg <<= 8;
 	reg |= i2c_smbus_read_byte_data(client, ELE_TOUCH_STATUS_0_ADDR);
 	if (reg < 0) {
 		dev_err(&client->dev, "i2c read error [%d]\n", reg);
-		goto out;
+		return;
 	}
 
 	reg &= TOUCH_STATUS_MASK;
@@ -155,8 +158,14 @@ static irqreturn_t mpr_touchkey_interrupt(int irq, void *dev_id)
 
 	}
 	input_sync(input);
+}
+
+static irqreturn_t mpr_touchkey_interrupt(int irq, void *dev_id)
+{
+	struct mpr121_touchkey *mpr121 = dev_id;
+
+	mpr_touchkey_report(mpr121->input_dev);
 
-out:
 	return IRQ_HANDLED;
 }
 
@@ -229,14 +238,10 @@ static int mpr_touchkey_probe(struct i2c_client *client,
 	int vdd_uv;
 	struct mpr121_touchkey *mpr121;
 	struct input_dev *input_dev;
+	u32 poll_interval = 0;
 	int error;
 	int i;
 
-	if (!client->irq) {
-		dev_err(dev, "irq number should not be zero\n");
-		return -EINVAL;
-	}
-
 	vdd_supply = mpr121_vdd_supply_init(dev);
 	if (IS_ERR(vdd_supply))
 		return PTR_ERR(vdd_supply);
@@ -274,6 +279,7 @@ static int mpr_touchkey_probe(struct i2c_client *client,
 	if (device_property_read_bool(dev, "autorepeat"))
 		__set_bit(EV_REP, input_dev->evbit);
 	input_set_capability(input_dev, EV_MSC, MSC_SCAN);
+	input_set_drvdata(input_dev, mpr121);
 
 	input_dev->keycode = mpr121->keycodes;
 	input_dev->keycodesize = sizeof(mpr121->keycodes[0]);
@@ -288,13 +294,40 @@ static int mpr_touchkey_probe(struct i2c_client *client,
 		return error;
 	}
 
-	error = devm_request_threaded_irq(dev, client->irq, NULL,
-					  mpr_touchkey_interrupt,
-					  IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
-					  dev->driver->name, mpr121);
-	if (error) {
-		dev_err(dev, "Failed to register interrupt\n");
-		return error;
+	device_property_read_u32(dev, "linux,poll-interval", &poll_interval);
+
+	if (client->irq) {
+		error = devm_request_threaded_irq(dev, client->irq, NULL,
+						  mpr_touchkey_interrupt,
+						  IRQF_TRIGGER_FALLING |
+						  IRQF_ONESHOT,
+						  dev->driver->name, mpr121);
+		if (error) {
+			dev_err(dev, "Failed to register interrupt\n");
+			return error;
+		}
+	} else if (poll_interval) {
+		if (poll_interval < MPR121_MIN_POLL_INTERVAL)
+			return -EINVAL;
+
+		if (poll_interval > MPR121_MAX_POLL_INTERVAL)
+			return -EINVAL;
+
+		error = input_setup_polling(input_dev, mpr_touchkey_report);
+		if (error) {
+			dev_err(dev, "Failed to setup polling\n");
+			return error;
+		}
+
+		input_set_poll_interval(input_dev, poll_interval);
+		input_set_min_poll_interval(input_dev,
+					    MPR121_MIN_POLL_INTERVAL);
+		input_set_max_poll_interval(input_dev,
+					    MPR121_MAX_POLL_INTERVAL);
+	} else {
+		dev_err(dev,
+			"invalid IRQ number and polling not configured\n");
+		return -EINVAL;
 	}
 
 	error = input_register_device(input_dev);
-- 
2.1.4

[PATCH input-next 4/4] ARM: dts: imx6dl-yapp4: Enable the MPR121 touchkey controller on Hydra

[Michal Vokáč]

Add the touch keyboard present on Hydra board. The controller
is connected only using I2C lines. The interrupt line is not
available hence we use the polling mode.

Signed-off-by: Michal Vokáč <michal.vokac@ysoft.com>
---
 arch/arm/boot/dts/imx6dl-yapp4-common.dtsi | 13 +++++++++++++
 arch/arm/boot/dts/imx6dl-yapp4-hydra.dts   |  4 ++++
 2 files changed, 17 insertions(+)

diff --git a/arch/arm/boot/dts/imx6dl-yapp4-common.dtsi b/arch/arm/boot/dts/imx6dl-yapp4-common.dtsi
index e8d800fec637..49e2bcd21a00 100644
--- a/arch/arm/boot/dts/imx6dl-yapp4-common.dtsi
+++ b/arch/arm/boot/dts/imx6dl-yapp4-common.dtsi
@@ -4,6 +4,7 @@
 
 #include <dt-bindings/gpio/gpio.h>
 #include <dt-bindings/interrupt-controller/irq.h>
+#include <dt-bindings/input/input.h>
 #include <dt-bindings/pwm/pwm.h>
 
 / {
@@ -330,6 +331,18 @@
 		vcc-supply = <&sw2_reg>;
 		status = "disabled";
 	};
+
+	touchkeys: keys@5a {
+		compatible = "fsl,mpr121-touchkey";
+		reg = <0x5a>;
+		vdd-supply = <&sw2_reg>;
+		autorepeat;
+		linux,keycodes = <KEY_1>, <KEY_2>, <KEY_3>, <KEY_4>, <KEY_5>,
+				<KEY_6>, <KEY_7>, <KEY_8>, <KEY_9>,
+				<KEY_BACKSPACE>, <KEY_0>, <KEY_ENTER>;
+		linux,poll-interval = <50>;
+		status = "disabled";
+	};
 };
 
 &iomuxc {
diff --git a/arch/arm/boot/dts/imx6dl-yapp4-hydra.dts b/arch/arm/boot/dts/imx6dl-yapp4-hydra.dts
index f97927064750..84c275bfdd38 100644
--- a/arch/arm/boot/dts/imx6dl-yapp4-hydra.dts
+++ b/arch/arm/boot/dts/imx6dl-yapp4-hydra.dts
@@ -45,6 +45,10 @@
 	status = "okay";
 };
 
+&touchkeys {
+	status = "okay";
+};
+
 &usdhc3 {
 	status = "okay";
 };
-- 
2.1.4